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Article
Publication date: 1 December 2017

Qiushi Hao, Benchen Fu, Yu Shao and Liying Wang

This study aims to explore the spatial distribution characteristics and spactial reciprocity between industrial parks (IPs) and vocational education parks (VEPs)…

Abstract

This study aims to explore the spatial distribution characteristics and spactial reciprocity between industrial parks (IPs) and vocational education parks (VEPs): agglomeration density, functional matching, spatial organization efficiency, as well as space intensive utility. To achieve this objective, IPs and VEPs in urban centers of Jiangsu Province are selected as the objects of the study. First, spatial analysis of thermodynamic diagrams is employed in this study to qualitatively analyze the evolutionary characteristics of the spatial distribution of IPs and VEPs to explore the spatial aggregation characteristics of their clustering, integration, and comprehensive crossover. Second, a horizontal comparison of the data and indexes concerned reveals that areas with high agglomeration and functional matching exhibit a sound spatial reciprocity. Third, this study crystallizes the four structural prototpye paradigms formed during the reciprocity evolution between IPs and VEPs; it compares spatial organization efficiency, with the agglomeration–core structure ranking first, followed by the circle–core structure. Finally, SPSS is used to analyze the space intensive utility in order to verify the conclusions of qualitative analysis. The findings can comprehensively explain the regularities of the spatial distribution and reciprocity between IPs and VEPs. The findngs can also elucidate the design of regional industrial development and educational programs.

Details

Open House International, vol. 42 no. 4
Type: Research Article
ISSN: 0168-2601

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Article
Publication date: 1 March 2017

Cheng Sun, Meng Zhen and Yu Shao

Rural residential energy consumption accounts for 46.6% of total building-related energy consumption of China. In Northeast China, energy consumption for space heating…

Abstract

Rural residential energy consumption accounts for 46.6% of total building-related energy consumption of China. In Northeast China, energy consumption for space heating represents a significant proportion of total rural residential energy consumption and has reached 100 million tce (tons of standard coal equivalent), or more than 60% of total household energy consumption. In terms of energy consumption per square meter of gross floor area, rural residential energy consumption for heating is more than that of cities (20kgce/m2). However, the average indoor temperature of most rural residence is below 10°C, much less than that in cities (18°C). Hence, it is an important task for Chinese energy saving and emission reduction to reduce rural residential energy consumption, while enhancing indoor thermal comfort at the same time.

Restricted by local technology and low economic level, rural residences currently have poor thermal insulation resulting in severe heat loss. This paper reports on research aimed at developing design strategies for improving thermal insulation properties of rural residences with appropriate technology. A field survey was conducted in six counties in severe cold areas of Northeast China, addressing the aspects of indoor and outdoor temperature, humidity, internal and external surface temperature of building envelop enclosure, and so on.

The survey data show the following:

1. Modern (after 2000) brick-cement rural residences perform much better than the traditional adobe clay houses and Tatou houses (a regional type of rural residence in Northeast China – see figure A) in overall thermal performance and indoor thermal comfort;

2. Among the traditional residential house types, adobe clay houses have better heat stability and thermal storage capacity than Tatou houses;

3. Applying an internal or external thermal insulation layer can greatly improve rural residential thermal insulation properties, and is an economical and efficient solution in rural areas;

4. In terms of roofing materials, tiled roofs show much better thermal insulation properties than thatch roofs;

5. Adopting passive solar techniques can form a transition space (greenhouse) against frigid temperatures, resulting in interior temperatures 5.91°C higher than the outside surroundings. It is evident that local passive solar room design offers significant heat preservation effects and lower cost ($12/m2), embodies the ecological wisdom of rural residents, and is therefore important to popularize.

The above experimental results can provide guidance in energy conservation design for both self-built residences and rural residences designed by architects. In addition, the results can also provide experimental data for energy-saving studies for rural residences in China.

Details

Open House International, vol. 42 no. 1
Type: Research Article
ISSN: 0168-2601

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Article
Publication date: 8 December 2020

Yu-Ming Chung, Shao-Yu Lee, Yung-Kai Lin, Yung-Hao Lin, Mohamed El-Shazly, Yung-Hsiang Lin and Chi-Fu Chiang

Rambutan (Nephelium lappaceum), a ubiquitous fruit in Southeastern Asia, was rich in vitamins and phytochemicals, which were beneficial for improving of skin conditions…

Abstract

Purpose

Rambutan (Nephelium lappaceum), a ubiquitous fruit in Southeastern Asia, was rich in vitamins and phytochemicals, which were beneficial for improving of skin conditions. The fermentation process increased phytochemicals and antioxidant capacity. Thus, the purpose of this paper is to examine whether phytochemicals can be increased through the fermentation process of rambutan extracts to improve skin aging.

