The Internet traffic volume continues to grow at a great rate, now driven by video and TV distribution. For network operators it is important to avoid congestion in the network, and to meet service level agreements with their customers. This thesis presents work on two methods operators can use to reduce links loads in their networks: traffic engineering and content caching.
This thesis studies access patterns for TV and video and the potential for caching. The investigation is done both using simulation and by analysis of logs from a large TV-on-Demand system over four months.
The results show that there is a small set of programs that account for a large fraction of the requests and that a comparatively small local cache can be used to significantly reduce the peak link loads during prime time. The investigation also demonstrates how the popularity of programs changes over time and shows that the access pattern in a TV-on-Demand system very much depends on the content type.
For traffic engineering the objective is to avoid congestion in the network and to make better use of available resources by adapting the routing to the current traffic situation. The main challenge for traffic engineering in IP networks is to cope with the dynamics of Internet traffic demands.
This thesis proposes L-balanced routings that route the traffic on the shortest paths possible but make sure that no link is utilised to more than a given level L. L-balanced routing gives efficient routing of traffic and controlled spare capacity to handle unpredictable changes in traffic. We present an L-balanced routing algorithm and a heuristic search method for finding L-balanced weight settings for the legacy routing protocols OSPF and IS-IS. We show that the search and the resulting weight settings work well in real network scenarios.
Those working in product development need to consider sustain ability, being careful not to compromise the future generations ability to satisfy its needs. Several strategies guide companies towards sustainability. This paper studies six of these strategies: eco-design, green design, cradle-to-cradle, design for environment, zero waste, and life cycle approaches. Based on a literature review and semi-structured interviews, it identifies 22 factors of sustainability from the perspective of manufacturers. The purpose is to determine which are the most important and to use them as a foundation for a new design strategy. A survey based on the 22 factors was given to people working with product development; they graded each factor by importance. The resulting qualitative data were analyzed using evidential reasoning. The analysis found the factors minimize use of toxic substances, increase competitiveness, economic benefits, reduce material usage, material selection, reduce emissions, and increase product functionality are more important and should serve as the foundation for a new approach to sustainable product development.
Navigation and orientation in an indoor environment are a challenging task for visually impaired people. This paper proposes a portable vision-based system to provide support for visually impaired persons in their daily activities. Here, machine learning algorithms are used for obstacle avoidance and object recognition. The system is intended to be used independently, easily and comfortably without taking human help. The system assists in obstacle avoidance using cameras and gives voice message feedback by using a pre-trained YOLO Neural Network for object recognition. In other parts of the system, a floor plane estimation algorithm is proposed for obstacle avoidance and fuzzy logic is used to prioritize the detected objects in a frame and generate alert to the user about possible risks. The system is implemented using the Robot Operating System (ROS) for communication on a Nvidia Jetson TX2 with a ZED stereo camera for depth calculations and headphones for user feedback, with the capability to accommodate different setup of hardware components. The parts of the system give varying results when evaluated and thus in future a large-scale evaluation is needed to implement the system and get it as a commercialized product in this area.
This paper investigates and implements six Machine Learning (ML) algorithms, i.e. Artificial Neural Network (ANN), Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF), Extra Tree (ET), and Gradient Boosted Trees (GBT) to classify different Pedestrians’ events based on Inertial Measurement Unit (IMU) and Global Positioning System (GPS) signals. Pedestrians’ events are pedestrian movements as the first step of H2020 project called SimuSafe1 with a goal to reduce traffic fatalities by doing risk assessments of the pedestrians. The movements the MLs’ models are attempting to classify are standing, walking, and running. Data, i.e. IMU, GPS sensor signals and other contextual information are collected by a smartphone through a controlled procedure. The smartphone is placed in five different positions onto the body of participants, i.e. arm, chest, ear, hand and pocket. The recordings are filtered, trimmed, and labeled. Next, samples are generated from small overlapping sections from which time and frequency domain features are extracted. Three different experiments are conducted to evaluate the performances in term of accuracy of the MLs’ models in different circumstances. The best performing MLs’ models determined by the average accuracy across all experiments is Extra Tree (ET) with a classification accuracy of 91%.
The double-mean-reverting model by Gatheral [1] is motivated by empirical dynamics of the variance of the stock price. No closed-form solution for European option exists in the above model. We study the behaviour of the implied volatility with respect to the logarithmic strike price and maturity near expiry and at-the- money. Using the method by Pagliarani and Pascucci [6], we calculate explicitly the first few terms of the asymptotic expansion of the implied volatility within a parabolic region.
