• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.4
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• pp.95-109
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• 1999

We propose a series of methodologies that can evaluate relative efficiency of logistics units(centers) in three categories; managerial, cost, and operational efficiency. Inputs and outputs of logistics systems are first defined. Appropriate quantitative and qualitative measures for the three categories are then selected. Employed also are Analytic Hierarchy Process, Weighted Scoring Method, Stochastic Frontier Model, and Data Envelopment Analysis for the development of a comprehensive assessment scheme. Our scheme not only assesses the degree of relative efficiency of logistics units but also identify the sources of inefficiency in each unit The methodologies are applied to a large telecommunications company which operates 12 distribution centers nation wide. Relative efficiencies of the centers are compared using 1995-1997 performance data. Summarized are the level of efficiency of each distribution center for each of the three categories. The degree and sources of inefficiency of each distribution center are also discussed.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.5
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• pp.1-7
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• 2002

In this paper, an extended type of a direct learning control(DLC) method is proposed for the effective control of systems which perform a given task repetitively. DLC methods have been suggested to overcome the defects of iterative learning control, the learning process should be resumed from the beginning even if a slight change occurs in the desired output pattern. If a given desired output trajectory is "proportional" to the output trajectories which are learned previously, we can obtain the desired control input directly without the iterative learning process by using the DLC. First, most existing DLC methods are shown to be applicable only to single-input single-output systems with the relative degree one and then, an extended type of DLC is proposed for a class of nonlinear systems having the relative degree more than or equal to one by using the known relative degree of a nonlinear system. By the simulation results for the arbitrary nonlinear system with the relative degree more than one, the validity and the performance of the proposed DLC method are examined.

• Journal of the Korean Home Economics Association
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• v.39 no.3
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• pp.35-45
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• 2001

The purposes of this study are to identify the factors associated with the degree of role conflict and the likelihood of exits of the labor force of working wives and to investigate the relationship between the role conflict and job quitting behavior of working wives. The major results of this study are as follows. First, the ratio of reservation wage relative to wife's earnings, wife's earnings, husband's behavioral support, the presence of child under age of 6, the type of occupation, and job satisfaction are associated with the role conflict of working wives. Second, there is a significant difference in the job quitting behavior of working wives according to the degree of role conflict of working wives. Third, the level of role conflict, educational level, the ratio of resonation wage relative to wife's earnings, husband's behavioral support, the presence of child under age of 6, the type of occupation, and job satisfaction are associated with the likelihood of job quitting of working wives.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.4
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• pp.189-197
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• 2003

The problem of designing a parallel feedforward compensator (PFC) is considered for a class of non-square linear systems such that the closed-loop system is strictly passive. If a given square system has (vector) relative degree one and is weakly minimum phase, the system can be rendered passive by a state feedback. However, when the system states are not always measurable and the given output is considered, passivation (i.e. rendering passive) of a non-minimum phase system or a system with high relative degree cannot be achieved by any other methodologies except by using a PFC. To passivate a non-square system we first determine a squaring gain matrix and design a PFC such that the composite system has relative degree one and is minimum phase. Then the system is rendered strictly passvie by a static output feedback law. Necessary and sufficient conditions for the existence of the PFC and the squaring gain matrix are given by the static output feedback formulation, which enables to utilize linear matrix inequality (LMI). As an application of the scheme, an alternative way of replacing the role of velocity measurements is provided for the PD-control law of a convey-crane system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1845-1865
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• 2019

Current Internet is designed by lots of service providers with different objects and policies which make the direct deployment of radically new architecture and protocols on Internet nearly impossible without reaching a consensus among almost all of them. Network virtualization is proposed to fend off this ossification of Internet architecture and add diversity to the future Internet. As an important part of network virtualization, virtual network embedding (VNE) problem has received more and more attention. In order to solve the problems of large embedding cost, low acceptance ratio (AR) and environmental adaptability in VNE algorithms, cognitive method is introduced to improve the adaptability to the changing environment and a cognitive virtual network embedding algorithm based on weighted relative entropy (WRE-CVNE) is proposed in this paper. At first, the weighted relative entropy (WRE) method is proposed to select the suitable substrate nodes and paths in VNE. In WRE method, the ranking indicators and their weighting coefficients are selected to calculate the node importance and path importance. It is the basic of the WRE-CVNE. In virtual node embedding stage, the WRE method and breadth first search (BFS) algorithm are both used, and the node proximity is introduced into substrate node ranking to achieve the joint topology awareness. Finally, in virtual link embedding stage, the CPU resource balance degree, bandwidth resource balance degree and path hop counts are taken into account. The path importance is calculated based on the WRE method and the suitable substrate path is selected to reduce the resource fragmentation. Simulation results show that the proposed algorithm can significantly improve AR and the long-term average revenue to cost ratio (LTAR/CR) by adjusting the weighting coefficients in VNE stage according to the network environment. We also analyze the impact of weighting coefficient on the performance of the WRE-CVNE. In addition, the adaptability of the WRE-CVNE is researched in three different scenarios and the effectiveness and efficiency of the WRE-CVNE are demonstrated.

