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  • 3851.
    Abdallah, Mohammed A.
    et al.
    Jönköping University.
    Biellmann, J. - F.
    Nordström, B.
    Brändén, C. I.
    The Conformation of Adenosine Diphosphoribose and 8-Bromoadenosine Diphosphoribose when Bound to Liver Alcohol Dehydrogenase1975In: European Journal of Biochemistry, ISSN 0014-2956, E-ISSN 1432-1033, Vol. 50, no 3, p. 475-481Article in journal (Refereed)
  • 3852.
    Abdallah, Mounawara
    et al.
    Mälardalen University, School of Education, Culture and Communication.
    Johansson, Sara
    Mälardalen University, School of Education, Culture and Communication.
    Att skapa goda relationer i förskolan: Förskolepersonalens syn på relationsskapande till barn i förskolan.2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Goda relationer påverkar barns utveckling och lärande. Personalen i förskolan ska skapa relationer som är personliga till varje enskilt barn oavsett deras olika förutsättningar och behov så att de får möjlighet att utvecklas och lära sig. Studiens syfte är att medvetandegöra och öka kunskapen om vilka olika uppfattningar förskolepersonal har om relationsskapande till barnen i förskolan. I en kvalitativ studie med semistrukturerade intervjuer som har sin utgångspunkt i fallbeskrivningar har vi undersökt detta. Resultatet visar att förskolepersonal uttrycker att respekten för individen samt bekräftelsen av barnets känslor är en viktig del i det relationsfrämjande arbetet. Relationens kvalitet ses av de intervjuade förskollärarna och barnskötarna som ett resultat av positiva händelser som gynnar såväl barn som personal. Vår slutsats är att förskolepersonalens relationskompetens har betydelsen för hur relationen till det enskilda barnet blir.

  • 3853.
    Abdallah, Muhammed
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Law, Department of Law.
    Polisens metoder i kampen mot grov organiserad brottslighet – en rättsanalys2014Student paper other, 20 credits / 30 HE creditsStudent thesis
  • 3854.
    Abdallah, Mustapha
    et al.
    The Nordic Africa Institute.
    Sapiano, Jenna
    Okyere, Frank
    Bentum, Doreen Ivy
    Exploring the post-Gaddafi Repercussions in the Sahel: Report from an experts’ workshop organised by the Kofi Annan International Peacekeeping Training Centre and the Nordic Africa Institute with the support of the Australian Government, 28-29 June 20122013Report (Other academic)
  • 3855.
    Abdallah, Nancy
    et al.
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics.
    Hansson, Mikael
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Hultman, Axel
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Topology of posets with special partial matchings2019In: Advances in Mathematics, ISSN 0001-8708, E-ISSN 1090-2082, Vol. 348, p. 255-276Article in journal (Refereed)
    Abstract [en]

    Special partial matchings (SPMs) are a generalisation of Brentis special matchings. Let a pircon be a poset in which every non-trivial principal order ideal is finite and admits an SPM. Thus pircons generalise Mariettis zircons. We prove that every open interval in a pircon is a PL ball or a PL sphere. It is then demonstrated that Bruhat orders on certain twisted identities and quasiparabolic W-sets constitute pircons. Together, these results extend a result of Can, Cherniaysky, and Twelbeck, prove a conjecture of Hultman, and confirm a claim of Rains and Vazirani.

  • 3856.
    Abdallah, Nancy
    et al.
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Hultman, Axel
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Combinatorial invariance of Kazhdan-Lusztig-Vogan polynomials for fixed point free involutions2018In: Journal of Algebraic Combinatorics, ISSN 0925-9899, E-ISSN 1572-9192, Vol. 47, no 4, p. 543-560Article in journal (Refereed)
    Abstract [en]

    When acts on the flag variety of , the orbits are in bijection with fixed point free involutions in the symmetric group . In this case, the associated Kazhdan-Lusztig-Vogan polynomials can be indexed by pairs of fixed point free involutions , where denotes the Bruhat order on . We prove that these polynomials are combinatorial invariants in the sense that if is a poset isomorphism of upper intervals in the Bruhat order on fixed point free involutions, then for all v amp;gt;= u.

  • 3857.
    Abdallah, Nathalie
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Bjurman, Elin
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Koncentrationssvårigheter hos elever i grundskolan2018Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 3858.
    Abdallah, Nour
    et al.
    University West, Department of Social and Behavioural Studies, Division for Educational Science and Languages.
    Nyman, Caroline
    University West, Department of Social and Behavioural Studies, Division for Educational Science and Languages.
    Naturvetenskap i förskolan: en kvalitativ studie om förskollärares syn på naturvetenskap i förskolan2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien har syftat till att ta reda på hur pedagoger tänker kring arbetet samt vilka möjligheter och svårigheter det finns med att arbeta med naturvetenskap i förskolan. Under vår undersökning har vi utgått ifrån olika övergripande frågeställningar som vilka arbetssätt pedagoger utgår från när det gäller naturvetenskap i förskolan, vad ser pedagoger för möjligheter att arbeta med naturvetenskap i förskolan samt vad för svårigheter pedagoger ser med att arbeta med naturvetenskap i förskolan? I studien utgick vi från den kvalitativa metoden där åtta intervjuer utfördes på två olika förskolor. Intervjufrågorna var öppna för att försöka fånga in så mycket av de intervjuades upplevelser och tankar kring ämnet naturvetenskap. Resultaten i studien visar att pedagoger har olika tankar om hur man arbetar med naturvetenskap samt att pedagoger arbetar på ett varierat sätt. När det gäller arbetsformen fann vi fyra subkategorier, att arbeta med begreppsförståelse, att ha spontana och planerade aktiviteter, att barnen ska upptäcka själva och att uppmuntra barnen till att lära sig genom sociala samspelet.Vi kom även fram till att det finns olika möjligheter samt svårigheter med naturvetenskap somexempelvis att ha en skog nära kan vara en stor möjlighet eftersom det kan underlätta pedagogers arbete. Svårigheter som kan uppstå är att om det förekommer brister på kunskaphos pedagoger kring ämnet naturvetenskap kan detta innebära att det blir svårt att lära barnen om naturvetenskap. Det blir svårt att exempelvis att svara på frågor.