The double-mean-reverting model by Gatheral is motivated by empirical dynamics of the variance of the stock price. No closed-form solution for European option exists in the above model. We study the behaviour of the implied volatility with respect to the logarithmic strike price and maturity near expiry and at-the-money. Using the method by Pagliarani and Pascucci, we calculate explicitly the first few terms of the asymptotic expansion of the implied volatility within a parabolic region.
This report presents a Master of Science in Engineering work, carried out at Mälardalen’sUniversity within the research project METRO. The aim for this work was to determineif a concrete column placed close to the tracks at a subway station can withstand theeffect and temperature of a fire in a burning train comparable to the effects and temperaturesthat showed at the full scale test carried out within the METRO project. A literature review was made before a following case study. The results from thiswork show that the column is negligible affected by the fire.
A common problem for autonomous vehicles is to define a coherent round boundary of unstructured roads. To solve this problem an evolutionary approach has been evaluated, by using a modified ant optimization algorithm to define a coherent road edge along the unstructured road in night conditions. The work presented in this paper involved pre-processing, perfecting the edges in an autonomous fashion and developing an algorithm to find the best candidates of starting positions for the ant colonies. All together these efforts enable ant colony optimization (ACO) to perform successfully in this application scenario. The experiment results show that the best paths well followed the edges and that the mid-points between the paths stayed centered on the road.
Several control methods have been proposed to stabilise riderless bicycles but they do not have sufficient simplicity for practical applications. This paper proposes a practical approach to model an instrumented bicycle as a combination of connected systems. Using this model, a PID controller is designed by a loop shaping method to stabilise the instrumented riderless bicycle. The initial results show that the bicycle can be stabilised when running on a roller. The work presented in this paper shows that it is possible to self stabilise a riderless bicycle using cascade PI/PID controllers.
Finnish students' success on all three content domains of each of the four cycles of the OECD's Programme for International Student Assessment (PISA) has created much international interest. It has also prompted Finnish academics to offer systemic explanations typically linked to the structural qualities of Finnish schooling and teacher education. Less well-known has been the modest mathematics performance of Finnish grade 8 students on the two Trends in International Mathematics and Science Study (TIMSS) in which Finland has participated, which, when compared with its PISA successes, has created something of an enigma. In this paper, we attempt to shed light on this enigma through analyses of Finnish mathematics classroom practice that draw on two extant data sets-interviews with Finnish teacher educators and video-recordings of sequences of lessons taught on standard topics. Due to the international interest in Finnish PISA success, the analyses focus primarily on the resonance between classroom practice and the mathematical literacy component of the PISA assessment framework. The analyses indicate that Finnish mathematics didactics are more likely to explain the modest TIMSS achievements than PISA successes and allude to several factors thought to be unique to the Finns, which, unrelated to mathematics teaching practices, may be contributory to the repeated Finnish PISA successes. Some implications for policy-borrowing are discussed.
ABSTRACT: Humane education programs designed to increase children’s empathy for animals are becoming more common. A quasi-experiment tested the effectiveness of one such program by comparing 80 children who had completed the program with a control group of 57 children who had not. The children read a story involving an injured dog and rated the degree of empathic concern they felt for him. The results showed that girls tended to express more empathy for a dog than did boys, but this difference was not significant for children who underwent an animal empathy training program. This suggests that humane education programs can reduce sex differences by increasing boys’ empathy.
Internet of Things (IoT) has revolutionized transportation systems by connecting vehicles consequently enabling their tracking, as well as monitoring of driver activities. Such an IoT platform requires a significant amount of data to be send from the on-board vehicle to the off-board servers, contributing to high network usage. The data can be send at regular intervals or in an event-based manner whenever relevant events occur. In interval-based approach, the data is send even if it is not relevant for reporting leading to a wastage of network resources, e.g., when the data does not change considerably compared to the previously sent value. In this paper, we investigate the possibility of using an event-based architecture to send data from the on-board system to the off-board system. The results show that our event-based architecture improves the accuracy of data available at the off-board system, by a careful selection of events. Moreover, we found that our event based architecture significantly decreases the frequency of sending messages, particularly during highway driving, leading to reduced average data transfer rates. Our results enable a customer to perform trade-offs between accuracy and data transfer rates.
Background and context: The occurrence of existential caregiving as a natural element of healthcare is the focus of this research. According to the literature, there is a lack of understanding of this issue, from a theoretical as well as a clinical point of view. In this design ‘existential’ and ‘spiritual’ are seen as synonymous and without religious association. Existential questions are regarded as questions about life, death, meaning, love, vulnerability, responsibility and dependence. The context for the project is an integrated anthroposophic hospital that offers rehabilitation for patients with cancer.
