• 한국측량학회지
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• 제24권1호
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• pp.131-138
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• 2006

최근 점사상을 활용하는 GIS 분야에서 많은 양의 점사상 축적과 함께 점분포 패턴을 정량적으로 평가하기 위한 알고리즘의 개발이 이루어지고 있다. 여러 연구에서 K-지표를 활용하여 점사상의 공간적 밀집 여부의 검증이 가능하며, 사건과 배경의 상호 관련성 평가가 가능함을 증명하고 있다. 한편 GIS 데이터로서의 점사상은 측량에 의해 실좌표가 관측된 사상보다는 주소와 같은 위치참조에 의해 간접적으로 좌표가 주어지는 경우가 많으며, 경우에 따라서는 통계자료와 같이 행정구역과 같은 지역단위의 집계자료로 대표되어 점사상 각각이 좌표를 가지지 못하는 경우도 많다. 본 연구에서는 GIS를 이용한 공간 분석 기법으로서 K-지표를 계산할 때, 집계자료의 사용이 K-지표의 산출에 미치는 영향을 평가하기 위하여, 원데이터(지번단위), 지형적인 집계(블록 단위), 행정적인 집계(행정구역 단위) 등 세 가지 형태의 데이터로부터 산출된 K-지표를 비교, 분석하였다. 연구결과 가까운 거리에서 밀집이 심하게 일어나는 점사상의 경우에는 행정구역과 같은 큰 지역단위를 이용하면 결과의 왜곡이 심하게 발생하여 활용이 곤란하나, 블록단위의 K-지표는 원데이터의 K-지표와 거의 유사함을 알 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.744-749
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• 2005

The train configuration is based on one unit like basic 4 cars to multiple unit operation. Each unit has unique node such as train formation number. Some equipments(TC, CC) of TCMS are connected to the master TC through the LonWorks network. When the train is consist of multiple unit, TCMS has to implement quick network for data communication overall train. But a variable time delay is generated when it is performed communication with point to point type using train formation number. In this paper we propose new method to know the node information of adjacent unit. that is to add digital input signals notifying cab direction at any cabin. Also, we provide the optimized screen design that all collected information via network is displayed by each unit.

• 대한전자공학회논문지SD
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• 제42권10호
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• pp.55-64
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• 2005

본 논문에서는 실시간 3D 가속을 효과적으로 하기 위해 기하학 처리 과정에 적합한 부동 소수점 연산기를 설계하였다. 설계한 부동 소수점 연산기는 IEEE-754 단정도 형식을 지원하도록 하여 기하학 처리에 적합하게 하였고 설계한 부동 소수점 연산기는 Xilinx-Vertex2에서 부동소수점 덧셈/곱셈기는 100 MHz, 부동소수점 NR 역수 계산기는 120 MHz, 부동 소수점 멱승기는 200 MHz, 부동 소수점 역 제곱근 연산기는 120 MHz의 동작 주파수를 각각 확인 하였다. 또한 설계된 부동소수점 연산기를 이용해 실제 기하학 프로세서를 구현하여 실제 3B 데이터 처리를 확인하였다.

• 한국조경학회지
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• 제29권1호
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• pp.22-31
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• 2001

The purpose of this study is to compare calculated pollutant loadings using pollutant load unit factors and vector type coverage, and expected mean concentration(EMC) and raster type of digital elevation model(DEM). This study is also focusing on comparison of the advantages and the disadvantages of the two methods, and seeking for a method of calculation of pollutant loadings using DEM. Estimation of pollutant inputs using pollutant load unit factors has limitations in identifying seasonal variations of pollutant loadings. Seasonal changes of runoffs should be considered in the calculation of pollutant loadings from catchments into reservoirs. Evaluation of pollutant inputs using runoff-coefficient and EMC can overcome these drawbacks. Proper EMC and runoff-coefficient values for the Koeup stream catchments of the Koheung estuarine lake were drawn from review of related papers. Arc/Info was employed to establish database of spatial and attribute data of point and non-point pollutant sources and characteristics of the catchments. ArcView was used to calculate point and non-point pollutant loadings. Pollutant loads estimated with either unit factors-coverages, i.e., pollutant load unit factors and vector coverages f point sources and land use, or EMC and digital elevation mode(DEM) were compared with stream monitoring loads. We have found that some differences were shown between monitoring results and estimated loads by Unit Factors-Coverage and EMC-DEM. Monthly variations of pollutant loads evaluated with EMC-DEM were similar to those with monitoring result. The method using EMC-DEM can calculate accumulated flows and pollutant loads and can be utilized to identify stream networks. A future research on correcting the difference between vector type stream using flow direction grid and digitalizing vector type should be conducted in order to obtain more exact calculation of pollutant loadings.

• 한국물환경학회지
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• 제26권4호
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• pp.598-607
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• 2010

One of constraints in the application of unit-load method to estimate non-point pollution loads in the total water pollutant load management system (TWPLMS) is the limited numbers of applicable unit-loads. Since only 7 unit-loads are currently available for total 28 land-use categories in the national land register data, each unit-loads inevitably have to represent several land-use categories regardless of their actual land coverage characteristics. As a way to minimize the problem, this study suggested a nested application of the available unit-loads based on the analysis of high resolution aerial images taken in the Kyeongan watershed. Statistical analysis of three selected land-use categories such as school, apartment complex, and golf course showed that there exit significant (95% confidence level) relationships between the registered land-uses and actual land coverages. The school and apartment complex currently considered as 100% ground have only 65% and 80% of ground characteristics, respectively. Golf course, which is considered as 100% pasture, has about 5% of ground area. This indicates that the unit-load method using in TWPLMS can give over estimated non-point pollutant loads for the school and apartment complex (19.8~54.4%) but under estimation for the golf course (80.9%).