  • 3859. Abdallah, Qasem M. A.
    et al.
    Phillips, Roger M.
    Johansson, Fredrik
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Helleday, Thomas
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Cosentino, Laura
    Abdel-Rahman, Hamdy
    Etzad, Jasarat
    Wheelhouse, Richard T.
    Kiakos, Konstantinos
    Bingham, John P.
    Hartley, John A.
    Patterson, Laurence H.
    Pors, Klaus
    Minor structural modifications to alchemix influence mechanism of action and pharmacological activity2012In: Biochemical Pharmacology, ISSN 0006-2952, E-ISSN 1356-1839, Vol. 83, no 11, p. 1514-1522Article in journal (Refereed)
    Abstract [en]

    Alchemix is an exemplar of a class of anthraquinone with efficacy against multidrug resistant tumours. We have explored further the mechanism of action of alchemix and investigated the effect of extending its side arm bearing the alkylating functionality with regard to DNA binding and activity against multidrug resistant cancer cells. Increasing the distance between the intercalating chromophore and the alkylating functionality of ICT2901 (propyl), ICT2902 (butyl) and ICT2903 (pentyl), led to a higher number of DNA alkylation sites, more potent topoisomerase II inhibition and generated more apoptotic and necrotic cells when analysed in p53-proficient HCT116 cells. Intriguingly, alchemix, the compound with the shortest distance between its intercalative chromophore and alkylating functionality (ethyl), did not conform to this SAR. A different toxicity pattern against DNA repair defective CHO cell lines as well as arrest of cells in Cl supports a somewhat distinct mode of action by alchemix compared with its analogues. Importantly, both alchemix and ICT2901 demonstrated greater cytotoxic activity against anthraquinone-resistant MCF-7/adr cells than wild-type MCF-7 cells. Subtle synthetic modification in this anthraquinone series has led to significant changes to the stability of DNA-compound complexes and cellular activity. Given that the failure of chemotherapy in the clinic is often associated with MDR, the results of both alchemix and ICT2901 represent important advances towards improved therapies.

  • 3860.
    Abdallah, Rosanne
    et al.
    University West, Department of Economics and IT, Division of Business Administration.
    Bajrakti, Lirije
    University West, Department of Economics and IT, Division of Business Administration.
    En studie om hur reklam på sociala medier påverkar individers köpbeteende2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Social media has grown, becoming more popular among millions of users. With its growth, companies are attracting more customers using advertising through social media. Companies are using online advertising to increase their customer base and market new products.

    Growth in social media can be determined by examining how advertising affects individual buying behavior. This study focuses on analyzing the purchasing behavior of young individuals through the influence of advertising in social media. The purpose of this study is to provide an effective basis for companies in practice; providing insight on individual behavior in regard to advertising within social media.

    We answered the research question using a qualitative approach with semi-structured interviews in conjunction with the ten selected respondents.

    The result indicated that young people are heavily influenced by advertising on social media. As a result, companies are using advertising to guide consumers in the direction of their interests. However, social media advertising may negatively influence customer interpretation if the message is not correlated with the consumers interests.

  • 3861.
    Abdallah, Sam
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Grupputvecklingssamtal - lärande för individen?: En kvalitativ studie om grupputvecklingssamtal och lärande hos medarbetare2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka grupputvecklingssamtal mellan chef och medarbetare på en avdelning på Akademiska sjukhuset som grund för medarbetarens lärande. Lärandet som undersöks är hur individer kan tillgodogöra sig arbetskunskap utifrån de lärandeprocesser som eventuellt uppstår i samband med gruppsamtal. Frågeställningarna som följer i denna uppsats är ”vad innefattar ett grupputvecklingssamtal på avdelningen på Akademiska sjukhuset?”, ”hur upplever medarbetarna grupputvecklingssamtalet som grund för deras professionella lärande?” och ”vilket slags lärande har premierats?”. Undersökningsmetoderna för denna studie är observation och intervju. Observation har genomförts för att ge svar på vad ett grupputvecklingssamtal på avdelningen på Akademiska sjukhuset innefattar och intervjuer har genomförts för att ge en bild av hur medarbetarna upplever grupputvecklingssamtalen som grund för deras professionella lärande. De analysverktyg som använts för att framställa studiens resultat är det empiriska materialet som framkommit från observationen samt intervjuerna och de teoretiska infallsvinklarna, ”kollektivt lärande” och ”dialog”. Resultaten har visat att ett grupputvecklingssamtal innefattar ett möte där medarbetarna får information om olika saker gällande arbetet och vad som händer på arbetsplatsen. Vidare har resultaten indikerat på att medarbetarna upplever grupputvecklingssamtalen som grund för deras professionella lärande och att det är kollektivt lärande som premierats. Denna studie har främst bidragit till att ge avdelningschefen och gruppcheferna som genomför dessa samtal en uppfattning om att samtalen gynnar medarbetarna i den mån att det ger dem ett kollektivt lärande. Det gör också medarbetarna uppmärksamma på att samtalen kan främja interaktionen mellan dem liksom utförandet av deras arbetsuppgifter.

  • 3862.
    Abdallah, Waleed
    et al.
    HBNI, Harish Chandra Res Inst, Chhatnag Rd, Allahabad 211019, Uttar Pradesh, India.;Cairo Univ, Fac Sci, Dept Math, Giza 12613, Egypt..
    Choubey, Sandhya
    KTH, School of Engineering Sciences (SCI), Physics, Theoretical Particle Physics. HBNI, Harish Chandra Res Inst, Chhatnag Rd, Allahabad 211019, Uttar Pradesh, India..
    Khan, Sarif
    HBNI, Harish Chandra Res Inst, Chhatnag Rd, Allahabad 211019, Uttar Pradesh, India.;Georg August Univ Gottingen, Inst Theoret Phys, Friedrich Hund Pl 1, D-37077 Gottingen, Germany..
    FIMP dark matter candidate(s) in a B - L model with inverse seesaw mechanism2019In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 6, article id 095Article in journal (Refereed)
    Abstract [en]

    The non-thermal dark matter (DM) production via the so-called freeze-in mechanism provides a simple alternative to the standard thermal WIMP scenario. In this work, we consider a popular U(1)(B-L) extension of the standard model (SM) in the context of inverse seesaw mechanism which has at least one (fermionic) FIMP DM candidate. Due to the added Z(2) symmetry, a SM gauge singlet fermion, with mass of order keV, is stable and can be a warm DM candidate. Also, the same Z(2) symmetry helps the lightest right-handed neutrino, with mass of order GeV, to be a stable or long-lived particle by making a corresponding Yukawa coupling very small. This provides a possibility of a two component DM scenario as well. Firstly, in the absence of a GeV DM component (i.e., without tuning its corresponding Yukawa coupling to be very small), we consider only a keV DM as a single component DM, which is produced by the freeze-in mechanism via the decay of the extra Z gauge boson associated to U(1)(B-L) and can consistently explain the DM relic density measurements. In contrast with most of the existing literature, we have found a reasonable DM production from the annihilation processes. After numerically studying the DM production, we show the dependence of the DM relic density as a function of its relevant free parameters. We use these results to obtain the parameter space regions that are compatible with the DM relic density bound. Secondly, we study a two component DM scenario and emphasize that the current DM relic density bound can be satisfied for a wide range of parameter space.

