An Error-Localization, Validation and Optimization Tool for Embedded Code Augmentation: an Architecture Oriented Approach

Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.Embedded systems are usually designed for a single or a specified set of tasks. This specificity means the system design as well as its hardware/software development can be highly optimized. Embedded software must meet the requirements such as high reliability operation on resource-constrained platforms, real time constraints and rapid development. This necessitates the adoption of static machine codes analysis tools running on a host machine for the validation and optimization of embedded system codes, which can help meet all of these goals. This could significantly augment the software quality and is still a challenging field.This dissertation contributes to an architecture oriented code validation, error localization and optimization technique assisting the embedded system designer in software debugging, to make it more effective at early detection of software bugs that are otherwise hard to detect, using the static analysis of machine codes. The focus of this work is to develop methods that automatically localize faults as well as optimize the code and thus improve the debugging process as well as quality of the code.Validation is done with the help of rules of inferences formulated for the target processor. The rules govern the occurrence of illegitimate/out of place instructions and code sequences for executing the computational and integrated peripheral functions. The stipulated rules are encoded in propositional logic formulae and their compliance is tested individually in all possible execution paths of the application programs. An incorrect sequence of machine code pattern is identified using slicing techniques on the control flow graph generated from the machine code.An algorithm to assist the compiler to eliminate the redundant bank switching codes and decide on optimum data allocation to banked memory resulting in minimum number of bank switching codes in embedded system software is proposed. A relation matrix and a state transition diagram formed for the active memory bank state transition corresponding to each bank selection instruction is used for the detection of redundant codes. Instances of code redundancy based on the stipulated rules for the target processor are identified.This validation and optimization tool can be integrated to the system development environment. It is a novel approach independent of compiler/assembler, applicable to a wide range of processors once appropriate rules are formulated. Program states are identified mainly with machine code pattern, which drastically reduces the state space creation contributing to an improved state-of-the-art model checking. Though the technique described is general, the implementation is architecture oriented, and hence the feasibility study is conducted on PIC16F87X microcontrollers. The proposed tool will be very useful in steering novices towards correct use of difficult microcontroller features in developing embedded systems.

Agile methodologies

Outlines of both Scrum and Dynamic Systems Development Model

Los métodos prospectivos aplicados a la educación : el mapa contextual.

Se analizan las ventajas del método prospectivo aplicado a la educación. Este método se viene aplicando desde hace poco por dos causas: su tardía integración entre las técnicas de la tecnología actual, y la falta de coordinación de las diversas investigaciones prospectivas. La proposición más atractiva en torno a la metodología prospectiva parte de P. E. Rosove, que se inspira previamente en las ideas de H. D. Laswell. La propuesta se basa en el establecimiento de observatorios sociales que tengan la finalidad de resolver los problemas educativos. De esta manera a la resolución de los problemas educativos puede participar la población en general. Se mantiene que el único inventario y evaluación de los métodos prospectivos aplicados a la educación es el realizado por la System Development Corporation. Su inventario incluye veintiún métodos, que son clasificados según su grado de utilidad científica. Se incluye una tabla con la relación de estos métodos. Uno de los más importantes es el del mapa contextual. El mapa contextual consiste en una exposición gráfica de las relaciones lógicas y causales de los fenómenos que son funcionalmente interdependientes entre sí, en orden a establecer una previsión, es decir, a determinar los futuros posibles. El método conviene particularmente en la elaboración de previsiones de tipo social, en donde los períodos temporales suelen ser muy largos y estar sometidos a grandes incertidumbres. Se señalan las conclusiones principales por las que se ha aplicado este método a la educación. Se incluye un cuadro con un mapa contextual.

