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Tiny energy harvesting sensors that operate intermittently, without batteries, have become an increasingly appealing way to gather data in hard to reach places at low cost. Frequent power failures make forward progress, data preservation and consistency, and timely operation challenging. Unfortunately, state-of-the-art systems ask the programmer to solve these challenges, and have high memory overhead, lack critical programming features like pointers and recursion, and are only dimly aware of the passing of time and its effect on application quality. We present Time-sensitive Intermittent Computing System (TICS), a new platform for intermittent computing, which provides simple programming abstractions for handling the passing of time through intermittent failures, and uses this to make decisions about when data can be used or thrown away. Moreover, TICS provides predictable checkpoint sizes by keeping checkpoint and restore times small and reduces the cognitive burden of rewriting embedded code for intermittency without limiting expressibility or language functionality, enabling numerous existing embedded applications to run intermittently., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Embedded and Networked Systems

Tiny energy harvesting sensors that operate intermittently, without batteries, have become an increasingly appealing way to gather data in hard to reach places at low cost. Frequent power failures make forward progress, data preservation and consistency, and timely operation challenging. Unfortunately, state-of-the-art systems ask the programmer to solve these challenges, and have high memory overhead, lack critical programming features like pointers and recursion, and are only dimly aware of the passing of time and its effect on application quality. We present Time-sensitive Intermittent Computing System (TICS), a new platform for intermittent computing, which provides simple programming abstractions for handling the passing of time through intermittent failures, and uses this to make decisions about when data can be used or thrown away. Moreover, TICS provides predictable checkpoint sizes by keeping checkpoint and restore times small and reduces the cognitive burden of rewriting embedded code for intermittency without limiting expressibility or language functionality, enabling numerous existing embedded applications to run intermittently., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Embedded Systems

Legacykod är något som är svårt för utvecklare att förhindra. Medan det finns mycket forskning kring att motarbeta legacykod och förnya legacysystem som använder utdaterade teknologier och designer, så har inte mycket fokus lagts på hur legacykod kan identifieras i sitt tidigaste skede. Hur dessutom definierar man legacykod? I denna studie så görs en litteraturstudie för att ta reda på vad för forskningsbakgrund det finns bakom legacykod i allmänhet. Därefter så utvecklas två prototyper i syfte att upptäcka mönster under utvecklingen som kan vara egenskaper till legacykod. I slutändan så utförs en enkät riktade åt mjukvaruutvecklare för att få insyn och tankar på vad legacykod betyder för dem och för att testa idéerna som togs fram från implementationerna. Den rekommenderade definitionen för legacykod är kod som inte har testats, ingen eller för lite dokumentation och är allmänt svår att förstå, vare sig med dokumentation eller utan. Observationerna från implementation av de två prototyperna bildade 7 riktlinjer som tar upp hur man kan identifiera uppväxten av legacykod., Legacy code proves to be something difficult for developers to prevent. While much research exists to combat legacy code and renewing legacy systems that use outdated technologies and designs, not much focus has been put on how legacy code can be detected at its earliest stage. And how do you define legacy code? In this study, a literature review is done to find out the scientific background behind legacy code in general. Afterwards, two implementations of the same software are done to observe any events during the software development that can be characteristics of legacy code. In the end phase, a questionnaire-based survey is handed out to developers to get their insight and thoughts on what legacy code means to them and to test the ideas brought up from the implementations. A recommended definition for legacy code is code with no testing and little to no documentation and generally being hard to understand, whether with documentation or not. From the observations implementing the prototypes, 7 guidelines are formed to help identify and discover legacy code evolution.

