• Korean Management Science Review
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• v.23 no.3
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• pp.209-224
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• 2006

The mobile communication technology would be one of the most appropriate means for achieving process innovation in the actual business area. This article performs a simulation study to examine the effect of introducing a mobile technology to the after-sales service and its logistics process. The performances of the two different systems, before and after introducing a mobile technology, are examined based on operational cost, operational efficiency, and customer service level using a discrete event simulation. The real-world data, extracted from a leading Korean electronics firm, was collected for this study. The results show that the TO-BE(after) model outperforms the AS-IS(before) model over all the performance indices. And the effects of introducing the mobile technology are more significant on the more tightly controlled inventory policy.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.17-19
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• 2008

An advanced TFT-LCD structure was proposed to increase aperture ratio (AR). In this structure, metal layers formed below the data lines are used as light-blocking layers, achieving higher AR ratio than that of a conventional structure. Since average misalignment between the metal light-blocking layers and pixel electrodes is smaller than that of black matrixes on color filter glass, substantially less light-blocking areas are needed to achieve misalignment margin. The AR of the LCD panel fabricated by using proposed structure was enhanced by 18.7 % over that of the conventionally structured panel.

• Proceedings of the KSR Conference
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• 2006.11a
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• pp.145-159
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• 2006

This paper describes the development of a clustering based fuzzy controller of an electromagnetic suspension vehicle using gain scheduling method and Kalman filter for a simplified single magnet system. Electromagnetic suspension vehicle systems are highly nonlinear and essentially unstable systems For achieving the levitation control of the DC electromagnetic suspension system, we considered a fuzzy system modeling method based on clustering algorithm which a set of input/output data is collected from the well defined Linear Quadratic Gaussian(LQG) controller. Simulation results show that the proposed clustering based fuzzy controller methodology robustly yields uniform performance with adequate gap response over the mass variation range.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1814-1820
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• 2010

Korean Train Express (KTX) has been commercially operating and achieving elevation on transport capacity since 2004. And the first hish-speed prototype test train, HSR-350x, was developed and succeeded in testing of running over 350km/h. Now KTX-II based on HSR-350x was started in service run. The new high-speed train development project, HEMU-400x project, has started since 2007. The protype train is being designed and manufactured. After the train are developed completely, it will run on the commercial line and will be test to verify the estimated performance. The authors devised the performance evaluation method and process of the HEMU-400x prototype system. And we introduce the definite performance test items and the method to vitrificate them in this paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.68-86
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• 2015

Future wireless network aims to integrate different radio access networks (RANs) to provide a seamless access and service continuity. In this paper, a new resource denotation method is proposed in the WLAN and LTE heterogeneous networks based on a concept of spectral bandwidth mapping. This method simplifies the denotation of system resources and makes it possible to calculate system residual capacity, upon which an economic model-based network selection algorithm is designed in both under-loaded and over-loaded scenarios in the heterogeneous networks. The simulation results show that this algorithm achieves better performance than the utility function-based access selection (UFAS) method proposed in [12] in increasing system capacity and system revenue, achieving load balancing and reducing the new call blocking probability in the heterogeneous networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.996-1015
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• 2016

A common concern regarding cooperative spectrum sensing (CSS) schemes is the occupied bandwidth and the energy consumption during the transmissions of sensing information to the fusion center over the reporting control channels. This concern is intensified if the number of cooperating secondary users in the network is large. This article presents a new fusion strategy for a CSS scheme, aiming at increasing the energy efficiency of a recently proposed bandwidth-efficient fusion scheme. Analytical results and computational simulations unveil a high increase in energy efficiency when compared with the original approach, yet achieving better performances in some situations, and lower implementation complexity.

• Archives of Plastic Surgery
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• v.40 no.6
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• pp.783-786
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• 2013

For years, the gold standard in facial rejuvenation has been the face lift. However, exploring new, less complex procedures for achieving the same goal is currently drawing interest. Rejuvenation of the perioral area is a difficult task for plastic surgeons because of the minimal effect that face lift procedures have over this region and the lack of published material on the subject. In this article, the descended mouth corner anguloplasty technique is presented. It is a 20-minutes lift technique that can correct this typical feature of the ageing mouth. The authors have treated 71 patients using the technique with consistently good results, with just one requiring revision. They conclude that this procedure by itself and in combination with other small operations or even a full face lift can rejuvenate the ageing face.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.550-554
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• 2003

In order to detect very short electromagnetic pulses (EMP) with picosecond width, a receiving antenna with a wide bandwidth and good sensitivity over several GHz is needed. In this paper, the receiving characteristics of various thin wire monopole (or dipole) antennas with nonreflecting resistive loading are analyzed for determining the optimum configurations. This study also indicates that it is possible to choose an ideal load impedance for achieving the required fidelity and sensitivity. The analysis is facilitated by introducing the frequency transfer function.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.559-573
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• 2016

In this paper, we investigate the problem of achieving proportional fairness in hierarchical wireless sensor networks. Combining clustering formulation and scheduling, we maximize total bandwidth utility for proportional fairness while controlling the power consumption to a minimum value. This problem is decomposed into two sub-problems and solved in two stages, which are Clustering Formulation Stage and Scheduling Stage, respectively. The above algorithm, called CSPF_PC, runs in a network formulation sequence. In the Clustering Formulation Stage, we let the sensor nodes join to the cluster head nodes by adjusting transmit power in a greedy strategy; in the Scheduling Stage, the proportional fairness is achieved by scheduling the time-slot resource. Simulation results verify the superior performance of our algorithm over the compared algorithms on fairness index.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.400-409
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• 2011

The purpose of this study was to investigate the influence of irrational beliefs on parenting stress of mothers with early children. For achieving this purpose, Irrational Belief Test and Parenting Stress Index were administered to 300 mothers with early children in Busan and data from 234 mothers were used for statistical analysis. Collected data were analyzed using Pearson correlation coefficient and stepwise multiple regression analysis. The results of correlational analysis showed that irrational beliefs were positively related to parenting stress. Anxious over-concern factor was related to all parenting stress variables. The results of stepwise regression analysis revealed that 2~4 irrational beliefs significantly influenced parenting stress; sub-factors of parenting stress variable that irrational beliefs had the most effect on was competence factor. Based upon these results, it can be concluded that irrational belief is an important variable which predicts parenting stress of mothers with early children.