Securing a distributed environment — A practical case study

This article describes how a UK Utility tackled the management of security in a distributed environment with some pragmatic in-house solutions.     

Hierarchical A1 based path planning — a case study

Usually it is impossible to know in advance how coarsely robot movements can be discretized in order to find a collision-free path from an initial robot position to a desired goal position in a presence of obstacles. Our solution to the problem is to introduce a new method of constructing hierarchical path planning algorithms. It is based on a novel application of the A¹ control strategy, called here Meta A¹.We test four hierarchical path planning algorithms, two of which are based on Meta A¹, using five simulated robot workcells. The simulations suggest that the Meta A¹ based planners, on average, find paths faster and consume less memory than the other two algorithms.     

Blockchain-based event processing in supply chains—A case study at IKEA

One of the major areas of interest for deployment of blockchains is in the supply chain sector where decentralisation combined with immutability is expected to enhance the transparency and robustness of transaction processing drastically. In this work we contribute to a feasibility study for permissioned blockchains in the context of a major international retail company. First, we characterise the types, relationships, and volumes of events that are created in the life cycle of a product from creation to ownership transfer. We use the created event model and the data from the company operations to identify the load that such an event processing system would have to manage. Then we create a prototype based on Quorum that deals with a significant subset of the events and expose the blockchain-based prototype to variations in load to identify the maximum throughput and average transaction processing time. This system can then form the basis of understanding the bottlenecks, configuration settings and platform choices needed in future potential deployment.     

Failures in fault-tolerant FPGA-based controllers – A case study

Nowadays, FPGA-based Networked Control Systems (NCSs) are frequently used. Transient and permanent faults occur often as a result of radiation in industrial environments. Accordingly, Fault-Tolerant (FT) FPGA-based NCSs are desired. In this paper, a novel NCS model is proposed composing of In-Loop and S2A architectures linked via an Ethernet switch. This architecture is used in shape detection machines with vision sensing requirements. FT techniques are applied in the controller nodes of the system along with Dynamic Partial Reconfiguration (DPR) for FPGA-based controller recovery. The reliability of the system due to changes in both the recovery rate and the conditional probability of failure occurrence (either transient or permanent), is presented in this paper. Accordingly, a Markov model is constructed for reliability calculations. A case study is used to illustrate the use of such a model to choose appropriate maintenance strategies as well as a quantitative measure for the ability of the FT techniques to increase system reliability. Coverage is then studied in the context of the same system. Furthermore, system failures are divided into safe system failures and unsafe system failures. Another Markov model is developed. Then, a case study is used to illustrate the effect of coverage on the probability of occurrence of an unsafe system failure.     

A university-timetabling problem and its solution using Benders’ partitioning—a case study

In this paper, we address a university-timetabling problem and present a methodology that relies on Benders’ partitioning for its solution. This partitioning results from the special nature of the underlying integer programming formulation for this problem. We have used our methodology to schedule courses offered by the College of Engineering as well as to those offered university-wide at Virginia Tech. The results clearly depict an improvement in the quality of course schedules obtained by our methodology over those currently used, when the performance of a timetable is measured by the total distance traveled by the faculty members from their offices in respective departments to the classrooms, where the courses are offered.     

Transputer系统上CS—Prolog和CSO—Prolog的实现

Ｔｒａｎｓｐｕｔｅｒ系统成功地应用在数值计算领域，但人工智能这个重要领域因缺乏相应的并行化编程程语言而得不到广泛应用，本文介绍了两种基于Ｔｒａｎｓｐｕｔｅｒ的并行Ｐｒｏｌｏｇ的语言，详细描述了它们的运行机制和在多机系统的实现。     

On the variation and specialisation of workload—A case study of the Gnome ecosystem community

Most empirical studies of open source software repositories focus on the analysis of isolated projects, or restrict themselves to the study of the relationships between technical artifacts. In contrast, we have carried out a case study that focuses on the actual contributors to software ecosystems, being collections of software projects that are maintained by the same community. To this aim, we defined a new series of workload and involvement metrics, as well as a novel approach— $\widetilde{\mathbf{T}}$ -graphs—for reporting the results of comparing multiple distributions. We used these techniques to statistically study how workload and involvement of ecosystem contributors varies across projects and across activity types, and we explored to which extent projects and contributors specialise in particular activity types. Using Gnome as a case study we observed that, next to coding, the activities of localization, development documentation and building are prevalent throughout the ecosystem. We also observed notable differences between frequent and occasional contributors in terms of the activity types they are involved in and the number of projects they contribute to. Occasional contributors and contributors that are involved in many different projects tend to be more involved in the localization activity, while frequent contributors tend to be more involved in the coding activity in a limited number of projects.     

