• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.544-545
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• 2012

In recent years, vehicle manufacturers have steadily developed fuel saving technologies such as multi-speed automatic transmission. With such a background, the Hyundai-powertech have developed the new 6-speed rear wheel drive(RWD)automatic transmission for FR vehicles. Despite having six-speed, it has the same number of planetary gears as a previously used five-speed automatic transmission and fewer brakes and one-way clutches than the 5 A/T, meaning that it is light, compact, and inexpensive. But, in addition to meshing this internal and external gear simultaneously and phase difference by the tooth contact point and the time difference occurs asymmetric and symmetric sideband noise and vibration caused by the modulation in the vehicle. In this paper presents a method for the design of the carrier phase difference by developing various theories and experiments for gear noise.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.766-768
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• 2001

본 논문에서는 MPEG4 표준에 의거한 멀티미디어 응용프로그램인 다자간 채팅 프로그램을 설계 구현하였다. 다자간 멀티미디어 채팅 프로그램의 영상모듈과 음성모듈은 데이터 성격상 큰 차이를 가지고 있어서 별개의 정보처리 및 전송 모델을 적용하여 설계, 구현하였다. 영상모듈은 분산처리 모델을 적용하여 실제 채팅 시에는 영상 정보를 멀티캐스트로 클라이언트간 직접 통신을 하도록 하였다. 멀티캐스트 방식은 송신자 측에서 여러 수신자 측에게 한 번에 메시지가 전송되도록 하여, 데이터의 중복전송으로 인한 네트워크 자원의 낭비를 최소화할 수 있게 된다. 반면 음성모듈은 Client-Server 모델을 적용하여 설계, 구현하였다. 음성처리 서버는 영상처리 서버와 달리 서버에서 각 클라이언트의 음성정보들을 합성하는 mixing작업을 수행하여 그 결과를 각 클라이언트로 전송하게 된다. 즉, 각 데이터 특성에 적합한 정보모델을 사용하여 다자간 채팅 프로그램을 설계, 구현하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.188-194
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• 2009

Consolidation settlement, a crucial parameter in geotechnical design of soft ground, has not been computed in a unique way due to different computation methods in practice. To improve computational error in calculating consolidation settlement, a number of researches has been attempted. Conventional 1-dimensional consolidation theory assumes the center of the clay layer as the representative point to obtain effective stress in calculation, which could resort to erroneous results. To calculate exact solutions considering initial distribution of effective stress, diving a stratum into multi-layers could resort to wasting time and effort. In the study, a novel methodology for calculating consolidation settlement via Guassian quadrature is developed. The method generally is capable of computing settlements in any case of the stress conditions encountered in fields.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.161-162
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• 2000

We propose multi-layer aspheric lenticular lens for rear projection screen to provide wide viewing angle. Each pitch of lenticular lens sheet is divided by three region and image light from projection optical system is propagated widely on each region due to different focal point. Besides, to improve vertical viewing angle of screen, we propose glass bead embedded screen on observer side of lenticular lens.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.13-17
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• 2004

As the usage of wireless LAN becomes common in working environment, the number of database systems that support both wired and wireless users increases rapidly. The characteristics of wireless LAN that its speed is slow relatively comparing to wired network and the users in its environment connects to different communication points as they moves creates another challenge to be resolved in database systems. In the environment of hybrid communication systems, wired and wireless for voluminous data amount and a number of users, the two layer architecture of the conventional client-server database systems has limitation in the system performance. This is due to that server is the only point of data service in client-server database systems. In this paper, we discuss a new extended database system architecture that data services are distributed among servers and clients based on user database access patterns in order to improve system performance. We analyze the expected system performance by using simulation technique and prove the practical utilization of the system by demonstrating experimental results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.95-102
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• 2013

This paper covers nulling algorithm. In this algorithm, we assume that nulling points are already known. In general, nulling algorithm using matrix equation was utilized. But, this algorithm is pointed out that computational complexity is disadvantage. So, we choose gradient method to reduce the computational complexity. In order to further reduce the computational complexity, we propose approximate gradient method using characteristic of trigonometric functions. The proposed method has same performance compared with conventional method while having half the amount of computation when the number of antenna and nulling point are 20 and 1, respectively. In addition, we could virtually eliminate the trigonometric functions arithmetic. Trigonometric functions arithmetic cause a big problem in actual implementation like FPGA processor(Field Programmable gate array). By utilizing the above algorithm in a multi-cell environment, beamforming gain can be obtained and interference can be reduced at same time. By the above results, the algorithm can show excellent performance in the cell boundary.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.47-51
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• 2004

Facility layout for enterprise's competitive power strengthening and construction of offensive manufacture line and direction presentation for design of production management system that is new by operation improvement according to S company. In enterprise in JIT(Just in Time) system of leading persons affecting in productions among a lot of habitat factor analyze. It is that through equipment Layout among those factors enterprise my problem improve and serves enterprise's absolute ability cultivation. Even if it is JIT production main point that affect to apply the modular production to productive system among at equipment Layout, lot size, bottleneck session etc. worker's multi-function anger, change of demand factor and productive capacity add. 'S' Through enterprise's example, I wish to establish Korean medium and small enterprises' manufacturing industry style equipment Layout model by taken place effect interpretation.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.5
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• pp.498-509
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• 2010

In this paper, a waypoint guidance law Line Tracking algorithm is designed for testing an Unmanned Airship. In order to verify, we develop an autonomous flight control and test system of unmanned airship. The flight test system is composed FCC (Flight Control Computer), GCS (Ground Control System), Autopilot & Guidance program, GUI (Graphic User Interface) based analysis program, and Test Log Sheet for the management of flight test data. It contains flight test results of single-path & multi-path following, one point continuation turn, LOS guidance, and safe mode for emergency.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.337-340
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• 2002

본 논문에서는 휠체어 시스템에 화자 독립 고립단어 인식을 위한 임베디드 시스템 설계에 관한 내용을 서술한다. 실제 환경에서는 잡음이 포함되어 있어 인식률을 저하시키므로, 잡음을 제거하는 방식 중 가장 간단한 방식인 스펙트럼 차감법(Spectral subtraction method)을 사용하여 잡음을 제거했다 전처리 단계에서는 12차 LPC&Cepstrum 방식을 사용했고, 인식 알고리즘은 DHMM (Discrete Hidden Markov Model)을 전반부 인식기로 사용했다. 이 알고리즘을 적용하기 위해서는 데이터 간소화를 위해 벡터양자화(Vector Quantization) 처리가 전제되어야한다 또한 인식알고리즘은 인식률을 향상을 위해 후처리 인식기로 신경망(MLP:Multi-layer Perceptron)을 통해서 인식률을 향상시켰다 화자 독립 시스템에 맞는 인식 단어의 구성은 총 7개단어로 남녀 총 25명 목소리로 구성하였다. 그리고 하드웨어 구성은 32-bits floating point 방식인 TMS320C32를 적용했고, 메모리 부분은 4Mbyte로 설계를 했으며, 메인보드의 설계는 현재 완성 단계에 있다.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.418-420
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• 2007

When the magnetic levitation system(MAGLEV) initially rise, The MAGLEV has a weak point that is very large variation of the electric current. In this paper, The author applied the multi-loop-control to stably control the magnetic levitation system(MAGLEV). The gains of the control algorithm were selected based on pole locations formulated from a prototype Bessel transfer function model. The design incorporate tradeoffs in DC-to-DC converter hard-ware para-meters and pole locations. In order to confirm the superiority of the proposed pole selection and controller, MATLAB simulation and experiment results are presented.