• 산업공학
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• 제15권4호
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• pp.452-459
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• 2002

The volume of B2C products rapidly increases according to the activation of the electronic commerce. Small and medium electronic commerce companies request the establishment of Parcel Warehouse &Distribution Center(PWDC) that is invested by the post office. This paper presents an economic evaluation method for PWDC from the perspectives fo PWDC and the post office. Two types of warehouses are considered as alternatives for PWDC. One is the conventional warehouse, and the other is the automamic warehouse that is characterized by AS/RS and automatic dispenser system. A benefit/cost analysis method is used to evaluate PWDC since it has the property of public enterprise. A PWDC which will be located in Seoul and adjacent to a concentrated post office is selected as a case study to illustrate the procedure of economic analysis.

• 산업경영시스템학회지
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• 제21권45호
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• pp.201-213
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• 1998

We address the problem of choosing the most economic mean value for an automatic filling operation on a production line through the sampling inspection. If quality characteristic of a unit is less than inspection specification then the goods is not accepted. Otherwise, it is accepted. The lots that the numbers of non-conforming units in a sample are larger than the allowable number of non-conforming units are rejected. The non-conforming units in the rejected lots are separated by the screening inspection. The non-conforming units separated are sold in discount price. We assume that quality characteristic is larger-the-better characteristic, the distribution of quality characteristic is normal distribution, and the standard deviation of the distribution is known. This paper presents total expected profit function model considering sales revenue, inspection costs, and material costs. The manufacturing process mean value maximizing total expected profit is determined, and the results of the process target value and total expected profit is analyzed as coefficients change.

• 한국인터넷방송통신학회논문지
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• 제17권2호
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• pp.25-31
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• 2017

본 논문은 웹하드, 토렌트 및 해외 웹사이트를 통해 불법적으로 유통되고 있는 웹툰 저작물에 대상으로 모니터링 및 식별 기술을 개발하여 불법 유통을 효과적으로 차단함으로서 웹툰 저작물의 저작권을 보호하고 건전한 시장을 조성하기 위한 연구이다. 본 논문에서는 웹툰 서비스 사이트로부터 웹툰 저작물을 자동으로 수집하고, 수집된 웹툰 저작물로부터 특징점을 추출하여 이를 데이터베이스에 저장하기 위한 기술을 다룬다. 이를 위하여 시스템의 성능 및 기능 요구사항을 분석하고 웹툰 서비스 사이트의 구조를 분석하여 웹툰 저작물 자동 수집 및 특징점 등록 시스템을 제시하고자 한다. 제시된 시스템을 통해 웹툰 저작물이 게시되어 특징점이 등록될 때까지 소요되는 시간 동안 발생하는 불법유통에서 매우 중요한 초기 차단도 가능해진다.

• 한국정보통신학회논문지
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• 제24권9호
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• pp.1215-1223
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• 2020

최근 서울 경기를 비롯한 전국에서 국지성 집중호우, 태풍 등 악천후 관련 자연재해가 증가함에 따라 이에 대한 방재 및 물관리 대책이 필요한 실정이다. 이러한 수재해를 관측하기 위해 사용되는 우량계는 지상의 강우를 연속적·직접적으로 측정할 수 있는 장점이 있는 반면, 우량계 미설치 영역에 대한 공간적인 강우 분포를 정확하게 제공할 수 없다. 이러한 문제를 해결하고자 강수의 공간분포를 측정할 수 있는 전자파 기반 센서인 전파강수계(EWRG, Electromagnetic Wave Rain Gauge)를 개발하였다. 본 논문에서는 전파강수계의 FPGA 기반 신호처리 설계 방법을 제안한다. 전파강수계의 신호처리는 크게 LFM 파형의 ADC 및 DDC와 펄스압축, 상관 계수 및 강수 파라미터 산정으로 설계하였다. 본 연구를 통해 LFM 파형과 펄스압축 신호를 이론적으로 분석하였으며, 전파강수계 신호처리 설계를 위해서 FPGA 기반의 신호처리 설계 및 검증을 수행하였다.