Effect of global position information in unknown world exploration — A case study using the Teleworkbench

This paper presents empirical results of the effect of the global position information on the performance of the modified local navigation algorithm (MLNA) for unknown world exploration. The results show that global position information enables the algorithm to maintain 100% success rate irrespective of initial robot position, movement speed, and environment complexity. Most mobile robot systems accrue an odometry error while moving, and hence need to use external sensors to recalibrate their position on an ongoing basis. We deal with position calibration to compensate the odometry error using the global position information provided by the Teleworkbench, which is a teleoperated platform and test bed for managing experiments using mini-robots. In this paper we demonstrate how we incorporate the global position information during and after the experiments.     

Chemogenomics knowledgebase and systems pharmacology for hallucinogen target identification—Salvinorin A as a case study

Drug abuse is a serious problem worldwide. Recently, hallucinogens have been reported as a potential preventative and auxiliary therapy for substance abuse. However, the use of hallucinogens as a drug abuse treatment has potential risks, as the fundamental mechanisms of hallucinogens are not clear. So far, no scientific database is available for the mechanism research of hallucinogens. We constructed a hallucinogen-specific chemogenomics database by collecting chemicals, protein targets and pathways closely related to hallucinogens. This information, together with our established computational chemogenomics tools, such as TargetHunter and HTDocking, provided a one-step solution for the mechanism study of hallucinogens. We chose salvinorin A, a potent hallucinogen extracted from the plant Salvia divinorum, as an example to demonstrate the usability of our platform. With the help of HTDocking program, we predicted four novel targets for salvinorin A, including muscarinic acetylcholine receptor 2, cannabinoid receptor 1, cannabinoid receptor 2 and dopamine receptor 2. We looked into the interactions between salvinorin A and the predicted targets. The binding modes, pose and docking scores indicate that salvinorin A may interact with some of these predicted targets. Overall, our database enriched the information of systems pharmacological analysis, target identification and drug discovery for hallucinogens.     

Transputer系统上CS－Prolog和CSO—Prolog的实现

Ｔｒａｎｓｐｕｔｅｒ系统成功地应用在数值计算领域，但人工智能这个重要领域因缺乏相应的并行化编程语言而得不到广泛应用．本文介绍了两种基于Ｔｒａｎｓｐｕｔｅｒ的并行Ｐｒｏｌｏｇ语言，详细描述了它们的运行机制和在多机系统的实现。     

Why do individuals use computer technology? A Finnish case study

Here we discuss the motivators for computer usage in Finland. IS and non-IS researchers have reported that perceived usefulness is a major determinant in a United States workplace. This study focuses on two aspects of motivation: extrinsic and intrinsic. Perceived usefulness is an example of extrinsic motivation, whereas perceived enjoyment is intrinsic. We found that extrinsic motivation plays a greater role in individuals' behavior and that perceived ease of use affects both perceived enjoyment and usefulness, as well as usage. Moreover, they were found to mediate fully the relationship between perceived ease of use and computer usage.     

Safety management of waterway congestions under dynamic risk conditions—A case study of the Yangtze River

With the continuous increase of traffic volume in recent years, inland waterway transportation suffers more and more from congestion problems, which form a major impediment to its development. Thus, it is of great significance for the stakeholders and decision makers to address these congestion issues properly. Fuzzy Techniques for Order Preference by Similarity to an Ideal Solution (TOPSIS) is widely used for solving Multiple Criteria Decision Making (MCDM) problems with ambiguity. When taking into account fuzzy TOPSIS, decisions are made in a static scenario with fixed weights assigned to the criteria. However, risk conditions usually vary in real-life cases, which will inevitably affect the preference ranking of the alternatives. To make flexible decisions according to the dynamics of congestion risks and to achieve a rational risk analysis for prioritising congestion risk control options (RCOs), the cost-benefit ratio (CBR) is used in this paper to reflect the change of risk conditions. The hybrid of CBR and fuzzy TOPSIS is illustrated by investigating the congestion risks of the Yangtze River. The ranking of RCOs varies depending on the scenarios with different congestion risk conditions. The research findings indicate that some RCOs (e.g. “Channel dredging and maintenance”, and “Prohibition of navigation”) are more cost effective in the situation of a high level of congestion risk, while the other RCOs (e.g. “Loading restriction”, and “Crew management and training”) are more beneficial in a relatively low congestion risk condition. The proposed methods and the evaluation results provide useful insights for effective safety management of the inland waterway congestions under dynamic risk conditions.     