• 전기학회논문지
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• 제58권6호
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• pp.1241-1245
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• 2009

As FFT(Fast Fourier Transform) processor is used in OFDM(Orthogonal Frequency Division Multiplesing) system. According to increase requirement about mobility and broadband, Research about low power and low area FFT processor is needed. So research concern in reduction of memory size and complex multiplier is in progress. Increasing points of FFT increase memory area of FFT processor. Specially, SRU(Signal Reordering Unit) has the most memory in FFT processor. In this paper, we propose a reduced method of memory size of SRU in FFT processor. SRU of 64, 1024 point FFT processor performed implementation by VerilogHDL coding and it verified by simulation. We select the APEX20KE family EP20k1000EPC672-3 device of Altera Corps. SRU implementation is performed by synthesis of Quartus Tool. The bits of data size decide by 24bits that is 12bits from real, imaginary number respectively. It is shown that, the proposed SRU of 64point and 1024point achieve more than 28%, 24% area reduction respectively.

• 한국통신학회논문지
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• 제21권5호
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• pp.1345-1359
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• 1996

This paper presents a floating point arithmetic unit (FPAU) for supescalar microprocessor that executes fifteen operations such as addition, subtraction, data format converting, and compare operation using two pipelined arithmetic paths and new rounding and normalization scheme. By using two pipelined arithmetic paths, each aritchmetic operation can be assigned into appropriate arithmetic path which high speed operation is possible. The proposed normalization an rouding scheme enables the FPAU to execute roundig operation in parallel with normalization and to reduce timing delay of post-normalization. And by predicting leading one position of results using input operands, leading one detection(LOD) operation to normalize results in the conventional arithmetic unit can be eliminated. Because the FPAU can execuate fifteen single-precision or double-precision floating-point arithmetic operations through three-stage pipelined datapath and support IEEE standard 754, it has appropriate structure which can be ingegrated into superscalar microprocessor.

• 한국정보통신학회논문지
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• 제17권12호
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• pp.2921-2926
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• 2013

본 논문에서 제안된 십진 부동소수점 연산 장치(decimal floating-point arithmetic unit, DFP)는 L.K.Wang에 의해 제안된 십진 부동소수점 유닛을 기반으로 하여 데이터의 병렬 처리를 통해 동일한 크기의 지수를 갖는 두 오퍼랜드의 가수 영역의 고속 연산을 지원하도록 재설계 하였다. 제안된 십진 부동소수점 연산 장치는 Xilinx ISE를 이용하여 xc2vp30-7ff896 타겟 디바이스로 합성하였으며 (주)시스템센트로이드의 Flowrian을 통해 시뮬레이션 검증하였다. 제안된 방식은 L.K.Wang에 의해 제안된 설계 방식 및 참고문헌 [6]의 설계 방식과 비교하여 동일한 입력 데이터를 이용하여 시뮬레이션 검증한 결과, L.K.Wang 방식보다 약 8.4%, 참고문헌 [6]의 방식보다 약 3% 정도의 처리 속도가 향상되었다.

• 한국습지학회지
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• 제19권3호
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• pp.279-286
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• 2017

본 연구에서는 기저유출을 고려한 관측 자료 기반 오염부하량을 이용하여 비점오염 유출특성과 신규 원단위의 활용 가능성을 검토하였다. 이를 위해 금강 수계 주원천 유역의 9개 강우사상을 대상으로 디지털 필터 기법을 이용하여 유출성분을 분리하고 수치적분법을 적용하여 비점오염부하량을 산정하였다. 연구결과 비점오염 평균 기여율은 BOD 31.34%, T-N 58.94%, T-P 50.42%로 BOD의 경우 기저유출의 영향이 큰 것으로 분석되었다. 또한, 신 원단위를 적용한 오염부하량이 구 원단위를 적용한 경우에 비해 관측부하량에 근접하는 것으로 분석되었다. 이러한 결과는 효율적인 유역의 수질관리를 위해서는 직접유출에 따른 오염부하뿐만 아니라 기저유출에 따른 오염부하 관리도 필요함을 의미한다.

• 환경영향평가
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• 제18권5호
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• pp.281-291
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• 2009

In Total Water Pollutant Load Management System of Korea, unit load approach based on land register data is currently used for the estimation of non-point pollutant load. However, a problem raised that land register data could not always reflect the actual land surface coverages which determine runoff characteristics of non-point pollution sources. As a way to overcome this, we tried to establish quantitative relationships between the aerial images (0.4m resolution) which reflect actual land surface coverages and the land registration maps according to the 19 major designated land-use categories in Kyeongan watershed. Analyses showed different relationships according to the land-use categories. Only a few land-use categories including forestry, road and river showed essentially identical and some categories such as orchard, parking lot and sport utility site showed no relationships at all between image data and land register data. Except for the two cases, all the other categories showed statistically significant linear relationships between image data and land register data. The analyses indicate that using high resolution aerial maps is a better way to estimate non-point pollutant load. If the aerial maps are not available, application of the linear relationships as conversion factors of land register data to image data could be an possible option to estimate non-point pollutant loads for the specific land-use categories in Kyeongan watershed.