Aims and objectives
: With the support of an anthroposophic and caring scientific view of human beings, and by using concrete examples, the aim is to develop and deepen an understanding of existential care for patients in life-decisive phases in the care and rehabilitation of cancer. Clinical application research was used in cooperation with academic researchers and clinically active colleagues. Eleven clinicians from varying professions and two researchers collaborated over the course of two years. The data used came from 65 case reports of significant care situations experienced by the team members. A joint interpretive qualitative analysis led to the formulation of the findings.
Conclusions
: Existential caregiving in practice requires an ‘existential literacy’, using the metaphor of human life as a text or a book whose contents are legible only for the one versed in the language. In order to gain a complete understanding of caregiving, an ability to read a suffering human’s language and decipher its meaning is essential. The patient’s narrative might open up a caregiver’s awareness in a single illuminating moment. An authentic and listening attitude together with an active restriction of one’s own suppositions increase the possibility of providing existential care. Compassion and professional judgement function as the caregiving compass and ‘lexica’ for existential care.
Implications for practice:
Aim: Rotavirus vaccines are effective against severe infections, but have a modest impact on mortality in high-income countries. Parental knowledge and attitudes towards vaccines are crucial for high vaccination coverage. This study aimed to identify why parents refused to let their infant have the vaccination or were unsure. Methods: This cross-sectional study was based on 1,063 questionnaires completed by the parents of newborn children in 2014. Stepwise logistic regression was used to identify the main predictors. Results: Most (81%) parents intended to vaccinate their child against the rotavirus, while 19% were unwilling or uncertain. Parents with less education and children up to five weeks of age were more likely to be unwilling or uncertain about vaccinating their child. Factors associated with a refusal or uncertainty about vaccinating were not having enough information about the vaccine, no intention of accepting other vaccines, paying little heed to the child health nurses' recommendations, thinking that the rotavirus was not a serious illness and not believing that the vaccine provided protection against serious forms of gastroenteritis. Conclusion: Early information, extra information for parents with less education and close positive relationships between parents and child health nurses were important factors in high rotavirus vaccination rates.
Providing autonomy for employees ensures innovation competence if balanced by integration into the organization. The aim of this article is to study processes leading to the integration of employees into the company culture. The two research questions are: What makes the culture of a work group similar to the company culture? How is a work group culture constructed? Theories that are employed concern culture as an organizing structure emerging in the interaction, company culture as a way to exert control, and social networks as a way to describe the interaction. Empirical data come from a merchant bank from which 105 respondents from ten work groups answered questions about their communication and their integration into the company culture. The results show that the sub-culture of the group emerges in communication between members of the group. There seems to be a self-reinforcing spiral between collegial talk, especially about goals, plans and changes at the work place, and cultural integration. All members of a group should be included in this communication to create a strong culture. The value system of the supervisor strongly influences the sub-culture of the work group. Appointing supervisors with values that correspond to the company culture and provide for employee communications is thus central for organizations using culture as a tool for control.
Purpose – The purpose of this paper is to discuss the philosophical baseline of two popular business schemes, the business model and a latter variation of human resource costing and accounting (HRCA). The aim is to identify crucial assumptions inherent in the models that may influence attempts of creating a symbiosis between them.
Design/methodology/approach – The paper provides a conceptual perspective on the two models. Data for the paper were gathered during a case study on the usefulness of HRCA for small and medium-sized enterprises (SME) as well as from extensive literature readings. These data have been compiled and analysed under the influence of Weick's method for generating theory.
Findings – While the business model and HRCA share a common purpose they try to provide different qualities to the organisation. Whereas the former seeks to realise dreams and ambitions, the latter supports displacements of threats towards organisations and managers. This difference is a potential source of friction that may result in a harmful organisational behaviour.
Practical implications – The paper also expands on the theoretical baseline of two popular business schemes. By identifying crucial differences, amendments and adaptions are possible to make within organisation or among business consultants that could override the problems. Some suggestions are made on this issue.
Originality/value – The paper expands the theoretical and philosophical understanding of popular business schemes. By introducing a theory of happiness a new perspective providing crucial information of the function of the two business schemes is revealed.
