• Journal of Korean Society for Quality Management
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• v.41 no.1
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• pp.39-52
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• 2013

Purpose: The purpose of this study was to investigate if purchasing companies' efforts of supplier development activities to supplier companies have positive impacts on the purchasing companies' performance as the first step. In the second step, we tried to confirm if the concept of Supply Chain Corporate Social Responsibility activities and Coexistence activities take the roles of moderate variable on relationship between supplier development and three performances respectively. Methods: The collected data through survey were analysed using multiple regression for the first step of the study and moderate regression for the second one of it. Results: The results of this study are as follows; supplier development efforts effect on all three performances positively. Moreover, Supply Chain CSR has significant moderate effect on relationship between supplier management and corporate performances, while Coexistence does between supplier management and logistics performances. In the case of relationship between supplier management and production performances, both Supply Chain CSR and Coexistence show significant moderate effect. Conclusion: Manufacturing companies in Korea need to make effort of supplier development in selective way when they want to practice Supply Chain CSR and Coexistence concurrently considering strategies and objectives.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.713-717
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• 2014

This paper presents a beamforming technique for locating impulsive sound source. The conventional frequency-domain beamformer is advantageous for localizing noise sources for a certain frequency band of concern, but the existence of many frequency components in the wide-band spectrum of impulsive noise makes the beamforming image less clear. In contrast to a frequency-domain beamformer, it has been reported that a time-domain beamformer can be better suited for transient signals. Although both frequency- and time-domain beamformers produce the same result for the beamforming power, which is defined as the RMS value of its output, we can use alternative directional estimators such as the peak value and crest factor to enhance the performance of a time-domain beamformer. In this study, the performance of three different directional estimators, the peak, crest factor and RMS output values, are investigated and compared with the incoherent interfering noise embedded in multiple microphone signals. The proposed formula is verified via experiments in an anechoic chamber using a uniformly spaced linear array. The results show that the peak estimation of beamformer output determines the location with better spatial resolution and a lower side lobe level than crest factor and RMS estimation in noise free condition, but it is possible to accurately estimate the direction of the impulsive sound source using crest factor estimation in noisy environment with stationary interfering noise.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10C
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• pp.929-936
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• 2009

In this paper, we consider designing a multi-input multi-output (MIMO) overlay system for fixed MIMO wireless link, where a frequency flat narrowband channel is shared by multiple transmitter and receiver pairs. Assuming the perfect knowledge of the second-order statistics of the received legacy signals and the composite channels from the overlay transmitter to the legacy receivers, the jointly optimal linear precoder and decoder matrices of the MIMO overlay system is derived to minimize the total mean squared error (MSE) of the data symbol vector, subject to total average transmission power and zero interference induced to legacy MIMO systems already existing in the frequency band of interest. Furthermore, the necessary and sufficient condition for the existence of the optimal solution is also derived.

• Journal of Ship and Ocean Technology
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• v.3 no.1
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• pp.27-41
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• 1999

The objective of the paper is to study the impact of changing the traditional hull design of bulk carriers by providing them with a double hull while keeping the same deadweight. It is demonstrated that by introducing the double hull the structural reliability is increased throughout the entire life and also the extend of the needed repair is reduced. The results are obtained with recently developed mathematical tools for the reliability assessment of ship hulls subjected to the existence of multiple cracks both in the stiffeners and in the plating and it models the crack growth process. The effect of corrosion is represented as time dependent. The long-term stress range acting on the elements is defined as a function of the local transverse pressure of the internal cargo and outside sea water combined with the stresses resulting from the longitudinal bending of the hull, which is a combined with the stresses resulting from the longitudinal bending of the hull, which is a combineation of horizontal and vertical bending moments. The effect of maintenance actions is modelled as a stochastic process. The results show that a different design of the midship section improves the structural safety and also the economy with respect to structural repair of bulk carriers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.83-89
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• 2010

This paper presents the impacts of Ultra Wide-Band(UWB) sensor using frequency of 4.5 GHz on Broadband Wireless communication system which uses frequency of 4.5 GHz. The Minimum Coupling Loss (MCL) method and Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) is used to evaluate the interference effects of UWB sensor on Broadband Wireless communication system, respectively. The minimum protection distance between single UWB sensor and mobile station of Broadband Wireless communication system should be more than 1.2 m to guarantee the co-existence. In case of multiple UWB sensors, UWB transmitting PSD of around -68.5 dBm/MHz below should be required to guarantee interference probability of 5% below for mobile station of Broadband Wireless communication system.

