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  • 1.
    Ahmady, Tobias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Klein Rosmar, Sander
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Translation of keywords between English and Swedish2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this project, we have investigated how to perform rule-based machine translation of sets of keywords between two languages. The goal was to translate an input set, which contains one or more keywords in a source language, to a corresponding set of keywords, with the same number of elements, in the target language. However, some words in the source language may have several senses and may be translated to several, or no, words in the target language. If ambiguous translations occur, the best translation of the keyword should be chosen with respect to the context. In traditional machine translation, a word's context is determined by a phrase or sentences where the word occurs. In this project, the set of keywords represents the context.

    By investigating traditional approaches to machine translation (MT), we designed and described models for the specific purpose of keyword- translation. We have proposed a solution, based on direct translation for translating keywords between English and Swedish. In the proposed solu- tion, we also introduced a simple graph-based model for solving ambigu- ous translations. 

  • 2.
    Araya, Cristian
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Singh, Manjinder
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Web API protocol and security analysis2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is problem that every company has its own customer portal. This problem can be solved by creating a platform that gathers all customers’ portals in one place. For such platform, it is required a web API protocol that is fast, secure and has capacity for many users. Consequently, a survey of various web API protocols has been made by testing their performance and security.

    The task was to find out which web API protocol offered high security as well as high performance in terms of response time both at low and high load. This included an investigation of previous work to find out if certain protocols could be ruled out. During the work, the platform’s backend was also developed, which needed to implement chosen web API protocols that would later be tested. The performed tests measured the APIs’ connection time and their response time with and without load. The results were analyzed and showed that the protocols had both pros and cons. Finally, a protocol was chosen that was suitable for the platform because it offered high security and fast connection. In addition, the server was not affected negatively by the number of connections. Reactive REST was the web API protocol chosen for this platform.

  • 3.
    Bandali, Benjamin
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Availability and perceived availability with interaction design: Cost-effective availability model for a multinational company2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Techniques of measuring web-service uptime have always been a key metric to improve interaction and system integration. Availability is a usual metric in the field of statistics where the goal is to attract customers, but perhaps more importantly the users and providers which can improve the services through this metric. Since availability differs a lot depending on type of service, company and usage, a common problem is to define what availability really is.

    The thesis will give the readers an introduction to availability, and also explain the reasons why it may vary, which is the theory of interaction design behind a service. Though availability is a metric that can be calculated through many different ways, the result is very complex to understand for the public that is interested in it.

    The goal of this thesis is to give the readers an understanding and guidelines of how to define perceived availability based on the system availability, but also present a method of defining, calculating and present the metric in a user-friendly procedure. The result will in turn consist of a cost-effective model for perceived availability and be tested at a multinational company.

  • 4.
    Björnström, Tommie
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Cederqvist, Reidar
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Comparison and Implementation of Software Frameworks for Internet of Things2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is no established standard for how Internet of Things devices are communicating with each other, every manufacturer uses their own proprietary software and protocols. This makes it difficult to ensure the best possible user experience. There are several projects that can become a standard for how devices discovering, communicating, networking etc. The goal for this thesis work was to compare such software frameworks in some areas and investigate how Inteno’s operating system Iopsys OS can be complemented by implement one of these frameworks. A literature study gave two candidates for the comparison, AllJoyn and Bonjour. The result of the comparison showed that AllJoyn was the most appropriate choice for Inteno to implement into their OS. AllJoyn was chosen because it has a potential to become an established standard and includes tools for easy implementation. To make a proof of concept, an AllJoyn application was created. The application together with a JavaScript web page, can show and control options for an AllJoyn Wi-Fi manager application and AllJoyn enabled lamps.

  • 5.
    Carlquist, Olle
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Boström Leijon, Santos
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Implikat: A System for Categorizing Products using Implicit Feedback on a Website2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Implicit feedback is a form a relevance feedback that is inferred from how users interact with an information retrieval system such as an online search engine. This degree project report describes a method of using implicit feedback to establish relevance judgments and rank products based on their relevance to a specified attribute. The report contains an overview of the benefits and limitations of implicit feedback, as well as a description on how those limitations can be mitigated.

    A prototype that interpreted user actions as relevance votes and calculat-ed a fair relevance score based on these votes with the help of an algo-rithm was developed. This system was then tested on a website with real users during a limited period of time. The results from the test period were evaluated and the system was concluded to be far from perfect, but that improvements could be made by making adjustments to the algo-rithm. The system performed better when looking at the algorithm’s pre-cision rather than its sensitivity.