• Journal of Family Resource Management and Policy Review
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• v.2 no.1
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• pp.15-31
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• 1998

The purpose of study is to understand the home management strategy to cope with rapid changing environments and to verify that how personal value orientation affect home management strategy. The research results are summarized below. First, variables that affect the value orientation of Korean urbanite are sex, area of dwelling, degree of information using and degree of stress recognition in case of material orientation, degree of information using in case of environmental orientation, academic career, sex, degree of information using, degree of stress recognition in cases of fate control orientation, number of children, sex, degree of information using in case of equilibrium orientation, sex, degree of stress recognition in case of present orientation and academic career, degree of stress recognition in case of individualistic orientation. Second, value orientation variables that affect overall home management strategy of Korean urbanite are material orientation, environmental orientation, fate control orientation and individualistic orientation. Third, variables that affect overall home management strategy of Korean urbanite are age, academic career, degree of information using, degree of stress recognition, perception level of living relative to others, environmental orientation and fate control orientation and it is shown that degree of information using is domineering variable.

• Journal of Family Resource Management and Policy Review
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• v.2 no.2
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• pp.1-19
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• 1998

The purpose of study is to understand the home management strategy to cope with rapid changing environments and to verify that how personal value orientation affect home management strategy. The research results are summarized below. First, variables that affect the value orientation of Korean urbanite are sex, area of dwelling, degree of information using and degree of stress recognition in case of material orientation, degree of information using in case of environmental orientation, academic career, sex, degree of information using, degree of stress recognition in cases of fate control orientation, number of children, sex, degree of information using in case of equilibrium orientation, sex, degree of stress recognition in case of present orientation and academic career, degree of stress recognition in case of individualistic orientation. Second, value orientation variables that affect overall home management strategy of Korean urbanite are material orientation, environmental orientation, fate control orientation and individualistic orientation. Third, variables that affect overall home management strategy of Korean urbanite are age, academic career, degree of information using, degree of stress recognition, perception level of living relative to others, environmental orientation and fate control orientation and it is shown that degree of information using is domineering variable.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.1
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• pp.171-184
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• 2015

The purpose of this study is to develop the self-diagnosis methodology based on process for improving the effectiveness in public institutions service and to suggest it. For this goal, we would like to select the management methodology which can be easily handled from the viewpoint of working personnel in the public institutions and make it as a process. First, the strategy for the public institutions and the strategic task for practicing it are acquired using BSC (Balanced Score Card) which is now under the active research. At this time, the relative degree of significance is derived using the AHP (Analytic Hierarchy Process) which is conducted for the professionals and management to get the degree of importance in the strategic tasks. The acquired relative degree of significance and the figures related to the performance of each strategic task derived from the subsequent questionnaire are used to get the final highly efficient strategic task through IPA (Importance Performance Analysis). In this study, this process based self diagnosis methodology will be explained in detail using the case of Project A in order to verify the effectiveness of the management science technique on the self diagnosis of the public institutions.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.164-173
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• 2012

Landing ship tank with well dock has the important mission transferring troops or landing equipments from sea to shore. Such transfers are usually carried out using landing crafts, which are loaded or unloaded in flooded well dock. In this situation, as relative motions are occur between well dock and landing craft, safety verifications are demanded. In this paper, seakeeping and safety performances are investigated through model test. First of all, well dock dimensions are reviewed and model tests are performed with sea state 3&4 in 180degree wave direction. Model tests are conducted for three relative positions and seakeeping performances are investigated each position.

• Journal of Korean Neurosurgical Society
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• v.44 no.3
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• pp.136-140
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• 2008

Objective : Numerous studies have compared the characteristics of familial intracranial aneurysms with those of non-familial aneurysms. To better understand familial subarachnoid hemorrhage (SAH), we studied a series of patients with SAH who had at least one first-degree relative with SAH, and compared our results with those of previous studies. Methods : We identified patients treated for SAH at our hospital between January 1993 and October 2006 and analyzed those patients with one or more first-degree relatives with SAH. We retrospectively collected data from patients with a family history and searched for patients who had relatives with aneurysms or who had been treated at other hospitals for SAH. Results : We identified 12 patients from six families with at least two first-degree relatives with SAH. All patients had affected first-degree relatives; in five families, they were siblings. The mean age at the time of rupture was 49.75 years; in four families, the age difference was within 5 years. In five patients (42%), the aneurysm was located in the middle cerebral artery. Only one patient had an aneurysm in the anterior communicating artery. Conclusion : In agreement with previous studies, our results showed that familial aneurysms, in comparison with non-familiar aneurysms, ruptured at a younger age and smaller size, had a high incidence in the middle cerebral artery, and were underrepresented in the anterior communicating artery. Interestingly, the age at the time of rupture was similar between relatives. Screening should be considered in the fifth or sixth decade for those who have a sibling with SAH.