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Article
Publication date: 5 May 2021

Shailaja Sanjay Mohite and Uttam D. Kolekar

Femtocells are low-power, inexpensive base stations (BS) used in business enterprises or homes. They could offer higher SNR in a smaller coverage area to enhance the data rates…

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Abstract

Purpose

Femtocells are low-power, inexpensive base stations (BS) used in business enterprises or homes. They could offer higher SNR in a smaller coverage area to enhance the data rates and QoS. Deployment of femtocell is expected to the witness constant development in upcoming years. Despite of all these benefits, there are certain challenges to be resolved that includes management of overlaying MC, interference among femtocells and the resource allocation between 2 tiers.

Design/methodology/approach

This work analyses the issues on cross-tier interfering and resource allocation alleviation in “full-duplex (FD) Orthogonal Frequency Division Multiple Access (OFDMA) oriented Heterogeneous Networks (HetNets) that includes macrocell as well as underlying femtocells”. This work concerns on three foremost contributions: portraying a single objective issue including subcarrier allocation, price allocation and power allocation of macrocell–femtocell networks. Moreover, this work introduces a novel Cat Swarm Mated-Lion algorithm (CSM-LA) for solving the defined optimization problem in macrocell–femtocell networks. At last, the supremacy of adopted scheme is proved over traditional models regarding statistical and convergence analysis.

Findings

By concerning the cost function, the developed CSM-LA attained 87.5, 60, 93.75 and 93.75% better than LM, WOA, LA and CSO respectively. For utility analysis, it accomplished 70.58% better than LM, 88.23% superior to GWO, 85.88% superior to WOA and 88.23% better than CSO. For statistical analysis, the median performance of developed CSM-LA attained better results, which was 80.52% superior to LA, 80.74% better than GWO, 72% superior to WOA and 48.7% better than LA. Hence, the developed CSM-LA proved its performance in terms of improved results and revealed its betterment over the conventional models.

Originality/value

This paper adopts a latest optimization algorithm called CSM-LA for analyzing the issues on cross-tier interfering and resource allocation alleviation in full-duplex (FD) orthogonal frequency division multiple access (OFDMA) oriented heterogeneous networks (HetNets). This is the first work that utilizes CSM-LA framework that proposes a new CSM-LA model for power control and resource allocation by considering the multi-objectives like price, subcarrier and power as well.

Details

International Journal of Intelligent Unmanned Systems, vol. 10 no. 4
Type: Research Article
ISSN: 2049-6427

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Article
Publication date: 1 March 1978

H. Hotta, K. Ohtuka, K. Natori, K. Umeda, M. Asaoka and S. Yuzawa

As Japan is surrounded by the sea, the research done for the development of this manipulator is stressed as being very important.

69

Abstract

As Japan is surrounded by the sea, the research done for the development of this manipulator is stressed as being very important.

Details

Industrial Robot: An International Journal, vol. 5 no. 3
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 13 March 2017

Samira Khodabandehlou and Mahmoud Zivari Rahman

This paper aims to provide a predictive framework of customer churn through six stages for accurate prediction and preventing customer churn in the field of business.

4947

Abstract

Purpose

This paper aims to provide a predictive framework of customer churn through six stages for accurate prediction and preventing customer churn in the field of business.

Design/methodology/approach

The six stages are as follows: first, collection of customer behavioral data and preparation of the data; second, the formation of derived variables and selection of influential variables, using a method of discriminant analysis; third, selection of training and testing data and reviewing their proportion; fourth, the development of prediction models using simple, bagging and boosting versions of supervised machine learning; fifth, comparison of churn prediction models based on different versions of machine-learning methods and selected variables; and sixth, providing appropriate strategies based on the proposed model.

Findings

According to the results, five variables, the number of items, reception of returned items, the discount, the distribution time and the prize beside the recency, frequency and monetary (RFM) variables (RFMITSDP), were chosen as the best predictor variables. The proposed model with accuracy of 97.92 per cent, in comparison to RFM, had much better performance in churn prediction and among the supervised machine learning methods, artificial neural network (ANN) had the highest accuracy, and decision trees (DT) was the least accurate one. The results show the substantially superiority of boosting versions in prediction compared with simple and bagging models.

Research limitations/implications

The period of the available data was limited to two years. The research data were limited to only one grocery store whereby it may not be applicable to other industries; therefore, generalizing the results to other business centers should be used with caution.