  • 3863.
    Abdallah, Wissam
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies.
    Det sistakorståget: Operation Barbarossa: En historiografisk studie om orsakerna till den tyska invasionen av Sovjetunionen2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 3864.
    Abdallah, Wissam
    Södertörn University College, School of Social Sciences.
    Gudsstyre?: En fallstudie av Irans regim2009Independent thesis Advanced level (degree of Master (One Year)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The aim of this Master´s thesis is to examine which type of regime the state Iran is. There has been much research on this issue and the discussion is not over yet. I have departed from three theoretical perspectives in order to understand which type of regime the Middle Eastern nation is: theocracy, democracy and hybrid regime. The theocratic regimetype is composed by David L. Websters archeological theory about governments ruled by God. For the democratic theory in this study Robert Dahls analytical framework about democracy and polyarchy is used. The hybrid regime is mainly represented by Andreas Schedler indicators. A qualitative case study approach is used for the purpose of this study where I have constructed an analytical framework containing indicators in order to apply these on the three regime models. The results and conclusion I can draw from this study is that Iran is more like a hybrid regime. However, there are several reservations and there need to be more studies to qualify this suggestion.

  • 3865.
    Abdallah, Wissam
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies.
    Vad är rättvisa?: En undersökning om vem eller vilka Platons teori riktar sig till2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Plato´s Republic is maybe the most widely read philosophical work of all times. It is the earliest surviving, systematic utopia in Europe´s history and continues to inspire people today. But who did Plato want to address with his work and why? In this paper I will discuss these issues. My thesis is that Plato wanted to direct his Republic to people, men and women, who have a good character and love wisdom in order to make them to think radically differently from the traditional norms. If these would-be philosophers could challenge the old-fashioned way of seeing things they could take the lead to establish a just society. I will also discuss critically two alternative approaches from other philosophers.

  • 3866.
    Abdallah, Wissam
    Södertörn University College, Lärarutbildningen.
    Varför religion?: En undersökning av hur eleverna i en skola upplever religionsämnet2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 3867.
    Abdallaoui Berrada, Chakir
    et al.
    Jönköping University, Jönköping International Business School.
    Ciro, aida
    Jönköping University, Jönköping International Business School.
    Bottlenecks in the Freight Forwarding sector in West - coast Africa2009Independent thesis Advanced level (degree of Master (One Year)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    Problem – The expansion of global trade and supply chain integration has put great emphasison logistics, particularly in the intermediary sector, freight forwarders. Whilst in developedcountries freight forwarders benefit from competitive markets and trade facilitatingpolicies, this sector in West coast Africa exhibits low logistics performance levels. Inorder to address such issues, one needs to analyse the problem and identify the causes; thisthesis focuses on identifying the bottlenecks in the freight-forwarding sector in west coastAfrica.Purpose – The main purpose of this study is to identify the bottleneck/s within thefreight-forwarding industry in west coast Africa, namely: Angola, Cameroon, DR of Congo,Gabon, and Nigeria.Method – This thesis employs a pre-study and case study method, to ensure sufficient collectionof relevant material, taking into account the lack of research in this subject. We usedthe material obtained from the interviews and the secondary source, to structure our purpose,research questions, and to define the case of our study.Results – The study concludes with a series of interesting findings; First, the activity of aFreight Forwarder depends on a series of factors that do not depend on the Freight Forwarderper se. And second, Freight Forwarders in order to accomplish their tasks, have accessto services that are shared by all providers, and that are beyond their control. To conclude,the study identifies infrastructure as a major bottleneck in the Freight Forwarding sector.

  • 3868.
    ABDALMAHMOODABADI, MAHBOOBEH
    KTH, School of Information and Communication Technology (ICT).
    The value of downstream information sharing in two-level supply chain: AN APPROACH TO AGENT-BASED MODELING2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many supply chain firms have taken initiatives to facilitate demand information sharing between downstream and upstream entities. Information sharing is a key factor of collaboration in supply chain management (SCM). In the last decades, many efforts have been made to model supply chain mathematically. Mathematical models are incapable of capturing the dynamic nature of the system. It is necessary to study multidimensional supply chain model in which not only there is communication between supplier and retailer but also communication among retailers must be considered. Mathematical models can be seen as a simple decision making optimization between two entities in which the effect of cooperation of other entities is completely ignored. These models are far from real world systems. The purpose of this thesis is to create an agent-based model, as a substitute to mathematical modeling, to appraise the importance of sharing information on supplier side when there is relation among retailers by means of stock sharing. The conceptual model of two-echelon supply chain is designed and implemented in Java using Repast suit. The model includes four types of agents namely supply chain, supplier, retailer and mediator agents that interact with each other in a discrete event based simulation. Multi level factorial design is used to evaluate performance of supply chain, in terms of total cost saving, under different demand patterns. The significant difference between experimental settings is tested statistically using ANOVA, Pairwise, and Univariate tests. Data analysis indicates that the significance of information sharing can be rather high, in particular when end customers' demands are considerably correlated. Such cost saving that is achieved by sharing information is due to reducing stock level and at the expense of increasing the amount of backorder.

  • 3869.
    Abdalmoaty, Mohamed
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control. KTH Royal Institute of Technology.
    Identification of Stochastic Nonlinear Dynamical Models Using Estimating Functions2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Data-driven modeling of stochastic nonlinear systems is recognized as a very challenging problem, even when reduced to a parameter estimation problem. A main difficulty is the intractability of the likelihood function, which renders favored estimation methods, such as the maximum likelihood method, analytically intractable. During the last decade, several numerical methods have been developed to approximately solve the maximum likelihood problem. A class of algorithms that attracted considerable attention is based on sequential Monte Carlo algorithms (also known as particle filters/smoothers) and particle Markov chain Monte Carlo algorithms. These algorithms were able to obtain impressive results on several challenging benchmark problems; however, their application is so far limited to cases where fundamental limitations, such as the sample impoverishment and path degeneracy problems, can be avoided.

    This thesis introduces relatively simple alternative parameter estimation methods that may be used for fairly general stochastic nonlinear dynamical models. They are based on one-step-ahead predictors that are linear in the observed outputs and do not require the computations of the likelihood function. Therefore, the resulting estimators are relatively easy to compute and may be highly competitive in this regard: they are in fact defined by analytically tractable objective functions in several relevant cases. In cases where the predictors are analytically intractable due to the complexity of the model, it is possible to resort to {plain} Monte Carlo approximations. Under certain assumptions on the data and some conditions on the model, the convergence and consistency of the estimators can be established. Several numerical simulation examples and a recent real-data benchmark problem demonstrate a good performance of the proposed method, in several cases that are considered challenging, with a considerable reduction in computational time in comparison with state-of-the-art sequential Monte Carlo implementations of the ML estimator.

    Moreover, we provide some insight into the asymptotic properties of the proposed methods. We show that the accuracy of the estimators depends on the model parameterization and the shape of the unknown distribution of the outputs (via the third and fourth moments). In particular, it is shown that when the model is non-Gaussian, a prediction error method based on the Gaussian assumption is not necessarily more accurate than one based on an optimally weighted parameter-independent quadratic norm. Therefore, it is generally not obvious which method should be used. This result comes in contrast to a current belief in some of the literature on the subject. 

