• 한국토양비료학회지
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• 제42권3호
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• pp.192-200
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• 2009

과학영농과 친환경농업이 대두되면서 토양검정량이 급속하게 증가하고 이에 대처하기 위해 신속하게 분석할 수 있는 분석 방법이 요구되고 있다. 따라서 본 연구에서는 신속 간편하게 분석할 수 있는 다성분동시 추출방법으로 개발된 Mehlich III법, Mod. Morgan법, Kelowna 법과 국내에서 사용 중인 유효태 인산 분석법인 Lancaster법, 치환성 양이온 분석법인 1M $NH_4OAc법으로 분석되는 분석치들 간의 상관관계를 검토하기 위하여 토양특성이 다양한 우리나라 농경지 115개소에서 토양을 채취하여 여러 가지 방법으로 화학적 분석을 실시하였다. 다성분동시추출 분석방법인 Mehlich III법, Mod. Morgan법, Kelowna법과 기존의 유효인산 분석방법인 Lancaster법과 치환성 양이온 분석방법인 1M $NH_4OAc법으로 추출한 분석치는 모두 고도로 유의한 직선적인 상관관계에 있었다. 유효인산은 Mehlich III법, Mod. Morgan법, Kelowna 법과 Lancaster법으로 추출되는 분석치간에 결정계수($R^2) 의 크기는 Mehlich III법($0.979^{***}$) > Kelowna법 ($0.977^{***}$) > Mod. Morgan법($0.553^{***}$)의 순으로 Mehlich III 법 이상관이 가장 높게 나타났고 Lancaster 법보다 토양 중의 인산을 평균적으로 28% 많이 추출하였다. 치환성 양이온에서도 화산회 토양에서 추출되는 나트륨 성분을 제외하고는 Mehlich III 법으로 추출되는 분석치가 1M $NH_4OAc법으로 추출되는 것과 가장 상관이 높았다. 따라서 ICP를 이용하여 유효인산과 치환성 양이온의 분석은 다성분동시추출방법인 Mehlich III법이 이용 가능할 것으로 판단되었다.

• 한국해양공학회지
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• 제25권1호
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• pp.8-13
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• 2011

A compact array system of small buoys is used for wave energy extraction. To evaluate the performance of this system, hydrodynamic analysis is carried out in regular waves using the higher order boundary element method. The motion response of each buoy is calculated considering hydrodynamic interactions caused by other buoys. The effect of energy extraction device is modeled as a linear damping load. The efficiencies of energy conversion are compared using the various sizes and arrangements of the array system and the damping coefficients for energy extraction. The increase in size or the packing ratio of the system gives better efficiency. However, the wave condition and the cost for the system should be considered to optimize performance from the perspective of engineering and economics. The proposed nondimensionalized damping coefficient for energy extraction is 0.1~0.5.

• 융합정보논문지
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• 제11권2호
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• pp.41-46
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• 2021

그레이스케일 수학적 형태학에 기초한 에지 검출 알고리즘의 방법은 영상 노이즈를 제거와 병렬처리 가능하고 연산속도가 빠르다는 장점을 갖고 있다. 그러나 단일 구조적 스케일 요소를 사용하여 영상의 에지 검출을 하는 방법은 영상정보에 따라서 영향을 받을 수 있다. 그레이스케일 형태학의 특성은 구조적원소를 반복하여 확장, 침식, 열림, 담힘 연산을 함으로써 연산 결과 에지정보 결과에 제한적일 수 있다. 본 논문에서 잡음에 강인한 방향성을 갖는 구조적원소를 적용한 후 원소내의 각 픽셀 정보에 가중치 엔트로피를 적용하는 에지 검출 알고리즘을 제안한다. 영상에 적용하는 멀티 스케일 구조적 요소를 적용한 결과와 방향성 가중치 엔트로피를 적용한 연산결과를 비교분석하였으며, 시뮬레이션 결과는 제안된 알고리즘이 에지 검출에서 우수함을 보였다.

• 전기학회논문지
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• 제56권7호
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• pp.1224-1230
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• 2007

In this paper, we study the classification of defects at steam generator tube in nuclear power plant using eddy current testing (ECT). We consider 4 defect patterns of SG tube: I-In type, I-Out type, V-In type, and V-Out type. Through numerical analysis program based on finite element modeling, 400 ECT signals are generated by varying width and depth of each defect type. In order to improve the classification performance, we propose new feature extraction technique. After extracting new features from the generated ECT signals, multi-layer perceptron is used to classify the defect patterns. Through the computer simulation study, it is shown that the proposed method achieves 100% classification success rate while the previous method yields 91% success rate.

