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1 – 10 of over 26000Abeer A. Zaki, Nesma A. Saleh and Mahmoud A. Mahmoud
This study aims to assess the effect of updating the Phase I data – to enhance the parameters' estimates – on the control charts' detection power designed to monitor social…
Abstract
Purpose
This study aims to assess the effect of updating the Phase I data – to enhance the parameters' estimates – on the control charts' detection power designed to monitor social networks.
Design/methodology/approach
A dynamic version of the degree corrected stochastic block model (DCSBM) is used to model the network. Both the Shewhart and exponentially weighted moving average (EWMA) control charts are used to monitor the model parameters. A performance comparison is conducted for each chart when designed using both fixed and moving windows of networks.
Findings
Our results show that continuously updating the parameters' estimates during the monitoring phase delays the Shewhart chart's detection of networks' anomalies; as compared to the fixed window approach. While the EWMA chart performance is either indifferent or worse, based on the updating technique, as compared to the fixed window approach. Generally, the EWMA chart performs uniformly better than the Shewhart chart for all shift sizes. We recommend the use of the EWMA chart when monitoring networks modeled with the DCSBM, with sufficiently small to moderate fixed window size to estimate the unknown model parameters.
Originality/value
This study shows that the excessive recommendations in literature regarding the continuous updating of Phase I data during the monitoring phase to enhance the control chart performance cannot generally be extended to social network monitoring; especially when using the DCSBM. That is to say, the effect of continuously updating the parameters' estimates highly depends on the nature of the process being monitored.
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Francesco De Luca, Hendrik Voll and Martin Thalfeldt
Exterior shading devices and dynamic shading systems constitute an efficient way to improve energy efficiency and occupants’ comfort in buildings through the reduction of direct…
Abstract
Purpose
Exterior shading devices and dynamic shading systems constitute an efficient way to improve energy efficiency and occupants’ comfort in buildings through the reduction of direct solar heat gains and disturbing glare. The purpose of this paper is to analyse the performance of different types of shading systems, fixed and dynamic, and their influence on the energy consumption and cooling loads for an office building located in Tallinn, Estonia. The scope is to determine the most performative configuration for energy consumption and cooling load reduction for office buildings and to provide designers and developers with the necessary knowledge to increase the performance of their buildings.
Design/methodology/approach
There are many types of fixed shading devices, most of which use rectangular planar elements, the orientation and layout of which depends on the building location and façade orientation. The dynamic shading systems vary on the base of the building occupancy schedules and occupants’ preferences. The paper presents a method to determine the most efficient type and size of fixed shading devices in relation to different windows’ size and orientation, and the quantity of windows panes. At the same time the dynamic shading system using a control algorithm developed by the authors is compared.
Findings
The results show that solar shading is an efficient way to control the energy consumption of office buildings, though with different efficacy by the static systems depending on orientation, window and shading type. Evidence shows that dynamic blind systems have more uniform performance and usually outperform static shading.
Originality/value
The paper compares the performances of different static and dynamic shading devices and systems for the location in Tallinn. The dynamic shading system tested uses a control algorithm developed by the authors. The indications for the energy reduction and cooling loads are a valuable resource for designers and developers to increase the energy efficiency of their buildings.
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Verklar is the leading maker of roof windows based in Europe. Its Austrian subsidiary has historically dominated the Austrian market, with about 85% market share. However, at the…
Abstract
Verklar is the leading maker of roof windows based in Europe. Its Austrian subsidiary has historically dominated the Austrian market, with about 85% market share. However, at the time of the case, its market share has dropped to about 75%, and many of its dealers have either dropped the line entirely or are buying not from the company, but from the few remaining large dealers who still buy directly from Verklar. This has prompted the president of the subsidiary to devise a new way—called the Quota System—to run the distribution channel in the country to improve performance. Asks the reader to examine the sources of market share decline and whether the proposed Quota System solves the channel's problems.
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Ahmed Hammad, Ali Akbarnezhad, Hanna Grzybowska, Peng Wu and Xiangyu Wang
The Middle East and North Africa (MENA) region is known for its extreme weather conditions during Summer. A major determinant of the sustainability of the design of a building is…
Abstract
Purpose
The Middle East and North Africa (MENA) region is known for its extreme weather conditions during Summer. A major determinant of the sustainability of the design of a building is its fenestrations. The purpose of this paper is to explore the problem of designing and locating windows on building facades such that a number of relevant criteria to the MENA region are optimised, including solar heat gain, privacy, daylighting and cost of installation.
Design/methodology/approach
A multi-objective optimisation problem is proposed with the focus on capturing the requirements of residential dwellings in the MENA region. Since the problem contains conflicting objectives that need to be optimised, a lexicographic approach is adopted. In order to display the Pareto curve, a bi-objective analysis based on the ε-constraint method is utilised.
