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1 – 10 of over 2000Warid Sayel Warid, Hashim Hizam, Norman Mariun and Noor Izzri Abdul-Wahab
This study aims to propose a sensitivity-based methodology for the optimum accommodation of distributed generation (DG) units in meshed power networks with appropriate…
Abstract
Purpose
This study aims to propose a sensitivity-based methodology for the optimum accommodation of distributed generation (DG) units in meshed power networks with appropriate technologies. The effect of load variation is incorporated into the proposed methodology to identify the most trusted locations for DG placement.
Design/methodology/approach
The effectiveness of minimizing active power losses is considered a key criterion. A priority list comprising both sensitivity indexes and realistic indicators is deduced to rank the optimum sites for the placement of DG units. A sorting index for distinguishing the suitable DG type(s) for each candidate location is organized. Three common DG types are considered in this work. The modified IEEE 30-bus meshed system is chosen to perform the proposed methodology.
Findings
Results demonstrate that the obtained priority index can be used to achieve the best real loss minimization rates. Numerous load buses can be safely excluded as candidate locations using the proposed approach. Consequently, the methodology can minimize the computational process of diagnosing the optimum sites for DG accommodation.
Originality/value
The findings determine that instead of installing many DG units at various locations with one DG type, a few certain load buses can be used to accommodate more than one DG type and significantly reduce losses.
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Keywords
Cultural heritage archives rely on environmental monitoring devices, such as dataloggers or more complex networked systems, to ensure collection preservation through collecting…
Abstract
Purpose
Cultural heritage archives rely on environmental monitoring devices, such as dataloggers or more complex networked systems, to ensure collection preservation through collecting temperature, humidity, light and/or air quality measures. Existing systems are often costly, inflexible and do not use a modern, internet of things (IoT) approach. This paper aims to determine the suitability of currently popular general-purpose IoT devices, standards and technologies to the environmental monitoring needs of archivists, as well as identify any challenges.
Design/methodology/approach
This paper describes an exploratory study detailing the design, construction and usability testing of a do-it-yourself datalogger and data dashboard system, which seeks to manage previously identified trade-offs in cost, required technical skill and maintainability.
Findings
The environmental monitoring system presented met archivists’ needs well and was generally noted to be easy-to-use, efficient and an improvement on existing systems. This suggests that an IoT approach can support archivists’ needs in this area.
Research limitations/implications
Potential limitations of this study include lack of archival staff with sufficient technical training to maintain such a system and the rapid pace of IoT evolution yielding unstable and constantly changing technologies.
Practical implications
The system design presented in this work provides a blueprint for cultural heritage organizations desiring a fuller-featured, lower cost environmental monitoring system for archival collections.
Originality/value
This research takes a novel user-centered, open-source, IoT approach to construct an environmental monitoring system that is designed directly from archivists’ requirements and is extensible for future needs.
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Mohammad Shahid, Zubair Ashraf, Mohd Shamim and Mohd Shamim Ansari
Optimum utilization of investments has always been considered one of the most crucial aspects of capital markets. Investment into various securities is the subject of portfolio…
Abstract
Purpose
Optimum utilization of investments has always been considered one of the most crucial aspects of capital markets. Investment into various securities is the subject of portfolio optimization intent to maximize return at minimum risk. In this series, a population-based evolutionary approach, stochastic fractal search (SFS), is derived from the natural growth phenomenon. This study aims to develop portfolio selection model using SFS approach to construct an efficient portfolio by optimizing the Sharpe ratio with risk budgeting constraints.
Design/methodology/approach
This paper proposes a constrained portfolio optimization model using the SFS approach with risk-budgeting constraints. SFS is an evolutionary method inspired by the natural growth process which has been modeled using the fractal theory. Experimental analysis has been conducted to determine the effectiveness of the proposed model by making comparisons with state-of-the-art from domain such as genetic algorithm, particle swarm optimization, simulated annealing and differential evolution. The real datasets of the Indian stock exchanges and datasets of global stock exchanges such as Nikkei 225, DAX 100, FTSE 100, Hang Seng31 and S&P 100 have been taken in the study.
Findings
The study confirms the better performance of the SFS model among its peers. Also, statistical analysis has been done using SPSS 20 to confirm the hypothesis developed in the experimental analysis.
