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.     

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。     

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.     

Object-oriented design of process line simulation and optimization—A case study in papermaking

Simulation-based optimization for industrial process lines is discussed in this paper. Our approach combines multidisciplinary modeling, modern sensitivity analysis methodology as well as multiobjective optimization by means of object-oriented software design principles. As a result, a simulation and optimization approach that can be extended and modified due to users’ needs can be developed. Our approach is illustrated by a real-world example from papermaking industry.     

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.     

Understanding human values in adopting new technology—A case study and methodological discussion

This paper proposes a method for understanding and modelling human values in the evaluation of new technology in social settings, and analyses the validity of the proposed method in a specific use case. The method, which is based on the Schwartz universal model of human values adopted from social psychology research, is used in the context of value analysis of the adoption of a technology-supported attendance control system in a primary school. The results are based on an evaluation of a 14-week trial where two classes of elementary school children used an attendance control system that was implemented using networked technology components, including smart cards, NFC-enabled mobile phones and card readers, a web portal, and SMS messaging. The findings from the trial are analysed from the viewpoint of three end-user groups, namely children, parents, and teachers.     

A study of the impacts of positive/negative feedback on collective wisdom—case study on social bookmarking sites

The core spirit for web 2.0 is collective wisdom (i.e., the contribution of users, and the creation of value through the interaction between users). Social bookmarking sites integrate all kind of contents on the Internet (especially those generated by users), and play the role of pivot between content production and consumption. This paper mainly investigates how the positive/negative feedbacks would impact the quality of the collective wisdom within the autonomous service environments (i.e., the social bookmarking sites). Our research findings show that the performance of social bookmarking sites has a tradeoff between collective filtering (i.e., results of positive feedbacks) and front page update frequency that should be carefully managed for ensuring the good quality in collective wisdom and service performance. Moreover, the negative feedback could also shape the collective wisdom and stabilize the system performance. The research findings are believed to provide some managerial guidelines for web 2.0 sites design and operations.     

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.     

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.     

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.     

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.     

A stepwise cluster analysis approach for downscaled climate projection – A Canadian case study

Downscaling techniques are used to obtain high-resolution climate projections for assessing the impacts of climate change at a regional scale. This study presents a statistical downscaling tool, SCADS, based on stepwise cluster analysis method. The SCADS uses a cluster tree to represent the complex relationship between large-scale atmospheric variables (namely predictors) and local surface variables (namely predictands). It can effectively deal with continuous and discrete variables, as well as nonlinear relations between predictors and predictands. By integrating ancillary functional modules of missing data detecting, correlation analysis, model calibration and graphing of cluster trees, the SCADS is capable of performing rapid development of downscaling scenarios for local weather variables under current and future climate forcing. An application of SCADS is demonstrated to obtain 10 km daily mean temperature and monthly precipitation projections for Toronto, Canada in 2070–2099. The contemporary reanalysis data derived from NARR is used for model calibration (1981–1990) and validation (1991–2000). The validated cluster trees are then applied for generating future climate projections.     

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.     

Identifying organizational barriers—A case study of usability work when developing software in the automation industry

This study investigates connections between usability efforts and organizational factors. This is an important field of research which so far appears to be insufficiently studied and discussed. It illustrates problems when working with software engineering tasks and usability requirements. It deals with a large company that manufactures industrial robots with an advanced user interface, which wanted to introduce usability KPIs, to improve product quality. The situation in the company makes this difficult, due to a combination of organizational and behavioural factors that led to a “wicked problem” that caused conflicts, breakdowns and barriers. Addressing these problems requires a holistic view that places context in the foreground and technological solutions in the background. Developing the right product requires communication and collaboration between multiple stakeholders. The inclusion of end users, who fully understand their own work context, is vital. Achieving this is dependent on organizational change, and management commitment. One step to beginning this change process may be through studying ways to introduce user-centred design processes.