  • 6.
    Chavez Alcarraz, Erick
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Moraga, Manuel
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Linked data performance in different databases: Comparison between SQL and NoSQL databases2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Meepo AB was investigating the possibility of developing a social rating and recommendation service. In a recommendation service, the user ratings are collected in a database, this data is then used in recommendation algorithms to create individual user recommendations.

    The purpose of this study was to find out which  demands are put on a DBMS, database management system, powering a recommendation service, what impact the NoSQL databases have on the performance of recommendation services compared to traditional relational databases, and which DBMS is most suited for storing the data needed to host a recommendation service.

    Five distinct NoSQL and Relational DBMS were examined, from these three candidates were chosen for a closer comparison.

    Following a study of recommendation algorithms and services, a test suite was created to compare DBMS performance in different areas using a data set of 100 million ratings.

    The results show that MongoDB had the best performance in most use cases, while Neo4j and MySQL struggled with queries spanning the whole data set.

    This paper however never compared performance for real production code. To get a better comparison, more research is needed. We recommend new performance tests for MongoDB and Neo4j using implementations of recommendation algorithms, a larger data set, and more powerful hardware.

  • 7.
    Cronebäck, Alexandra
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Input interface requirements on board mounted DC/DC converters2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out on behalf of the department of Power Modules at Ericsson.

    In a telecom system interface A is a physical point between the power supply system and the telecommunication equipment described in a European standard called ETSI EN 300 132-2. This interface is also described in the American standard ATIS-0600315.2007. For board-mounted products, such as DC/DC converters, a well-defined input interface description is lacking.

    The goal of this thesis was to evaluate if the requirements in the standards ETSI EN 300 132-2 and ATIS-0600315.2007 are viable for the input interface of DC/DC converters. A part of this goal was also to investigate and analyze how the systems, in which the DC/DC converters operate, works.

    To be able to determine if any of the two standards, ETSI and ATIS, are viable for use for the input interface, both were reviewed and described with focus on voltage levels and transients.

    In the information gathering phase it became clear that an extended limitation was needed. Therefore, in order to investigate what happens from interface A to the input interface of DC/DC converters, the system used in this thesis is the EBS LOD (Ericsson Blade System – Low Ohmic Distribution). EBS is one of the systems in Core sites.

    The report describes the construction of EBS where in the PFM (Power Fan Module), backplanes and various boards are important parts. Furthermore some key principles within Core sites, such as HOD (High Ohmic Distribution), LOD, Two-wire system and Three-wire system, are also described in order to explain how the EBS system works.

    EBS (including PIM (Power Interface Module)) was modeled in OrCad PSpice, with both one board and 26 boards, and was simulated with different transients at an input to the system. The simulation results show that the high voltages never reach the DC/DC converter and that they therefore are well protected from transients in an EBS LOD system.

    In order to determine whether the standards ETSI and ATIS are viable for the input interface of DC/DC converters, it is concluded that more investigations, tests and simulations are needed.

  • 8.
    Ekman, Jonas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Evaluation of HCI models to control a network system through a graphical user interface2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    SAAB has a project under development for a network system with connected nodes, where the nodes are both information consumer and producer of different communication types. A node is an equipment or an object that are used by the army e.g. it can be a soldier, military hospital or an UAV. The nodes function as a part of a mission e.g. a mission can be Defend Gotland. The aim of this project is that the user will rank different missions from the one with the highest priority to the lowest. This will affect the network in a way that the communication between the nodes at the mission with the highest rank will be prioritised over the communication between the underlying missions. A user can via the GUI rank the missions, and then set the associated settings for them. Via the GUI the user should be able to work at three different levels. The first is to plan upcoming missions. The second one is in real time see if the system delivers the desired conditions. The last one is to simulate if the system can deliver the desired conditions.

    This thesis investigated various HCI models that could be used to create a GUI, to reduce the risk of a user configuring the system incorrectly. The study showed that there are no HCI models that take account for misconfigurations, and therefore a new model was created. The new model was used and evaluated by creating a prototype of a GUI for SAAB’s project and was tested on a potential user. The test showed that the new model reduced the risk of misconfigurations.

  • 9.
    Foitzik, John
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Comparison between two methods for 3D imaging of machine parts2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today the production time is shortened when components are made with additive manufac- turing and the finished products typically have very few defects. If the components quality is to be validated, it’s done with a Non-destructive testing method. In this thesis a test piece made of Inconel 939, that is used in high temperature application was examined with a non- destructive testing technique (NDT), computed tomography (CT) and with destructive test- ing (DT) by grinding the test piece down to a given position and taking images of the ex- posed surface. The purpose was to validate computed tomography images by doing a two- dimensional correlation between images from CT and DT using MATLAB. Due to tech- nical problems the resulting images were however not showing the same par of the test piece. Therefore the correlation method was instead validated. Modifying a 2D image from CT and running it in the code written in MATLAB could quantify the distortions in the images. Results are presented in figures and in tables. The table shows more detailed in- formation with exact coordinates and what correlation each area has. The figure shows the movements and direction of the changes. The result shows that the method can detect changes and does what was intended. 