Legacykod är något som är svårt för utvecklare att förhindra. Medan det finns mycket forskning kring att motarbeta legacykod och förnya legacysystem som använder utdaterade teknologier och designer, så har inte mycket fokus lagts på hur legacykod kan identifieras i sitt tidigaste skede. Hur dessutom definierar man legacykod? I denna studie så görs en litteraturstudie för att ta reda på vad för forskningsbakgrund det finns bakom legacykod i allmänhet. Därefter så utvecklas två prototyper i syfte att upptäcka mönster under utvecklingen som kan vara egenskaper till legacykod. I slutändan så utförs en enkät riktade åt mjukvaruutvecklare för att få insyn och tankar på vad legacykod betyder för dem och för att testa idéerna som togs fram från implementationerna. Den rekommenderade definitionen för legacykod är kod som inte har testats, ingen eller för lite dokumentation och är allmänt svår att förstå, vare sig med dokumentation eller utan. Observationerna från implementation av de två prototyperna bildade 7 riktlinjer som tar upp hur man kan identifiera uppväxten av legacykod., Legacy code proves to be something difficult for developers to prevent. While much research exists to combat legacy code and renewing legacy systems that use outdated technologies and designs, not much focus has been put on how legacy code can be detected at its earliest stage. And how do you define legacy code? In this study, a literature review is done to find out the scientific background behind legacy code in general. Afterwards, two implementations of the same software are done to observe any events during the software development that can be characteristics of legacy code. In the end phase, a questionnaire-based survey is handed out to developers to get their insight and thoughts on what legacy code means to them and to test the ideas brought up from the implementations. A recommended definition for legacy code is code with no testing and little to no documentation and generally being hard to understand, whether with documentation or not. From the observations implementing the prototypes, 7 guidelines are formed to help identify and discover legacy code evolution.

[ES] Este Trabajo de Final de Grado consistirá en la aplicación de un modelo con el objetivo de predecir el precio de las acciones de la empresa IAG (International Airlines Group) cotizada en el IBEX 35 bajo el símbolo IAG.MC. Para llevar a término esa predicción se empleará el modelo Lognormal que con las cotizaciones de un histórico de tamaño apropiado es capaz de predecir el valor del activo. Los parámetros del modelo son la tendencia y la volatilidad del activo. Una de las partes importantes del proyecto será desarrollar código web, para pasar de un paradigma imperativo a uno orientado a objetos, y dotarlo de tests efectivos por medio de TDD (test driven development o diseño guiado por tests) para así pasar de un Legacy Code (Código heredado) a un sistema mainstream (un sistema de fácil mantenimiento y extensión). Además se dotará de una base de datos para el almacenamiento de los datos permitiendo así mostrar una mayor cantidad de información en la web.

[ES] Este Trabajo de Final de Grado consistirá en la aplicación de un modelo con el objetivo de predecir el precio de las acciones de la empresa IAG (International Airlines Group) cotizada en el IBEX 35 bajo el símbolo IAG.MC. Para llevar a término esa predicción se empleará el modelo Lognormal que con las cotizaciones de un histórico de tamaño apropiado es capaz de predecir el valor del activo. Los parámetros del modelo son la tendencia y la volatilidad del activo. Una de las partes importantes del proyecto será desarrollar código web, para pasar de un paradigma imperativo a uno orientado a objetos, y dotarlo de tests efectivos por medio de TDD (test driven development o diseño guiado por tests) para así pasar de un Legacy Code (Código heredado) a un sistema mainstream (un sistema de fácil mantenimiento y extensión). Además se dotará de una base de datos para el almacenamiento de los datos permitiendo así mostrar una mayor cantidad de información en la web.

[ES] Este Trabajo de Final de Grado consistirá en la aplicación de un modelo con el objetivo de predecir el precio de las acciones de la empresa IAG (International Airlines Group) cotizada en el IBEX 35 bajo el símbolo IAG.MC. Para llevar a término esa predicción se empleará el modelo Lognormal que con las cotizaciones de un histórico de tamaño apropiado es capaz de predecir el valor del activo. Los parámetros del modelo son la tendencia y la volatilidad del activo. Una de las partes importantes del proyecto será desarrollar código web, para pasar de un paradigma imperativo a uno orientado a objetos, y dotarlo de tests efectivos por medio de TDD (test driven development o diseño guiado por tests) para así pasar de un Legacy Code (Código heredado) a un sistema mainstream (un sistema de fácil mantenimiento y extensión). Además se dotará de una base de datos para el almacenamiento de los datos permitiendo así mostrar una mayor cantidad de información en la web.

[ES] Este Trabajo de Final de Grado consistirá en la aplicación de un modelo con el objetivo de predecir el precio de las acciones de la empresa IAG (International Airlines Group) cotizada en el IBEX 35 bajo el símbolo IAG.MC. Para llevar a término esa predicción se empleará el modelo Lognormal que con las cotizaciones de un histórico de tamaño apropiado es capaz de predecir el valor del activo. Los parámetros del modelo son la tendencia y la volatilidad del activo. Una de las partes importantes del proyecto será desarrollar código web, para pasar de un paradigma imperativo a uno orientado a objetos, y dotarlo de tests efectivos por medio de TDD (test driven development o diseño guiado por tests) para así pasar de un Legacy Code (Código heredado) a un sistema mainstream (un sistema de fácil mantenimiento y extensión). Además se dotará de una base de datos para el almacenamiento de los datos permitiendo así mostrar una mayor cantidad de información en la web.