Pleistocene geochronologies for fluvial sedimentary sequences: an archaeologist's perspective

Current models of Pleistocene fluvial system development and dynamics are assessed from the perspective of European Lower and Middle Palaeolithic stone tool assemblages recovered from fluvial secondary contexts. Fluvial activity is reviewed both in terms of Milankovitch-scale processes across the glacial/interglacial cycles of the Middle and Late Pleistocene, and in response to sub-Milankovitch scale, high-frequency, low-magnitude climatic oscillations. The chronological magnitude of individual phases of fluvial activity is explored in terms of radiocarbon-dated sequences from the Late Glacial and early Holocene periods. It is apparent that fluvial activity is associated with periods of climatic transition, both high and low magnitude, although system response is far more universal in the case of the high magnitude glacial/ interglacial transitions. Current geochronological tools do not permit the development of high-resolution sequences for Middle Pleistocene sediments, while localised erosion and variable system responses do not facilitate direct comparison with the ice core records. However, Late Glacial and early Holocene sequences indicate that individual fluvial activity phases are relatively brief in duration (e.g. 10(2) and 10(3) yr). From an archaeological perspective, secondary context assemblages can only be interpreted in terms of a floating geochronology, although the data also permit a reinvestigation of the problems of artefact reworking. Copyright (c) 2005 John Wiley I Sons, Ltd.

A lightweight technique for assessing risks in requirements analysis

A simple and practical technique for assessing the risks, that is, the potential for error, and consequent loss, in software system development, acquired during a requirements engineering phase is described. The technique uses a goal-based requirements analysis as a framework to identify and rate a set of key issues in order to arrive at estimates of the feasibility and adequacy of the requirements. The technique is illustrated and how it has been applied to a real systems development project is shown. How problems in this project could have been identified earlier is shown, thereby avoiding costly additional work and unhappy users.

A lightweight technique for assessing risks in requirements analysis

A simple and practical technique for assessing the risks, that is, the potential for error, and consequent loss, in software system development, acquired during a requirements engineering phase is described. The technique uses a goal-based requirements analysis as a framework to identify and rate a set of key issues in order to arrive at estimates of the feasibility and adequacy of the requirements. The technique is illustrated and how it has been applied to a real systems development project is shown. How problems in this project could have been identified earlier is shown, thereby avoiding costly additional work and unhappy users.

Acquisition of automatic imitation is sensitive to sensorimotor contingency

The associative sequence learning model proposes that the development of the mirror system depends on the same mechanisms of associative learning that mediate Pavlovian and instrumental conditioning. To test this model, two experiments used the reduction of automatic imitation through incompatible sensorimotor training to assess whether mirror system plasticity is sensitive to contingency (i.e., the extent to which activation of one representation predicts activation of another). In Experiment 1, residual automatic imitation was measured following incompatible training in which the action stimulus was a perfect predictor of the response (contingent) or not at all predictive of the response (noncontingent). A contingency effect was observed: There was less automatic imitation indicative of more learning in the contingent group. Experiment 2 replicated this contingency effect and showed that, as predicted by associative learning theory, it can be abolished by signaling trials in which the response occurs in the absence of an action stimulus. These findings support the view that mirror system development depends on associative learning and indicate that this learning is not purely Hebbian. If this is correct, associative learning theory could be used to explain, predict, and intervene in mirror system development.

Dysregulation of REST-regulated coding and non-coding RNAs in a cellular model of Huntington's disease

Huntingtin (Htt) protein interacts with many transcriptional regulators, with widespread disruption to the transcriptome in Huntington's disease (HD) brought about by altered interactions with the mutant Htt (muHtt) protein. Repressor Element-1 Silencing Transcription Factor (REST) is a repressor whose association with Htt in the cytoplasm is disrupted in HD, leading to increased nuclear REST and concomitant repression of several neuronal-specific genes, including brain-derived neurotrophic factor (Bdnf). Here, we explored a wide set of HD dysregulated genes to identify direct REST targets whose expression is altered in a cellular model of HD but that can be rescued by knock-down of REST activity. We found many direct REST target genes encoding proteins important for nervous system development, including a cohort involved in synaptic transmission, at least two of which can be rescued at the protein level by REST knock-down. We also identified several microRNAs (miRNAs) whose aberrant repression is directly mediated by REST, including miR-137, which has not previously been shown to be a direct REST target in mouse. These data provide evidence of the contribution of inappropriate REST-mediated transcriptional repression to the widespread changes in coding and non-coding gene expression in a cellular model of HD that may affect normal neuronal function and survival.