    Furthermore, we introduce the estimating functions approach, which was mainly developed in the statistics literature, as a generalization of the maximum likelihood and prediction error methods. We show how it may be used to systematically define optimal estimators, within a predefined class, using only a partial specification of the probabilistic model. Unless the model is Gaussian, this leads to estimators that are asymptotically uniformly more accurate than linear prediction error methods when quadratic criteria are used. Convergence and consistency are established under standard regularity and identifiability assumptions akin to those of prediction error methods.

    Finally, we consider the problem of closed-loop identification when the system is stochastic and nonlinear. A couple of scenarios given by the assumptions on the disturbances, the measurement noise and the knowledge of the feedback mechanism are considered. They include a challenging case where the feedback mechanism is completely unknown to the user. Our methods can be regarded as generalizations of some classical closed-loop identification approaches for the linear time-invariant case. We provide an asymptotic analysis of the methods, and demonstrate their properties in a simulation example.

  • 3870.
    Abdalmoaty, Mohamed
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Learning Stochastic Nonlinear Dynamical Systems Using Non-stationary Linear Predictors2017Licentiate thesis, monograph (Other academic)
    Abstract [en]

    The estimation problem of stochastic nonlinear parametric models is recognized to be very challenging due to the intractability of the likelihood function. Recently, several methods have been developed to approximate the maximum likelihood estimator and the optimal mean-square error predictor using Monte Carlo methods. Albeit asymptotically optimal, these methods come with several computational challenges and fundamental limitations.

    The contributions of this thesis can be divided into two main parts. In the first part, approximate solutions to the maximum likelihood problem are explored. Both analytical and numerical approaches, based on the expectation-maximization algorithm and the quasi-Newton algorithm, are considered. While analytic approximations are difficult to analyze, asymptotic guarantees can be established for methods based on Monte Carlo approximations. Yet, Monte Carlo methods come with their own computational difficulties; sampling in high-dimensional spaces requires an efficient proposal distribution to reduce the number of required samples to a reasonable value.

    In the second part, relatively simple prediction error method estimators are proposed. They are based on non-stationary one-step ahead predictors which are linear in the observed outputs, but are nonlinear in the (assumed known) input. These predictors rely only on the first two moments of the model and the computation of the likelihood function is not required. Consequently, the resulting estimators are defined via analytically tractable objective functions in several relevant cases. It is shown that, under mild assumptions, the estimators are consistent and asymptotically normal. In cases where the first two moments are analytically intractable due to the complexity of the model, it is possible to resort to vanilla Monte Carlo approximations. Several numerical examples demonstrate a good performance of the suggested estimators in several cases that are usually considered challenging.

  • 3871.
    Abdalmoaty, Mohamed R.
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Application of a Linear PEM Estimator to a Stochastic Wiener-Hammerstein Benchmark Problem2018In: 18th IFAC Symposium on System Identification, 2018Conference paper (Refereed)
    Abstract [en]

    The estimation problem of stochastic Wiener-Hammerstein models is recognized to be challenging, mainly due to the analytical intractability of the likelihood function. In this contribution, we apply a computationally attractive prediction error method estimator to a real-data stochastic Wiener-Hammerstein benchmark problem. The estimator is defined using a deterministic predictor that is nonlinear in the input. The prediction error method results in tractable expressions, and Monte Carlo approximations are not necessary. This allows us to tackle several issues considered challenging from the perspective of the current mainstream approach. Under mild conditions, the estimator can be shown to be consistent and asymptotically normal. The results of the method applied to the benchmark data are presentedand discussed.

  • 3872.
    Abdalmoaty, Mohamed R.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Application of a Linear PEM Estimator to a Stochastic Wiener-Hammerstein Benchmark Problem⁎2018In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 51, no 15, p. 784-789Article in journal (Refereed)
    Abstract [en]

    The estimation problem of stochastic Wiener-Hammerstein models is recognized to be challenging, mainly due to the analytical intractability of the likelihood function. In this contribution, we apply a computationally attractive prediction error method estimator to a real-data stochastic Wiener-Hammerstein benchmark problem. The estimator is defined using a deterministic predictor that is nonlinear in the input. The prediction error method results in tractable expressions, and Monte Carlo approximations are not necessary. This allows us to tackle several issues considered challenging from the perspective of the current mainstream approach. Under mild conditions, the estimator can be shown to be consistent and asymptotically normal. The results of the method applied to the benchmark data are presented and discussed.

  • 3873.
    Abdalmoaty, Mohamed R.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Consistent Estimators of Stochastic MIMO Wiener Models based on Suboptimal Predictors2018Conference paper (Refereed)
  • 3874.
    Abdalmoaty, Mohamed R.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Linear Prediction Error Methods for Stochastic Nonlinear Models2019In: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 105, p. 49-63Article in journal (Refereed)
    Abstract [en]

    The estimation problem for stochastic parametric nonlinear dynamical models is recognized to be challenging. The main difficulty is the intractability of the likelihood function and the optimal one-step ahead predictor. In this paper, we present relatively simple prediction error methods based on non-stationary predictors that are linear in the outputs. They can be seen as extensions of the linear identification methods for the case where the hypothesized model is stochastic and nonlinear. The resulting estimators are defined by analytically tractable objective functions in several common cases. It is shown that, under certain identifiability and standard regularity conditions, the estimators are consistent and asymptotically normal. We discuss the relationship between the suggested estimators and those based on second-order equivalent models as well as the maximum likelihood method. The paper is concluded with a numerical simulation example as well as a real-data benchmark problem.

    The full text will be freely available from 2021-04-01 16:05
  • 3875.
    Abdalmoaty, Mohamed R.
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Rojas, Cristian R.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Identication of a Class of Nonlinear Dynamical Networks2018Conference paper (Refereed)
    Abstract [en]

    Identifcation of dynamic networks has attracted considerable interest recently. So far the main focus has been on linear time-invariant networks. Meanwhile, most real-life systems exhibit nonlinear behaviors; consider, for example, two stochastic linear time-invariant systems connected in series, each of which has a nonlinearity at its output. The estimation problem in this case is recognized to be challenging, due to the analytical intractability of both the likelihood function and the optimal one-step ahead predictors of the measured nodes. In this contribution, we introduce a relatively simple prediction error method that may be used for the estimation of nonlinear dynamical networks. The estimator is defined using a deterministic predictor that is nonlinear in the known signals. The estimation problem can be defined using closed-form analytical expressions in several non-trivial cases, and Monte Carlo approximations are not necessarily required. We show, that this is the case for some block-oriented networks with no feedback loops and where all the nonlinear modules are polynomials. Consequently, the proposed method can be applied in situations considered challenging by current approaches. The performance of the estimation method is illustrated on a numerical simulation example.

