• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.29-35
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• 2012

Most Augmentative and Alternative Communication(AAC) use exclusive equipment or studied desktop, tablet PC based windows. Besides, the preceding study offers proper noun dictionary so, henceforward study has problem to innumerable proper noun processing. This paper suggests a method of proper noun processing using a mobile smart equipment. And via the button with virtual keyboard input method and the errors that can occur is also proposing a complementary way. AAC system to check availability for application on Android has been implemented. Experimental results, depending on user location and selection of proper nouns in the around could produce a sentence is derived.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.145-150
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• 2000

Out-of-sphericity is degree of deformation of an air bearing sphere deviated from a perfect sphere. This paper investigates numerically the effect of out-of-sphericity error on the radial stiffness of an air bearing Three types of out-of-sphericity modes are considered. in this study the stiffness is calculated from pressure distribution at the bearing surface which is obtained by solving th Reynolds equation. in some cases large out-of-sphericity errors are found to improve the stiffnesses of air bearings. This implies that an air bearing of perfect hemispheres is not necessarily of the best performance. Thus much labor and cost in manufacturing air bearings can be saved, In addition the radial stiffness of an air bearing depends greatly on the application direction.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.105-112
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• 2001

The purpose of this study is to assess the stability of tunnel for a high speed railway crossing the fault zone. The area where the tunnel crossed the fault zone can be unstable during construction and operation. Geotechnical investigations have been conducted to determine an optimum excavation method by obtaining the material properties around the fault zone and to check the stability of the tunnel. For the numerical analysis, the FLAC, numerical analysis code based on finite difference method, was utilized to analyze the behavior of the fault at three points having typical ground conditions. Based on the results of numerical analysis, the combinations of compaction grouting and LW grouting were determined as suitable methods for pre-excavation Improvement of the ground surrounding the tunnel opening. In conclusion, the stability of the tunnel construction for the high speed railway within the fault zone may be obtained by adopting the optimum excavation method and the reinforcement method. The numerical analysis based on FLAC program contains errors caused by assumptions used in numerical analysis, therefore constant monitoring with respect to the change of ground condition and groundwater is highly recommended to minimize the numerical error and the possibility of damage to tunnel.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.136-137
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• 2008

A current transformer(CT) should provide the faithful reproduction of the primary current to the measurement or the protection equipments. The exciting current resulting from the hysteresis characteristics of the core causes an error between the primary current and the secondary current of the CT. A compensating algorithm for the secondary current of the current transformer that removes the effects of the hysteresis characteristics of the iron-core has proposed. The core flux linkage is calculated by integrating the measured secondary current, and then inserted into the flux-magnetizing current curve to obtain the magnetizing current. The exciting current at every sampling interval is obtained by summing the core-loss and magnetizing currents and added to the measured current to obtain the correct current. This paper describes the innovative new product of the iron-cored electronic current transformer. This product composes an iron-cored CT and an intelligent electronic device(IED) ported the compensating algorithm. The test results of the iron-cored electronic current transformers in Korea Electro-technology Research Institute(KERI) are presented.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.508-509
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• 2008

마이크로그리드는 소형 분산 에너지원(MicroSource)으로 이루어진 분산전원망의 총칭으로 다수의 수용가들을 위하여 수요지에서 전력을 생산 및 공급하는 기술로 기본적으로 여러 수용가의 부하 및 분산발전기들이 하나의 덩어리를 형성하게 되는 새로운 개념의 배전망이다. 계통과 분리하여 운전이 가능한 마이크로그리드는 계통 연계 시 과도현상을 줄이기 위해 연계지점의 전압, 주파수, 위상을 일치하여 투입되어야 한다. 본 논문에서는 마이크로그리드 계통 재 연계 시 과도 특성을 모의한 결과를 제시하였다. 전력계통과의 분리 후 MicroSource의 전압의 크기, 주파수 및 위상을 제어하여 전력계통에 재연계하여 과도현상을 모의하는 기초연구를 진행하였다.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.307-309
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• 2007