In the last decade, electronics and software have replaced many mechanical components in vehicles at an unprecedented rate. New emerging technologies have found their way into the vehicular domain,like for instance, ADAS systems. This change brings some particular challenges with it in terms of functionalities, safety and security. Many vehicle distributed functions require hard real-time and secure communication. Therefore, the electrical and electronic (E/E architectures) architectures are in a continuously adapting trend to meet the new standards.The adaptation from a distributed to a domain-centralized architectureis already present. It is crucial to facilitate reuse of system architectural solutions in order to make system development more efficient. Therefore, we propose the use of communication architectural patterns. We present a method to map communication patterns on a certain layer ofabstraction. The method has been evaluated through several industrialuse cases. Furthermore, this work sets precedence for future research and development, as well as future applications of the method.
This paper presents results and conclusions from design, manufacturing, and benchmarking of a heterogeneous computing low power fault tolerant computer, realized on an industrial Qseven® small form factor (SFF) platform. A heterogeneous computer in this context features multi-core processors (CPU), a graphical processing unit (GPU), and a field programmable gate array (FPGA). The x86 compatible CPU enables the use of vast amounts of commonly available software and operating systems, which can be used for space and harsh environments. The developed heterogeneous computer shares the same core architecture as game consoles such as Microsoft Xbox One and Sony Playstation 4 and has an aggregated computational performance in the TFLOP range. The processing power can be used for on-board intelligent data processing and higher degrees of autonomy in general. The module feature quad core 1.5 GHz 64 bit CPU (24 GFLOPs), 160 GPU shader cores (127 GFLOPs), and a 12 Mgate equivalent FPGA fabric with a safety critical ARM® Cortex-M3 MCU.
Trace-based timing analysis is a technique, which assesses the software timing requirements against the timing information contained in so-called traces, which are files collected from simulation tools or by running the actual systems. In this experience report, we describe our joint effort with Volvo Group Trucks Technology in designing and developing a round-trip, model-based framework for the trace-based timing analysis of automotive software. To validate the proposed framework, we use a mix of observational and descriptive methods. In particular, we validate the correctness and feasibility of the proposed approach using the Washer Wiper automotive functionality. Eventually, we discuss lessons learnt, the benefits and limitations of the proposed framework.
In this paper, we present our ongoing work on proposing solutions to integrate legacy end-stations into Time-Sensitive Network (TSN) communication systems where the legacy end-stations are synchronized via their legacy clock synchronization protocol. To this end, we experimentally identify the effects of lacking synchronization or partial synchronization in TSN networks. In the experiments we show the effects of clock synchronization in different scenarios on jitter and clock drifts. Based on the experiments, we propose preliminary solutions to overcome the identified effects.
Solar home systems (SHSs) represent a viable technical solution for providing electricity to households and improving standard of living conditions in areas not reached by the national grid or local grids. For this reason, several rural electrification programmes in developing countries, including Namibia, have been relying on SHSs to electrify rural off-grid communities. However, the limited technical know-how of service providers, often resulting in over- or under-sized SHSs, is an issue that has to be solved to avoid dissatisfaction of SHSs’ users. The solution presented here is to develop an open-source software that service providers can use to optimally design SHSs components based on the specific electricity requirements of the end-user. The aim of this study is to develop and validate an optimization model written in MS Excel-VBA which calculates the optimal SHSs components capacities guaranteeing the minimum costs and the maximum system reliability. The results obtained with the developed tool showed good agreement with a commercial software and a computational code used in research activities. When applying the developed optimization tool to existing systems, the results identified that several components were incorrectly sized. The tool has thus the potentials of improving future SHSs installations, contributing to increasing satisfaction of end-users.
This paper presents an adapter to link the Matlab/Simulink model of a custom braking system into an open-source road traffic simulator, namely SUMO. The traditional braking models in SUMO work on a coarser level, generally modeling the deceleration of the vehicle based on a single equation. Substituting this model with a detailed system allows adjustments on a very low level, including delays between components, the traction of individual tires, and controllers for the anti-locking system by simulating those in Simulink. Besides introducing the novel adapter linked into SUMO and discussing parameter fitting to mimic the behavior of the traditional braking system, this paper discusses the amount of performance deterioration as the price for simulating a more sophisticated braking system.
Developing efficient and effective decision making support includes identifying means to reduce repeated manual work and providing possibilities to take advantage of the experience gained in previous decision situations. For this to be possible, there is a need to explicitly model the context of a decision case, for example to determine how much the evidence from one decision case can be trusted in another, similar context. In earlier work, context has been recognized as important when transferring and understanding outcomes between cases. The contribution of this paper is threefold. First, we describe different ways of utilizing context in an envisioned decision support system. Thereby, we distinguish between internal and external context usage, possibilities of context representation, and context inheritance. Second, we present a systematically developed context model comprised of five types of context information, namely organization, product, stakeholder, development method & technology, and market & business. Third, we exemplary illustrate the relation of the context information to architectural decision making using existing literature.