Design/methodology/approach

In this study, the authors used the three stages of fermentation with Saccharomyces cerevisiae, Lactobacillus plantarum TCI028 and Acetobacter aceti under red light to develop a fermented rambutan extract.

Findings

The level of polyphenols of red-light-based fermented rambutan extract (RLFRE) were significantly increased 108.9% (p < 0.01) and 97% (p <0.01) compared with fermented rambutan extract (FRE) and pure rambutan extract (RE), respectively. The human skin fibroblasts treated with 0.03 or 0.06% of RLFRE can significantly decrease reactive oxygen species (ROS) levels by 0.74- (p <0.001) and 0.84-fold (p <0.001) compared with H2O2 group, respectively. And 0.03% of RLFRE can significantly increase in elastin content by 1.13-fold (p <0.05). Also, ten compounds were identified including one new phenolic compound and nine known compounds from RLFRE. Moreover, red light could enhance the levels of compounds 4, 9 and 3 by 5, 2.5 and 2.5-fold, respectively, relative to the results of FRE. The last, RLFRE isolated compounds significantly facilitated the elastin content on fibroblast (compound 1, 7, 9, 10 compared with control: p <0.001, compound 2 compared with control: p <0.001).

Originality/value

In short, this was the first study to unveil that the red-light-based fermentation can enrich the antioxidant content in a rambutan extract and its product had the potential to be developed a functional product for health-promoting effects such as skin aging.

Details

Nutrition & Food Science , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 30 October 2018

Yanqin Zhang, Zhiquan Zhang, Xiangbin Kong, Rui Li and Hui Jiang

The purpose of this paper was to obtain the lubrication characteristics of heavy hydrostatic bearing in heavy equipment manufacturing industry through theoretical analysis…

Abstract

Purpose

The purpose of this paper was to obtain the lubrication characteristics of heavy hydrostatic bearing in heavy equipment manufacturing industry through theoretical analysis and numerical simulation.

Design/methodology/approach

This paper discusses the influence of oil film thickness variation on velocity field, outlet-L and outlet-R flow velocity under the hydrostatic bearing running in no-load 0 N, load 400 KN, full load 1,500 KN and rotating speeds of 10 r/min, 20 r/min, 30 r/min, 40 r/min, 50 r/min and 60 r/min, by using dynamic mesh technology and FLUENT software.

Findings

When the working table rotates clockwise, in the change process of oil film thickness, the fluid flow pattern of the lubricating oil at the edge of the sealing oil is the rule of laminar flow, and the oil cavity has a vortex. The outlet-R flow velocity becomes higher and higher by increasing the bearing load and working table speed, and the flow velocity increases with the decrease in oil film thickness; the outlet-L flow velocity increases with the decrease in oil film thickness under low rotating speed (less than 10 r/min) condition and decreases with the decrease of oil film thickness under high rotating speed (more than 60 r/min) condition.

Originality/value

The influence of the oil film thickness on the flow state distribution of the oil film was analyzed under different working conditions, and the influence rules of oil film thickness on the flow velocity of hydrostatic bearing oil pad was obtained by using dynamic mesh technology.

Details

Industrial Lubrication and Tribology, vol. 71 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 11 October 2019

Chunxia Yu, Zhiqin Zou, Yifan Shao and Fengli Zhang

The purpose of this paper is to develop a novel integrated supplier selection approach incorporating decision maker’s risk attitude using the artificial neural network…

Abstract

Purpose

The purpose of this paper is to develop a novel integrated supplier selection approach incorporating decision maker’s risk attitude using the artificial neural network (ANN), analytic hierarchy process (AHP) and technique for order of preference by similarity to ideal solution (TOPSIS) methods.

Design/methodology/approach

In the proposed approach, the ANN model is used to classify decision maker’s risk attitude; the fuzzy AHP method is used to determine the relative weights of evaluation criteria; and the fuzzy TOPSIS method is used to evaluate ratings of suppliers. Finally, experiments are conducted to verify the feasibility and efficiency of the proposed integrated approach.

Findings

Experiments results show that the proposed integrated approach is effective and efficient to help decision makers to select suitable suppliers according to their risk attitudes.

Originality/value

The aim of this paper is to develop a novel integrated supplier selection approach incorporating decision maker’s risk attitude using the ANN, AHP and TOPSIS methods. The decision maker’s risk attitude toward procurement transaction is originally considered in supplier selection process.