  • 3876.
    Abdalmoaty, Mohamed R.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Rojas, Cristian R.
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Identification of a Class of Nonlinear Dynamical Networks⁎2018In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 51, no 15, p. 868-873Article in journal (Refereed)
    Abstract [en]

    Identification of dynamic networks has attracted considerable interest recently. So far the main focus has been on linear time-invariant networks. Meanwhile, most real-life systems exhibit nonlinear behaviors; consider, for example, two stochastic linear time-invariant systems connected in series, each of which has a nonlinearity at its output. The estimation problem in this case is recognized to be challenging, due to the analytical intractability of both the likelihood function and the optimal one-step ahead predictors of the measured nodes. In this contribution, we introduce a relatively simple prediction error method that may be used for the estimation of nonlinear dynamical networks. The estimator is defined using a deterministic predictor that is nonlinear in the known signals. The estimation problem can be defined using closed-form analytical expressions in several non-trivial cases, and Monte Carlo approximations are not necessarily required. We show, that this is the case for some block-oriented networks with no feedback loops and where all the nonlinear modules are polynomials. Consequently, the proposed method can be applied in situations considered challenging by current approaches. The performance of the estimation method is illustrated on a numerical simulation example.

  • 3877.
    Abdalmoaty, Mohamed
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Henrion, D.
    Rodrigues, L.
    Measures and LMIs for optimal control of piecewise-affine systems2013In: 2013 European Control Conference, ECC 2013, IEEE, 2013, p. 3173-3178, article id 6669627Conference paper (Refereed)
    Abstract [en]

    This paper considers the class of deterministic continuous-time optimal control problems (OCPs) with piecewise-affine (PWA) vector field, polynomial Lagrangian and semialgebraic input and state constraints. The OCP is first relaxed as an infinite-dimensional linear program (LP) over a space of occupation measures. This LP is then approached by an asymptotically converging hierarchy of linear matrix inequality (LMI) relaxations. The relaxed dual of the original LP returns a polynomial approximation of the value function that solves the Hamilton-Jacobi-Bellman (HJB) equation of the OCP. Based on this polynomial approximation, a suboptimal policy is developed to construct a state feedback in a sample-and-hold manner. The results show that the suboptimal policy succeeds in providing a suboptimal state feedback law that drives the system relatively close to the optimal trajectories and respects the given constraints.

  • 3878.
    Abdalmoaty, Mohamed
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    A Simulated Maximum Likelihood Method for Estimation of Stochastic Wiener Systems2016In: 2016 IEEE 55th Conference on Decision and Control, CDC 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 3060-3065, article id 7798727Conference paper (Refereed)
    Abstract [en]

    This paper introduces a simulation-based method for maximum likelihood estimation of stochastic Wienersystems. It is well known that the likelihood function ofthe observed outputs for the general class of stochasticWiener systems is analytically intractable. However, when the distributions of the process disturbance and the measurement noise are available, the likelihood can be approximated byrunning a Monte-Carlo simulation on the model. We suggest the use of Laplace importance sampling techniques for the likelihood approximation. The algorithm is tested on a simple first order linear example which is excited only by the process disturbance. Further, we demonstrate the algorithm on an FIR system with cubic nonlinearity. The performance of the algorithm is compared to the maximum likelihood method and other recent techniques.

  • 3879.
    Abdalmoaty, Mohamed
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control.
    On Re-Weighting, Regularization Selection, and Transient in Nuclear Norm Based Identification2015Conference paper (Refereed)
    Abstract [en]

    In this contribution, we consider the classical problem of estimating an Output Error model given a set of input-output measurements. First, we develop a regularization method based on the re-weighted nuclear norm heuristic. We show that the re-weighting improves the estimate in terms of better fit. Second, we suggest an implementation method that helps in eliminating the regularization parameters from the problem by introducing a constant based on a validation criterion. Finally, we develop a method for considering the effect of the transient when the initial conditions are unknown. A simple numerical example is used to demonstrate the proposed method in comparison to classical and another recent method based on the nuclear norm heuristic.

  • 3880.
    Abdalmoaty, Mohamed
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Simulated Pseudo Maximum Likelihood Identification of Nonlinear Models2017In: The 20th IFAC World Congress, Elsevier, 2017, Vol. 50, p. 14058-14063Conference paper (Refereed)
    Abstract [en]

    Nonlinear stochastic parametric models are widely used in various fields. However, for these models, the problem of maximum likelihood identification is very challenging due to the intractability of the likelihood function. Recently, several methods have been developed to approximate the analytically intractable likelihood function and compute either the maximum likelihood or a Bayesian estimator. These methods, albeit asymptotically optimal, are computationally expensive. In this contribution, we present a simulation-based pseudo likelihood estimator for nonlinear stochastic models. It relies only on the first two moments of the model, which are easy to approximate using Monte-Carlo simulations on the model. The resulting estimator is consistent and asymptotically normal. We show that the pseudo maximum likelihood estimator, based on a multivariate normal family, solves a prediction error minimization problem using a parameterized norm and an implicit linear predictor. In the light of this interpretation, we compare with the predictor defined by an ensemble Kalman filter. Although not identical, simulations indicate a close relationship. The performance of the simulated pseudo maximum likelihood method is illustrated in three examples. They include a challenging state-space model of dimension 100 with one output and 2 unknown parameters, as well as an application-motivated model with 5 states, 2 outputs and 5 unknown parameters.

  • 3881.
    Abdalmunim, Rand
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Effektivisering av bygglovsprocessen gällande ändring av kulturhistoriskt värdefull bebyggelse: En fallstudie av ett miljonprogramsområde-Nya Nordostprojektet i Gävle2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En stor del av Sveriges bebyggelse har byggts mellan 1965 och 1974 eftersom det rådde stor bostadsbrist i Sverige. Regeringen beslutade att en miljon bostäder skulle uppföras under denna tid, det s.k. miljonprogrammet. Det byggdes bostäder i varierande former och storlekar för att bygga bort bostadsbristen. Storskaligheten och en stor grad av upprepning av identiska hus är kännetecken för miljonprogrammets bebyggelser. Nu är det dags att renovera dessa byggnader. I och med att dessa byggnader är av allmänt intresse då de speglar en del av Sveriges arkitekturhistoria ställer kommunerna vissa krav vid renovering av dem. Det kommunala företaget Gavlegårdarna i Gävle tar initiativ till att utveckla bygglovsprocessen för sådana bebyggelser. Detta görs för att reducera tiden för framställande av ett godkänt bygglov samt effektivisera och underlätta kommunikationen med kommunen under hela projektet. För att kunna bevara dessa byggnader i högsta möjliga mån har Gavlegårdarna utarbetat en effektiviseringsprocess genom att hyra in en extern bevarandeexpert för att fungera som en bro mellan företaget och kommunen samt för att kunna dela med sig av sina erfarenheter gällande bevarandet av det eventuella området. Dessutom har Gavlegårdarna låtit kommunen vara med från ett tidigt skede, d.v.s. redan från den första presentationen av förslaget. Därmed har kommunen fått vara med och medverka i förslaget, redan innan bygglovsansökan.