Retirement of old IT - systems to newer ones has become more up-to-date, due to increases in performance in hardware and new programming languages. Nevertheless for companies it is not uncomplicated how this retirement process is best handled, and there are not many studies covering this phenomenon. In this thesis the goal is to find general guidelines regarding retirement of IT - systems. This is done by doing a case study on retirement for the old (MAPPER/BIS) platform to a more modern C# system which is currently used at Handelsbanken, one of Sweden’s largest banks. With the help of a qualitative research method, literature study and with interviews at Handelsbanken and external parts, we aim to understand and analyze what’s important in a retirement process. In order to create recommendations for our guidelines by also using some parts from the EM3: Software Retirement Process Model. The result of the thesis report is in total 16 guidelines that are presented as tables in the study, which companies can use in their retirement process. Ten guidelines are concerned with the retirement of the platform and six guidelines regarding conversion rules. Nonetheless the study has shown that not all systems on the MAPPER platform were possible to retire., Pensionering av IT-system har idag blivit en mer aktuell fråga än någonsin, till följd av att system blir gamla och inte är anpassade till dagens hårdvara eller moderna programmeringsspråk. Det är inte okomplicerat hur en sådan pensionering ska ske, speciellt då det inte gjorts så många studier kring det ämnet. I denna uppsats är målet att ta fram riktlinjer gällande pensionering, detta gjordes genom att utföra en fallstudie. Fallstudien gjordes på uppdrag av Handelsbanken, en av de största bankerna i Sverige, kring pensionering av (MAPPER/BIS) plattformen till en annan mer moderna plattform i C#. Med hjälp av en kvalitativ forskningsmetod, litteraturstudie samt intervjuer med personal på Handelsbanken och externa parter, ämnar vi att förstå och analysera vad som är viktigt vid en pensioneringsprocess. För att kunna skapa rekommendationer till de riktlinjer kring pensionering som detta arbete presenterar. Vissa utvalda delar av EM3: Software Retirement Process Model kommer också att ligga till grund för riktlinjerna. Uppsatsrapporten har resulterat i totalt 16 riktlinjerna som presenteras i tabeller som företag kan använda i sina pensioneringsprocesser. Tio stycken riktlinjer grundar sig i pensioneringen av en plattform och ytligare sex stycken gäller konvertering. Studien visade dock att alla system på MAPPER plattformen inte var möjliga att pensionera.

Retirement of old IT - systems to newer ones has become more up-to-date, due to increases in performance in hardware and new programming languages. Nevertheless for companies it is not uncomplicated how this retirement process is best handled, and there are not many studies covering this phenomenon. In this thesis the goal is to find general guidelines regarding retirement of IT - systems. This is done by doing a case study on retirement for the old (MAPPER/BIS) platform to a more modern C# system which is currently used at Handelsbanken, one of Sweden’s largest banks. With the help of a qualitative research method, literature study and with interviews at Handelsbanken and external parts, we aim to understand and analyze what’s important in a retirement process. In order to create recommendations for our guidelines by also using some parts from the EM3: Software Retirement Process Model. The result of the thesis report is in total 16 guidelines that are presented as tables in the study, which companies can use in their retirement process. Ten guidelines are concerned with the retirement of the platform and six guidelines regarding conversion rules. Nonetheless the study has shown that not all systems on the MAPPER platform were possible to retire., Pensionering av IT-system har idag blivit en mer aktuell fråga än någonsin, till följd av att system blir gamla och inte är anpassade till dagens hårdvara eller moderna programmeringsspråk. Det är inte okomplicerat hur en sådan pensionering ska ske, speciellt då det inte gjorts så många studier kring det ämnet. I denna uppsats är målet att ta fram riktlinjer gällande pensionering, detta gjordes genom att utföra en fallstudie. Fallstudien gjordes på uppdrag av Handelsbanken, en av de största bankerna i Sverige, kring pensionering av (MAPPER/BIS) plattformen till en annan mer moderna plattform i C#. Med hjälp av en kvalitativ forskningsmetod, litteraturstudie samt intervjuer med personal på Handelsbanken och externa parter, ämnar vi att förstå och analysera vad som är viktigt vid en pensioneringsprocess. För att kunna skapa rekommendationer till de riktlinjer kring pensionering som detta arbete presenterar. Vissa utvalda delar av EM3: Software Retirement Process Model kommer också att ligga till grund för riktlinjerna. Uppsatsrapporten har resulterat i totalt 16 riktlinjerna som presenteras i tabeller som företag kan använda i sina pensioneringsprocesser. Tio stycken riktlinjer grundar sig i pensioneringen av en plattform och ytligare sex stycken gäller konvertering. Studien visade dock att alla system på MAPPER plattformen inte var möjliga att pensionera.