Details

Kybernetes, vol. 49 no. 9
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 13 November 2017

Changjin Xu and Peiluan Li

The purpose of this paper is to study the existence and exponential stability of anti-periodic solutions of a class of shunting inhibitory cellular neural networks…

Abstract

Purpose

The purpose of this paper is to study the existence and exponential stability of anti-periodic solutions of a class of shunting inhibitory cellular neural networks (SICNNs) with time-varying delays and continuously distributed delays.

Design/methodology/approach

The inequality technique and Lyapunov functional method are applied.

Findings

Sufficient conditions are obtained to ensure that all solutions of the networks converge exponentially to the anti-periodic solution, which are new and complement previously known results.

Originality/value

There are few papers that deal with the anti-periodic solutions of delayed SICNNs with the form negative feedback – aij(t)αij(xij(t)).

Details

International Journal of Intelligent Computing and Cybernetics, vol. 10 no. 4
Type: Research Article
ISSN: 1756-378X

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Article
Publication date: 18 June 2019

Jing Liu, Linfeng Wang, Zhifeng Shi, Wennian Yu and Huifang Xiao

The purpose of this study is to investigate the contact models for contact and vibration features of cylindrical roller bearings (CRBs). CRBs are important parts of…

Abstract

Purpose

The purpose of this study is to investigate the contact models for contact and vibration features of cylindrical roller bearings (CRBs). CRBs are important parts of rotating machinery. The contact deformation between the roller and the raceway is an essential research topic for the CRBs. The contact deformation between the roller and the raceway can greatly affect vibration characteristics and fatigue life of the CRBs. In this investigation, six different methods are adopted to calculate the contact deformation, contact area width and contact stress between the roller and raceways of a CRB.

Design/methodology/approach

In this paper, the contact deformations and the contact stiffnesses between the roller and the raceway of a CRB obtained by various well-known empirical methods (Lundberg’s, Palmgren’s, Houpert’s, Cheng’s and Hertzian methods) are directly compared with those by the finite element (FE) method. A two degree-of-freedom (2 DOF) dynamic model of the CRB is applied to investigate the effects of the contact stiffness obtained by different line contact deformation calculation methods on the vibration characteristics, such as the root mean square (RMS), the peak to peak (PTP), the crest factor and the kurtosis of the displacement, velocity and acceleration of the inner raceway.

Findings

The computational results show that different calculation methods for the contact deformations between rollers and raceways have significant effects on the vibrations of the CRB. It is found that that the differences of computational results obtained by Palmgren’s and Lundberg’s models with respect to the FE method are smaller than those by the other three methods, i.e. Houpert’s, Cheng’s and Hertzain models. The amplitude and peak frequency of the frequency response functions from Palmgren’s method are much more similar to those from the finite element method. The above results indicate that Palmgren’s method is a better calculation method for predicting the contact deformations and dynamics of the CRBs.

Originality/value

This work adopts six different methods to calculate the contact deformation, contact area width and contact stress between the roller and raceways of a CRB. Moreover, a vibration model of a CRB is used to investigate the effect of contact stiffness obtained by the above methods on the vibrations of the CRB. The works can give some guidance for the accurate analytical method for calculating the contact deformations between rollers and raceways and the vibrations of the CRB.

Details

Engineering Computations, vol. 36 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 6 June 2016

Jhony Choon Yeong Ng, Iris Yu Ting Shao and Yiping Liu

Many fresh graduates have unrealistic career expectations. When reality sets in after graduation, they may be disappointed. Due to factors such as the limited availability…

Abstract

Purpose

Many fresh graduates have unrealistic career expectations. When reality sets in after graduation, they may be disappointed. Due to factors such as the limited availability of feasible alternative career options, employees who have to stay in jobs they dislike may feel trapped. To alleviate the resulting stresses, they may engage in avoidance coping strategies, such as non-work-related social media use, to discharge their mental strains. The purpose of this paper is to discuss how the perception of being trapped can result in the adoption of avoidance coping strategies, and how these strategies can influence individual performance and social media use.

Design/methodology/approach

Based on the literature on avoidance coping strategy, goal orientation theory, and performance theory, the authors proposed a theoretical model on how the avoidance coping strategy of an individual can influence their performance and workplace behavior.

Findings

The authors propose that when a fresh graduate feels “trapped” in a job, the stresses experienced may cause them to hide behind their defense mechanisms. An avoidance coping strategy may then be adopted, and this will influence the individual’s workplace behavior (in terms of non-work-related use of social media) and performance.

Practical implications

If an avoidance coping strategy is an antecedent to non-work-related use of social media, then controlling the use of social media in the workplace may only cause these employees to switch to other forms of self-distraction (for instance, spending more time chatting with colleagues). Under some circumstances, the use of such control mechanisms may even give cyberloafers stronger urges to use social media for non-work-related purposes. If this is the case, managers should reconsider their current approach in handling the related behavior.