Practical implications

Business owners must try to enforce a clear rule to provide a prize for a certain number of purchased items. Of course, the prize can be something other than the purchased item. Business owners must accept the items returned by the customers for any reasons, and the conditions for accepting returned items and the deadline for accepting the returned items must be clearly communicated to the customers. Store owners must consider a discount for a certain amount of purchase from the store. They have to use an exponential rule to increase the discount when the amount of purchase is increased to encourage customers for more purchase. The managers of large stores must try to quickly deliver the ordered items, and they should use equipped and new transporting vehicles and skilled and friendly workforce for delivering the items. It is recommended that the types of services, the rules for prizes, the discount, the rules for accepting the returned items and the method of distributing the items must be prepared and shown in the store for all the customers to see. The special services and reward rules of the store must be communicated to the customers using new media such as social networks. To predict the customer behaviors based on the data, the future researchers should use the boosting method because it increases efficiency and accuracy of prediction. It is recommended that for predicting the customer behaviors, particularly their churning status, the ANN method be used. To extract and select the important and effective variables influencing customer behaviors, the discriminant analysis method can be used which is a very accurate and powerful method for predicting the classes of the customers.

Originality/value

The current study tries to fill this gap by considering five basic and important variables besides RFM in stores, i.e. prize, discount, accepting returns, delay in distribution and the number of items, so that the business owners can understand the role services such as prizes, discount, distribution and accepting returns play in retraining the customers and preventing them from churning. Another innovation of the current study is the comparison of machine-learning methods with their boosting and bagging versions, especially considering the fact that previous studies do not consider the bagging method. The other reason for the study is the conflicting results regarding the superiority of machine-learning methods in a more accurate prediction of customer behaviors, including churning. For example, some studies introduce ANN (Huang et al., 2010; Hung and Wang, 2004; Keramati et al., 2014; Runge et al., 2014), some introduce support vector machine ( Guo-en and Wei-dong, 2008; Vafeiadis et al., 2015; Yu et al., 2011) and some introduce DT (Freund and Schapire, 1996; Qureshi et al., 2013; Umayaparvathi and Iyakutti, 2012) as the best predictor, confusing the users of the results of these studies regarding the best prediction method. The current study identifies the best prediction method specifically in the field of store businesses for researchers and the owners. Moreover, another innovation of the current study is using discriminant analysis for selecting and filtering variables which are important and effective in predicting churners and non-churners, which is not used in previous studies. Therefore, the current study is unique considering the used variables, the method of comparing their accuracy and the method of selecting effective variables.

Details

Journal of Systems and Information Technology, vol. 19 no. 1/2
Type: Research Article
ISSN: 1328-7265

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Article
Publication date: 15 May 2017

Tayfun Abut and Servet Soyguder

This paper aims to use the adaptive computed torque control (ACTC) method to eliminate the kinematic and dynamic uncertainties of master and slave robots and for the control of…

387

Abstract

Purpose

This paper aims to use the adaptive computed torque control (ACTC) method to eliminate the kinematic and dynamic uncertainties of master and slave robots and for the control of the system in the presence of forces originating from human and environment interaction.

Design/methodology/approach

In case of uncertainties in the robot parameters that are utilized in teleoperation studies and when the environment where interactions take place is not known and when there is a time delay, very serious problems take place in system performance. An adaptation rule was created to update uncertain parameters. In addition to this, disturbance observer was designed for slave robot. Lyapunov function was used to analyze the system’s position tracking and stability. A visual interface was designed to ensure that the movements of the master robot provided a visual feedback to the user.

Findings

In this study, a visual interface was created, and position and velocity control was achieved utilizing teleoperation; the system’s position tracking and stability were analyzed using the Lyapunov method; a simulation was applied in a real-time environment, and the performance results were analyzed.

Originality/value

This study consisted of both simulation and real-time studies. The teleoperation system, which was created in a laboratory environment, consisted of six-degree-of-freedom (DOF) master robots, six-DOF industrial robots and six-DOF virtual robots.

Details

Industrial Robot: An International Journal, vol. 44 no. 3
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 20 August 2019

Alex Barre Epenetus, Meera CS, Santhakumar Mohan and Mukul Kumar Gupta

Key challenges in evaluating the performance of a robotic manipulator are disturbances that rise internally and externally. Effects of non-linear disturbances like varying payload…

110

Abstract

Purpose

Key challenges in evaluating the performance of a robotic manipulator are disturbances that rise internally and externally. Effects of non-linear disturbances like varying payload and joint friction can adversely affect the tracking performance in a robotic manipulator. This paper aims to discuss motion control of a three-link spatial manipulator using a computed torque observer-based control technique.

