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Article
Publication date: 21 February 2020

Payam Farhadi and Seyed Masoud Moghaddas Tafreshi

The use of power sectionalizers in electric power distribution networks as disconnecting devices for optimum network configuration is indispensable. Major reasons to use…

Abstract

Purpose

The use of power sectionalizers in electric power distribution networks as disconnecting devices for optimum network configuration is indispensable. Major reasons to use sectionalizers, here manual sectionalizers, is their lower installation and operating prices compared to other types of disconnecting devices and that most of conventional realistic electric power distribution systems are still using manual sectionalizers due to their ease of procurement. However, in case of failure for these switches, power supply interruptions are unavoidable unless optimum solutions are used for configuration (and possibly reconfiguration) of sectionalizers. Thus, in this research, binary exchange market algorithm (BEMA) as a novel evolutionary metaheuristic is used to meet the maximized customer satisfaction by optimized configuration of sectionalizers within electric power distribution networks in the presence of distributed generations (DGs). To solve the problem, BEMA is used on sectionalizing switch placement problem, which has only two open and close (0/1) states. A novel multi-objective optimization problem has been formulated as a function of two aspects, namely, improved reliability index (for customer benefit) and minimized sectionalizing switch costs (for utility benefits). Simulations are carried out in three different case studies to validate the effectiveness of the BEMA both in theory and practice: Standard IEEE 33-bus test system, practical feeder-8 of MeshkinShahr Town’s electric power distribution network in northwest of Iran; and Roy Billinton test system Bus 4 (RBTS-Bus 4). The obtained results are compared with those of the previously validated ant colony optimization (ACO) technique in RBTS-Bus 4.

Design/methodology/approach

The optimum configuration of sectionalizers in the presence of DGs has been formulated as a multi-objective function consisting of two conflicting objectives. First objective is to improve the power distribution network reliability indices. Second objective is to fulfill the first objective with a minimized sectionalizing switch cost. The latter is probably obtained by reducing the number of installed sectionalizers. The obtained results by BEMA have been compared with those of ACO technique.

Findings

In this paper, optimal configuration of sectionalizers has been performed based on a multiobjective function by binary exchange market algorithm. By simulations carried out on two standards and one practical test systems, the proposed algorithm effectiveness was confirmed and the obtained results were compared to ACO algorithm. Changing weighting factors shows that better satisfaction can be obtained when difference between the weighting factors is relatively greater. In other words, the reliability membership function is more than switch cost membership, and thus, if the values of two weighting factors are close enough, the satisfaction level reduces. The number of installed sectionalizing switches by BEMA and ACO techniques in different scenarios were performed.

Originality/value

Proposal of a novel multi-objective function for finding optimal location of sectionalizers in the presence of DGs with binary exchange market algorithm whose merit over the other heuristics is to consider all the problem specifications only in one multi-objective function. Despite previously reported works that have used various high-priced protective devices for achieving the enhanced reliability this research only utilizes inexpensive manual sectionalizers with the least possible cost in the presence of DGs. Two standard test cases IEEE 33-bus test system and RBTS-Bus 4 and one realistic test case feeder-8 of MeshkinShahr Town power distribution network in northwest of Iran are used to demonstrate the effectiveness of the proposed technique in theory and real-world applications. Thus, utilities may take the advantage of the proposed method for configuration of sectionalizers in their own local power distribution systems throughout the country.

Article
Publication date: 14 October 2019

Nasim Rezaeimanesh, Soodeh Razeghi Jahromi, Abdorreza Naser Moghadasi, Pegah Rafiee, Zeinab Ghorbani, Nahid Beladi Moghadam, Azita Hekmatdoost and Mohammad Ali Sahraian

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare disease with unknown risk factors. The role of oxidative stress and nutritional factors is imprecise in NMOSD development…

Abstract

Purpose

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare disease with unknown risk factors. The role of oxidative stress and nutritional factors is imprecise in NMOSD development. Therefore, this paper aims to evaluate the effects of dietary total antioxidant capacity (TAC) on the odds of NMOSD.

Design/methodology/approach

Dietary TAC was determined in 70 definite NMOSD cases and 164 healthy controls in term of Ferric Reducing Antioxidant Power (FRAP) method. A validated 168-item semi-quantitative food frequency questionnaire (FFQ) was used for dietary assessment. Three multivariate regression models were applied to analyze the odds of NMOSD across the TAC quartiles.