  • 10.
    Grahn, Erik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Evaluation of MEMS accelerometer and gyroscope for orientation tracking nutrunner functionality2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the production industry, quality control is of importance. Even though today's tools provide a lot of functionality and safety to help the operators in their job, the operators still is responsible for the final quality of the parts. Today the nutrunners manufactured by Atlas Copco use their driver to detect the tightening angle. There- fore the operator can influence the tightening by turning the tool clockwise or counterclockwise during a tightening and quality cannot be assured that the bolt is tightened with a certain torque angle. The function of orientation tracking was de- sired to be evaluated for the Tensor STB angle and STB pistol tools manufactured by Atlas Copco. To be able to study the orientation of a nutrunner, practical exper- iments were introduced where an IMU sensor was fixed on a battery powered nutrunner. Sensor fusion in the form of a complementary filter was evaluated. The result states that the accelerometer could not be used to estimate the angular dis- placement of tightening due to vibration and gimbal lock and therefore a sensor fusion is not possible. The gyroscope by itself can be used to provide the angular displacement around every axis with high accuracy without taking into account the gimbal lock phenomena or external forces in the form of vibration of the tool. The gyroscope provided data with a probability to measure ±1° in future tightenings by 69,76%. The gyroscope provided data with high accuracy and stability and can be used in real world application and production for true angle functionality of the tools. 

  • 11.
    Hammer, Joakim
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lind, Olle
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Scalable platform for health service integrations2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis was performed at the company ShapeUp Club located in Stockholm, Sweden. ShapeUp Club offers a digital calorie counter service for the web, iOS and Android with data synchronization across the platforms.

    ShapeUp Club wants to provide their users with the option to synchronize data between ShapeUp Club and external health services. The objective for this thesis has been to develop an extension to ShapeUp Clubs current backend platform where new external health services can be plugged-in quickly and scalable. External partner APIs will be examined and implemented in the system to validate the functionality of the system. The amount of code needed to plug-in a service should be as minimal as possible for a developer to quickly add another service. To allow for scalability the platform also needs to adapt logic for how often users should be allowed to poll for data from their connected services, to minimize the database load for all parts.

    To handle these demands, an extension to ShapeUp Club’s current backend solution was built using the Django framework for Python. By providing a generic base class that new services inherit from, the amount of code necessary for implementing a new service is reduced to methods for API- requests, authorization and serialization of data. To reduce the number of redundant poll requests, users are placed into groups. Each group is a cluster of users with similar frequency of updates. Django’s cache framework is used to handle the concurrency of the sync tasks, which locks a user from syncing the same partner in parallel. 

  • 12.
    Hededal Klincov, Lazar
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Symeri, Ali
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Devising a Trend-break-detection Algorithm of stored Key Performance Indicators for Telecom Equipment2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A problem that is prevalent for testers at Ericsson is that performance test results are continuously generated but not analyzed. The time between occurrence of problems and information about the occurrence is long and variable. This is due to the manual analysis of log files that is time consuming and tedious. The requested solution is automation with an algorithm that analyzes the performance and notifies when problems occur. A binary classifier algorithm, based on statistical methods, was developed and evaluated as a solution to the stated problem. The algorithm was evaluated with simulated data and produced an accuracy of 97.54 %, to detect trend breaks. Furthermore, correlation analysis was carried out between performance and hardware to gain insights in how hardware configurations affect test runs.

  • 13.
    Hermansson, Rickard
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Hellström, Johan
    KTH, School of Technology and Health (STH).
    Discretionary Version Control: Access Control for Versionable Documents2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A common problem in the workplace is sharing digital documents with coworkers. Forsome companies the problem extends to wanting the documentskept internally backedup and controlling which people in the company has rights to read and revise certaindocuments.This paper shows different systems and models for access control, version control,and distribution of the documents that can be used to create asystem that solves theseproblems.One requirement for this system was a user interface where users can upload, down-load and manage access to their documents. Another requirement was a service thathandles version control for the documents, and a way to quickly connect and distributethe documents. The system also needed to be able to handle access control of the ver-sioned documents on document level, referred to as "fine grained access control" in thispaper.These models and systems were evaluated based on aspects of the access control mod-els, version control systems, and distribution systems andprotocols. After evaluating,appropriate selections were made to create a prototype to test the system as a whole.The prototype ended up meeting the goals that Nordicstationset for the project butonly with basic functionality. Functionality for retrieving any version from a docu-ments history, controlling access for the documents at document level, and a simpleweb based user interface for managing the documents.