A mature code-base of 1 300 000 LOC for a period of 20 months has been examined. This paper investigates if churn is a significant factor in finding refactoring candidates. In addition it looks at the variables Lines of Code (LOC), Technical Debt (TD), Duplicated lines and Complexity to find out if any of these indicators can inform a coder as to what to refactor. The result is that churn is the strongest variable out of the studied variables followed by LOC and TD., En kodbas på 1 300 000 rader kod har undersökts under 20 månader. Denna uppsats undersöker om kodens användningsfrekvens är en signifikant faktor för att finna refaktoreringskandidater. Uppsatsen tittar även antal kodrader, teknisk skuld, antal duplicerade kodrader och komplexitet för att undersöka om dessa indikatorer kan informera en programmerare om vad som ska refaktoreras. Resultatet är att kodens användningsfrekvens är den starkaste variabeln följt av antal kodrader samt teknisk skuld.

A mature code-base of 1 300 000 LOC for a period of 20 months has been examined. This paper investigates if churn is a significant factor in finding refactoring candidates. In addition it looks at the variables Lines of Code (LOC), Technical Debt (TD), Duplicated lines and Complexity to find out if any of these indicators can inform a coder as to what to refactor. The result is that churn is the strongest variable out of the studied variables followed by LOC and TD., En kodbas på 1 300 000 rader kod har undersökts under 20 månader. Denna uppsats undersöker om kodens användningsfrekvens är en signifikant faktor för att finna refaktoreringskandidater. Uppsatsen tittar även antal kodrader, teknisk skuld, antal duplicerade kodrader och komplexitet för att undersöka om dessa indikatorer kan informera en programmerare om vad som ska refaktoreras. Resultatet är att kodens användningsfrekvens är den starkaste variabeln följt av antal kodrader samt teknisk skuld.

A mature code-base of 1 300 000 LOC for a period of 20 months has been examined. This paper investigates if churn is a significant factor in finding refactoring candidates. In addition it looks at the variables Lines of Code (LOC), Technical Debt (TD), Duplicated lines and Complexity to find out if any of these indicators can inform a coder as to what to refactor. The result is that churn is the strongest variable out of the studied variables followed by LOC and TD., En kodbas på 1 300 000 rader kod har undersökts under 20 månader. Denna uppsats undersöker om kodens användningsfrekvens är en signifikant faktor för att finna refaktoreringskandidater. Uppsatsen tittar även antal kodrader, teknisk skuld, antal duplicerade kodrader och komplexitet för att undersöka om dessa indikatorer kan informera en programmerare om vad som ska refaktoreras. Resultatet är att kodens användningsfrekvens är den starkaste variabeln följt av antal kodrader samt teknisk skuld.

A mature code-base of 1 300 000 LOC for a period of 20 months has been examined. This paper investigates if churn is a significant factor in finding refactoring candidates. In addition it looks at the variables Lines of Code (LOC), Technical Debt (TD), Duplicated lines and Complexity to find out if any of these indicators can inform a coder as to what to refactor. The result is that churn is the strongest variable out of the studied variables followed by LOC and TD., En kodbas på 1 300 000 rader kod har undersökts under 20 månader. Denna uppsats undersöker om kodens användningsfrekvens är en signifikant faktor för att finna refaktoreringskandidater. Uppsatsen tittar även antal kodrader, teknisk skuld, antal duplicerade kodrader och komplexitet för att undersöka om dessa indikatorer kan informera en programmerare om vad som ska refaktoreras. Resultatet är att kodens användningsfrekvens är den starkaste variabeln följt av antal kodrader samt teknisk skuld.