Testing is an important activity in engineering of industrial software. For such software, testing is usually performed manually by handcrafting test suites based on specific design techniques and domain-specific experience. To support developers in testing, different approaches for producing good test suites have been proposed. In the last couple of years combinatorial testing has been explored with the goal of automatically combining the input values of the software based on a certain strategy. Pairwise testing is a combinatorial technique used to generate test suites by varying the values of each pair of input parameters to a system until all possible combinations of those parameters are created. There is some evidence suggesting that these kinds of techniques are efficient and relatively good at detecting software faults. Unfortunately, there is little experimental evidence on the comparison of these combinatorial testing techniques with, what is perceived as, rigorous manually handcrafted testing. In this study we compare pairwise test suites with test suites created manually by engineers for 45 industrial programs. The test suites were evaluated in terms of fault detection, code coverage and number of tests. The results of this study show that pairwise testing, while useful for achieving high code coverage and fault detection for the majority of the programs, is almost as effective in terms of fault detection as manual testing. The results also suggest that pairwise testing is just as good as manual testing at fault detection for 64% of the programs.
The aim of this study is to construct a new model to measure the supply and demand non-equilibrium of transportation system, which is more accuracy and effect compared to the traditional model. Based on the non-equilibrium problem of supply greater or less than demand, which is common in current city agglomeration transportation system, the supply and demand non-equilibrium depth of city agglomeration transportation system is proposed. From the perspective of the connotation of supply and demand non-equilibrium depth of city agglomeration transportation system, the category is definitely divided, and then the corresponding functions of supply and demand of the city agglomeration transportation system are established. According to the interaction mechanism of the supply and demand of the city agglomeration transportation system, the non equilibrium depth in a narrow and general sense can be calculated respectively, also the total non-equilibrium depth is obtained, containing its three-dimensional structure and the fitting surface. In the case study, it is indicated that the research conclusion meets the actual requirements completely.
Electric vehicle (EV) batteries provide new business opportunities through circularity, but identifying these opportunities requires multi-stakeholder collaboration considering the interests of stakeholders, the environment, and society. However, circular business model frameworks to support and guide firms in identifying and mapping multidirectional value in the early phases of designing new circular business models are lacking. Thus, this research proposes a framework that could support stakeholders in the EV battery value chain in identifying and mapping circular business opportunities and multidirectional value among stakeholders in order to generate a win–win–win situation in the value-creation process. The proposed framework for multi-stakeholder circular business model innovation consists of four phases—namely, initiation, ideation, testing, and implementation—subdivided into eight steps to address key challenges facing firms and encourage discussions on shared values and visions among all stakeholders in the early phases of designing the circular business model.
Software architecture is no more a mere system specification as resulting from the design phase, but it includes the process by which its specification was carried out. In this respect, design decisions in component-based software engineering play an important role: They are used to enhance the quality of the system, keep the current market level, keep partnership relationships, reduce costs, and so forth. For non trivial systems, a recurring situation is the selection of an asset origin, that is if going for in-house, outsourcing, open-source, or COTS, when in the need of a certain missing functionality. Usually, the decision making process follows a case-by-case approach, in which historical information is largely neglected: hence, it is avoided the overhead of keeping detailed documentation about past decisions, but it is hampered consistency among multiple, possibly related, decisions.The ORION project aims at developing a decision support framework in which historical decision information plays a pivotal role: it is used to analyse current decision scenarios, take well-founded decisions, and store the collected data for future exploitation. In this paper, we outline the potentials of such a knowledge repository, including the information it is intended to be stored in it, and when and how to retrieve it within a decision case.
The ISO 26262 functional safety standard provides appropriate development processes, requirements and safety integrity levels specific for the automotive domain. One crucial requirement consists of the creation of a safety case, a structured argument, which inter-relates evidence and claims, needed to show that safety-critical systems are acceptably safe. The standard is currently not mandatory to be applied to safety critical systems installed in heavy trucks; however, this is likely to be changed by 2016. This paper describes the experience gathered by applying the standard to the Fuel Level Estimation and Display System, a subsystem that together with other subsystems plays a significant role in terms of global system safety for heavy trucks manufactured by Scania. More specifically, exploratory and laborious work related to the creation of a safety case in compliance with ISO 26262 in an inexperienced industrial setting is described, and the paper ends with presenting some lessons learned together with guidelines to facilitate the adoption of ISO 26262.