  • 14.
    Ho, Henry
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Odelberg, Axel
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Efficient caching of rich data sets2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The importance of a smooth user experience in applications is increasing. To achieve more performance when interacting with resource intensive data it is important to implement an efficient caching method. The goal of this thesis is to investigate how to implement an efficient cache in an Android application. The use case is to download metadata and images of movies from a WebAPI provided by June AB.

    In order to investigate which caching method is the most efficient, a pre-study was done on some of the most common caching methods today. Based on the results of the pre-study, two different caching algorithms were tested and evaluated: First-In First-Out (FIFO) and Least Recently Used (LRU). These two algorithms were then implemented in an Android application.

    The resulting prototype has a responsive user interface capable of caching large amounts of data without noticeable performance loss compared to a non-cached version. The results from the prototype showed that LRU is the better strategy in our use case, however what we discovered was that the buffer size of the cache has the biggest impact on performance, not the cache eviction strategy.

  • 15.
    Jernberg, Robert
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Hultgren, Tobias
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Flexible Data Extraction for Analysis using Multidimensional Databases and OLAP Cubes2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Bright is a company that provides customer and employee satisfaction surveys, and uses this information to provide feedback to their customers. Data from the surveys are stored in a relational database and information is generated both by directly querying the database as well as doing analysis on extracted data. As the amount of data grows, generating this information takes increasingly more time. Extracting the data requires significant manual work and is in practice avoided. As this is not an uncommon issue, there is a substantial theoretical framework around the area.

    The aim of this degree project is to explore the different methods for achieving flexible and efficient data analysis on large amounts of data. This was implemented using a multidimensional database designed for analysis as well as an OnLine Analytical Processing (OLAP) cube built using Microsoft's SQL Server Analysis Services (SSAS). The cube was designed with the possibility to extract data on an individual level through PivotTables in Excel.

    The implemented prototype was analyzed, showing that the prototype consistently delivers correct results severalfold as efficient as the current solution as well as making new types of analysis possible and convenient. It is concluded that the use of an OLAP cube was a good choice for the issue at hand, and that the use of SSAS provided the necessary features for a functional prototype. Finally, recommendations on possible further developments were discussed.

  • 16.
    Kers, Simon
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Configuration and device identification on networkgateways2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To set up port forwarding rules on network gateways, certain technical skills are requiredfrom end-users. These assumptions in the gateway software stack, can lead to an increasein support calls to network operators and resellers of customer premises equipment. Theuser interface itself is also an important part of the product and a complicated interfacewill contribute to a lessened user experience. Other issues with an overwhelming userinterface include the risk of faulty configuration by the user, potentially leaving the networkvulnerable to attacks.We present an enhancement of the current port forwarding configuration in the gatewaysoftware, with an extensible library of presets along with usability improvements. To helpusers with detecting available services, a wrapper for a network scanner is implemented, fordetecting devices and services on the local network. These parts combined relieves end-usersof looking up forwarding rules for ports and protocols to configure their gateway, basingtheir decisions on data collected by the network scanner or by using an applications nameinstead of looking up its ports. Another usability improvement is an internal DNS service,which enables access to the gateway interface through a human-memorable domain name,instead of using the LAN IP address.Using the Nmap utility for identifying services on the network, could be consideredharmful activity by network admins and intrusion detection systems. The preset libraryis extensible and generic enough to be included in the default software suite shipping withthe network equipment. Working within the unified configuration system of OpenWrt, thepreset design will add value and allow resellers to easily customize it to their services. Thisproposal could reduce support costs for the service operators and improve user experiencein configuring network gateways.

  • 17.
    Kåhre, Jonathan
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Boeryd, David
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Resolution for dynamic configuration of consumer placed equipment2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Networking devices and other internet-enabled hardware require configuration to work correctly and manually configuring each and every device is expensive and slow. In order to relieve these problems, the concept of automatic configuration was conceived. For this to be possible, a device must be able to not only find the location of the host keeping the configuration but also negotiate how the configuration will take place. In this paper, two new protocols are proposed to resolve configuration servers for the device to negotiate with and the negotiation protocol to arrange the actual configuration procedure. Additionally a business model is presented in order to structure and maintain the system supplementing existing production and sales.