Originality/value
In the recent past, researchers have already proposed a significant number of models to solve portfolio selection problems using the meta-heuristic approach. However, this is the first attempt to apply the SFS optimization approach to the problem.
Details
Keywords
Management, strategy, entrepreneurship.
Abstract
Subject area
Management, strategy, entrepreneurship.
Study level/applicability
MBA, executive education.
Case overview
The case deals with the challenges of fundraising and location decision making for a high technology start up company based in the United Arab Emirates. Tan Rasab is a Chief Executive and co-founder of Sensehere, a high technology start up company involved in the design and development of semiconductors for wireless sensors. The company has developed a unique technology that allows sensors to dramatically reduce energy consumption and thereby improve battery life of sensors.The company is currently based in the UAE, where it finds the environment highly supportive overall but challenging from the point of view of fund raising. On the other hand in China the company is meeting significant investor interest and several partnerships have been concluded. Despite the advantages offered by the UAE environment, the company is considering moving some or all of its operations to China.
Expected learning outcomes
Familiarise students with the challenges of fundraising for new ventures.
Understand the implications of technological breakthroughs in different application areas.
Develop an understanding for the different considerations to be made when choosing a location for business functions.
Familiarise students with the challenges of fundraising for new ventures.
Understand the implications of technological breakthroughs in different application areas.
Develop an understanding for the different considerations to be made when choosing a location for business functions.
Supplementary materials
Teaching notes.
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Keywords
Zi-qian Bai, Jeanne Tan, Clare Frances Johnston and Xiao-Ming Tao
The purpose of this paper is to investigate how electronic components can be utilized and integrated into polymeric optical fibre (POF) textiles to refine the design aesthetic…
Abstract
Purpose
The purpose of this paper is to investigate how electronic components can be utilized and integrated into polymeric optical fibre (POF) textiles to refine the design aesthetic, tactile quality and initiate the interaction of textiles with the users; and to study the design process of interactive products by using a novel design process model.
Design/methodology/approach
Fashion and textile design methods, textile technology are used in combination with modern technologies such as laser engraving, sensing, short-distance communication technology, throughout the entire process of development of interactive photonics creations.
Findings
The results of evaluation indicate that the engineered prototypes can enhance the interactive function of interior furnishing. The usability of interactive POF cushions is optimized by innovative design methods considering both design and technology.
Originality/value
This research explores to combine knowledge from different disciplines, including textile, electronics, sensor and laser to create interactive soft furnishings. The inter-disciplinary research provides a new perspective on how POF fabric can be utilized as a new media to change the way people interact with their living surroundings. The interior soft furnishings are no longer unresponsive to people, but can react to them, adapt to their behaviors, change color according to their preferences and therefore merge into our daily life. The developed prototypes reshape interior soft furnishing, and therefore have both theoretical and practical significance.
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Keywords
A. Augugliaro, L. Dusonchet, S. Favuzza, M.G. Ippolito and E. Riva Sanseverino
This paper proposes to identify a new model of the fixed voltage nodes (PV nodes) for medium voltage distribution systems analysis. The model is used within backward/forward (b/f…
Abstract
Purpose
This paper proposes to identify a new model of the fixed voltage nodes (PV nodes) for medium voltage distribution systems analysis. The model is used within backward/forward (b/f) analysis method applied to solve radial and weakly meshed systems.
Design/methodology/approach
The model is based on the compensation currents method for multi‐port systems which has been extensively used, within b/f analysis methods, to take into account the presence of meshes and PV nodes.
Findings
Test results prove the approach to be more efficient and precise than previous methodologies and put into evidence the good performance of the proposed model in terms of speed and convergence properties.
Research limitations/implications
The model is developed to be used within b/f methodology.
Practical implications
Utilities are quite interested in such items, since the deregulation electricity market in last years has determined an evolution of the medium voltage distribution networks, due to the presence of distributed generation. So it is necessary to take into account and to model in an opportune way the nodes with distributed generators (PV nodes), also in weakly meshed networks, for the load flow analysis.
Originality/value
The paper presents a new model to treat the fixed voltage nodes (PV nodes) for medium voltage distribution networks analysis.
Details
Keywords
Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community…
Abstract
Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.