SVDD의 scale prob1em을 해결하기 위하여, 학습 데이터를 sub-groupings하여 group 단위로 SVDD를 통해 학습함으로써 학습 시간을 줄이는, K-means clustering을 이용한 SVDD 방범(KMSVDD)이 제안되었다. 하지만 KMSVDD는 K-means clustering 알고리즘의 본질상 최적의 K값을 정하기 힘들다는 문제와, 동일한 데이터를 학습할지라도 clustered group이 램덤하게 형성되기 때문에 매번 학습의 결과가 달라지는 문제점이 있었다. 또한 데이터의 분포 상태와 관계없이 무조건 타원(dlliptic) 형태의 K개의 cluster로 나누기 때문에 각각의 나눠진 cluster들은 데이터 분포에 대한 특징을 나타내기 힘들게 된다. 이러한 문제점을 해결하기 위하여 본 논문에서는 데이터 분포에서 mode를 먼저 찾은 후 이 mode를 기준으로 clustering하는 Mean Shift clustering 방법을 이용한 SVDD를 제안하고자 한다. 제안된 알고리즘은 KMSVDD와 비교해 데이터 학습 속도에서는 큰 차이가 없으면서도 데이터의 분포 상태를 고려한 형태로 clustering 한 sub-group을 학습하므로 학습의 정확도가 일정하게 되며, 각각의 cluster는 데이터 분표의 특징을 포함하는 효과가 있다. 또한 Mean Shift Kernel의 bandwidth의 결정은 K-Means의 K와는 달리 어느 정도 여유를 갖고 결정되어도 학습 결과에는 차이가 없다. 다양한 데이터들을 이용한 모의실험을 통하여 위의 내용들을 검증하도록 한다.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.65-68
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• 2002

Distributed Generators (DG) are rapidly increasing and most of them are interconnected with distribution network to supply power into the network. Therefore, DG may make significant impacts on distribution system operation. protection, and control with respect to the voltage regulation, voltage flicker, harmonics, fault current levels, the losses of the network, etc. These impacts would be demerits for both of DG and distribution networks. And the operation of DG may be influenced by the abnormal grid condition such as disturbances occurred in the neighboring distribution feeders as well as the feeder directly connected with DG. This paper describes the influence of fault occurred in the interconnected power network on the DG operation and the impact of DG on the network load during the interruptions of utility power.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.7
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• pp.354-360
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• 2008

Power-related issues have become important considerations in current generation microprocessor design. One of these issues is that of elevated on-chip temperatures. This has an adverse effect on cooling cost and, if not addressed suitably, on chip reliability. In this paper we investigate the general trade-offs between temporal and spatial hot spot mitigation schemes and thermal time constants, workload variations and microprocessor power distributions. By leveraging spatial and temporal heat slacks, our schemes enable lowering of on-chip unit temperatures by changing the workload in a timely manner with Operating System (OS) and existing hardware support.

• Korean Journal of Head & Neck Oncology
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• v.28 no.1
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• pp.46-49
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• 2012

Primary tumors of the parapharyngeal space are rare and account for only 0.5% of head and neck neoplasm. About 80% of parapharyngeal tumors are benign and 20% are malignant. Parapharyngeal space is classified into the Prestyloid space and the Poststyloid space. The Poststyloid tumors are usually benign lesions such as neurogenic tumors, paragangliomas, vascular tumors, or aneurisms. The origins of prestyloid tumors are much more diverse pathology, the pleomorphic adenoma in parotid deep lobe is most common type. Several surgical approaches have been introduced for management of parapharyngeal tumor, such as transcervical, transparotid-transcervical and the transcervical-transmandibular approaches. This paper is aimed to present a large parapharyngeal space tumor removed via transoral approach. It is possible to remove easier by using microdebrider. The pathologic diagnosis was pleomorphic adenoma.

• The Journal of Engineering Geology
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• v.11 no.3
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• pp.295-301
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• 2001

Geological and geophysical surveys were performed to examined the cause of the rock-mass slide occurred at the opening site of the Wanglim tunnel of the Seoul-Pusan High Speed Railway. The results of geophygical survey and geometrical analysis for the geological structures indicate that the rock-mass slide was triggered by the heavy rainfall which increases the groundwater level and results in high pore pressure in the N60$^{\circ}$ E-trending major fractured zone of the slope, and that the foliation dipping toward the vertical open face of the slope acted as a main sliding plane during movement.