Companies are challenged to achieve maximised benefits in time, money and novelty when introducing new products or technologies into their existing manufacturing systems. This paper set the focus on the introduction of new materials into existing products and if the adverse effects on manufacturing will outweigh the benefits. An automotive case was studied where discrete event simulation was used as tool to evaluate process consequences when introducing new material and process technologies into the production system. The question concerned if discrete event simulation can verify production system capabilities even in early conceptual design stages. The case analysis is concluded by three challenge areas concerning early stages of production system design. The difficulties of evaluating operational key performance indicators early in design processes become evident and needed future research efforts within the area are pointed out. © 2016 The Authors.
Federated learning (FL) is an emerging and privacy-preserving machine learning technique that is shown to be increasingly important in the digital age. The two challenging issues for FL are: (1) communication overhead between clients and the server, and (2) volatile distribution of training data such as class imbalance. The paper aims to tackle these two challenges with the proposal of a federated fuzzy learning algorithm (FFLA) that can be used for data-based construction of fuzzy classification models in a distributed setting. The proposed learning algorithm is fast and highly cheap in communication by requiring only two rounds of interplay between the server and clients. Moreover, FFLA is empowered with an an imbalance adaptation mechanism so that it remains robust against heterogeneous distributions of data and class imbalance. The efficacy of the proposed learning method has been verified by the simulation tests made on a set of balanced and imbalanced benchmark data sets.
Purpose – Research has shown that companies focus their internal processes when they adopt enterprise resource planning (ERP) systems. However, the ERP systems need to expand their functionality to include customers and suppliers (with e-commerce functionality) to reach their full potential. The purpose of this paper is to consider business relationships as a resource but also a limitation when companies strive to get an extended ERP system.
Design/Methodology/approach – The paper presents an illustrative case study of an industrial company’s process of developing an extended ERP and how the company’s portfolio of business relationships has affected the solution. The analysis is supported by the markets-as-networks theory.
Findings – The process of developing an extended ERP system needs to incorporate the company’s business partners (customers and suppliers). It is a simultaneously bottom-up and top-down process given that the operative frontline staff hold the knowledge about the company’s business relationships while the corporate management has the means of extending the ERP system functionality and align it with the focal company’s strategy.
Research implications – Companies need to consider the fact that the technological and financial status of their customers and suppliers differ. Thus, an effective and flexible extended ERP system needs to include both a high-end and low-end solution as well as understand that a full interorganizational integration might not be realistic.
Originality/value – The paper puts forth business relationship portfolios as an important factor to consider when extending the ERP system functionality in the supply chain and towards customers.
The manufacturing industry contributes to climate change and must take action to reach its high-set target. Implementation of circularity to reach sustainability has shown to be beneficial for products, but there is a lack of knowledge on how to transfer the concept to the design of factories. The purpose of the paper is to identify and systemically analyse areas of importance to enable circularity in production development to better understand what requires attention to achieve a circular factory. The focus of the study is on production development narrowed down to production equipment. A case study approach was used with interviews as the main method for data collection. Four main themes were identified: competence, collaboration, mindset and time. These were considered as areas of importance to enable circularity and to understand what needs further attention they were analysed in a systemic view of macro-, meso- and microlevel. The findings stress the need for investing in circularity in early phases to achieve circularity and that all levels of the industry need to take part in the transition towards circularity. Further, research within areas with similar complexities could benefit and learn from each other.
Software testing is a complex, intellectual activity based (at least) on analysis, reasoning, decision making, abstraction and collaboration performed in a highly demanding environment. Naturally, it uses and allocates multiple cognitive resources in software testers. However, while a cognitive psychology perspective is increasingly used in the general software engineering literature, it has yet to find its place in software testing. To the best of our knowledge, no theory of software testers’ cognitive processes exists. Here, we take a first step towards such a theory by presenting a cognitive model of software testing based on how problem solving is conceptualized in cognitive psychology. Our approach is to instantiate a general problem solving process for the specific problem of creating test cases. We then propose a controlled experiment for testing our cognitive test design model. The experiment makes use of verbal protocol analysis to understand the mechanisms by which human testers choose, design, implement and evaluate test cases and test design strategies. An initial evaluation was then performed with five students as subjects. The results support a problem solving-based model of test design for capturing testers’ cognitive processes.