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Keywords
Hongwei Li, Xiao Wang, Junmu Lin, Lei Wu and Tong Liu
This study aims to provide a solution of the power flow calculation for the low-voltage ditrect current power grid. The direct current (DC) power grid is becoming a reliable and…
Abstract
Purpose
This study aims to provide a solution of the power flow calculation for the low-voltage ditrect current power grid. The direct current (DC) power grid is becoming a reliable and economic alternative to millions of residential loads. The power flow (PF) in the DC network has some similarities with the alternative current case, but there are important differences that deserve to be further concerned. Moreover, the dispatchable distributed generators (DGs) in DC network can realize the flexible voltage control based on droop-control or virtual impedance-based methods. Thus, DC PF problems are still required to further study, such as hosting all load types and different DGs.
Design/methodology/approach
The DC power analysis was explored in this paper, and an improved Newton–Raphson based linear PF method has been proposed. Considering that constant impedance (CR), constant current (CI) and constant power (CP) (ZIP) loads can get close to the practical load level, ZIP load has been merged into the linear PF method. Moreover, DGs are much common and can be easily connected to the DC grid, so V nodes and the dispatchable DG units with droop control have been further taken into account in the proposed method.
Findings
The performance and advantages of the proposed method are investigated based on the results of the various test systems. The two existing linear models were used to compare with the proposed linear method. The numerical results demonstrate enough accuracy, strong robustness and high computational efficiency of the proposed linear method even in the heavily-loaded conditions and with 10 times the line resistances.
Originality/value
The conductance corresponding to each constant resistance load and the equivalent conductance for the dispatchable unit can be directly merged into the self-conductance (diagonal component) of the conductance matrix. The constant current loads and the injection powers from dispatchable DG units can be treated as the current sources in the proposed method. All of those make the PF model much clear and simple. It is capable of offering enough accuracy level, and it is suitable for applications in DC networks that require a large number of repeated PF calculations to optimize the energy flows under different scenarios.
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Keywords
Antonio Liotta, Daniël Geelen, Gert van Kempen and Frans van Hoogstraten
At present the energy generation and distribution landscape is changing rapidly. The energy grid is becoming increasingly smart, relying on an information network for the purposes…
Abstract
Purpose
At present the energy generation and distribution landscape is changing rapidly. The energy grid is becoming increasingly smart, relying on an information network for the purposes of monitoring and optimization. However, because of the particularly stringent regulatory and technical constraints posed by smart grids, it is not possible to use ordinary communication protocols. The purpose of this paper is to revisit such constraints, reviewing the various options available today to realize smart‐metering networks.
Design/methodology/approach
After describing the regulatory, technological and stakeholders' constraints, the authors provide a taxonomy of network technologies, discussing their suitability and weaknesses in the context of smart‐metering systems. The authors also give a snapshot of the current standardization panorama, identifying key differences among various geographical regions.
Findings
It is found that the field of smart‐metering networks still consists of a fragmented set of standards and solutions, leaving open a number of issues relating to the design and deployment of suitable systems.
Originality/value
This paper addresses the need to better understand state‐of‐the‐art and open issues in the fast‐evolving area of smart energy grids, with particular attention to the challenges faced by communication engineers.
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Keywords
Niels Koester, Oliver Koenig, Alexander Thaler and Oszkár Bíró
The Cauer ladder network (CLN) model order reduction (MOR) method is applied to an industrial inductor. This paper aims to to anaylse the influence of different meshes on the CLN…
Abstract
Purpose
The Cauer ladder network (CLN) model order reduction (MOR) method is applied to an industrial inductor. This paper aims to to anaylse the influence of different meshes on the CLN method and their parameters.
Design/methodology/approach
The industrial inductor is simulated with the CLN method for different meshes. Meshes considering skin effect are compared with equidistant meshes. The inductor is also simulated with the eddy current finite element method (ECFEM) for frequencies 1 kHz to 1 MHz. The solution of the CLN method is compared with the ECFEM solutions for the current density in the conductor and the total impedance.
Findings
The increase of resistance resulting from the skin effect can be modelled with the CLN method, using a uniform mesh with elements much larger than the skin depth. Meshes taking account of the skin depth are only needed if the electromagnetic fields have to be reconstructed. Additionally, the convergence of the impedance is used to define a stopping criterion without the need for a benchmark solution.
Originality/value
The work shows that the CLN method can generate a network, which is capable of mimicking the increase of resistance usually accompanied by the skin effect without using a mesh that takes the skin depth into account. In addition, the proposed stopping criterion makes it possible to use the CLN method as an a priori MOR technique.
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