     

    Detta examensarbete tar upp konsekvenserna av de nya tillagda rutinerna och hur de har påverkat bygglovsansökningsprocessen för Nya Nordostprojektet. Genom att intervjua de inblandade aktörerna i det undersökta projektet har slutsatsen dragits att dessa rutiner har bidragit till att processen bedrivits mer effektivt jämfört med företagets tidigare projekt. Därutöver visar denna uppsats hur hyresgästerna har engagerat sig i det eventuella arbetet. Enkätundersökning har utförts för att kunna höra hyresgästernas åsikt.

     

    Det har visat sig att de nya rutinerna har effektiviserat tiden för bygglovsansöknings-processen. Tiden har förkortats jämförts med Gavlegårdarnas övriga projekt. Fördröjning i tid kostar företaget mer pengar. Dessutom har den förbättrade kommunikationen underlättat för båda parter att ta emot klagomål lättare och acceptera det. Det bidrar till att kommande problem kan lösas smidigare. Undersökningen har även visat att i projekt som Nya Nordost tas inte stor hänsyn till hyresgästernas åsikter, då byggherren redan är styrd från kommunen, vilket försvårar att flera kan vara med och välja. Ett annat resultat av denna undersökning var att de intervjuade personerna hade olika åsikter om bevarandet gällande Nordost. De flesta tyckte att Nordost ej var värt att bevara. Undersökningen visade även att hyresgästerna inte har engagerat sig lika mycket i bevarandet av gamla byggnader jämfört med att bo i ett modernare och nyrenoverat område.

  • 3882. Abd-Alrahman, Ahmed Mustafa
    et al.
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Modelling Health Information during Catastrophic Events - A Disaster Management System for Sudan2017In: IST-Africa 2017: Conference Proceedings / [ed] Paul Cunningham, Miriam Cunningham, International Information Management Corporation Limited, 2017, p. 1-9Conference paper (Refereed)
    Abstract [en]

    There is an increasing trend of disastrous events during past decade with significant damage in terms of lives, infrastructure, economics and environment. Disastrous events are affecting communities worldwide and, apart for the actual and personal suffering involved, can fundamentally disrupt societal functions for many years. This is particularly the case in already vulnerable regions, which often require external assistance of various kinds. In order to reduce catastrophic effects of disasters, disaster mitigation measures and crisis reduction must be systematically planned and managed. This includes correct damage assessment, fast, efficient and prepared responses, adequate resource allocation and organisation of the relief processes. Obviously, the conditions and abilities to implement such measures are very different in various locations, where regions have particularly severe conditions. In this paper, we discuss crisis management in Sudan and highlight the need for national and regional disaster management processes and activities as well as general framework for the design of an efficient disaster management program in Sudan.

  • 3883.
    Abdalrahman, Moutoz
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Brice, Alistair
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management.
    Effektivisering av en produktionsprocess: En fallstudie på Corroventa AB2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A major concern for companies today is the necessity to manufacture a wide range of products with short lead times and at a low cost. This puts greater demands on companies to have a good product mix and volume flexibility while maintaining a high level of efficiency. In addition, companies need to be aware of the source of unknown losses in their organisation and production process in order to minimise them.  This study was conducted at Corroventa avfuktning AB in Bankeryd, Sweden, a company that specialises in products that are used to dehumidify buildings and neutralise radon radiation. Their production process mainly focuses on maintaining stock levels, but adverse weather conditions that cause flooding and water damage could push demand levels to a point where they are unable to guarantee a short enough lead time to win a customer order. This puts pressure on them to make their production process more flexible and efficient while reducing their lead time.  The case study was carried out in a pre-assembly department for the final assembly of adsorption dehumidifiers. The department had been identified as a bottleneck for the whole system during high demand, and the study was undertaken to identify the underlying problem. With a firm theoretical framework and in-depth status analysis the authors identified key areas to improve the overall performance of the pre-assembly department. The improvements included a new production layout, a more balanced assembly process and a reduction in material handling. This led to improved product mix and volume flexibility, and reduced lead times. As a final step, a discussion and conclusion has been written that discusses the validity and reliability of the study, sums up all the areas of improvement and determines further studies that need to be undertaken in order to facilitate future improvements throughout the plant.

  • 3884.
    Abdalrhman, Slah Aldeen
    University West, Department of Engineering Science, Division of Production Systems.
    Virtual model of a production process: Seam sealing line at Scania2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The concept of digital factories is becoming more popular among the manufactures due to its contributions in simplifying the work of plant engineers and reducing time to market of the products [1]. The main aim of this thesis was to investigate the possible applications of a digital copy of production processes by creating a virtual model of a seam sealing line in the paint department at Scania in Oskarshamn. The main usage of the virtual model was to perform offline programming of the robots. The benefits of offline programming were investigated and compared to online programming. Some comparisons between offline and online programming were made when it comes to the time needed for programming, the accuracy of generated robot paths, the workflow of both approaches and the required knowledge to turn from online programming to offline programming.

    The result of the conducted experiment showed that the time of robot programming can be reduced, and the accuracy of robot paths increases by implementing an offline programming tool. The other application of virtual which was investigated in this thesis was virtual commissioning. Virtual commissioning is a method used to test and validate robot and control (PLC) programs in a virtual environment before implementing in the real plant. The software in the loop was selected as an approach for building the virtual commissioning model after presenting the different existed approaches. The result of the model showed great benefits of virtual commissioning not just in reducing the time of traditional of the new built line but even when replacing parts in an already existing manufacturing. Virtual commissioning is still new in the manufacturing, therefore, there are many issues which should be solved to get an optimal model that imitates perfectly the real plant.

  • 3885.
    Abdalsalam Noman, Riam
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Alqaisy, Ahmad
    Mälardalen University, School of Innovation, Design and Engineering.
    Design av hörnväggfixtur2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 3886.
    Abdel Alim, Richard
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Formation of Soft Particles in Drop-in Fuels2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As the mission to the decrease global warming and phase out highly pollutingenvironmental practices globally, regulations including Euro 6 and policies generated by theUnited Nations Framework Convention on Climate Change (UNFCCC) are pushing companiesto be more innovative when it comes to their energy sources. These regulations involve manyfactors related to the cleanliness of the fuel and produced emissions, for example, propertiesof the fuels such as sulfur content, ash content, water content, and resulting emission valuesof Carbon dioxide (CO2) and Nitrogen Oxides (NOx). Furthermore, Sweden has set achallenging target of a fossil-fuel-independent vehicle fleet by 2030 and no net greenhousegasemissions by 2050.One way to cut down on the polluting properties in the fuel, as well as weakening thedependence on fossil fuel based fuel includes utilizing higher blending ratios of biofuels in thetransport sector. This transition to biofuels comes with many challenges to the transportindustry due to higher concentrations of these new fuels leads to clogging of the filters in theengine, as well as, internal diesel injector deposits (IDIDs) that produce injector fouling. Thisclogging of the filters leads to lower performance by the engines which leads to higher repairtimes (uptime) and less time on the road to transport goods. The formation of these softparticles at the root of the clogging issue is a pivotal issue because the precise mechanismsbehind their formation are highly unknown. Scania, a leader in the Swedish automotiveindustry, is very interested in figuring out what mechanisms are the most influential in theformation of these particles in the engine. Understanding the key mechanisms would allowScania to make appropriate adjustments to the fuel or the engines to ensure more time onthe road and less maintenance.There are many conditions known to be possible causes of the formation of softparticles in engines such as water content, ash content, and temperature. After generatingsoft particles using a modified accelerated method, particles were analyzed using infraredtechnology (RTX-FTIR) and a Scanning Electric Microscope (SEM-EDX). Many differentexperiments were performed to be able to make a conclusion as to which mechanisms weremost influential including temperature, time, water, air, and oil. The combination of agingbiofuels (B100, B10, HVO) with metals, and water produced the largest amount of particlesfollowed by aging the biofuels with aged oil, metals, and water. Aging the fuels with aged oilincreased particles, meanwhile the addition of water prevented particle production possiblydue to additives. B100 produced the highest amount of particles when aged with Copper, B10with Brass, and HVO with Iron.