A mature code-base of 1 300 000 LOC for a period of 20 months has been examined. This paper investigates if churn is a significant factor in finding refactoring candidates. In addition it looks at the variables Lines of Code (LOC), Technical Debt (TD), Duplicated lines and Complexity to find out if any of these indicators can inform a coder as to what to refactor. The result is that churn is the strongest variable out of the studied variables followed by LOC and TD., En kodbas på 1 300 000 rader kod har undersökts under 20 månader. Denna uppsats undersöker om kodens användningsfrekvens är en signifikant faktor för att finna refaktoreringskandidater. Uppsatsen tittar även antal kodrader, teknisk skuld, antal duplicerade kodrader och komplexitet för att undersöka om dessa indikatorer kan informera en programmerare om vad som ska refaktoreras. Resultatet är att kodens användningsfrekvens är den starkaste variabeln följt av antal kodrader samt teknisk skuld.

A mature code-base of 1 300 000 LOC for a period of 20 months has been examined. This paper investigates if churn is a significant factor in finding refactoring candidates. In addition it looks at the variables Lines of Code (LOC), Technical Debt (TD), Duplicated lines and Complexity to find out if any of these indicators can inform a coder as to what to refactor. The result is that churn is the strongest variable out of the studied variables followed by LOC and TD., En kodbas på 1 300 000 rader kod har undersökts under 20 månader. Denna uppsats undersöker om kodens användningsfrekvens är en signifikant faktor för att finna refaktoreringskandidater. Uppsatsen tittar även antal kodrader, teknisk skuld, antal duplicerade kodrader och komplexitet för att undersöka om dessa indikatorer kan informera en programmerare om vad som ska refaktoreras. Resultatet är att kodens användningsfrekvens är den starkaste variabeln följt av antal kodrader samt teknisk skuld.

On multi-core processors, memories are preferably distributed and supporting Distributed Shared Memory (DSM) is essential for the sake of reusing huge amount of legacy code and easy programming. However, the DSM organization imports the inherent overhead of translating virtual memory addresses into physical memory addresses, resulting in negative performance. We observe that, in parallel applications, different data have different properties (private or shared). For the private data accesses, it's unnecessary to perform Virtual-to-Physical address translations. Even for the same datum, its property may be changeable in different phases of the program execution. Therefore, this paper focuses on decreasing the overhead of Virtualto- Physical address translation and hence improving the system performance by introducing hybrid DSM organization and supporting run-time partitioning according to the data property. The hybrid DSM organization aims at supporting fast and physical memory accesses for private data and maintaining a global and single virtual memory space for shared data. Based on the data property of parallel applications, the run-time partitioning supports changing the hybrid DSM organization during the program execution. It ensures fast physical memory addressing on private data and conventional virtual memory addressing on shared data, improving the performance of the entire system by reducing virtual-to-physical address translation overhead as much as possible. We formulate the run-time partitioning of hybrid DSM organization in order to analyze its performance. A real DSM based multi-core platform is also constructed. The experimental results of real applications show that the hybrid DSM organization with run-time partitioning demonstrates performance advantage over the conventional DSM counterpart. The percentage of performance improvement depends on problem size, way of data partitioning and computation/communication ratio of parallel applications, netwo, QC 20140912

There is a need for integration of external models in high-level system design flows. We introduce a set of partial refinement operations to implement models of heterogeneous embedded systems. The models are in form of process networks where each process belongs to a single model of computation. A semi-formal design flow has been introduced based on these operations to incrementally refine system specifications to their implementation. Wrapper processes, which allow co-simulation of a system model in the framework with external models and implementations are used to keep the intermediate system models after each refinement step verifiable. Additionally, this design flow has the advantage of integrating legacy code and IP cores. Using a simple example as the case study, we have shown how we can apply this design methodology to a simple system., © 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.QC 20120201, SYSMODEL

There is a need for integration of external models in high-level system design flows. We introduce a set of partial refinement operations to implement models of heterogeneous embedded systems. The models are in form of process networks where each process belongs to a single model of computation. A semi-formal design flow has been introduced based on these operations to incrementally refine system specifications to their implementation. Wrapper processes, which allow co-simulation of a system model in the framework with external models and implementations are used to keep the intermediate system models after each refinement step verifiable. Additionally, this design flow has the advantage of integrating legacy code and IP cores. Using a simple example as the case study, we have shown how we can apply this design methodology to a simple system., © 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.QC 20120201, SYSMODEL

