• ETRI Journal
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• v.40 no.3
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• pp.355-365
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• 2018

The increase in data traffic calls for investment in mobile networks; however, the saturating revenue of mobile broadband and increasing capital expenditure are discouraging mobile operators from investing in next-generation mobile networks. Mobile network sharing is a viable solution for operators and regulators to resolve this dilemma. This research uses a difference-in-differences analysis of 33 operators (including 11 control operators) to empirically evaluate the cost reduction effect of mobile network sharing. The results indicate a reduction in overall operating expenditure and short-term capital expenditure by national roaming. This finding implies that future technology and standards development should focus on flexible network operation and maintenance, energy efficiency, and maximizing economies of scale in radio access networks. Furthermore, mobile network sharing will become more viable and relevant in a 5G network deployment as spectrum bands are likely to increase the total cost of ownership of mobile networks and technical enablers will facilitate network sharing.

• Steel and Composite Structures
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• v.28 no.5
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• pp.607-615
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• 2018

The dynamic behavior of the deployment and folding process of a foldable boom based on the Miura origami pattern is investigated in this paper. Firstly, mechanical behavior of a single storey during the motion is studied numerically. Then the deployment and folding of a multi-storey boom is discussed. Moreover, the influence of the geometry parameters and the number of Miura-ori elements n on the dynamic behavior of the boom is also studied. Finally, the influence of the imperfection on the dynamic behavior is investigated. The results show that the angles between the diagonal folds and horizontal folds will have great effect on the strains during the motion. A bistable configuration can be obtained by choosing proper fold angles for a given multi-storey boom. The influence of the imperfection on the folding behavior of the foldable mast is significant.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.2
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• pp.197-205
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• 2017

During the sea trial, we discovered EMI between MOSCOS and ES DF antenna. CW emitted by MOSCOS raised the threshold level of ES DF antenna. As a result, direction finding rate of ES has been decreased. This is a study for the improvement of EMI between the antennas mounted on a surface ship. An analysis is accomplished for MOSCOS, ES DF antenna and Jamming transmitter. This paper presents the method how to solve EMI based on the measurements and calculations about the ES DF antenna receiving level, MOSCOS radiation pattern and Jamming transmitter thermal noise. The test was performed with optimal deployment of MOSCOS on a surface ship. After changing the position of MOSCOS, EMI has been decreased significantly.

• Smart Structures and Systems
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• v.10 no.3
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• pp.209-228
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• 2012

Structural health monitoring with wireless sensor networks has received much attention in recent years due to the ease of sensor installation and low deployment and maintenance costs. However, sensor network technology needs to solve numerous challenges in order to substitute conventional systems: large amounts of data, remote configuration of measurement parameters, on-site calibration of sensors and robust networking functionality for long-term deployments. We present a structural health monitoring network that addresses these challenges and is used in several deployments for monitoring of bridges and buildings. Our system supports a diverse set of sensors, a library of highly optimized processing algorithms and a lightweight solution to support a wide range of network runtime configurations. This allows flexible partitioning of the application between the sensor network and the backend software. We present an analysis of this partitioning and evaluate the performance of our system in three experimental network deployments on civil structures.

• Journal of Korean Society for Quality Management
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• v.32 no.1
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• pp.130-143
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• 2004

Although consumer needs for better products force manufactures to put emphasis on design, often development of a product has been done without the formal process to consider consumer needs. In order to identify the implicit needs of customers and the areas of potential demand on a product, several analysis scheme such as QFD (Quality Function Deployment) has been developed. QFD, also known as the House of Quality, is the efficient tool ever created to tie product and service design decisions directly to customer wants and needs, i.e. VoC (Voice of Customer) To utilize this tool on a product design, first of all, the consumers attributes and the engineering characteristics must be exactly investigated. However there were only few studies about them on shoe design. Hence in this paper we developed an innovative framework for shoes design based on QFD. As a result, we uncovered 29 dominant human satisfaction dimensions as the consumers attributes for customer-oriented quality evaluation of a comfortable shoes. Here, 29 human satisfaction dimensions for a shoe design were identified as the dimensions that represent the human sensitivity and psychological feeling on comfortable shoes. Also, we proposed 60 human interface elements as the engineering characteristics. The relationships between human satisfaction dimensions and human interface elements were investigated. This study will help the designers and manufacturers clarify the conceptual and abstract aspect of the design evaluation by proposing a more systematic and process-oriented method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.7 s.238
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• pp.921-929
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• 2005