Findings

A significant inverse association was found between dietary TAC and odds of being assigned to the NMOSD group in all three regression models. In the fully adjusted model ORs (95% CI) in the second, third and fourth quartiles of TAC vs the first quartile were as follows: 0.11 (0.04-0.29), 0.05 (0.01-0.16) and 0.01 (0.00-0.05), respectively. Odds of NMOSD also indicated a significant decreasing trend across the quartiles of dietary TAC (p-trend: <0.01). Total energy (p < 0.01) as well as consumption of vegetables (p < 0.01), whole grains (p < 0.01), tea and coffee (p < 0.01), legumes (p < 0.01) and poultry (p < 0.01) significantly increased through the TAC quartiles.

Originality/value

In the present study, a new hypothesis was proposed concerning the influence of dietary TAC on the odds of NMOSD. A diet rich in foods with high TAC can be effective in the modification of the NMOSD odds.

Details

Nutrition & Food Science , vol. 50 no. 4
Type: Research Article
ISSN: 0034-6659

Keywords

Book part
Publication date: 17 September 2014

Christopher J. L. Cunningham

This chapter explores religion and spirituality as a form and source of demographic differences relevant to the study of occupational stress and well-being. The purpose of the…

Abstract

This chapter explores religion and spirituality as a form and source of demographic differences relevant to the study of occupational stress and well-being. The purpose of the chapter is to provide a resource and starting point to occupational health and stress researchers who may be interested in religion/spirituality. A review of critical religion/spirituality concepts is provided, along with a discussion of how religion/spirituality can be integrated into common occupational stress theories and reconciled with commonly studied variables within this domain. A series of future research directions involving religion/spirituality and occupational health and stress are ultimately presented.

Details

The Role of Demographics in Occupational Stress and Well Being
Type: Book
ISBN: 978-1-78350-646-0

Keywords

Book part
Publication date: 5 October 2018

Aminah Robinson Fayek and Rodolfo Lourenzutti

Construction is a highly dynamic environment with numerous interacting factors that affect construction processes and decisions. Uncertainty is inherent in most aspects of…

Abstract

Construction is a highly dynamic environment with numerous interacting factors that affect construction processes and decisions. Uncertainty is inherent in most aspects of construction engineering and management, and traditionally, it has been treated as a random phenomenon. However, there are many types of uncertainty that are not naturally modelled by probability theory, such as subjectivity, ambiguity and vagueness. Fuzzy logic provides an approach for handling such uncertainties. However, fuzzy logic alone has some limitations, including its inability to learn from data and its extensive reliance on expert knowledge. To address these limitations, fuzzy logic has been combined with other techniques to create fuzzy hybrid techniques, which have helped solve complex problems in construction. In this chapter, a background on fuzzy logic in the context of construction engineering and management applications is presented. The chapter provides an introduction to uncertainty in construction and illustrates how fuzzy logic can improve construction modelling and decision-making. The role of fuzzy logic in representing uncertainty is contrasted with that of probability theory. Introductory material is presented on key definitions, properties and methods of fuzzy logic, including the definition and representation of fuzzy sets and membership functions, basic operations on fuzzy sets, fuzzy relations and compositions, defuzzification methods, entropy for fuzzy sets, fuzzy numbers, methods for the specification of membership functions and fuzzy rule-based systems. Finally, a discussion on the need for fuzzy hybrid modelling in construction applications is presented, and future research directions are proposed.

Details

Fuzzy Hybrid Computing in Construction Engineering and Management
Type: Book
ISBN: 978-1-78743-868-2

Keywords

Article
Publication date: 11 January 2008

M. Gorji and N. Ghorbani

In recent years, hydraulic transfer in solid‐liquid flows has been paid considerable attention by many researchers. One of the most important parameters of this kind of flow is…

Abstract

Purpose

In recent years, hydraulic transfer in solid‐liquid flows has been paid considerable attention by many researchers. One of the most important parameters of this kind of flow is the pressure losses. This paper aims to focus on this aspect.