  • 3887. Abdel Aziz, Adam
    et al.
    Abdel, Karim
    Methods for ergonomics assessment of agricultural work with hand tools2001Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of the study was to develop methods for ergonomics assessment of agricultural work with hand tools in the laboratory and thereafter adapted in the field. A total of eight male graduate students (mean age, height and weight were 29.4 years, 176.8 cm and 81.0 kg respectively) participated in a digging task using a hand hoe. The digging task was performed within three minutes in a 2 m * 1.5 m metal box full of moist sand. 3 video cameras were installed to record the working posture. At the last minute, during interval of 15 seconds, heart rates (HR) along with rate of perceived exertion (RPE) 6-20 were measured to assess the physical load. Awkward postures while the hoe lifted up as well as stroke the soil were frozen and different joint angles were measured to provide input for 3- dimesional static strength prediction programme (3D SSPP). The data analyses included linear regression for HR as a function of RPE: 3D SSPP software calculated the percentage of population capable of performing the task and low-back compressive forces. Compression force on L5/S1 was plotted as a function of HR and RPE. The results revealed that the correlation coefficient (r) for HR and RPE (p<0.05) was 0.59: the measured and perceived physical load range from light to heavy. the output obtained from the software showed that low-back compressive forces were below the niosh recommended safe limit (3400 n) when the hoe lifted up. however, when the hoe stroke the soil, compression force on l5/s1 for 25% from the subjects exceeded the niosh safe limit and therefore they were at high risk of back injury. when the force on l5/s1 plotted as a function of hr and rpe, the results showed that there was no linear relationship between these variables. in conclusion, hr a long with rpe proved to be used in the laboratory as well as in the field. 3d sspp could be used in the laboratory, nevertheless, in the field, one video camera would be appropriate.

  • 3888.
    Abdel Aziz Saad, Olivia
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Theology, Department of Theology, History of Religions.
    Islamism och antirasism: En jämförelse av Sayyid Qutbs rassyn på 1940- och 60-talen2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3889.
    Abdel Ghani, Rania Mahmoud
    et al.
    Faculty of Nursing, Cairo University.
    Berggren, Vanja
    Kristianstad University, School of Health and Society.
    Parturient needs during labor: Egyptian women’s perspective toward childbirth experience, a step toward an excellence in clinical practice2011In: Journal of Basic and Applied Scientific Research, ISSN 2090-4304, Vol. 1, no 12, p. 2935-2943Article in journal (Refereed)
    Abstract [en]

    Background:

    Every woman giving birth has expectations. Identifying women’s expectations, wishes, needs and fears enable the health care provider(s) to work toward a common goal of safe and positive childbirth experience.

    Aim:

    The aim was to determine women’s preferences and needs during labor.

    Design:

    Analytic- cross sectional study.

    Setting:

    El Kasr- Aini, - Cairo- University Maternity Hospitals.

    Sample:

    A random sample of 400 women were recruited in the present study with the following criteria; age ranged between 20-30 years old, can read and write, primigravida, nulliparous woman with singleton low risk pregnancies, in the third trimester, up to 37 weeks of gestational age, no previous abortion and free from any medical complains.

    Procedure:

    Data collection took place in the antenatal clinic, each interview administrated questionnaire took a time between 10-15 minutes. Mothers completed the questionnaire in the antenatal clinics during their waiting for medical examination.

    Results:

    Twenty two need requirements emerged from the women's perspective. The highest ranked needs for parturient women during labor are; maintaining privacy through all procedures of 86.5%, accessibility of nurses demonstrate empathy of 67.5%, availability to ventilate and expressing fear and anxiety of 57.5%, quick response to request of 67.5%, frequent monitoring of 52.8%, accessibility of caring medical staff of 47.2% and short delivery of 52.8%.

    Conclusion:

    Despite good general coverage of labor care among women, there were clear variations in the type of management given to them or needed by them. This study confirms that different factors predict the multidimensionality of childbirth satisfaction.

  • 3890. Abdel Ghani, Rania Mahmoud
    et al.
    Khalaf, Atika
    Kristianstad University, School of Health and Society.
    Westergren, Albert
    Kristianstad University, School of Health and Society.
    Berggren, Vanja
    Kristianstad University, School of Health and Society.
    A structured evidence-based approach to decrease cardiovascular complications among pregnant women with rheumatic disease: a pilot randomized controlled trial2010In: An annual Research Day in King Khalid University, 2010Conference paper (Refereed)
  • 3891.
    Abdel Ghani, Rania Mahmoud
    et al.
    Faculty of Nursing, Cairo University.
    Khalaf, Atika
    Kristianstad University, School of Health and Society.
    Westergren, Albert
    Kristianstad University, School of Health and Society.
    Berggren, Vanja
    Kristianstad University, School of Health and Society.
    Abdel Fadeel, Nagwa
    Faculty of Nursing, Cairo University.
    A structured evidence-based approach to decrease cardiovascular complications among pregnant women with reumatic disease: a pilot randomized controlled trial2010In: Journal of Medicine and Biomedical Science, ISSN 2078-0273, no 1, p. 8-15Article in journal (Refereed)
    Abstract [en]

    Background: Recent reports from the developing world have documented rheumatic fever (RE) incidence rates as high as 206/100 000 and Rheumatic Heart Disease (RHD) prevalence rates as high as 18.6/1000. The high frequency of RHD in the developing world necessitates aggressive prevention and control measures. Aim: The aim of the study was to examine the effect of intensive antenatal follow up program on decreasing cardiovascular complications among rheumatic pregnant woman. Design: Randomized controlled trial. Setting: This study was conducted at El Kasr-EL Aini, maternity hospital- Cairo- University Hospitals. Sample: A total of 100 rheumatic pregnant women that attended the antenatal clinic at El Kasr-EL Aini, maternity hospital who could read and write, had functional class I and II cardiac disease, primigravida, nullipara with single fetus were recruited to this study and assigned randomly into two groups. Procedure: Women who met the inclusion criteria were interviewed and baseline assessment was done. The intervention was an intensive antenatal follow up program for decreasing cardiovascular complications among rheumatic pregnant woman. Patients in the study group (SG) were offered an intervention at three levels, basic, intermediate and comprehensive. Evaluation of the program was carried out in term of assessment of maternal and neonatal outcome. Results: There were several significant differences between the study group (SG) and control group (CG). In the SG, antepartum complications was less common, gestational age at birth was higher, postnatal hospital stay shorter, birth weight higher, more had vaginal deliveries with episiotomy, fewer had caesarean section, forceps deliveries and termination of pregnancy, and cardiac class was better at follow up as compared to the CG. Conclusion: The difficult issues in pregnancy complications by cardiac disease are best managed through a team approach. Establishing a pre-pregnancy plan will foster a better therapeutic relationship between all parties and allow for better understanding of the patient’s beliefs regarding pregnancy, her disease and attitude towards medications.