Modular product design with grouping genetic algorithm—a case study

Modular products are products that fulfill various functions through the combination of distinct modules. These detachable modules are constructed both according to the maximum physical and functional relations among components and maximizing the similarity of specifically modular driving forces. Accordingly, a non-linear programming is proposed to identify separable modules and simultaneously optimize the number of modules. This paper presents a systematic approach to accomplish modular product design in four major phases. Phase 1 is by means of functional and physical interaction analysis to format a component-to-component correlation matrix. Phase 2 is the exploration of design requirements to evaluate the relative importance of each modular driver. In phase 3, non-linear programming is used to formulate the objective function. In the final phase, a heuristic grouping genetic algorithm is adopted to search for the optimal or near-optimal modular architecture. This process and its application are illustrated by a real case of an electrical consumer product provided by an Original Design Manufacturer. The results demonstrate that the designer could direct a new approach to establish product modules according to the relative importance of modular drivers and the interaction among components.     

以并行机制实现CS—Prolog

本文分析和讨论了在多Transputer环境中,如何扩充Prolog语言成为CS—Prolog,使之保持回溯机制,适应并行特点。     

A comparison study for displacement computation – Horn and Shunck's method versus March's method

The aim of this study is to reveal the effectiveness of a displacement computation method proposed by March in 1988. In common with a method proposed by Horn and Shunck in 1981, March's method also utilizes the measure of the departure from smoothness in the computed displacement as a regularization term. However, these two method have a difference in the definition of the correspondence error between images. Horn and Shunck eliminated the second and higher order terms of spatial brightness variation, so that the correspondence error is defined as a linear model. On the other hand, March defined a non-linear model in which the second and higher order terms are preserved. In order to verify the difference between two methods experimentally, we compare two methods with simulation images. Consequently, it is shown that March's method gives more accurate displacement for non-linearity in the brightness variation and less computation cost.     

Unconsciously interactive Films in a cinema environment—a demonstrative case study

‘Many worlds’ is a short narrative live-action film written and directed so as to provide multiple linear routes through the plot to one of four endings, and designed for showing in a cinema environment. At two points during the film, decisions are made based on audience bio-signals as to which plot route to take. The use of bio-signals is to allow the audience to remain immersed in the film, rather than explicitly selecting plot direction. Four audience members have a bio-signal measured sensor for each person: ECG (heart rate), EMG (muscle tension), EEG (‘brain waves’) and Galvanic Skin Response (perspiration). The four are interpreted as a single average of emotional arousal. ‘Many worlds’ was the first live-action linear plotted film to be screened in a cinema to the general public utilizing multiple biosensor types. The film has been shown publically a number of times, and lessons learned from the technical and cinematic production are detailed in this paper.     

A synthetical development approach for rehabilitation assistive smart product–service systems: A case study

Digital transformation (DT), the combination of information, computing, communication and connectivity technologies, which has triggered an effective upgrade of different aspects of market strategy, customer experience etc. Nowadays, rehabilitation assistive devices (RADs) are evolving to be more digital, intelligent and personalized. Digitalization and servitization have fostered to an emerging business model—the smart product–service system (Smart PSS). Therefore, DT of the RADs’ industry advocates not only the design of products and functions, the more important is the management of service processes and resource integration. With the increase in the elderly and disabled population, the requirement for RADs is becoming more urgent. However, research on Smart PSS for RAD is still limited. The rehabilitation assistive smart product–service systems (RASPSS) was introduced into the development of RADs based on the “Design and Management of DT” strategy through the service design of assistive devices and user requirements analysis. Further, an integrated design of RAD and Smart PSS has been created, a development method of RASPSS proposed, the theoretical model of the Smart PSS based on RADs built. To specify the service framework, this case study discusses the development of a home rehabilitation assistive system for femoral stem fracture patients. This paper evaluates the usability of the system, the results of which prove usability and effectiveness of the RASPSS development method. The RASPSS development model is designed to meet needs of stakeholders, improve the user rehabilitation experience, promote the service innovation of Smart PSS, bring certain market benefits of rehabilitation aids and create social value.