There is a need for integration of external models in high-level system design flows. We introduce a set of partial refinement operations to implement models of heterogeneous embedded systems. The models are in form of process networks where each process belongs to a single model of computation. A semi-formal design flow has been introduced based on these operations to incrementally refine system specifications to their implementation. Wrapper processes, which allow co-simulation of a system model in the framework with external models and implementations are used to keep the intermediate system models after each refinement step verifiable. Additionally, this design flow has the advantage of integrating legacy code and IP cores. Using a simple example as the case study, we have shown how we can apply this design methodology to a simple system., © 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.QC 20120201, SYSMODEL

There is a need for integration of external models in high-level system design flows. We introduce a set of partial refinement operations to implement models of heterogeneous embedded systems. The models are in form of process networks where each process belongs to a single model of computation. A semi-formal design flow has been introduced based on these operations to incrementally refine system specifications to their implementation. Wrapper processes, which allow co-simulation of a system model in the framework with external models and implementations are used to keep the intermediate system models after each refinement step verifiable. Additionally, this design flow has the advantage of integrating legacy code and IP cores. Using a simple example as the case study, we have shown how we can apply this design methodology to a simple system., © 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.QC 20120201, SYSMODEL

There is a need for integration of external models in high-level system design flows. We introduce a set of partial refinement operations to implement models of heterogeneous embedded systems. The models are in form of process networks where each process belongs to a single model of computation. A semi-formal design flow has been introduced based on these operations to incrementally refine system specifications to their implementation. Wrapper processes, which allow co-simulation of a system model in the framework with external models and implementations are used to keep the intermediate system models after each refinement step verifiable. Additionally, this design flow has the advantage of integrating legacy code and IP cores. Using a simple example as the case study, we have shown how we can apply this design methodology to a simple system., © 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.QC 20120201, SYSMODEL

Supporting Distributed Shared Memory (DSM) is essential for multi-coreNetwork-on-Chips for the sake of reusing huge amount of legacy code and easy programmability. We propose a microcoded controller as a hardware module in each node to connect the core, the local memory and the network. The controller is programmable where the DSM functions such as virtual-to-physical address translation,memory access and synchronization etc. are realized using microcode. To enable concurrent processing of memory requests from the local and remote cores, ourcontroller features two mini-processors, one dealing with requests from the local coreand the other from remote cores. Synthesis results suggest that the controller consumes 51k gates for the logic and can run up to 455 MHz in 130 nm technology. To evaluate its performance, we use synthetic and application workloads. Results show that, when the system size is scaled up, the delay overhead incurred by the controller may become less significant when compared with the network delay. In this way, the delay efficiency of our DSM solution is close to hardware solutions on average but still have all the flexibility of software solutions., QC 20120209

In today’s multicore era, parallelization of serial code is essential in order to exploit the architectures performance potential. Parallelization, especially of legacy code, however, proves to be a challenge as manual efforts must either be directed towards algorithmic modifications or towards analysis of computationally intensive sections of code for the best possible parallel performance, both of which are difficult and time-consuming. Automatic parallelization uses sophisticated compile-time techniques in order to identify parallelism in serial programs, thus reducing the burden on the program developer. Similar sophistication is needed to improve the performance of hand-parallelized programs. A key difficulty is that optimizing compilers are generally unable to estimate the performance of an application or even a program section at compile time, and so the task of performance improvement invariably rests with the developer. Automatic tuning uses static analysis and runtime performance metrics to determine the best possible compile-time approach for optimal application performance. This paper describes an offline tuning approach that uses a source-to-source parallelizing compiler, Cetus, and a tuning framework to tune parallel application performance. The implementation uses an existing, generic tuning algorithm called Combined Elimination to study the effect of serializing parallelizable loops based on measured whole program execution time, and provides a combination of parallel loops as an outcome that ensures to equal or improve performance of the original program. We evaluated our algorithm on a suite of hand-parallelized C benchmarks from the SPEC OMP2001 and NAS Parallel benchmarks and provide two sets of results. The first ignores hand-parallelized loops and only tunes application performance based on Cetus-parallelized loops. The second set of results considers the tuning of additional parallelism in hand-parallelized code. We show that our implementatio