Design/methodology/approach

The overall motion control problem consists of derivation of kinematic and dynamic model of the manipulator followed by the control design to achieve desired manipulator response. In this study, the manipulator is subjected to uncertain varying load disturbances. The proposed motion controller compensates the effect of the disturbances and guarantees the convergence of tracking error to steady state value.

Findings

One major advantage of using observer-based control is positioning accuracy with robustness to parameter uncertainty and fast dynamics response. The performance of the proposed control technique is validated through real-time experiments conducted on the manipulator. The experiment results confirm the superior performance of the control system in achieving perfect tracking.

Originality/value

This paper demonstrates an observer-based control technique over a serial spatial manipulator which can be applied different robotic configurations under the effect of varying disturbances.

Details

World Journal of Engineering, vol. 16 no. 4
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 3 October 2023

Jie Lu, Desheng Wu, Junran Dong and Alexandre Dolgui

Credit risk evaluation is a crucial task for banks and non-bank financial institutions to support decision-making on granting loans. Most of the current credit risk methods rely…

342

Abstract

Purpose

Credit risk evaluation is a crucial task for banks and non-bank financial institutions to support decision-making on granting loans. Most of the current credit risk methods rely solely on expert knowledge or large amounts of data, which causes some problems like variable interactions hard to be identified, models lack interpretability, etc. To address these issues, the authors propose a new approach.

Design/methodology/approach

First, the authors improve interpretive structural model (ISM) to better capture and utilize expert knowledge, then combine expert knowledge with big data and the proposed fuzzy interpretive structural model (FISM) and K2 are used for expert knowledge acquisition and big data learning, respectively. The Bayesian network (BN) obtained is used for forward inference and backward inference. Data from Lending Club demonstrates the effectiveness of the proposed model.

Findings

Compared with the mainstream risk evaluation methods, the authors’ approach not only has higher accuracy and better presents the interaction between risk variables but also provide decision-makers with the best possible interventions in advance to avoid defaults in the financial field. The credit risk assessment framework based on the proposed method can serve as an effective tool for relevant policymakers.

Originality/value

The authors propose a novel credit risk evaluation approach, namely FISM-K2. It is a decision support method that can improve the ability of decision makers to predict risks and intervene in advance. As an attempt to combine expert knowledge and big data, the authors’ work enriches the research on financial risk.

Details

Industrial Management & Data Systems, vol. 123 no. 12
Type: Research Article
ISSN: 0263-5577

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Book part
Publication date: 13 September 2017

Takashi Tsuji

Citizen participation has attracted attention in the context of decentralization. In a disaster reconstruction process, a business plan for reconstruction can be modified in line…

Abstract

Citizen participation has attracted attention in the context of decentralization. In a disaster reconstruction process, a business plan for reconstruction can be modified in line with diversified situations of disaster-affected areas by citizen participation. In Japan, the central government makes a decision about the authority in charge of an overall disaster reconstruction and the budget planning, whereas local governments are in charge of creating and implementing a business plan for reconstruction of each local municipality. Therefore, local governments play an important role in organizing citizen participation to realize the reconstruction that fits reality. It has yet to be shown as decentralization reform and citizen participation system in Japan produce the socio-spatial inequality after the Great East Japan Earthquake. However, it remains to be elucidated how local government and community have to operate the institution about citizen participation during the disaster reconstruction process. I have been doing fieldwork on three tsunami-affected sites in Miyagi Prefecture over past 4 years: Onagawa Town, Higashimatsushima City, and Natori City. I have investigated the social processes of making and implementing a reconstruction plan, and citizen participation. The findings from my fieldwork are as follows: First, citizen participation is based on organizing residents at the community level. Second, traditional community organization (such as neighborhood organization abd industrial associations) contribute to organize residents especially in the emergency phase. Third, as the disaster phase moves, local government and community organization need to change the previous participation frame to ensure residents representation and policy legitimacy.

Details

Recovering from Catastrophic Disaster in Asia
Type: Book
ISBN: 978-1-78635-296-5

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Article
Publication date: 9 April 2020

Xiaofeng Wang, Haoyue Chu and Qingshan Yang

This paper aims to numerically study the effects of boundary conditions, pre-stress, material constants and thickness on the dynamic performance of a wrinkled thin membrane.