  • 18.
    Lind, Oskar
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    An E-commerce Platform Evaluation basedon the DoSAM Framework2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The goal of the thesis work was to give Softronic AB, a management and IT consulting company, an overview of strengths and weaknesses of the four content management systems Magento CE 1.6.2, Episerver Commerce 1 R2 SP1, Wipcore eNOVA 5.3 and Umbraco CMS, as platforms for ecommerce. The evaluation was to be made from a marketing perspective as well as from a user and in-house developer's perspective. Additionally, the goal was to provide an overview of how certain functionality from a current project could be implemented on the Magento CE platform.

    To be able to evaluate the platforms, a study of current evaluation and comparison models was performed. This resulted in the choice of the framework Domain-specific Architecture Comparison Model. A comparison framework was derived and defined from this model, and applied on the platforms. The choice of what was to be measured, and how, was determined from literature studies of the e-commerce domain, as well as studies of current e-commerce platforms. The demonstration of the capabilities of the Magento platform was solved by creating a new Magento store instance, implementing two components from a reference project, as well as parts of the graphical user interface, and deploying the solution on a cloud server.

    The evaluation resulted in a description of the platforms' strengths and weaknesses, and a table showing the properties of the platforms. The evaluation indicated that the platforms Magento CE and Episerver Commerce were the strongest when it came to functionality and market readiness. Wipcore eNOVA and Umbraco CMS's strongest side was performance efficiency, while none of the platforms were assessed as particularly strong in terms of maintainability. 

  • 19.
    Lundmark, Magnus
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Dahlman, Carl-Johan
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Differential privacy and machine learning: Calculating sensitivity with generated data sets2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Privacy has never been more important to maintain in today’s information society. Companies and organizations collect large amounts of data about their users. This information is considered to be valuable due to its statistical usage that provide insight into certain areas such as medicine, economics, or behavioural patterns among individuals.

    A technique called differential privacy has been developed to ensure that the privacy of individuals are maintained. This enables the ability to create useful statistics while the privacy of the individual is maintained. However the disadvantage of differential privacy is the magnitude of the randomized noise applied to the data in order to hide the individual.

    This research examined whether it is possible to improve the usability of the privatized result by using machine learning to generate a data set that the noise can be based on. The purpose of the generated data set is to provide a local representation of the underlying data set that is safe to use when calculating the magnitude of the randomized noise.

    The results of this research has determined that this approach is currently not a feasible solution, but demonstrates possible ways to base further research in order to improve the usability of differential privacy. The research indicates limiting the noise to a lower bound calculated from the underlying data set might be enough to reach all privacy requirements. Furthermore, the accuracy of the machining learning algorithm and its impact on the usability of the noise, was not fully investigated and could be of interest in future studies. 

  • 20.
    Maan, Narbir Singh
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Hanchi, Hamza
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Secure Access for Public Clients to Web API:s with Minimum Performance Loss2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A lot of information nowadays is made available through Web APIs on the Internet and without security and encryption; it is very easy for malicious users to access confidential information.

    The goal was to find out what different mechanisms that are available for providing a safe communication with a web API from web clients and mobile applications with little as possible impact on the performance. Learning, implementing and maintaining the mechanisms are also im- portant aspects looked at in the evaluation.

    Many mechanisms are available for use to secure the communication but not all are suitable for public clients. The suitable mechanisms are Digest authentication and OAuth 2.0. The chosen mechanisms were developed, tested and evaluated in regard to safety, performance impact and usabil- ity from a company perspective.

    The authentication and authorization mechanism, which was the most suitable, was OAuth 2.0as it has least impact on performance and better security features than the other mechanisms.

  • 21.
    Niemelä, Jimmy
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Impostor Rendering with Oculus Rift2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report studies impostor rendering for use with the virtual reality head mounted display Oculus Rift. The technique is replacing 3D models with 2D versions to speed up rendering, in a 3D engine. It documents the process of developing a prototype in C++ and DirectX11 and the required research needed to complete the assignment. Included in this report are also the steps involved in getting Oculus Rift support to work in a custom 3D engine and measuring the impact of impostor rendering when rendering to two screens of the head mounted display. The goal was to find the maximum models the engine could draw, while keeping the frame rate locked at 60 frames per second. 2 testers at Nordicstation came to the conclusion that 40-50 meters was the optimal distance for impostor rendering. Any closer and the flatness was noticeable. The results showed a clear improvement in frame rate when rendering a graphically intensive scene. The end result showed that the goal could be achieved at a maximum of 3000 trees with 1000 leaves. Impostor rendering was deemed effective when drawing beyond 500 trees at a time. Less than that and the technique was not needed to achieve 60 frames per second.