Findings
The conflicting nature of the proposed problem is indicated via the Pareto optimal solutions yielded. Depending on the preference of criteria adopted in lexicographic optimisation, the location of the windows on the building façade tends to change. The bi-objective analysis indicates the importance of balancing out the daylight factor against each of privacy, solar heat gain and installation cost criteria. Furthermore, an analysis conducted in three major cities in the MENA region highlights the discrepancy in design alternatives generated depending on the local climatic condition.
Originality/value
This work proposes a novel mathematical optimisation model which focuses on producing a sustainable design and layout for windows on the facades of residential dwellings located in the MENA region. The proposed model provides designers with guidance through an automated support tool that yields optimised window designs and layout to ensure the sustainability of their designed buildings.
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Yicun Li, Yuanyang Teng, Dong Wu and Xiaobo Wu
To answer the questions: what roles windows of opportunity act in the catchup process of latecomers, what strategies latecomer enterprises should adopt to size windows of…
Abstract
Purpose
To answer the questions: what roles windows of opportunity act in the catchup process of latecomers, what strategies latecomer enterprises should adopt to size windows of opportunity to catch-up with incumbents even going beyond?
Design/methodology/approach
This paper studies the catch-up history of the Chinese mobile phone industry and proposes a sectoral innovation system under scenario of technology paradigm shifts. Then a history-friendly simulation model and counterfactual analysis are conducted to learn how different windows of opportunity and catch-up strategies influence the catch-up performance of latecomers.
Findings
Results show latecomers can catch up with technology ability by utilizing technology window and path-creating strategy. However, catching up with the market is not guaranteed. Demand window can help latecomers to catch up with market as it increases their survival rates, different sized windows benefit different strategies. However, it also enlarges incumbents' scale effect. Without technology window technology catch up is not guaranteed. Two windows have combination effects. Demand window affects the “degree” of change in survival rates, while the technology window affects the “speed” of change. Demand window provides security; technology window provides the possibility of a breakthrough for technology ability.
Practical implications
The findings of this paper provide theoretical guidance for latecomer enterprises to choose appropriate catch-up strategies to seize different opportunity windows.
Originality/value
This paper emphasizes the abrupt change of industrial innovation system caused by technology paradigm shifts, which makes up for the shortcomings of previous researches on industrial innovation system which either studied the influence of static factors or based on the influence of continuous changes.
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Pinsheng Duan, Jianliang Zhou and Shiwei Tao
The outbreak of the pandemic makes it more difficult to manage the safety or health of construction workers in infrastructure construction. Risk events in construction workers'…
Abstract
Purpose
The outbreak of the pandemic makes it more difficult to manage the safety or health of construction workers in infrastructure construction. Risk events in construction workers' material handling tasks are highly relevant to workers' work-related musculoskeletal disorders. However, there are still many problems to be resolved in recognizing risk events accurately. The purpose of this research is to propose an automatic and non-invasive recognition method for construction workers in material handling tasks during the pandemic based on smartphone and machine learning.
Design/methodology/approach
This research proposes a method to recognize and classify four different risk events by collecting specific acceleration and angular velocity patterns through built-in sensors of smartphones. The events were simulated with anterior handling and shoulder handling methods in the laboratory. After data segmentation and feature extraction, five different machine learning methods are used to recognize risk events and the classification performances are compared.
Findings
The classification result of the shoulder handling method was slightly better than the anterior handling method. By comparing the accuracy of five different classifiers, cross-validation results showed that the classification accuracy of the random forest algorithm was the highest (76.71% in anterior handling method and 80.13% in shoulder handling method) when the window size was 0.64 s.
Originality/value
Less attention has been paid to the risk events in workers' material handling tasks in previous studies, and most events are recorded by manual observation methods. This study provided a simple and objective way to judge the risk events in manual material handling tasks of construction workers based on smartphones, which can be used as a non-invasive way for managers to improve health and labor productivity during the pandemic.
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The purpose of this research is to investigate natural illumination properties of one of the classrooms in the School of Architecture at Izmir Institute of Technology, located in…
Abstract
Purpose
The purpose of this research is to investigate natural illumination properties of one of the classrooms in the School of Architecture at Izmir Institute of Technology, located in Turkey, which is the northern hemisphere.
Design/methodology/approach
In this study, the definitions of the basic terms in daylighting, such as daylight factor, illuminance, glazing ratio, are given first. Then, a luxmeter and a lighting simulation software, Velux, are used in order to calculate variable lighting factors during daytime, at different storeys, at different directions, for the classes. Velux is a proprietary software and it enables natural lighting analysis practically.