  • 3892. Abdel Hai, R
    et al.
    Yassin, A
    Ahmad, MF
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Comparing an e-Learning Reproductive Health Module with Traditional Lectures at a Medical School in Egypt2010In:  , 2010Conference paper (Other academic)
  • 3893. Abdel Hai, R
    et al.
    Yassin, A
    Ahmad, MF
    Fors, Uno
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Exploring Knowledge, Attitudes and Behaviors of Medical Students Towards Using Computer Technology in Learning2010In:  , 2010Conference paper (Other academic)
  • 3894.
    Abdel Hussein, Mustafa
    KTH, School of Electrical Engineering (EES).
    Modeling and Control of Unmanned Air Vehicles2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3895.
    Abdel Rahman, Assem
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Electrical Evaluation of a Low Concentrating PVT Collector Based on Performance Ratio2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Photovoltaic Thermal/Hybrid collectors are an emerging technology that combines PV

    and solar thermal collectors by producing heat and electricity simultaneously. In this paper,

    the electrical performance evaluation of a low concentrating PVT collector was done

    through two testing parts: power comparison and performance ratio testing. For the

    performance ratio testing, it is required to identify and measure the factors affecting the

    performance ratio on a low concentrating PVT collector. Factors such as PV cell

    configuration, collector acceptance angle, flow rate, tracking the sun, temperature

    dependence and diffuse to irradiance ratio.

    Solarus low concentrating PVT collector V12 was tested at Dalarna University in Sweden

    using the electrical equipment at the solar laboratory. The PV testing has showed

    differences between the two receivers. Back2 was producing 1.8 energy output more than

    Back1 throughout the day. Front1 and Front2 were almost the same output performance.

    Performance tests showed that the cell configuration for Receiver2 with cells grouping (6-

    32-32-6) has proved to have a better performance ratio when to it comes to minimizing

    the shading effect leading to more output power throughout the day because of lowering

    the mismatch losses. Different factors were measured and presented in this thesis in

    chapter 5.

    With the current design, it has been obtained a peak power at STC of 107W per receiver.

    The solar cells have an electrical efficiency of approximately 19% while the maximum

    measured electrical efficiency for the collector was approximately 18 % per active cell area,

    in addition to a temperature coefficient of -0.53%/ ˚C. Finally a recommendation was

    done to help Solarus AB to know how much the electrical performance is affected during

    variable ambient condition and be able to use the results for analyzing and introducing

    new modification if needed.

  • 3896.
    Abdel Rehim, Abbi
    et al.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Abdel Rehim, Mohamed
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Screening and determination of drugs in human saliva utilizing microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry2013In: BMC Biomedical chromotography, ISSN 0269-3879, E-ISSN 1099-0801, Vol. 27, no 9, p. 1188-1191Article in journal (Refereed)
    Abstract [en]

    This study presents a new method for collecting and handling saliva samples using an automated analytical microsyringe and microextraction by packed syringe (MEPS). The screening and determination of lidocaine in human saliva samples utilizing MEPS and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were carried out. An exact volume of saliva could be collected. The MEPS C-8-cartridge could be used for 50 extractions before it was discarded. The extraction recovery was about 60%. The pharmacokinetic curve of lidocaine in saliva using MEPS-LC-MS/MS is reported.

  • 3897.
    Abdel Rehim, Abobakr
    KTH, School of Biotechnology (BIO).
    Elucidating CD3-gamma-epsilon and T-cell receptor-beta ectodomain interaction2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 3898.
    Abdelamer, Liena
    Karlstad University, Faculty of Social and Life Sciences.
    Den stressade eleven: En enkätstudie om stressorer som utsätter barnen för stress2011Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Researchers claim that stress has become a word of fashion and is now frequently used. They also state that there is no accepted definition that can easily describe the concept. In this essay, I have examined children and stress. The aim of the diploma work is to illustrate stress more closely the stress concept, the underlying reasons that can influence children and how teachers and school staff support children in their stress handling. My three issues are: What is stress? What stressors put children, at home and at school, in a stress situation? How can teachers help children to manage their stress? The diploma work is based on a literature study in order to find out what has been written on the subject in earlier research. Moreover, the work is based on four interviews with three class teachers and a school nurse in order to illustrate their experiences of what stresses children at school. In order to get a good base for the work the children's participation was of utmost importance to get a good base for the work, therefore questionnaires were given to 89 children in class 4 and 5. The results of the questionnaires showed that children had little or no knowledge of the stress concept. They associate it most often with lack of time and having to hurry. Children can be stressed just like adults. In addition, stress levels differ greatly between them, which means that some children feel more stress-tolerant than others. The conclusion that can be drawn from this study is that the child's environment affects the child, school and home being the greatest stress factors.

                                                                                             

    Keywords: Children under stress, stress, stressor, stress handling.

  • 3899. Abdel-Aty, M A
    et al.
    Radwan, A E
    Developing crash predictive models for a principal arterial2000Report (Other (popular science, discussion, etc.))
  • 3900. Abdel-Aty, M.
    et al.
    Larson, Jonas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    Eleuch, H.
    Obada, A. S. F.
    Multi-particle entanglement of charge qubits coupled to a nanoresonator2011In: Physica. E, Low-Dimensional systems and nanostructures, ISSN 1386-9477, E-ISSN 1873-1759, Vol. 43, no 9, p. 1625-1630Article in journal (Refereed)
    Abstract [en]

    The dynamics of charge qubits coupled to a nanomechanical resonator under the influence of both a phonon bath in contact with the resonator and irreversible decay of the qubits is considered. The focus of our analysis is devoted to multi-particle entanglement and the effects arising from the coupling to the reservoir. Even in the presence of the reservoirs, the inherent entanglement is found to be rather robust. Due to this fact, together with control of system parameters, the system may, therefore, be especially suited for quantum information processing. Our findings also shed light on the evolution of open quantum many-body systems. For instance, due to intrinsic qubit-qubit couplings our model is related to a driven XY spin model.

75767778798081 3851 - 3900 of 1198670
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