Managing Change in Information Systems : technological challenges

Information systems and other computer-based systems must continuously undergo change in order to reflect change in their environments. The present technology used to implement such systems, including models, methods, tools and languages, does not have an inherent understanding of the nature of evolution. The rigidity of existing systems is a hindrance for user requested enhancements.Propagating changes correctly is a particular problem. It is common to find that necessary changes consequent on some other change have not been made, so that the system is inconsistent and will eventually fail to operate correctly. The paper discusses tools for system maintenance and focuses on the issue of automation. A tool that automatically generates and maintains all the information it needs is presented. To provide more information about the form and extent of the evolution in real-world systems, the same tool was instructed to collect change measurements. Information about the evolution of a large health management system was recorded over a period of 18 months. Methods for and problems of automatic change measurements collection are discussed

Lie Algebraic Unscented Kalman Filter for Pose Estimation

An unscented Kalman filter for matrix Lie groups is proposed where the time propagation of the state is formulated on the Lie algebra. This is done with the kinematic differential equation of the logarithm, where the inverse of the right Jacobian is used. The sigma points can then be expressed as logarithms in vector form, and time propagation of the sigma points and the computation of the mean and the covariance can be done on the Lie algebra. The resulting formulation is to a large extent based on logarithms in vector form, and is therefore closer to the UKF for systems in $\mathbb{R}^n$. This gives an elegant and well-structured formulation which provides additional insight into the problem, and which is computationally efficient. The proposed method is in particular formulated and investigated on the matrix Lie group $SE(3)$. A discussion on right and left Jacobians is included, and a novel closed form solution for the inverse of the right Jacobian on $SE(3)$ is derived, which gives a compact representation involving fewer matrix operations. The proposed method is validated in simulations

Software Process Improvement and Human Judgement Heuristics

This paper exemplifies how better knowledge about human judgement strategies known as heuristics can be used to improve software processes, especially estimation and prediction processes. Human judgement heuristics work well when they exploit a fit between their structure and the structure of the environment in which they are used. This use of environmental fit may lead to amazingly good judgements based on little information and simple computations compared with more formal approaches. Sometimes, however, the heuristics may lead to poor judgements. Knowing more about the strengths and weaknesses of human judgement heuristics we may be able to (1) know when to use formal process improvement approaches and when to use less expensive expert judgements, (2) support the experts in situations where the experts’ judgements strategies are known to perform poorly, (3) improve the formal processes with elements from the experts’ strategies, and (4) train the experts in the use of more optimal judgement strategies. A small-scale experiment was carried out to evaluate the use of the representativeness heuristic in a software development effort estimation context. The results indicate that the actual use of the representativeness heuristic differed very much among the estimators and was not always based on an awareness of fit between the structure of the heuristic and the structure of the environment. Estimation strategies only appropriate in low uncertainty development environments were used in high uncertainty environments. A possible consequence of this finding is that expert estimators should be trained in assessing how well previous software projects predict new software projects, i.e., the uncertainty of the environment, and how this uncertainty should impact the estimation strategy

PISA : politique, problèmes fondamentaux et résultats paradoxaux

Durant la dernière décennie, PISA a renforcé fortement son influence sur les politiques éducatives dans les pays participants. Les résultats de ces enquêtes ouvrent bien des débats publics sur la qualité de l’enseignement scolaire. En effet, les résultats concernant les tableaux de scores et les classements des pays, bien que souvent pris dans leur valeur nominale, sont exploités tant par les médias que par les politiques et les décideurs. Cet article fait état de certaines réserves quant à la validité de ces scores et de ces classements que nous exposerons plus loin. Mais il y a, tout d’abord, lieu de soulever certaines questions fondamentales sur les raisons du lancement du projet PISA par l'OCDE. Des raisons qui sont, bien évidemment, fortement liées aux objectifs politiques d’ensemble de l’OCDE et à son engagement sous-jacent dans une économie de marché mondiale et concurrentielle. Pour étayer ce propos, des exemples seront donnés pour expliquer l’influence qu’exerce PISA sur les politiques éducatives. Nous commencerons par émettre deux catégories de critiques qui seront discutées. La première a trait au projet PISA en tant que tel. Nous montrerons qu'il est impossible de construire d’une manière objective une enquête qui peut être utilisée pour des pays et des cultures différents. De même, l’exclusion du local et du spécifique va à l’encontre des préconisations de l'UNESCO, de celles des éducateurs et des programmes scolaires nationaux relatifs à l'éducation scientifique. La deuxième catégorie de critiques se rapporte à certains résultats paradoxaux. Il semble que les élèves dans les pays à hauts scores développent les attitudes les plus négatives envers la science. Il ressort également que les scores sont indépendants de certains facteurs comme le niveau des ressources pédagogiques, la taille des classes, etc. Enfin, les résultats sont corrélés négativement à l'utilisation des méthodes pédagogiques actives, des démarches d’investigation et des TIC. En tous les cas que l'on croie ou non au bien fondé du projet PISA, de tels résultats aussi surprenants soient-ils méritent d’être discutés.The PISA project has in the last decade steadily increased its influence on educational policies in participating countries. Tables of PISA scores and country rankings are often taken at face value, not only in media, but also by policymakers and politicians. This article will raise some of the concerns that would require further. I will start by raising some basic questions about why OECD has initiated the PISA project. The intentions of PISA are, not surprisingly, strongly related to the overall political aims OECD and the underlying commitment to a competitive global free market economy. Examples are given on how PISA exerts influence on educational policy. Then I will provide critical points of two categories. The first category relates to the PISA project as such. I will argue that it is impossible to construct a test that in a fair and objective way can be used across countries and cultures. The requirement of “fair testing” implies by necessity that all local, current and topical issues must be excluded. This runs against most current thinking in e.g. science education, where “science in context” and “a localized curriculum” are ideals promoted by e.g. UNESCO, educators as well as in many national curricula. The second category of critical points relates to some of the rather intriguing results: It seems that pupils in high-scoring countries also develop the most negative attitudes to the subject. It also seems that PISA scores are unrelated to educational resources, class size etc. PISA scores also seem to be negatively related to the use of active teaching methods, inquiry based instruction and the use of ICT. Whether one believes in PISA or not, such intriguing results need to be discussed