• Journal of Environmental Science International
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• v.12 no.5
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• pp.511-519
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• 2003

It is difficult to define the urban fringe using a specific geographical designation in the physical planning system because the existence of the urban fringe is certainly not equal in all directions from the inner urban area to the rural area, and is often a discontinuous spatial phenomenon from the inner fringe to the urban shadow. Nevertheless, the urban fringe raises land use management issues which stem from its own peculiar set of land use characteristics. For example, in the UK, how the public can enjoy access to the countryside in the urban fringe while at the same time recognising and acknowledging the importance of landowners and farmers property rights\ulcorner how can a poor quality environment and degraded landscape be improved aesthetically and physically to meet the multiple recreational needs of a diverse population when local authorities are confronted with limited ability to fund and acquire land for these purposes\ulcorner The challenge of addressing these land use management issues necessitates approaches which build a coalition of interest groups and public and non-government organizations in the management processes in order to improve the physical, economic and social environments and facilitate the management mechanism.

• Journal of the Korean Home Economics Association
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• v.50 no.8
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• pp.53-63
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• 2012

The purpose of this study is to examine the influence of the child-mother attachment and the child-father attachment (secure attachment, insecure avoidant and insecure disorganized attachment) on children's mutual friendships and mutual antipathy relations. The subjects consisted of 116 5-6 year old kindergarteners (64 boys & 52 girls) and they were asked to respond to the Attachment Story Completion Task by Bretherton & Cassidy (1990), based on the sociometric popularity postulated by Coie & Dodge (1988). Data were analyzed by the logistic regression analysis and the one-way ANOVA method and the Scheffe test in multiple comparisons analysis. The results concluded that 1)There were differences in terms of child-mother attachment and child-father attachment when it came to a child's mutual friendship. The secure child-mother and child-father attachment groups had more mutual friendships than the insecure attachment groups. 2)There were no differences in terms of child-mother attachment and child-father attachment when it came to child's mutual antipathy. 3) 78.0% of the mutual friendships were accurately classified as existence with respect to child-mother and child-father attachment.

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.100-105
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• 2004

Installed capacity markets in the northeast of the United States ensure that adequate generation exists to satisfy regional loss of load probability (LOLP) criterion. LOLP studies are conducted to determine the amount of capacity that is needed, but they do not consider several factors that substantially affect the calculated distribution of available capacity. These studies do not account for the fact that generation availability increases during periods of high demand and therefore prices, common-cause failures that result in multiple generation units being unavailable at the same time, and the negative correlation between load and available capacity due to temperature and humidity. A categorization of incidents in an existing bulk power reliability database is proposed to analyze the existence and frequency of independent failures and those associated with resource dynamics. Findings are augmented with other empirical findings. Monte Carlo methods are proposed to model these resource dynamics. Using the IEEE Reliability Test System as a single-bus case study, the LOLP results change substantially when these factors are considered. Better data collection is necessary to support the more comprehensive modeling of resource adequacy that is proposed. In addition, a parallel processing method is used to offset the increase in computational times required to model these dynamics.

• Journal of computational fluids engineering
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• v.14 no.4
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• pp.56-61
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• 2009

This study deals with the numerical investigation on two-dimensional lubrication characteristics of micro-dimple shapes fabricated on solid surfaces by using the commercial CFD code (Fluent V.6.3) to examine the influence of micro dimple depth and width on the reduction in friction under the sliding plate condition. In addition, single and multiple dimple arrays are simulated, all for a fixed area fraction of dimple on the surface. As a result, it is found that the existence of micro-dimpled surface makes it possible to substantially reduce the friction forces exerted on the surfaces, and such an optimum dimple depth would be present because the dimple depth larger than the optimum value did no longer affect the reduction in shear stresses, indicating that the reduction of friction is likely to be associated with inner flows of lubricant inside dimples. Moreover, it is observed that at the fixed area fraction, the friction reduction increases with the increase of dimple diameter.

• Journal of Korean Academy of Nursing
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• v.39 no.1
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• pp.21-32
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• 2009

Purpose: The purpose of this study was to investigate the level of life satisfaction and the significant factors which impact on life satisfaction of young-old (60-69 yr), old (70-79 yr), and oldest-old (80 yr or above) women. Methods: The participants for this study were 289 elderly Korean women living in the city of Daegu and Kyongpook province. The data were collected using structured questionnaires. ANOVA, Chi-square, and multiple regression with the SPSS program were used to analyze the data. Results: There were statistically significant differences among young-old, old, and oldest-old women regarding the existence of spouse, income, educational status, and religions. The model including variables related to physical, psychological, financial, and social aspects of life, explained variance of life satisfaction of elderly women differently, such as 55% of young-old, 37% of old, and 66% of oldest-old. Finally, self-esteem was the only predictor in explaining the level of life satisfaction among old women regardless age. Conclusion: Based on the findings of the study, implications for practical services for elderly women and recommendations of further study are provided. Nursing interventions should be developed to improve life satisfaction of elderly women according to age differences.