RE1 silencing transcription factor/neuron-restrictive silencing factor regulates expansion of adult mouse subventricular zone-derived neural stem/progenitor cells in vitro

Adult neural stem cell (aNSC) activity is tuned by external stimuli through the recruitment of transcription factors. This study examines the RE1 silencing transcription factor (REST) in neural stem/progenitor cells isolated from the subventricular zone of adult mouse brain and provides the first extensive characterization of REST-mediated control of the cellular and molecular properties. This study shows that REST knockdown affects the capacity of progenitor cells to generate neurospheres, reduces cell proliferation, and triggers cell differentiation despite the presence of growth factors. Genome- and transcriptome-wide analyses show that REST binding sites are significantly enriched in genes associated with synaptic transmission and nervous system development and function. Seeking candidate regulators of aNSC function, this study identifies a member of the bone morphogenetic protein (BMP) family, BMP6, the mRNA and protein of which increased after REST knockdown. The results of this study extend previous findings, demonstrating a reciprocal control of REST expression by BMPs. Administration of exogenous BMP6 inhibits aNSC proliferation and induces the expression of the astrocytic marker glial fibrillary acidic protein, highlighting its antimitogenic and prodifferentiative effects. This study suggests that BMP6 produced in a REST-regulated manner together with other signals can contribute to regulation of NSC maintenance and fate. © 2015 Wiley Periodicals, Inc.

Connexin-mediated communication controls cell proliferation and is essential in retinal histogenesis

Connexin (Cx) channels and hemichannels are involved in essential processes during nervous system development such as apoptosis, propagation of spontaneous activity and interkinetic nuclear movement. In the first part of this study, we extensively characterized Cx gene and protein expression during retinal histogenesis. We observed distinct spatio-temporal patterns among Studied Cx and an overriding, ubiquitous presence of Cx45 in progenitor cells. The role of Cx-mediated communication was assessed by using broad-spectrum (carbenoxotone, CBX) and Cx36/Cx50 channel-specific (quinine) blockers. In vivo application of CBX, but not quinine, caused remarkable reduction in retinal thickness, suggesting changes in cell proliferation/apoptosis ratio. Indeed, we observed a decreased number of mitotic cells in CBX-injected retinas, with no significant changes in the expression of PCNA, a marker for cells in proliferative state. Taken together, Our results pointed a pivotal role of Cx45 in the developing retina. Moreover, this study revealed that Cx-mediated Communication is essential in retinal histogenesis, particularly in the control of cell proliferation. (C) 2009 ISDN. Published by Elsevier Ltd. All rights reserved.

Enhanced Neural Progenitor/Stem Cells Self-Renewal via the Interaction of Stress-Inducible Protein 1 with the Prion Protein

Prion protein (PrPC), when associated with the secreted form of the stress-inducible protein 1 (STI1), plays an important role in neural survival, neuritogenesis, and memory formation. However, the role of the PrP(C)-STI1 complex in the physiology of neural progenitor/stem cells is unknown. In this article, we observed that neurospheres cultured from fetal forebrain of wild-type (Prnp(+/+)) and PrP(C)-null (Prnp(0/0)) mice were maintained for several passages without the loss of self-renewal or multipotentiality, as assessed by their continued capacity to generate neurons, astrocytes, and oligodendrocytes. The homogeneous expression and colocalization of STI1 and PrP(C) suggest that they may associate and function as a complex in neurosphere-derived stem cells. The formation of neurospheres from Prnp(0/0) mice was reduced significantly when compared with their wild-type counterparts. In addition, blockade of secreted STI1, and its cell surface ligand, PrP(C), with specific antibodies, impaired Prnp(+/+) neurosphere formation without further impairing the formation of Prnp(0/0) neurospheres. Alternatively, neurosphere formation was enhanced by recombinant STI1 application in cells expressing PrP(C) but not in cells from Prnp(0/0) mice. The STI1-PrP(C) interaction was able to stimulate cell proliferation in the neurosphere-forming assay, while no effect on cell survival or the expression of neural markers was observed. These data suggest that the STI1-PrP(C) complex may play a critical role in neural progenitor/stem cells self-renewal via the modulation of cell proliferation, leading to the control of the stemness capacity of these cells during nervous system development. STEM CELLS 2011;29:1126-1136