  • 22.
    Nordvall, Andreas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Agile regression system testing2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes the work on automating the testing of nodes at CCS (Common Control System) in Ericsson. The goal was to every three hours configure nodes with the latest build and run the tests. This process is to be fully automatic without user in-put. The existing configuration tool CICC (Core Integration node Control Center) is to be used for configuration. Before work started fault reports were analyzed and creating a usecase for testing restarts should reduce some faults.The first step was to make the configuration tool CICC automated. To schedule the test-ing the continuous integration tool Jenkins was used. But Jenkins can’t by itself run CICC nor interpret the result. Therefore a wrapper layer was implemented. When the wrapper is finished it stores the results of the configuration run in a XML (eXtensible Markup Language) file, which Jenkins reads. Results can then be seen in Jenkins through web interface. If there were any failures during configuration or testing the failed step will have an error message.The project shows that automation is possible. Automating the testing reduce the time for correcting errors because they are more likely to be found early in the process. Be-fore implementing this project in production some improvements should be made. The most significant improvement is making the configuration and testing of each node par-allel with each other, in order to make the time limit for configuration and testing less of an issue.

  • 23.
    Nylund, Andreas
    KTH, School of Technology and Health (STH), Medical Engineering.
    Off-resonance correction for magnetic resonance imaging with spiral trajectories2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The procedure of cardiographic magnetic resonance imaging requires patients to hold their breath for up to twenty seconds, creating an uncomfortable situation for many patients. It is proposed that an acquisition scheme using spiral trajectories is preferable due to their much shorter total scan time; however, spiral trajectories suffer from a blurring effect caused by off-resonance frequencies in the image area.

    There are several methods for reconstructing images with reduced blur and Conjugate Phase Reconstruction has been chosen as a method for implementation into Matlab-script for evaluation in regards to image reconstruction quality and computation time. This method finds a conjugate to the off-resonance from a field map to demodulate the image and an algorithm for frequency‑segmented Conjugate Phase Reconstruction is implemented along with an improvement called Multi-frequency Interpolation.

    The implementation is tested through simulation of spiral magnetic resonance imaging using a Shepp‑Logan phantom. Different off-resonance frequencies and field maps are used to provide a broad view of the functionality of the code. The two algorithms are then compared to each other in terms of computation speed and image quality.

    It is concluded that this implementation might reconstruct images well but that further testing on actual scan sequences is required to determine the usefulness. The Multi-frequency Interpolation algorithm yields images that are not useful in a clinical context. Further study of other methods not requiring a field map is suggested for comparison.

  • 24.
    Oldsberg, Patrik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Field Service Support with Google Glass and WebRTC2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Internet is dramatically changing the way we communicate, and it is becoming increasingly important for communication services to adapt to context in which they are used.

    The goal of this thesis was to research how Google Glass and WebRTC can be used to create a communication system tailored for field service support.

    A prototype was created where an expert is able to provide guidance for a field technician who is wearing Google Glass. A live video feed is sent from Glass to the expert from which the expert can select individual images. When a still image is selected it is displayed to the technician through Glass, and the expert is able to provide instructions using real time annotations.

    An algorithm that divides the selected image into segments was implemented using WebGL. This made it possible for the expert to highlight objects in the image by clicking on them.

    The thesis also investigates different options for accessing the hardware video encoder on Google Glass.

  • 25.
    Palm, Emanuel
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Graphics’ Card Utility withWebGL and N-Buffering: Improving performance using N-buffer strategies with WebGL2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis covers the utilization of N buffers in order to reduce resource contention on an abstract WebGL machine, and subsequently freeing up machine processing time. The buffers touched are frame buffers and vertex buffers.

    The paper also briefly covers the purpose and function of N buffering in relation to graphics and the function of a WebGL machine, the research and production of benchmark prototypes, some relevant benchmark results, and analysis and conclusions.

    The conclusion is made that the use of N>1 buffering is a potentially viable strategy for increasing WebGL performance, and some theories are outlined and suggestions given for further research to be made for the resolving of how this performance gain may be improved.