Managing change in persistent object systems

Persistent object systems are highly-valued technology because they o er an e ec- tive foundation for building very long-lived persistent application systems (PAS). The technology becomes more e ective as it o ers a more consistently integrated computational context. For it to be feasible to design and construct a PAS it must be possible to in- crementally add program and data to the existing collection. For a PAS to endure it must o er exibility: a capacity to evolve and change. This paper examines the capacity of persistent object systems to accommodate incremental construction and change. Established store based technologies can support incremental construction but methodologies are needed to deploy them e ectively. Evolving data description is one motivation for inheritance but inheritance alone is not enough to support change management. The case for supporting incremental change is very persuasive. The challenge is to provide technologies that will facilitate it and methodologies that will organise it. This paper identi es change absorbers as a means of describing how changes should propagate. It is argued that if we systematically develop an adequate reper- toire of change absorbers then they will facilitate much better quality change man- agement

Ex post fusjonsanalyse : en deskriptiv analyse av markedet for konsumegg etter fusjonen mellom Prior og Norgården

I min masterutredning vil jeg foreta en deskriptiv analyse av utviklingen i engrosmarkedet for konsumegg etter fusjonen mellom Prior og Norgården i 2006 frem til 2009. Konkurransetilsynet nedla forbud mot fusjonen i 2005, men den ble gjennomført etter vedtak av Kongen i statsråd. Oppgaven er blant annet inspirert av et nytt metodeverk i EU for evaluering av fusjonskontrollen til konkurransemyndigheter, samt den unike muligheten til å undersøke effektene av en fusjon som både Konkurransetilsynet og Fornyings- og administrasjonsdepartementet fastslo at var skadelig for konkurransen. Jeg vil benytte enkle modeller for fusjon i oligopolistiske markeder, og fremsette hypoteser på bakgrunn av hva teoriene predikerer. Deretter vil jeg samle den nødvendige informasjon for å få bekreftet eller avkreftet hypotesene, og så gjøre en samlet vurdering av hvorvidt fusjonen har begrenset konkurransen

Pupil`s oral participation in English class

Bacheloroppgave, grunnskolelærerutdanning, 2017.Norsk: Elevers vanskeligheter med å tørre å prate engelsk i undervisningen er en utfordring som det trengs å ta tak i. Mange elever sitter med ferdigheter de velger å ikke vise fram, og det finnes flere grunner til at det er slik, og forslag til hva som kan gjøres for å bedre dette. En av de største årsakene er elevenes redsel for å bli gjort narr av i klassen for å ha sagt noe feil. Større fokus på miljøet i klassen, i tillegg til mer forberedelse for elevene, er to ting som kan være med å hjelpe på elevenes vegring for å prate engelsk.English: Pupil`s struggling with being insecure and afraid of speaking English in activities in class is a problem that needs to be taken hand of. There are a lot of reasons why pupils behave like this, and a lot of different ways they can get help. One of the biggest reasons behind their shyness, and their problems, are other pupils in class making fun of oral mistakes. A better environment for learning and more preparation for the pupils are a couple of ways to help them on their way to feel good about speaking

Effectiveness for detecting faults within and outside the scope of testing techniques: an independent replication

The verification and validation activity plays a fundamental role in improving software quality. Determining which the most effective techniques for carrying out this activity are has been an aspiration of experimental software engineering researchers for years. This paper reports a controlled experiment evaluating the effectiveness of two unit testing techniques (the functional testing technique known as equivalence partitioning (EP) and the control-flow structural testing technique known as branch testing (BT)). This experiment is a literal replication of Juristo et al. (2013).Both experiments serve the purpose of determining whether the effectiveness of BT and EP varies depending on whether or not the faults are visible for the technique (InScope or OutScope, respectively). We have used the materials, design and procedures of the original experiment, but in order to adapt the experiment to the context we have: (1) reduced the number of studied techniques from 3 to 2; (2) assigned subjects to experimental groups by means of stratified randomization to balance the influence of programming experience; (3) localized the experimental materials and (4) adapted the training duration. We ran the replication at the Escuela Politécnica del Ejército Sede Latacunga (ESPEL) as part of a software verification & validation course. The experimental subjects were 23 master?s degree students. EP is more effective than BT at detecting InScope faults. The session/program andgroup variables are found to have significant effects. BT is more effective than EP at detecting OutScope faults. The session/program and group variables have no effect in this case. The results of the replication and the original experiment are similar with respect to testing techniques. There are some inconsistencies with respect to the group factor. They can be explained by small sample effects. The results for the session/program factor are inconsistent for InScope faults.We believe that these differences are due to a combination of the fatigue effect and a technique x program interaction. Although we were able to reproduce the main effects, the changes to the design of the original experiment make it impossible to identify the causes of the discrepancies for sure. We believe that further replications closely resembling the original experiment should be conducted to improve our understanding of the phenomena under study