Combinatorial testing has been suggested as an effective method of creating test cases at a lower cost. However, industrially applicable tools for modeling and combinatorial test generation are still scarce. As a direct effect, combinatorial testing has only seen a limited uptake in industry that calls into question its practical usefulness. This lack of evidence is especially troublesome if we consider the use of combinatorial test generation for industrial safety-critical control software, such as are found in trains, airplanes, and power plants. To study the industrial application of combinatorial testing, we evaluated ACTS, a popular tool for combinatorial modeling and test generation, in terms of applicability and test efficiency on industrial-sized IEC 61131-3 industrial control software running on Programmable Logic Controllers (PLC). We assessed ACTS in terms of its direct applicability in combinatorial modeling of IEC 61131-3 industrial software and the efficiency of ACTS in terms of generation time and test suite size. We used 17 industrial control programs provided by Bombardier Transportation Sweden AB and used in a train control management system. Our results show that not all combinations of algorithms and interaction strengths could generate a test suite within a realistic cut-off time. The results of the modeling process and the efficiency evaluation of ACTS are useful for practitioners considering to use combinatorial testing for industrial control software as well as for researchers trying to improve the use of such combinatorial testing techniques.
Women's position as informal carers has been taken for granted in social policy and social professions, while relatively few discussions have elaborated on caring as a later life activity for men and the impact on family care. This study explores the processes connected to informal caregiving in later life through the position of adult daughters of older fathers engaged with long-term caregiving responsibilities for a partner. A sample of eight daughters, with fathers having primary caregiving responsibility for their ill partners was recruited and in-depth interviews were carried out and analysed according to qualitative procedures. The daughters' descriptions of their relationships with their fathers show that being an older man who engages in caring can have a positive outcome on relations. Even if some of the daughters have doubts about their fathers “masculine authenticity”, all of them appear to cherish “his helping hands” as a carer and closer more intimate relationships with their fathers. Caring for an old and frail spouse may potentially present alternative ways of being a man beyond traditional ‘male activities’ and that caring might also sometimes involve a re-construction of gender identities. It is suggested that social work professionals may use a gendered understanding to assess and work strategically with daughters and other family members who support caring fathers.
In this case study, we, the student Nadya and her supervisor Lena, will describe the processand challenges associated with conducting an empirical study for a master’s degree in caringscience in psychiatric nursing. We will describe how the idea for the thesis evolved, theoreticaland practical preparations, as well as methodological procedures in relation to data collectionand analysis. We will also share some reflections we made in relation to challengesencountered during this study. Many of these reflections were directed toward methodologicalaspects of the study. However, along the way, it also became clear that experiences fromconducting the study also yielded important knowledge and understanding about mental healthcare. The reflections about what happened in the encounter between Nadya and theparticipants added depth not only to our understanding of the subject for this study, that is,how mental health, care, and recovery are experienced by people in a Christian monastery incontemporary Sweden, but also shed light on important aspects of mental health nursing inrelation to modern psychiatry.
I det här kapitlet belyses samverkan från dimensionerna uppåt (med Tillväxtverket för att söka nya samverkansformer med högskoleaktörer), utåt (mellan projekt vid andra högskolor/universitet), inåt (mellan olika delar av akademin och olika delar av högskolan) och nedåt (mot studenter, vilket kom att utvecklas under projektets gång).
Utgångspunkten för detta exempel på samverkan och samproduktion är ett treårigt pilotprojekt för att etablera entreprenörskap inom vård- och omsorgsutbildningar. Projektet startade 2012, pågick till och med 2014 och ingick i ett av Tillväxtverket finansierat pilotprogram tillsammans med fyra andra lärosäten (se Samverkan i projektet nedan). Pilotprojektet har dessutom identifierat tre samverkansinriktningar: explorerande samverkan (bygga ny kunskap tillsammans), expanderande samverkan (engagera fler i värdeskapande aktiviteter) och evolverande samverkan (ömsesidig kontinuerlig anpassning). I analysen och diskussionen återkommer denna kategorisering. Utöver detta diskuteras relationen mellan styrning och koordination samt hur skillnader i målsättningar bör påverka upplägget för samverkan och samproduktion.
Objective: To describe the thoughts, reflections, and experiences of friends-with-benefits relationships among a group of Swedish adolescents. Design and Sample: A qualitative study with an explorative and descriptive design. Eight adolescents, aged 16-18, were interviewed. Measures: Individual in-depth interviews were undertaken. Data were analyzed using latent content analysis. Results: The informants involved themselves in Friends-with-benefits (FWB) relationships to find physical and psychological intimacy without any expectations or demands. FWB relationships were perceived to have more advantages when the partner was a close friend with whom an informant felt comfortable. There was ambivalence about the legitimacy of romantic feelings in an FWB relationship, although it was quite common. Sexual concurrency was common and often accepted. Sexual risk-taking behavior involving the use of alcohol and a lack of contraception was considered common in FWB relationships. Informants requested more education and support as regards their sexual behavior. Conclusions: FWB relationships were often initiated to find physical and psychological intimacy with no expectations or demands. Advantages such as sexual concurrency and no demands were central. A deeper understanding of how adolescents think and reason about sexuality and relationships can make a difference when working to improve young people's sexual and reproductive health.