En analys av testprocesser med TMap som testmetod

Today there are many system development projects that break both budget and time plan. Often this depends on defects in the information systems that could have been prevented. The cost of test can in some cases be as high as 50 % of the projects total cost and it's at the same time an important part of development. Test as such has moved its focus from the software it self and its faults to a wider perspective on whole infrastructures of information systems where assure a good quality is important. Sogeti in the Netherlands have developed a test method called TMap (Test Management approach) that can be used for structured testing of information systems. TMap haven't been used as much as desired in the office in Borlänge. Because Microsoft is releasing a new version of their platform Visual Studio Team System (VSTS 2010) some colleges at Sogeti in the Netherlands are about to develop a template that can support the use of TMap in VSTS 2010. When we write this the template is still in development. The goal for Sogeti was to find out the differences between the test functionality in VSTS 2008 and 2010. By using the purpose with this essay, which was to analyze the test process in VSTS 2008 with TMap against the test process in VSTS 2010 together with the template we got much help to achieve the goal. The analysis was done with four different aspects: The TPI and TMMi models, problem and strength analyses and a few question formulations. The TPI and TMMi models where used to analyses and evaluate the test process. The analysis showed that there were differences between the both test processes. VSTS 2010 together with the template gave a better support to use TMap and perform test. In VSTS 2010 the test tool Camano is connected to TFS and the tool is also to make the execution and logging of tests easier. This leads to a test process that is easier to handle and has a better support for TMap.

En beskrivning av manuellt test : Svagheter och styrkor med och utan stöd avett testverktyg

Test is an area in system development. Test can be performed manually or automated. Test activities can be supported by Word documents and Excel sheets for documenting and executing test cases and as well for follow up, but there are also new test tools designed to support and facilitate the testing process and the activities of the test. This study has described manual test and identified strengths and weaknesses of manual testing with a testing tool called Microsoft Test Manager (MTM) and of manual testing using test cases and test log templates developed by the testers at Sogeti. The result that emerged from the problem and strength analysis and the analysis of literature studies and firsthand experiences (in terms of creating, documenting and executing test cases) addresses the issue of the following weaknesses and strengths. Strengths of the test tool is that it contains needed functionality all in one place and it is available when needed without having to open up other programs which saves many steps of activity. Strengths with test without the support of test tools is mainly that it is easy to learn and gives a good overview, easy to format text as desired and flexible to changes during execution of a test case. Weaknesses in test with the support of test tools include that it is difficult to get a good overview of the entire test case, that it is not possible to format the text in the test steps. It is as well not possible to modify the test steps during execution. It is also difficult to use some of the test design techniques of TMap, for example a checklist, when using the test tool MTM. Weaknesses with test without the support of the testing tool MTM is that the tester gets many more steps of activities to do compared to doing the same activities with the support of the testing tool MTM. There is more to remember because the documents the tester use are not directly linked. Altogether the strengths of the test tool stands out when it comes to supporting the testing process.