This paper presents an accelerated life test for burnout of tungsten filament of incandescent lamp. From failure analyses of field samples, it is shown that their root causes are local heating or hot spots in the filament caused by tungsten evaporation and wire sag. Finite element analysis is performed to evaluate the effect of vibration and impact for burnout, but any points of stress concentration or structural weakness are not found in the sample. To estimate the burnout life of lamp, an accelerated life test is planned by using quality function deployment and fractional factorial design, where voltage, vibration, and temperature are selected as accelerating variables. We assumed that Weibull lifetime distribution and a generalized linear model of life-stress relationship hold through goodness of fit test and test for common shape parameter of the distribution. Using accelerated life testing software, we estimated the common shape parameter of Weibull distribution, life-stress relationship, and accelerating factor.

• Korean Management Science Review
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• v.33 no.2
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• pp.75-87
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• 2016

Quality function deployment (QFD) is a widely adopted customer-oriented product development methodology by analyzing customer requirements. It is a main activity in QFD planning process to determine the optimal values of the technical attributes (TAs) so as to achieve the customer requirements (CRs) from the House of Quality (HoQ). In most of the previous research, all the TAs in QFD are assumed to have either continuous or discrete values. In the real world applications, the continuous TAs and the discrete TAs are often mixed in QFD. In this paper, a mixed integer linear programming model is formulated to obtain the optimal values for the continuous TAs and the discrete TAs in QFD planning as well as Branch and Bound (B and B) algorithm is proposed as the solution approach. Finally, the proposed model and solution approach are illustrated with an office chair under multi-segment market, and the sensitivity analysis is performed to study how the proposed model and its solutions respond to the variation for the two elements which are budget and CRs' weights.

• Asia-Pacific Journal of Business
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• v.3 no.2
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• pp.23-33
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• 2012

Sustainable competitive advantage depends on formulation and implementation of appropriate human resource management (HRM) strategies and deployment of their competencies effectively in dynamic and complex environment. Competencies deployment is an approach to make decisions on the intentions and plans of organization concerning employment relationship and its recruitment, training, development, performance appraisal, reward and employee relations policies and practice. The improvement of organizational effectiveness is an overall objective of people management in organizations. In light of these, this study explores the present practices of HRM like: HR departments, HR policies and strategies, HR planning, recruitment selection and placement, training and development, performance appraisal, compensation and benefit, employee relations and communications. Based on the survey in 204 Nepalese organizations as a unit of analysis, the study concludes that HR practices in few organizations have action program for minorities, ethnic group, older employees and people with disabilities. Due to centralized organizational structure, most of HR decisions are taken into central office and line managers being involved highly in planning and implementing HR policies. In a nutshell, though HRM practices are not developed like developed countries, Nepalese organizations are realizing the significance of people management at work and changing their practices in the present dynamic environment.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.101-109
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• 2007

This research is for developing a usability evaluation model based on customer sensation using Quality Function Deployment, which evaluates the relationship between consumer sensation and usability among the physical design factors of dishwashers. Four aspects of the evaluation model; overall sensation factors, detail sensation factors, usability evaluation factors and physical design factors of products were analyzed in three sequential processes of QFD. The sensation evaluation factors and the usability evaluation factors were created from regression analysis of the results of the sensation and usability test. Moreover, thirty-one physical design factors selected through group discussion of ergonomist and manufacturers. Among them, 19 physical design factors according to priority were applied to evaluation model using QFD. With the evaluation model using four aspects, physical design factors influencing user sensation were generated. These factors were 'alarm sound', 'dishwasher size', 'button size' and 'display size'. Consequently, the degree of influences was tested. Design guidelines for dishwashers were derived from finally generated physical design factors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6A
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• pp.594-599
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• 2010

This paper studies the effect of the deployment position of the relay stations on the downlink signal-to-interference-noise-ratio (SINR) in multihop cellular networks. Two different relay deployment scenarios are considered where relay stations are located either inside cells or on the boundary among adjacent cells. The fundamental contribution is to compare fairly the average SINR between two scenarios with the proposed relay modeling framework that includes multi-cell geometries and inter-cell interferences. The mathematical results show that the SINR increases when relay stations are located inside cells because of higher received signal power.