Social implications

If the cause of non-work-related use of social media in the workplace is an avoidance coping strategy, then the engagement of such workplace behaviors should not be considered “intentionally harmful actions”. One important criterion for workplace behavior to qualify as a type of counterproductive behavior is that such behavior must be conducted to be intentionally harmful. Given this, the resulting actions of an avoidance coping strategy should not be considered a form of counterproductive behavior, and the authors should reconsider the conceptualization of cyberloafing provided in the organizational literature.

Originality/value

The authors believe that this research represents one of the first attempts to bridge the gap between clinical and managerial literature. It attempts to explain non-work-related use of social media in the workplace from the perspective of trapped perception and avoidance coping strategy, and it argues that not all forms of non-work-related use of social media in the workplace are instances of cyberloafing.

Details

Employee Relations, vol. 38 no. 4
Type: Research Article
ISSN: 0142-5455

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Article
Publication date: 6 July 2021

Yunlong Li, Zhinong Li, Dong Wang and Zhike Peng

The purpose of this paper is to discuss the asymptotic models of different parts with a pitting fault in rolling bearings.

Abstract

Purpose

The purpose of this paper is to discuss the asymptotic models of different parts with a pitting fault in rolling bearings.

Design/methodology/approach

For rolling bearings with a pitting fault, the displacement deviation between raceways and rolling elements is usually considered to vary instantaneously. However, the deviation should change gradually. Based on this shortcoming, the variation rule and calculation method of the displacement deviation are explored. Asymptotic models of different parts with a pitting fault are discussed, respectively. Besides, rolling bearing systems have prominent fractional characteristics unconsidered in the traditional models. Therefore, fractional calculus is introduced into the modeling of rolling bearings. New dynamic asymptotic models of different parts with a pitting fault are proposed based on fractional damping. The numerical simulation is performed based on the proposed model, and the dynamic characteristics are analyzed through the bifurcation diagrams, trajectory diagrams and frequency spectrograms.

Findings

Compared with the model based on integral calculus, the proposed model can better reflect the periodic characteristics and fault characteristics of rolling bearings. Finally, the proposed model is verified by the experiment. The dynamic characteristics of rolling bearings at different rotating speeds are analyzed. The experimental results are consistent with the simulation results. Therefore, the proposed model is effective.

Originality/value

(1) The above models are idealized, i.e. the local pitting fault is treated as a rectangle. When a component comes into contact with the fault, the displacement deviation between the component and the fault component immediately releases if the component enters the fault area and restores if the component leaves. However, the displacement deviation should change gradually. Only when the component touches the fault bottom, the displacement deviation reaches the maximum. (2) Due to the material's memory and fluid viscoelasticity, rolling bearing systems exhibit significant fractional characteristics. However, the above models are all proposed based on integral calculus. Integral calculus has some local characteristics and is not suitable for describing historical dependent processes. Fractional calculus can better describe the essential characteristics of the system.

Details

Engineering Computations, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 9 November 2010

Lindsay A. Lechner and Timothy C. Ovaert

The last few years in the financial markets have shown great instability and high volatility. In order to capture the amount of risk a financial firm takes on in a single…

Abstract

Purpose

The last few years in the financial markets have shown great instability and high volatility. In order to capture the amount of risk a financial firm takes on in a single trading day, risk managers use a technology known as value‐at‐risk (VaR). There are many methodologies available to calculate VaR, and each has its limitations. Many past methods have included a normality assumption, which can often produce misleading figures as most financial returns are characterized by skewness (asymmetry) and leptokurtosis (fat‐tails). The purpose of this paper is to provide an overview of VaR and describe some of the most recent computational approaches.

Design/methodology/approach

This paper compares the Student‐t, autoregressive conditional heteroskedastic (ARCH) family of models, and extreme value theory (EVT) as a means of capturing the fat‐tailed nature of a returns distribution.

Findings

Recent research has utilized the third and fourth moments to estimate the shape index parameter of the tail. Other approaches, such as extreme value theory, focus on the extreme values to calculate the tail ends of a distribution. By highlighting benefits and limitations of the Student‐t, autoregressive conditional heteroskedastic (ARCH) family of models, and the extreme value theory, one can see that there is no one particular model that is best for computing VaR (although all of the models have proven to capture the fat‐tailed nature better than a normal distribution).

Originality/value

This paper details the basic advantages, disadvantages, and mathematics of current parametric methodologies used to assess value‐at‐risk (VaR), since accurate VaR measures reduce a firm's capital requirement and reassure creditors and investors of the firm's risk level.

Details

The Journal of Risk Finance, vol. 11 no. 5
Type: Research Article
ISSN: 1526-5943

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