Production control mechanisms have been broadly investigated by researchers, where each type of production control mechanism has different performance depending on the situation. However, the situation with high variety products in a divergent production line has been rarely studied. This paper presents a study on the applicability of four different production control mechanism; three different variants of POLCA as well as one type of CONWIP control in an automotive production company with high variety of products and divergent line. ExtendSim simulation software has been used for discrete event simulation in order to analyse the production line and compare strategies. The main criteria for comparing the performance were throughput, shop floor throughput time and level of work in process (WIP). The study shows that m-CONWIP (as a variant of CONWIP) is recommended in this situation, as it leads to more reduction in WIP amount and throughput time, while throughput value does not drop.
Handling the software complexity of modern vehicular systems has become very challenging due to their non-centralized nature and real-time requirements that they impose. Among many software development paradigms for these systems, model-based development excels for several reasons including its ability to verify timing predictability of software architectures of these systems using pre-runtime timing analysis techniques. In this work, we propose a comprehensive framework that captures the timing related information needed for the modeling languages to facilitate these timing analyses. We validate the applicability of the framework by comparing two modeling languages and their respective tool-chains, Rubus-ICE and APP4MC, that are used for software development in the vehicle industry. Based on our results, both modeling languages support the design and analysis of vehicle software, but with different. Both modeling languages support time-, event- and data-driven activation of software components and modeling of single- and multi-rate transactions. Amalthea targets applications on single nodes with multi-core architectures while RCM focuses on single-core single-node and distributed embedded systems with ongoing work for supporting single-node multi-core architectures. In comparison to Amalthea, RCM provides a generic message model which can easily be re-modeled according to protocol-specific properties.
Combinatorial coverage has been proposed as a way to measure the quality of test cases by using the input interaction characteristics. This paper describes the results of empirically measuring combinatorial coverage of manually created test cases by experienced industrial engineers. We found that manual test cases achieve on average 78% 2-way combinatorial coverage, 57% 3-way coverage, 40% 4-way coverage, 20% 5-way combinatorial coverage and 13% for 6-way combinatorial coverage. These manual test cases can be augmented to achieve 100% combinatorial coverage for 2-way and 3-way interactions by adding eight and 66 missing tests on average, respectively. For 4-way interactions, full combinatorial coverage can achieved by adding 658 missing tests. For 5-way and 6-way interactions, full combinatorial coverage can be achieved by adding 5163 and 6170 missing tests on average, respectively. The results of this paper suggest that manual tests created by industrial engineers do no achieve high combinatorial coverage and can be improved by using combinatorial testing at the expense of the number of test cases to be executed.
The lack of formal system specifications is a major obstacle to the widespread adoption of formal verification techniques in industrial settings. Specification patterns represent a promising approach that can fill this gap by enabling non-expert practitioners to write formal specifications based on reusing solutions to commonly occurring problems. Despite the fact that the specification patterns have been proven suitable for specification of industrial systems, there is no engineer-friendly tool support adequate for industrial adoption. In this paper, we present a tool called SESAMM Specifier in which we integrate a subset of the specification patterns for formal requirements specification, called SPS, into an existing industrial tool-chain. The tool provides the necessary means for the formal specification of system requirements and the later validation of the formally expressed behavior.
Track-based flow management systems like transportation systems and traffic control systems play a crucial role in our daily life. Safety and performance are among the most important quality requirements for these systems. This paper presents AdaptiveFlow as a framework for modeling, safety checking and performance analysis of track-based flow management systems. AdaptiveFlow is based on the Hewitt actors computation model. In particular, tracks are modeled as actors and moving objects as messages. Timed Rebeca is used for modeling, and the model checking tool Afra is used for safety verification and performance evaluation in AdaptiveFlow. To react to dynamic changes in the environment, AdaptiveFlow provides support for three adaptive policies, which can be examined and compared in different scenarios. To demonstrate the applicability of AdaptiveFlow, we consider the Electric Site Research Project of Volvo Construction Equipment as a case study. In this project, a fleet of autonomous haulers is utilized to transport materials in a quarry site. Furthermore, to show the reusability of the framework for other flow management scenarios, an experiment on an urban garbage collection system is presented. © 2020 Information Processing Society of Japan.