Design/methodology/approach

Two‐ and three‐layer models introduced by Doron are significantly capable of predicting the influences of slurry velocity on the pressure losses. In this research paper, using numerical methods, the related equations are solved for two‐ and three‐layer models and the influence of the slurry velocity on the pressure losses is studied.

Findings

The results show that, as long as there is a stable bed at the bottom of the pipe, the pressure losses are independent of the slurry velocity.

Originality/value

When the height of the stable bed becomes zero (when the stable bed disappears), the pressure losses increase considerably as the slurry velocity increases.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 18 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Book part
Publication date: 5 October 2018

Mohammad Raoufi, Nima Gerami Seresht, Nasir Bedewi Siraj and Aminah Robinson Fayek

Several different simulation techniques, such as discrete event simulation (DES), system dynamics (SD) and agent-based modelling (ABM), have been used to model complex…

Abstract

Several different simulation techniques, such as discrete event simulation (DES), system dynamics (SD) and agent-based modelling (ABM), have been used to model complex construction systems such as construction processes and project management practices; however, these techniques do not take into account the subjective uncertainties that exist in many construction systems. Integrating fuzzy logic with simulation techniques enhances the capabilities of those simulation techniques, and the resultant fuzzy simulation models are then capable of handling subjective uncertainties in complex construction systems. The objectives of this chapter are to show how to integrate fuzzy logic and simulation techniques in construction modelling and to provide methodologies for the development of fuzzy simulation models in construction. In this chapter, an overview of simulation techniques that are used in construction is presented. Next, the advancements that have been made by integrating fuzzy logic and simulation techniques are introduced. Methodologies for developing fuzzy simulation models are then proposed. Finally, the process of selecting a suitable simulation technique for each particular aspect of construction modelling is discussed.

Details

Fuzzy Hybrid Computing in Construction Engineering and Management
Type: Book
ISBN: 978-1-78743-868-2

Keywords

Article
Publication date: 4 March 2014

Masoud Karami, Omid Olfati and Alan J. Dubinsky

– The main purpose of this research was to investigate whether there is a relationship between religiosity and ethical behavior of salespeople.

1141

Abstract

Purpose

The main purpose of this research was to investigate whether there is a relationship between religiosity and ethical behavior of salespeople.

Design/methodology/approach

To investigate this association, structural equation modeling (SEM) was used; also, both exploratory and confirmatory factor analyses were undertaken to examine a scale measuring salespeople's ethical behaviors. The context in which the study was conducted was in Iranian retail specialty stores.

Findings

The results revealed for the first time the impact of religiosity on ethical behavior of the seller, a key entity in the buyer-seller dyad, that had been virtually ignored in extant empirical work.

Research limitations/implications

The study focused solely on retail salespeople in Iran. Future research should examine the religiosity-ethical behavior nexus using other kinds of sales personnel and those practicing other kinds of religion than the Shia Muslim faith investigated here. The investigation examined the association between religiosity and ethical behavior. Future work could include additional measures of religion (e.g. religious orientation) as well other individual, cultural, and organizational factors that may have an influence on salespeople's ethical conduct.

Practical implications

Sales managers should try to convince salespeople to behave ethically. Also, sales managers should not establish unachievable sales objectives for salespeople and try to employ more religious individuals as salespeople. Multinational corporations (MNCs) should treat Shia Muslim salespersons with the utmost of respect, relying on their word. Similarly, MNCs should incorporate ethical guidelines into their training classes in order to be able to communicate conveniently with local salespeople and persuade them to act more ethically.

Originality/value

The authors believe that this research can arouse managers in retail stores to set specific plans for evaluating their ethical behaviors. This research also has managerial and research implications for designing and formulating operations strategy in providing ethical standards for sales force.

Details

Journal of Islamic Marketing, vol. 5 no. 1
Type: Research Article
ISSN: 1759-0833

Keywords

Article
Publication date: 7 July 2020

Sakthivel V.P., Suman M. and Sathya P.D.

Economic load dispatch (ELD) is one of the crucial optimization problems in power system planning and operation. The ELD problem with valve point loading (VPL) and multi-fuel…

110

Abstract

Purpose

Economic load dispatch (ELD) is one of the crucial optimization problems in power system planning and operation. The ELD problem with valve point loading (VPL) and multi-fuel options (MFO) is defined as a non-smooth and non-convex optimization problem with equality and inequality constraints, which obliges an efficient heuristic strategy to be addressed. The purpose of this study is to present a new and powerful heuristic optimization technique (HOT) named as squirrel search algorithm (SSA) to solve non-convex ELD problems of large-scale power plants.

