• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.119-125
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• 2005

The current automotive is seeking the improvement of performance, the prevention of environmental pollution and the saving of energy resources according to miniaturization and lightweight of the components. And the variance analysis on the basis of structure analysis and DOE is applied to the lower control am. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering weight, stress and fatigue lift. The lower control arm is performed the fatigue analysis using the load history of real road test. The design model is determined using the optimization of acquired load history with the fatigue characteristic. The characteristic function is made use of the optimization according to fatigue characteristics to consider constrained function in the optimization of DOE. The structure optimization of a lower control arm according to fatigue characteristics is performed. And the optimized design variable is D=47 m, T=36mm, W=12 mm. In the real engineering problem of considering many objective functions, the multi-objective optimization process using the mathematical programming and the characteristic function is derived an useful design solution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.967-975
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• 1998

This paper presents a system to cancel the multi-user interference of synchronous DS/CDMA systems by using the estimation circuit and the reference correlator. In the code-division multiple access(CDMA) scheme, the spectrum of the user's signal is directly spreaded by means of the Simplex coed or the phase offsetted PN code. It is interesting for the Simplex code and the PN code to have a similar correalation property. It these codes are used in DS/CDMA systems, the number of acceptable users can be increased in comparison with conventioal DS/CDMA systems. This thesis presents a interference cancellation model to cancel the multi-use interference in DS/CDMA systems by using Simples code of PN code as a spreading sequence. In AWGN environment, we analyze interference generated from other users and compare the resulting performance with that of the conventioanl receiver in same user side.

• Journal of the Semiconductor & Display Technology
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• v.5 no.3 s.16
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• pp.29-32
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• 2006

Because of new requirements related to the employment of SMT(Surface Mounting Technology) manufacturing and the diversity of components on high density PCB(Printed Circuit Boards), Thermal control of the reflow process is required in order to achieve acceptable yields and reliability of SMT assemblies. Accurate control of the temperature distribution during the reflow process is one of the major requirements, especially in lead-free assembly. This study has been performed for reflow process using the commercial CFD(Computational Fluid Dynamics) tool for predicting flow and temperature distributions. Porous plate was installed to prevent leakage flow which was one of the major problem of temperature uniformity in the reflow process. There is a separation region where the flow is turned. Outside wall made of porous plate is to prevent and minimize separation region for acquiring uniform temperature during operation. This paper provided design concept from CFD results of the steady state temperature distribution and flow field inside a reflow oven.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.100-103
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• 2007

A microlens array has been required to improve light conversion efficiency in image sensors. A microlens array can be usually fabricated by photoresist reflow, hot-embossing, micro injection molding, and UV-imprinting. Among these processes, a UV-imprinting, which is operated at room temperature with relatively low applied pressure, can be a desirable process to integrate microlens array on image sensors, because this process provides the components with low thermal expansion, enhanced stability, and low birefringence, furthermore, it is more suitable for mass production of high quality microlens array. In this study, to analyze the optical properties of the wafer scale microlens array integrated image sensor, another wafer scale simulated image sensor chip array was designed and fabricated. An aspherical square microlens was designed and integrated on a simulated image sensor chip array using a UV-imprinting process. Finally, the optical performances were measured and analyzed.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.2
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• pp.94-100
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• 2013

Musculoskeletal ultrasound has unique advantages that may be free from exposure to radiation, low price compared to MRI, outpatient procedure that can be easily accessible, and better accuracy combined with physical examination. Dynamic ultrasound performed with stress tests are known to be useful for detecting the hidden lesions in the tendons, ligaments, nerves. Ultrasound in the elbow can be used easily in the outpatient for evaluation of the joint surface and synovial space; diagnosis for tendon diseases such as lateral epicondylitis, medial epicondylitis and morbidity of peripheral nerves; guide for anterior-posterior bursal and intra-articular injections.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.984-990
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• 2016

In wireless mesh sensor networks (WMSNs), sensor nodes are connected in the form of a mesh topology and transfer sensor data by multi-hop routing. A data aggregation method for WMSNs is required to minimize the number of routing hops and the energy consumption of each node with limited battery power. This paper presents a shortest path data aggregation method for WMSNs. The proposed method utilizes a simple hash function based on shuffled row major indexing for addressing sensor nodes. This allows sensor data to be aggregated without complex routing tables and calculation for deciding the next hop. The proposed data aggregation algorithms work in a fractal fashion with different mesh sizes. The method repeatedly performs gathering and moves sensor data to sink nodes in higher-level clusters. The proposed method was implemented and simulations were performed to confirm the accuracy of the proposed algorithms.

• Physical Therapy Korea
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• v.7 no.4
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• pp.16-38
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• 2000

일상생활동작(activities of daily living)을 주요 목적이자 치료 수단으로 사용하고 있는 작업치료사들이 그 활동 중의 하나인 성적 욕구의 표현(sexual expression)에 대해 체계적인 접근이 미진하다는 지적을 극복 하고자 본 연구가 계획되었다. 특히 만성 장애가 있는 65세 이상 연령층의 성생활에 대해 기술적으로 접근하는 방법을 고안하는 것은 상당한 임상적 의미를 부여 할 수 있다. 본 연구의 주된 목적은 관절염이 65세 이상의 미국인의 성생활에 미치는 영향과 대책에 대한 논의를 작업치료사의 입장에서 자연스럽게 유도하기 위한 질문내용을 고안하는데 있다. 본 연구자들은 광범위한 문헌연구를 바탕으로 7개항의 질문을 작성하여 10명의 노인학 전공 작업치료사들에게 비평을 의뢰하였다. 7명의 작업치료사들이 전문가로서의 세밀한 답변을 해주었고 그들은 공통적으로 일상생활 중의 하나인 성생활이 삶의 질을 향상시키는데 매우 중요한 역할을 함을 강조하였다. 이들 전문가들의 조언을 바탕으로 새로운 질문서가 완성되었다.

• Journal of IKEEE
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• v.5 no.1 s.8
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• pp.52-58
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• 2001

This paper describes a TTL-to-CMOS input buffer of an SRAM which dissipates a small operating power dissipation. The input buffer utilizes a transistor structure with latch circuit controlled by a internal activation clock pulse. During the low state of that pulse, input buffer is disabled to eliminate dc current. Otherwise, the input buffer operates normally. Simulation results showed that the power-delay product of the purposed input buffer is reduced by 33.7% per one input.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.862-865
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• 2011

WebGL is a cross-platform web standard for a low-level 3D graphics API based on OpenGL ES 2.0 and presents 3D graphics in web browsers without installing extra plug-ins. The reason that WebGL is notable is because it is included in the HTML5 standard which is getting the spotlight as a next-generation RIA(Rich Internet Application) platform for variable devices such as PCs, smart phones, table PCs, and smart TVs. In this research, we would like to introduce and develop a behavior engine for easy and rapid authoring of complicated interactions and 3D object's behavior models in WebGL-based contents.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.6
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• pp.502-507
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• 2006

According to large-sized LCD, the CCFL used in backlight is getting longer and a backlight using one lamp makes a needed brightness by arranging lamp in parallel because of the limit of brightness. In this paper, the inverter to nu the large back-light in 42inch LCD TV using 20 CCFLs was designed to produce the same output on each lamp in any input condition. Supplementing the conventional high-low method driving CCFL, by adopting high-high one, the brightness variation among each lamp sides is improved. Additionally, to improve the brightness variation, the method connecting the lamp and the capacitor in series is used. The proposed system was verified by the experiment.