  • 26.
    Persson, Lucas
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Markström, Sebastian
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Indoor localization of hand-held Shopping Scanners2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates applicable indoor navigation systems for the next generation of hand-held shopping scanners, on behalf of the company Virtual Stores. The thesis research and review applicable indoor localization methods and ways to combine and evaluate received localization data in order to provide accurate navigation without introducing any other worn equipment for a potential user. Prototype navigation systems was proposed, developed and evaluated using a combination of carefully placed radio transmitters that was used to provide radio based localization methods using Bluetooth or UltraWide Band (UWB) and inertial sensors combined with a particle filter. The Bluetooth solution was deemed incapable of providing any accurate localization method while the prototype using a combination of UWB and inertial sensors proved promising solution with below 1m average error under optimal conditions or 2.0m average localization error in a more realistic environment. However, the system requires the surveyed area to provide 3 or more UWB transmitters in the line of sight of the UWB receiver of the user at every location facing any direction to provide accurate localization. The prototype also requires to be scaled up to provide localization to more than 1 radio transmitters at the time before being introduced to the Fast moving consumer goods market. 

  • 27.
    Reimers, Axel
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Gustafsson, Isak
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Indexing and Search Algorithmsfor Web shops: 2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Web shops today needs to be more and more responsive, where one part of this responsivenessis fast product searches. One way of getting faster searches are by searching against anindex instead of directly against a database.

    Network Expertise Sweden AB (Net Exp) wants to explore different methods of implementingan index in their future web shop, building upon the open-source web shop platformSmartStore.NET. Since SmartStore.NET does all of its searches directly against itsdatabase, it will not scale well and will wear more on the database. The aim was thereforeto find different solutions to offload the database by using an index instead.

    A prototype that retrieved products from a database and made them searchable through anindex was developed, evaluated and implemented. The prototype indexed the data with aninverted index algorithm, and was made searchable with a search algorithm that mixed typeboolean queries with normal queries.

  • 28.
    Sakhi, Imal
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Database security in the cloud2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the thesis is to get an overview of the database services available in cloud computing environment, investigate the security risks associated with it and propose the possible countermeasures to minimize the risks. The thesis also analyzes two cloud database service providers namely; Amazon RDS and Xeround. The reason behind choosing these two providers is because they are currently amongst the leading cloud database providers and both provide relational cloud databases which makes the comparison useful. The focus of the analysis has been to provide an overview of their database services as well as the available security measurements. A guide has been appended at the end of the report to help with technical configurations of database migration and connecting applications to the databases for the two mentioned cloud database providers.

    The thesis has been conducted on behalf of the Swedish Armed Forces and after reviewing the security risks associated with cloud databases, it is recommended that the Armed Forces should refrain from public cloud database services. Security deficiencies such as vague physical security and access control procedures, unavailability of preferred monitoring tools and most importantly the absence of proper encryption and key management schemes make the public database services useless for an authority such as the Armed Forces.  The recommended solutions are therefore to either use a jointly-owned community cloud database solution for less confidential data only or to use on-premise private cloud database solution for all but the TOP SECRET classified data.  

     

    Keywords: Cloud computing, cloud database services, Swedish Armed Forces, security risks, Xeround, Amazon RDS 

  • 29.
    Stahl, Alexander
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    nsAnalyser: Speech quality testing application for telephone service2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project was made in collaboration with Nordicstation. The project task was to develop a testing application for a self-developed telephone survey service, which uses third party software. This third party software showed to be unreliable at higher loads. The purpose of the application is to analyse the speech quality of clients connected to the service. This report gives an introduction to the speech quality algorithms Perceptual Evaluation of Speech Quality (PESQ) and Single Sided Speech Quality Measure (3SQM). It also gives descriptions of the methods used to develop the application. The final chapters in this report are about the testing of the telephone service. The primary result of the testing was that the telephone service is unable to acceptably handle 80+ clients and recommendations to Nordicstation is to set a maximum of parallel connected clients to 80 or find an alternative to the third party software currently in use.

  • 30.
    Stefan, Vasic
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Nicklas, Lindgren
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Product categorisation using machine learning2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Machine learning is a method in data science for analysing large data sets and extracting hidden patterns and common characteristics in the data. Corporations often have access to databases containing great amounts of data that could contain valuable information.

    Navetti AB wants to investigate the possibility to automate their product categorisation by evaluating different types of machine learning algorithms. This could increase both time- and cost efficiency.

    This work resulted in three different prototypes, each using different machine learning algorithms with the ability to categorise products automatically. The prototypes were tested and evaluated based on their ability to categorise products and their performance in terms of speed. Different techniques used for preprocessing data is also evaluated and tested.

    An analysis of the tests shows that when providing a suitable algorithm with enough data it is possible to automate the manual categorisation. 