Findings
Chosen classrooms are examined regarding their having sufficient natural illumination. The height of windows from the floor is changed, and the resultant effects on natural lighting in the classrooms are determined by using the lighting simulation program, Velux. The study shows that daylight factor and illumination near the window decreases as the height of the window above the floor increases. However, the illumination increases away from the window, giving greater uniformity to the lighting. At the same time, the usable depth of the classroom increases. The tall and narrow windows bring the daylight near themselves.
Social implications
Practical window design decisions can help architects to provide effective and healthy natural lighting for interiors.
Originality/value
Adjustment of the dimensions of the windows is important in order to balance the energy consumption of buildings. This study investigates natural lighting depending on both experimental measurements and simulation software, Velux.
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S.S.Y. Lau, Fuk Ming Li, D.K.C. Leung, Grace W.K. Tang, Baharuddin, A.L. Ye, K.W. Chau and S.K. Wong
The purpose of this paper is to discuss the significance and relevance of social and habitual behaviours of home occupants to the building design process. It argues that…
Abstract
Purpose
The purpose of this paper is to discuss the significance and relevance of social and habitual behaviours of home occupants to the building design process. It argues that introducing quantitative measures such as daylight level alone may not result in a “healthy and functional” kitchen without appreciating or factoring‐in the impacts of the social roles and user expectations of kitchens in high‐rise and compact urban situations.
Design/methodology/approach
The study investigated three common types of apartment buildings in Hong Kong. Case studies suggested that it is crucial to include in a design process proper considerations of human behaviours by way of preferred approaches and modes of living, space usage, and weightings of end‐user responses that would influence architectural design in a direct and crucial way.
Findings
The study noted that daylight quality of a kitchen is perceived by most families to be not as important as building control officials and designers thought it would. Instead, it is found that social and cultural factors are more important parameters for users. The study observed that designers rely on physical and quantitative approaches such as daylight factor, window size and window‐to‐room area ratio to qualify a design solution and ignore the socio‐cultural parameters.
Originality/value
The paper calls for designers and building control officials to incorporate the study of functionality and socio‐cultural preferences of users groups in the building design process. The study envisages that an integrated design methodology would enhance the living environment.
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Nazanin Eisazadeh, Frank De Troyer and Karen Allacker
The aim is to holistically assess the environmental performance of windows and analyse how their design and characteristics contribute to the overall performance of the…
Abstract
Purpose
The aim is to holistically assess the environmental performance of windows and analyse how their design and characteristics contribute to the overall performance of the building/space. This study focuses on the performance of windows in patient rooms hosting less mobile people.
Design/methodology/approach
This study investigates the life cycle environmental impacts of different glazing types, window frames and fire safety doors at the product level. This article also presents a building-integrated environmental analysis of patient rooms that considers the multiple functionalities of windows by incorporating dynamic energy analysis, comfort and daylighting performance with a life cycle assessment (LCA) study.
Findings
The results indicate that the amount of flat glass is the main contributor to the environmental impacts of the glazing units. As for the patient rooms, global warming shows the most significant contribution to the environmental costs, followed by human toxicity, particulate matter formation and eutrophication. The key drivers for these impacts are production processes and operational energy use. This study highlights the significance of evaluating a wide range of criteria for assessing the performance of windows.
Originality/value
An integrated assessment approach is used to investigate the influence of windows on environmental performance by considering the link between window/design parameters and their effects on energy use/costs, daylighting, comfort and environmental impacts. The embodied impacts of different building elements and the influence of various design parameters on environmental performance are assessed and compared. The environmental costs are expressed as an external environmental cost (euro).
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Ali Selamat and Choon‐Ching Ng
With the rapid emergence and explosion of the internet and the trend of globalization, a tremendous number of textual documents written in different languages are electronically…
Abstract
Purpose
With the rapid emergence and explosion of the internet and the trend of globalization, a tremendous number of textual documents written in different languages are electronically accessible online from the world wide web. Efficiently and effectively managing these documents written in different languages is important to organizations and individuals. Therefore, the purpose of this paper is to propose letter frequency neural networks to enhance the performance of language identification.
Design/methodology/approach
Initially, the paper analyzes the feasibility of using a windowing algorithm in order to find the best method in selecting the features of Arabic script documents language identification using backpropagation neural networks. Previously, it had been found that the sliding window and non‐sliding window algorithm used as feature selection methods in the experiments did not yield a good result. Therefore, this paper proposes, a language identification of Arabic script documents based on letter frequency using a backpropagation neural network and used the datasets belonging to Arabic, Persian, Urdu and Pashto language documents which are all Arabic script languages.
Findings
The experiments have shown that the average root mean squared error of Arabic script document language identification based on letter frequency feature selection algorithm is lower than the windowing algorithm.
Originality/value
This paper highlights the fact that using neural networks with proper feature selection methods will increase the performance of language identification.
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