• 한국수학사학회지
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• 제20권3호
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• pp.59-72
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• 2007

복소수 발견초기 수학자들은 복소수에 대한 거부감이 상당했으나 복소수의 대수적 연산에는 큰 어려움이 없었다. 복소수가 수학적 대상으로 인정받기까지 많은 시간이 필요했던 이유는 복소수의 기하적 해석에 많은 시행착오와 시간이 필요했기 때문이다. 본 논문은 복소수의 기하적 해석의 싹을 Euclid 원론에서 찾고, Descarte, Wallis, Wessel를 거치면서 그 싹이 틔어가는 과정을 밝히고 있다. 복소수의 기하적 해석에 대한 세 명의 수학자들의 생각은 서로 다르지만 밀접한 관계가 있다. 이들은 선분과 복소수의 관계에 주목하고, 곱셈 연산을 일반화하면서 복소수의 기하적 해석을 시도하였다.

• 한국항공운항학회지
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• 제28권2호
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• pp.29-35
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• 2020

In this paper, we established a prediction model of fuel consumption at the aircraft's taxi operation. To look for countermeasures to reduce fuel consumption and carbon emissions, Airbus A380's actual ground taxi data was used. As a result, the number of stops or turnings during the taxi operation was not related to fuel consumption. It was confirmed that the amount of fuel consumption in the taxi operation was the taxi time and the thrust change. It can be confirmed that ground control optimization, which is the result of close cooperation between the control organization and the airline, is absolutely necessary to reduce taxi time and minimize the occurrence of thrust change events.

• 한국초전도ㆍ저온공학회논문지
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• 제20권1호
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• pp.11-14
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• 2018

High Temperature Superconducting (HTS) power cables are capable of transmitting bulk power without any loss compared to conventional copper cables. The major challenge in the design of such HTS cables is the high stresses (electro-thermal/electro-mechanical) developed at high voltages, high currents and cryogenic temperatures. The safe and reliable operation of HTS cables involves lots of instrumentation for monitoring, measurement, control and safe operation. In principle, a four probe method for resistance (RTD PT-100) is used for temperature measurements at various locations of HTS cable. The number of connecting leads required for this is four times that of the number of sensors. The present paper discusses a novel way of connecting 128 RTD sensors with the help of only 14 leads using a cold electronics based multiplexer board. LabVIEW 11.0 software was used for interfacing and displaying the readings of all the sensors on computer screen.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.39-42
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• 2012

Pusher-Loaded Scrapers are important construction equipment for large earthmoving operations. Production rates of a Pusher-Loaded Scraper vary greatly in accordance with the temperature or elevation, the equipment performance, haul speed, haul-road conditions, the method of loading, and Number of scrapers per one pusher. Determining of most economical scrapers fleet regarding the size of equipment, model name, and number of scrapers demands time-consuming calculation because it needs to reference of varied performance charts or tables and repeat complicated calculation. In this study, decision-making support system for the Optimal Pusher-loaded Scrapers Fleet is suggested for the purpose of calculating easily and handling effectively variables which are changed depend of the work conditions. The prototype of this program is developed using MATLAB. And the Database of Pusher-loaded Scraper embodies Performance chart & Retarder chart, soil properties, and calculation-support table.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 10월 학술대회지
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• pp.448-455
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• 1996

In this paper, we have proposed a VQ algorithm which uses a generating order to make quantize feature vector of speech signal. The proposed algorithm inspects what codeword follows a(ter present codeword and adds new index to established codebook, when mapping speech signal. We present a variable bit rate for new codebook, and propose an efficient compressed way of information. In this way, the number of computation and the number of codewords to be searched are reduced considerably. The performance of the proposed VQ algorithm is evaluated by spectrum distortion measure and bit rate. The obtained spectrum distortion is reduced about 0.22 [db], and the bit rate is saved over 0.21 bit/frame.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1063-1070
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• 2005

Number of subway train units that Seoul Metropolitan Subway Corporation as at September 2005 is 1.944 on 4 routes from 60 units at the time of commencement of operation, having grown exponentially. Along with increase in the number of passengers the role of subway as safer and expedient means of transportation is now being required. Furthermore, the Corporation has been researching on means of improving the safety and reliability of subway entry/exit doors which has become an essential task and directly effect the safety of the passengers. In this Study, has developed sensory control system for the entry/exit door of the subway train using non-contact proximity sensor as a part of review of and measures against various issues of entry/exit door of the subway trains currently under operation. In addition, this sensor system was verified through test production and tests. If this technology becomes commercialized and practically utilized in the future, it would be able to make definite contribution to the safer transportation of passengers.

• 한국도서관정보학회지
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• 제6권
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• pp.27-52
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• 1979

The book number, among various steps of book processing works, needs more careful attention and better-organized knowledge, and it is more sensitive than other parts of cataloging. This paper will give some suggestions on ways of constructing a book number, including the definition and the types of edition indication within a book number, and analyse some problems related to their application into real situation. Three possible ways of edition indication with in a book number were explained, and examples were given for each of them. Problems occurring when these codes were applied to books were analysed. In addition to the generally recognized meaning of the book number as a mean of differentiating similar works, the edition indication can make it possible for both the library staffs and the users to identify the characteristics of a work only with the book number. Searches for mere convenient and effective ways of edition indication might be related to the cost-effectiveness of book processing, and of library operation.

• 정보학연구
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• 제12권2호
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• pp.39-47
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• 2009

Residue Number System is used for the purpose of increasing the speed of processing in the many application parts of Image Processing, Computer Graphic, Neural Computing, Digital Signal Processing etc, since it has the characteristic of parallelism and no carry propagation at each moduli. DRNS has the twice RNS Conversion, it is used to decreases the size of the operator in RNS. But it has a week point on the Second Residue to First Residue Conversion time. So, in this paper SRTFR(Second Residue to First Residue) Converter using MRC(Mixed Radix Conversion) is designed to decrease the size of RTB(Residue to Binary) Converter. Since the proposed SRTFR Converter using MRC(Mixed Rdix Convertion) has a pipeline processing. Also, modular operation is applied to at each partitioned SAM(Subtraction and Addition) and MA(Multiplication and addition). In the following study, the more effective design on MA is needed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.520-522
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• 1998

A development and application of machine vision system is introduced, which automatically recognizes the serial number of nuclear fuel tube. For the recognition, a indirect back light illuminating system is designed and a pattern matching algorithm based on neural network is applied. The various operation and management functions are also developed, on a PC under windows OS, for easy operation and data management, respectively. By the successful application of the vision system the productivity of the nuclear fuel tube recognition process is highly improved.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.288-290
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• 2003

The transformer is expected to be an essential component of resistive type superconducting fault current limiter (SFCL) for both the increase of voltage ratings in SFCL and the simultaneous quench due to different critical current between HTSC elements. However, for the design to prevent the saturation of iron core and the effective fault current limitation, the analysis for operation of SFCL with consideration for the magnetization characteristics are required. In this paper, the fault current limiting characteristics related with the magnetization ones were investigated through the variation of the ratio of the number of turns in the 1st and the 2nd windings. The proper design condition with variation of the number of turns to make the effective fault current limiting operation could be determined.