  • 31.
    Stråle, Johan
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lindén, Helena
    KTH, School of Technology and Health (STH).
    An evaluation of platforms for open government data2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Municipalities and government agencies are producers of information that may be of interest to the public concerning areas such as population statistics, weather data and policy decisions. In the Digital Agenda, the Swedish Government emphasizes the importance for data to be spread and promotes the development and innovation of new e-services created by other parties than government agencies. Various development initiatives of platforms have been taken around the world but there are no specific standards regarding how data should be made public.

    Softronic currently offer their customers a proprietary platform for the publication of open data. In order to improve or alternatively replace this, Softronic wanted an evaluation of a number of already existing platforms.

    This report contains an evaluation of the Softronic platform along with three other candidates: CKAN, Socrata and OpenDataSoft. The included aspects in the evaluation were selected based on requests from Softronic, covering among other things the installation process, performance and upgrades. To assess the API function of the platforms and demonstrate how an application using open data can be implemented, a graphical client was developed.

    Socrata received the highest score in the evaluation, followed by in turn OpenDataSoft, CKAN and Softronic. Socrata is recommended as a platform for publishing open government data mainly because it offered extensive functionality, required few technical skills and provided plenty of support services.

  • 32.
    Thun, Julia
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Kadouri, Rebin
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Automating debugging through data mining2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Contemporary technological systems generate massive quantities of log messages. These messages can be stored, searched and visualized efficiently using log management and analysis tools. The analysis of log messages offer insights into system behavior such as performance, server status and execution faults in web applications.

    iStone AB wants to explore the possibility to automate their debugging process. Since iStone does most parts of their debugging manually, it takes time to find errors within the system. The aim was therefore to find different solutions to reduce the time it takes to debug.

    An analysis of log messages within access – and console logs were made, so that the most appropriate data mining techniques for iStone’s system would be chosen. Data mining algorithms and log management and analysis tools were compared. The result of the comparisons showed that the ELK Stack as well as a mixture between Eclat and a hybrid algorithm (Eclat and Apriori) were the most appropriate choices. To demonstrate their feasibility, the ELK Stack and Eclat were implemented. The produced results show that data mining and the use of a platform for log analysis can facilitate and reduce the time it takes to debug.

  • 33.
    Tran, Tony
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Levin, Mats
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Blockchain, the future opportunity for trading progression?2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The rapid expansion of computer technology have forced several business sectors to integrate with the continuous development of techniques in order to assist them in various tasks. Many fields have happily embraced the technology implementing it in numerous ways, however the development speed have proven difficult to keep up with. The insurance industry have struggled with ridding themselves of old and monolithic legacy systems with a haphazard construction. These systems are costly, cumbersome and often reliant on a “third party” centered structure creating such flaws as data leaks and monopolisation.

    Blockchain is a distributed ledger operating over a peer-to-peer basis, with the intention to unshackle contemporary system from their dependence towards central authorities. Additionally, the peer-to-peer architecture introduced a new form of transparency which differs from contemporary solutions used in centralised systems, beyond the peer-to-peer architecture, the blockchain also incorporated consensus algorithms, allowing peers to verify one another to achieve consensus regarding the validity of each block. This resulted in a "trustless system" considering no single party in the community is dependent on the credibility of a central authority.

    In order for the blockchain technology to be applicable on the market it must overcome obstacles such as privacy and the new EU data protection regulation “General protection data regulation”. However a vague definition of personal data have caused ambiguity which appears to be irreconcilable with the blockchain technology. Research have therefore shifted its focus to explore opportunities for the technology to collaborate with techniques from centralisation in order to overcome its obstacles.

  • 34.
    Trunehag, Tobias
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Kättström, Mathias
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Monitoring an integration service in Windows Azure2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When selling a service to companies or individuals, it’s important to deliver what you sell.

    Currently, Softronic provides companies with a platform that provides different types of services. These services create opportunities to efficiently develop government functions in accordance with the Government’s action plan for e-governance. These services are hosted by using the cloud computing platform Microsoft Windows Azure.

    The services’ functionality is important for both Softronic and their customers’ businesses. To know early whether there is a problem or if there will be problems with the services, Softronic wanted to monitor one of these services with the help of an external monitoring service.

     

    The aim of this thesis was to compare three different systems for monitoring cloud-based services, implement the most suitable one and develop an application for Windows 8 where customers can see the status of their message channel inside the service. The monitoring systems tested were chosen and judged according to Softronics needs and monitoring requirements.

    A monitoring service called New Relic was chosen for implementation. New Relic has support for most of the required features, and for the rest of the features, an application was developed. A Windows 8 application and a website were developed that show information about customers’ message channels, and a web service was developed to supply both of them with the data they need.

1 - 34 of 34
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