247

Abstract

Purpose

This paper aims to numerically study the effects of boundary conditions, pre-stress, material constants and thickness on the dynamic performance of a wrinkled thin membrane.

Design/methodology/approach

Based on the stability theory of plates and shells, the dynamic equations of a wrinkled thin membrane were developed, and they were solved with the Lanczos method

Findings

The effects of wrinkle-influencing factors on the dynamic performance of a wrinkled membrane are determined by the wrinkling stage. The effects are prominent when wrinkling deformation is evolving, but they are very small and can hardly be observed when wrinkling deformation is stable. Mode shapes of a wrinkled membrane are sensitive to boundary conditions, pre-stress and Poisson’s ratio, but its natural frequencies are sensitive to all these five factors.

Practical implications

The research work in this paper is expected to help understand the dynamic behavior of a wrinkled membrane and present access to ensuring its dynamic stability by controlling the wrinkle-influencing factors.

Originality/value

Very few documents investigated the dynamic properties of wrinkled membranes. No attention has yet been paid by the present literature to the global dynamic performance of a wrinkled membrane under the influences of the factors that play a pivotal role in the wrinkling deformation. In view of this, this paper numerically studied the global modes and corresponding frequencies of a wrinkled membrane and their variation with the wrinkle-influencing factors. The results indicate that the global dynamic properties of a wrinkled membrane are sensitive to these factors at the stage of wrinkling evolution.

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Article
Publication date: 3 July 2007

Harry K.H. Chow, K.L. Choy and W.B. Lee

The purpose of this study is to survey knowledge management (KM) practices and to examine the applications and technologies adopted when developing the knowledge management system…

4532

Abstract

Purpose

The purpose of this study is to survey knowledge management (KM) practices and to examine the applications and technologies adopted when developing the knowledge management system (KMS) in build‐to‐order supply chains (BOSC).

Design/methodology/approach

This paper uses a literature review of research articles from 1996 to 2007 with keyword indexes to survey the KM practice, KMS technology and its application in BOSC. Such keyword indexes include: BOSC, SCM, KM, KMS, expert system, knowledge‐based system and information system on the Elsevier online database, ScienceDirect, EBSCO, Proquest, Emerald, DOAJ, and Wiley Inter Science. A total of 1,500 articles were found but only 149 articles related to the keywords of KMS application and KM practices within SCM and BOSC.

Findings

The important findings indicate that the KMS application is solely focused on single knowledge problem for enabling individual SC members to attain operational excellence. There is a need for further research into the development of KMS with features of knowledge coordination that cross organizational borders in attaining the BOSC integration.

Research limitations/implications

Perhaps, the limitation of this study was the narrowness of the scope of the paper based on the keywords used for searching.

Practical implications

Validation of the multi‐disciplines of KM practices and KMS applications provides enterprises with useful guidelines for implementing KM‐ and KMS‐related projects within their current BOSC practices.

Originality/value

This paper provides useful knowledge by highlighting the characteristics of KMS technology within BOSC and empirical insights into the relationship between KM and BOSC practices.

Details

Industrial Management & Data Systems, vol. 107 no. 6
Type: Research Article
ISSN: 0263-5577

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Article
Publication date: 1 April 2000

W.J. Plumbridge

Impressions gained from two visits to Japan, discussing with representatives of industry and academe the current status regarding the implementation of lead‐free technology, are…

255

Abstract

Impressions gained from two visits to Japan, discussing with representatives of industry and academe the current status regarding the implementation of lead‐free technology, are presented. Driven by the commercial rewards of lead‐free goods, Japan appears to have more clearly articulated targets for the removal of lead, in advance of the expected timescales in EU legislation. Various strategies for combating problems associated with the higher melting point of lead‐free solder alloys have been investigated. Design and development generally involve a broader approach than in Europe, involving stress analysis, materials properties and life prediction to underpin empirical data obtained by thermal cycling of boards. Despite the existence of several committees to facilitate the introduction of lead‐free solders, a lack of cohesion is sometimes apparent, particularly regarding heat treatment of materials prior to testing. It is proposed that a challenge as demanding as this would benefit from greater collaboration internationally.

Details

Soldering & Surface Mount Technology, vol. 12 no. 1
Type: Research Article
ISSN: 0954-0911

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