• 센서학회지
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• 제19권6호
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• pp.490-496
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• 2010

In this study, in order to overcome the weakness of acoustic field analysis which is generally used for ultrasonic probe performance evaluation, automatic acoustic field measurement system and evaluation parameters were proposed. The comparisons between acoustic field simulation and measured acoustic distribution data of normal and abnormal channels were conducted to evaluate the availability of proposed system and evaluation parameters. First, the impulse response characteristic of sample probe was investigated to classify the normal elements and abnormal elements. And then, normal channels and abnormal channels with abnormal element were chosen. The suggested 12 evaluation parameters were calculated using the acoustic fields of these channels. The availability of proposed automatic acoustic field measurement system and evaluation parameters was confirmed. And the performance evaluation of ultrasonic probe using acoustic field analysis could be easier and faster.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1399-1410
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• 2003

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

• Journal of Communications and Networks
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• 제8권2호
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• pp.212-219
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• 2006

In this paper, a new turbo codes-based hybrid automatic repeat request (TC-HARQ) scheme with segment selective repeat (SSR) is proposed. The main strategy is, upon retransmission, to repeat the data that are most important for the next round of decoding based on the distribution of residual errors after current decoding. The performance in terms of reliability and throughput is analyzed. To adapt to correlated fading channels where an inter-leaver is always employed before transmission, we further modify the SSR strategy so that data having experienced correlated deep fading are selected for retransmission. Finally, this proposed scheme is applied to the wideband code division multiple access (WCDMA) system under frequency selective fading channels. Simulation results demonstrate that in all single and multiple user cases, SSR-based TC-HARQ leads to significant throughput improvement with similar bit error rate (BER) performance as compared to type-I TC-HARQ.

• 융합보안논문지
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• 제10권3호
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• pp.9-14
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• 2010

본 논문에서는 디지털 콘텐츠에 대한 안전하고 신뢰성 있는 유통, 전달, 취약성 점검을 위한 정보보호의 자동분석 방법을 위한 네트워크 구조와 분석 모델을 제시한다. 제시된 네트워크에서는 firewall과 IDS(Intrusion Detection System)를 이용하며, 자체적인 위협을 평가하기 위한 에이전트를 활용하는 방안을 제시하며, 주요 기능으로는 보안 범위 선정, 관련 데이터 수집/분석, 수준평가 및 대책 제시 등을 포함한다. 효율적인 자동화 분석 모델을 개발하기 위해서는 콘텐츠의 상호 유통과 웹서버-사용자간 트래픽 분석에 기초한 네트워크의 설계와 정보보호 및 자동분석 알고리즘의 개발 그리고 효율적인 DRM/PKI 등의 도구 개발이 필요함을 알 수 있다.

• 산업경영시스템학회지
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• 제10권16호
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• pp.133-141
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• 1987

Man-machine assignment problem with random service and processing times is considered in this paper. Assuming heterogeneous semi-automatic machines, the problem is dealt with as follow; 1. For the different type of machines that have probabilistics distribution of processing time and nan service time, man·machine assignment problem is solved by heuristic method using expected time value if machine. 2. Since each related time is a random variable, the performance of the optimal assignment obtained from the above method is verified through monte carlo simulation method. 3. The above procedures are programed by BASIC language to use easily and rapidly in the personal computer. The result of this study can contribute to productivity enhancement by increasing the efficiencies of both operators and machines.

• 조명전기설비학회논문지
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• 제27권9호
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• pp.108-113
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• 2013

Change of supply voltage, customer load, output of distributed generation, etc cause voltage change in distribution system. OLTC and SVR are usually used to supply normal voltage at customer. But usage of these devices is inefficient and uneconomical in certain circumstances. To solve this problem, new pole transformer which has automatic tap changer is developed. The transformer changes tap when voltage changes. And it has latch switch and reactor for supplying power without outage. To verify normal operation of tap changer, test is conducted. SVR and 50kVA load is used for test.