• 한국통신학회논문지
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• 제32권2A호
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• pp.195-202
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• 2007

A differential space-frequency block code - orthogonal frequency division multiplexing (SFBC-OFDM) scheme as a multiple-input multiple-output (MIMO) transmission technique for next-generation digital multimedia broadcasting (DMB) is proposed in this paper. A linear decoding method for differential SFBC, which performs comparably to the ML decoding method, is derived for the cases of two or four transmit antennas. A simple table lookup method is proposed to improve the efficiency of the encoding/decoding process of DSFBC for the case of non-constant modulus constellations. A DMB MIMO channel model, developed by extending the 3GPP MIMO model to fit DMB environments, is used to compare BER performances of differential space block code schemes for various channel environments. Simulation results show that the differential SFBC-16QAM scheme using either four transmit antennas with one receive antenna or two transmit antennas with two receive antennas achieves a performance gain of 12dB than that of the conventional DQPSK scheme, even with a data rate twice faster.

• 정보과학회지
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• 제4권2호
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• pp.65-73
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• 1986

Compiler 교육용 Compiler의 필요성은 강조할 필요가 있다. 이 교육용 Compiler가 가져야 할 성질은 다음과 같다. 첫째, Modular programming Technique사용하여 이해하기 쉬운 작은 program 형태로 만들어야 한다. 그렇게 함으로써 학생들이 상호결합(interface)변수와 형태를 알고 Compiler의 한 부분을 자신의 program으로 대치한 후 실험하여 볼 수 있다. 둘째; 내부에서 사용되는 Table은 간단한 형태로 구성한다. 세째; 다른 언어의 Compiler를 쓸때 사용하는 program(예를들면 parser generator)이 있어야 한다. 이것을 이용하여 학생들은 자신이 만든 언어의 Compiler를 학기중에 만들 수 있다. 넷째; REAL TIME clock을 이용하여 각 program module이 사용한 시간을 찍어낼 수 있어야 한다. 이렇게 함으로써 어떤 module이 가장 많은 시간을 소모하며, 이것을 개선하는 방 법을 찾아낼 수 있다. 다섯째; Compile된 결과를 Assembler 언어로도 출시시킬 수 있어야 한다. 위와 같은 교육용 Compiler의 제작 방법과 그 문제점에 대하여 서술하려고 한다.

• 산업공학
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• 제15권2호
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• pp.147-151
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• 2002

Presented in this paper is a prototype of dedicated CAM system for a human bust, not a relief, machining. The input of this system is a STL file which comes from measuring machine, and the output is machining data for a 3-axis CNC milling machine with an index table. The system consists of three main modules, which are shape import and transformation, modeling of jig and fixture, and calculation of machining area. Proposed system architecture and the main modules are briefly described. To get machining region for semi-finish and finish machining stages, two concepts of machining area, machinable and scannable, were tried. Machinable area was suitable for the purpose.

• 한국음향학회지
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• 제18권1호
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• pp.45-52
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• 1999

본 논문에서는 HDTV 비디오 신호를 처리함에 있어 신호의 병목현상을 없애주고 신호의 원활한 처리를 위해 새로운 알고리듬을 적용하여 54MHz의 동작 주파수를 갖는 패커를 제안하고 설계하였다. 또한 제안된 패커의 성능을 검증하기 위해 조합논리를 이용한 ROM 테이블 구조를 갖는 DCT 계수 부호화부를 함께 설계하므로써 DCT 계수 부호화부의 출력을 제안된 패커의 입력 데이타로 사용하였다. 본 논문의 회로는 VHDL 코드를 이용하였고 SYNOPSYS tool의 $0.65{\mu}m$ 공정을 이용한 모델링과 시뮬레이션을 수행하였다.

• 시스템엔지니어링학술지
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• 제9권2호
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• pp.55-68
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• 2013

This study aims to analyze how much KF-X production impacts on national economy by measuring economic spread effect based on inter-industry analysis. In order to evaluate the economic impact of KF-X production, we used input-output table of year 2007 of Korea. The results shows that KF-X production induces the production of 3,129 billon won and the value added of 1,206 billon won respectively. Also there are the creation of about 13,208 employment in the industry. The results from this study can be used as a basis for the further research on whether or not KF-X production could be processed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.7-10
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• 2001

We have developed a prototype dedicated CAM system for machining a human bust that is not a relief. The input is STL file format, and the output is NC-codes for machining on a 3-axis general purpose CNC milling machine with an index table attached. Main modules are STL import, STL transformation, modeling jig/fixture, master model generation, and calculation of machining area. System architecture is proposed and main modules are briefly described. We adopted the angle between tool-axis and the surface normal vector to calculate machining area, and tested at several degrees.

• 디지털산업정보학회논문지
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• 제8권1호
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• pp.107-115
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• 2012

This paper proposes on the structure for reducing the circuit area and increasing the computation speed in implementing to hardware using the SEED algorithm of a 128-bit block cipher. SEED cipher can be implemented with S/W or H/W method. It should be important that we have minimize the area and computation time in H/W implementation. To increase the computation speed, we used the structure of the pipelined systolic array, and this structure is a simple thing without including any buffer at the input and output circuit. This circuit can record the encryption rate of 320 Mbps at 10 MHz clock. We have designed the circuit with the Verilog HDL coding showing the circuit performances in the figures and the table.

• 한국정밀공학회지
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• 제17권7호
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• pp.106-112
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• 2000

The purpose of this paper is to study on the control of the engine idle speed under sudden A/C load which is one of the most severe disturbances on engines. Three types of the closed-loop controller are developed for the stable engine idle speed control. The input of the controller is an error of rpm. The output of the controller is an ISCV duty cycle. The anticipation delay is considered to deal with the delay time of the air mass in engine. The PID, Fuzzy and PID-type Fuzzy controllers with the anticipation delay have improved the engine idle speed condition more than current ECU map table under the A/C load.

• 농촌계획
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• 제23권3호
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• pp.147-161
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• 2017

Climate changes from global warming and reduction in agricultural land result in volatility of prices of agricultural products, causing a imbalance of food market in Korea. It is necessary to develop a transnational food industry cooperation system among Korea, China and Russia that directly or indirectly affect food industry in terms of the whole industrial network. This study analyzes the value chain and linkage in the agriculture, forestry and fisheries industries in three nations. The unit structure and the industrial patterns of three nations were derived using the World Input-output Table (WIOT) from 2004 to 2014 every five years. This paper is expected to contribute to develop food security cooperation in the northern part of the Korean peninsula and to promote the mutual growth of food industry through industry linkage and cooperation.

• 한국통신학회논문지
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• 제22권7호
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• pp.1403-1410
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• 1997

Because streaming mode connection server suitable to wide area ATM networks performs transmission, reception and lookup with time restriction for the transmission time of a cell, it has demerits of large cell loss incase that burst traffic occurs. Therefore, in this paper to decrease cell loss we propose a high speed CAM (Content Addressable Memory) which is capable of processing data of streaming mode connections server at a high speed. the proposed CAM is applied to forwarding table VPC map which performs function to output connection numbers about input VPI(Virtual Path Identifier)/VCI(Virtual Channel Identifier). The designed high speed CAM consist of DBL(Dual Bit Line) CAM structure performed independently write operation and match operation and two-port SRAM structure. Also, its simulation verification and full-custom layout is performed by Hspice and Composs tools in 0.8 .$\mu$m design rule.