Legacy codes must be adapted to multicore in order to sustain the current rate of progress made in science and commerce. The goal of this seedling was to study the suitability of particular automatic parallelization techniques for parallelizing legacy codes. We found that n-gram (i.e., repeated instruction sequences) parallelism does exist, but it is not easily leveraged. We found parallelism in many codes previously thought to be inherently sequential. We believe that efforts that consider input data can help liberate high-order parallelism from almost all such "sequential" codes., Performed in cooperation with Columbia University, New York, NY and George Mason University, Fairfax, VA. Sponsored in part by the Defense Advanced Research Projects Agency (DARPA).

This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.

This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.

This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.

This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.

This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.

This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.

Embedded systems and networks are becoming increasingly prevalent in critical sectors. Therefore, malicious or accidental failures in embedded systems can have dire consequences. Hence, the integrity of embedded software infrastructures, such as configuration and code, is of paramount importance. The autonomous nature of embedded systems also poses new challenges in the context of system integrity. Embedded systems and networks also often have to operate autonomously in a dynamic environment. Therefore, an embedded system has to adapt its behavior to the change in environment or the overall goal. Unauthorized or unverified updates to the infrastructure of an embedded system can also compromise its integrity. In recent years, there have been significant advances in the area of software security. However, all these techniques are not directly applicable in the context of embedded systems because of following reasons: 1) Embedded systems are generally deployed in environments that are highly dynamic and configurable. 2) Functional requirements of an embedded system change over time. 3) Frequently an embedded system is a complex network of components. Therefore, a malicious or accidental fault in a component can lead to a complex cascade of events in the network. 4) Embedded systems are frequently deployed in mission critical applications where consequences of failures can be dire. Therefore, recovery from failures is extremely important in the context of embedded systems. Extending existing techniques in software security to handle the four above mentioned characteristics of embedded systems is an important research direction. I will provide details of two such research directions., Presented at the 2007 ARO Planning Workshop on Embedded Systems and Network Security, held in Raleigh, NC on 22-23 Feb 2007and published in proceedings of the same. The original document contains color images. This article is from ADA485570 Proceedings of the ARO Planning Workshop on Embedded Systems and Network Security Held in Raleigh, North Carolina on February 22-23, 2007

The goal of this work is to explore techniques for making today's software, which is largely written in type-unsafe, low-level languages such as C, as reliable and trustworthy as code written in type-safe, high-level languages such as Java or ML. Type-safe languages automatically block or prevent common vulnerabilities such as buffer overruns, format string attacks, and overflow attacks which are all too common in today's critical software infrastructure. To this end, we have implemented a prototype compiler called Cyclone, which provides the benefits of type safety through a combination of static analysis, programmer annotations, and run-time checks. Particular emphasis has been placed on scalable, static analyses to ensure that programmers can retain good performance and high reliability., Prepared in cooperation with Cornell University, Ithaca, NY. Report no. 40078.

The maintenance of legacy software systems that were developed using a procedural design approach is becoming increasingly expensive. The procedural approach is often ill suited for complex systems that need to integrate with other codes. Furthermore, these legacy systems are usually written in FORTRAN, for which there is increasingly less personnel available compared to, say, C++. While it would be desirable to convert these legacy systems into object-oriented codes described in C++, such a conversion process is nontrivial. Currently, the structural design must be manually examined, interpreted, and converted into an object-oriented design described in an object-oriented language. Therefore, the conversion process is likely to introduce numerous new inconsistencies and errors, which degrades the software's quality and increases its costs. The preferred solution would be to automate this conversion process. Automation would promote consistency by eliminating the manual variations in interpretation and implementation. It would therefore maximize the likelihood that the converted code does not introduce new errors relative to the original code. The work presented here automates the conversion process from procedural design described in the FORTRAN77 language into object-oriented design described in the C++ language. It demonstrates the extraction of object-oriented elements using FORTRAN common block structures and FORTRAN subroutine and function-calling hierarchies. The result is a consistent, first-cut converted design, which enhances cohesion within classes and reduces coupling between classes. This result is described in the contemporary, broadly used computer language C++, which integrates with adjacent modules that might still remain procedural and described in FORTRAN.