Design/methodology/approach

The suggested SSA approach is aimed to minimize the total fuel cost consumption of power plant considering their generation values as decision variables while satisfying the problem constraints. It confers a solution to the ELD issue by anchoring with foraging behavior of squirrels based on the dynamic jumping and gliding strategies. Furthermore, a heuristic approach and selection rules are used in SSA to handle the constraints appropriately.

Findings

Empirical results authenticate the superior performance of SSA technique by validating on four different large-scale systems. Comparing SSA with other HOTs, numerical results depict its proficiencies with high-qualitative solution and by its excellent computational efficiency to solve the ELD problems with non-smooth fuel cost function addressing the VPL and MFO. Moreover, the non-parametric tests prove the robustness and efficacy of the suggested SSA and demonstrate that it can be used as a competent optimizer for solving the real-world large-scale non-convex ELD problems.

Practical implications

This study has compared various HOTs to determine optimal generation scheduling for large-scale ELD problems. Consequently, its comparative analysis will be beneficial to power engineers for accurate generation planning.

Originality/value

To the best of the authors’ knowledge, this manuscript is the first research work of using SSA approach for solving ELD problems. Consequently, the solution to this problem configures the key contribution of this paper.

Book part
Publication date: 28 May 2019

Kadir Beycioglu and Mehmet Sincar

The role and effects of basic emotions in organisations have been an important issue of researchers. In this chapter, the authors aimed to see how school principals conceptualise…

Abstract

The role and effects of basic emotions in organisations have been an important issue of researchers. In this chapter, the authors aimed to see how school principals conceptualise the emotion of shame and to reveal the role of shame and its effects on the behaviours of school principals’ work in schools through data obtained from six principals working in state schools in Turkey. Results showed that principals conceptualise the feeling of shame in terms of moral base in the formation of interpersonal relations in school organisations. The study also showed that shame experienced by school principals has restorative effects on school leaders’ behaviours. The authors claimed that this effect of shame on school principals could be affected by the collectivist nature of the Turkish culture.

Details

Emotion Management and Feelings in Teaching and Educational Leadership
Type: Book
ISBN: 978-1-78756-011-6

Keywords

Article
Publication date: 24 April 2024

Haider Jouma, Muhamad Mansor, Muhamad Safwan Abd Rahman, Yong Jia Ying and Hazlie Mokhlis

This study aims to investigate the daily performance of the proposed microgrid (MG) that comprises photovoltaic, wind turbines and is connected to the main grid. The load demand…

Abstract

Purpose

This study aims to investigate the daily performance of the proposed microgrid (MG) that comprises photovoltaic, wind turbines and is connected to the main grid. The load demand is a residential area that includes 20 houses.

Design/methodology/approach

The daily operational strategy of the proposed MG allows to vend and procure utterly between the main grid and MG. The smart metre of every consumer provides the supplier with the daily consumption pattern which is amended by demand side management (DSM). The daily operational cost (DOC) CO2 emission and other measures are utilized to evaluate the system performance. A grey wolf optimizer was employed to minimize DOC including the cost of procuring energy from the main grid, the emission cost and the revenue of sold energy to the main grid.

Findings

The obtained results of winter and summer days revealed that DSM significantly improved the system performance from the economic and environmental perspectives. With DSM, DOC on winter day was −26.93 ($/kWh) and on summer day, DOC was 10.59 ($/kWh). While without considering DSM, DOC on winter day was −25.42 ($/kWh) and on summer day DOC was 14.95 ($/kWh).

Originality/value

As opposed to previous research that predominantly addressed the long-term operation, the value of the proposed research is to investigate the short-term operation (24-hour) of MG that copes with vital contingencies associated with selling and procuring energy with the main grid considering the environmental cost. Outstandingly, the proposed research engaged the consumers by smart meters to apply demand-sideDSM, while the previous studies largely focused on supply side management.

Details

Smart and Sustainable Built Environment, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2046-6099

Keywords

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