Upplevda problem med projektstyrningsmetoden Scrum i systemutvecklingsprojekt : En studie av Scrums-relaterade problem hos IT- företag i Borlängeregion

Många projekt misslyckas och en av anledningarna är dålig styrning av projektet i allmänhet och inom IT branschen i synnerhet. Baserad på kritik av de traditionella metoderna under de senaste åren, så har det uppkommit flera lättrörliga metoder som kallas Agila metoder. Scrum är den mest kända Agila metoden som används idag. Metoden lovar goda resultat, men i en artikel ur tidningen Computer Sweden (feb 2009) står det ”siffror visar att nio av tio Scrumprojekt misslyckas”. Artikeln triggade vårt intresse av att ta reda på vilka problem specifika för Scrum som många har kritiserat och valde därför att rikta in vår studie mot detta. Uppsatsen syftar till att undersöka om lokala IT-företag i Borlänge, Headlight, Sogeti ochstatliga nätkapacitetleverantören Trafikverket ICT lider av det allmänna problem som de andra Scrumanvändarna upplever i samband med användningen av metoden. Denna uppsats har fokus på fyra problemområden: bristfällig dokumentation, sämre effektivitet i arbetsprocessen, sämre effektivitet i arbetsprocessen i stora projekt samt bristande stöd för utvärdering. För vår studie har litteraturstudier och intervjuer genomförts. Intervjuserier gjordes på elva personer hos våra fallföretag. Målgruppen för våra intervjuer är Product Owner (PO) ScrumMaster (SM) och utvecklare. Vi kan efter genomförd studie dra slutsatsen att de allmänna upplevda problem som de andra Scrumanvändaren upplever har vi även kunnat identifiera hos våra fallföretag. Resultaten har bekräftats med insamlade data och vår teoretiska ram. I diskussionen presenterar vi rekommendationer för att undvik relaterade problem med Scrum.

Mått för att mäta kodkvalitet undersystemutvecklingsprocessen

Viljan att hålla en hög kvalitet på den kod som skrivs vid utveckling av system och applikationerär inte något nytt i utvecklingsvärlden. Flera större företag använder sig av olika mått för attmäta kvaliteten på koden i sina system med målet att hålla en hög driftsäkerhet.Trafikverket är en statlig myndighet som ansvarar för driften av bland annat de system somhåller igång Sveriges järnvägsnät. Eftersom systemen fyller en viktig del i att säkra driften ochse till att tågpositioner, planering av avgångar och hantering av driftstörningar fungerar dygnetrunt för hela landet anser de att det är viktigt att sträva efter att hålla en hög kvalitet påsystemen.Syftet med det här examensarbetet var att ta reda på vilka mått som kan vara möjliga attanvända under systemutvecklingsprocessen för att mäta kvaliteten på kod och hur måtten kananvändas för att öka kvaliteten på IT-lösningar. Detta för att redan på ett tidigt stadie kunnamäta kvaliteten på den kod som skrivs i både befintliga och nyutvecklade system.Studien är en fallstudie som utfördes på Trafikverket, de olika måtten som undersöktes varcode coverage, nivån på maintainability index och antalet inrapporterade incidenter för varjesystem. Mätningar utfördes på sju av Trafikverkets system som i analysen jämfördes motantalet rapporterade incidenter. Intervjuer utfördes för att ge en bild över hur arbetssättet vidutveckling kan påverka kvaliteten. Genom litteraturstudier kom det fram ett mått som inte kundeanvändas praktiskt i det här fallet men är högst intressant, detta är cyclomatic complexity somfinns som en del av maintainability index men som även separat påverkar möjligheten att skrivaenhetstest.Resultaten av studien visar att måtten är användbara för ändamålet men bör inte användassom enskilda mått för att mäta kvalitet eftersom de fyller olika funktioner. Det är viktigt attarbetssättet runt utveckling genomförs enligt en tydlig struktur och att utvecklarna både harkunskap om hur man arbetar med enhetstest och följer kodprinciper för strukturen. Tydligakopplingar mellan nivån på code coverage och inflödet av incidenter kunde ses i de undersöktasystemen där hög code coverage ger ett lägre inflöde av incidenter. Ingen korrelation mellanmaintainability index och incidenter kunde hittas.