• 한국측량학회지
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• 제37권5호
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• pp.293-302
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• 2019

In mountain accident events, it is important for the search team commander to determine the search area in order to secure the Golden Time. Within this period, assistance and treatment to the concerned individual will most likely prevent further injuries and harm. This paper proposes a method to determine the search priority area based on missing persons behavior and missing persons incidents statistics. GIS (Geographic Information System) and MCDM (Multi Criteria Decision Making) are integrated by applying WLC (Weighted Linear Combination) techniques. Missing persons were classified into five types, and their behavioral characteristics were analyzed to extract seven geographic analysis factors. Next, index values were set up for each missing person and element according to the behavioral characteristics, and the raster data generated by multiplying the weight of each element are superimposed to define models to select search priority areas, where each weight is calculated from the AHP (Analytical Hierarchy Process) through a pairwise comparison method obtained from search operation experts. Finally, the model generated in this study was applied to a missing person case through a virtual missing scenario, the priority area was selected, and the behavioral characteristics and topographical characteristics of the missing persons were compared with the selected area. The resulting analysis results were verified by mountain rescue experts as 'appropriate' in terms of the behavior analysis, analysis factor extraction, experimental process, and results for the missing persons.

• 자원환경지질
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• 제27권5호
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• pp.469-477
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• 1994

Many researchers have investigated most representative sequential extraction method using various reagents for determining the chemical forms of metals in soils and sediments. In this paper, a newly modified method for sequential extraction scheme based on Tessier's method by Environmental Geochemistry Research, Centre for Environmental Technology, Imperial College, was introduced and examined. In comparison with Tessier's method, originally designed for sediment analysis by Atomic Absorption Spectrophotometry (AAS), the sequential extraction scheme has been developed for the multi-element analysis by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The partitioning of particulate trace elements was classified into five fractions: (i) exchangeable, (ii) bound to carbonates or specially adsorbed, (iii) bound to Fe and Mn oxides, (iv) bound to organic matter and sulphides and (v) residuals. The experimental results of the pilot study for in-house reference material (HRM2) and certified international standard reference material (SRM2711) using the modified method showed not only reasonable precision and accuracy but also acceptable overall recovery rates. In addition, mine dump soils sampled in the Dalsung Cu-W mine, Korea were prepared and sequentially extracted using the method. Most of Cu was bound to organic matter/sulphides and residual fractions. The dominant fraction of soil Pb and Zn in the study area was found in the residuals. The fraction of Cd showed a wide variation between samples and could be found bound to the carbonates or specially adsorbed, oxides, organic fraction and residuals. The recovery rates of Cd, however, were poor due to relatively low Cd concentrations in soils. The heavy metals in these mine dumps appear to be in the more inert forms and should not be readily bioavailable. The soils, however, had very low pH values (average 4.1) and had sandy textures; consequently, rapid infiltration of rainfall may increase leaching of Zn and Cd which were found to be around 5 to 10% of the exchangeable fraction. As a result of the investigation of this study, it has been strongly recommended that these mine waste materials should still be considered a significant contaminant source and will need environmental remediation to prevent pollutants from being released into the environment.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.357-360
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• 2007

Efficient extraction and update of imagery is a crucial element in establishing latest geospatial information in today's fast changing Information society. Provision of Quick Bird imagery, with 61cm resolution panchromatic imagery and 2.5m resolution multi-chromatic imagery is contributing greatly in the application field if high density geospatial information. This research have conducted digital plotting utilizing stereo images provided by QuickBird satellite and evaluated the accuracy through comparison and analysis with digital map results. It turned out that result has smaller error than standard deviation of scale of 1:5,000 set by the NGII. This proves that the production of digital map at scale of 1:5,000 is possible.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.375-379
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• 1990

A microprocessor-based multi-function switchgear for the protection, measurement and control of the power system is presented. For the extraction of the RMS values of the fundamental components of current and voltage signals, a simple digital filter based on cross-correlation of the distorted signal with even and odd heptagonal waves is used. The frequency response of this filter is almost identical to that of the filter based on the discrete fourier transform, while its computational requirement is far less. For the time delay element relaying, a new log-table based relaying algorithm is suggested. The suggested use of the heptagonal wave cross-correlation digital filter algorithm and a new relaying algorithm reduce the computational needs so drastically that all functions of the switchgear can be implemented on the microprocessor system. Real time testing of the implemented daboratory prototype show good practical response under different operating conditions.

• 한국전자파학회논문지
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• 제20권8호
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• pp.730-738
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• 2009

본 논문에서는 선행 연구된 LTCC(Low Temperature Co-fired Ceramic) 적층형 대역 통과 필터 구조에 대해 기생 성분을 고려한 등가회로를 제시하고 SOC(Short-Open Calibration) 기법을 적용하여 소자값을 추출하는 과정을 보인다. 추출된 소자 값을 제시한 등가회로에 적용함으로써 위성 DMB에 적용 가능한 2차 LTCC 필터를 설계 제작하였다. 비유전율 7.8의 Dupont951을 사용하여 제작된 필터의 크기는 $2.4{\times}3.8{\times}0.378mm^3$이다. 측정 결과 1.4 dB의 삽입 손실과 32.3 dB의 반사 손실을 보였으며 설계 사양과 대체로 일치함을 보인다.

• 대한전자공학회논문지TC
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• 제45권8호
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• pp.114-120
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• 2008

본 논문에서는 단락 개방 Calibration (SOC) 방법을 이용하여 MIM 구조로 구성된 커패시터의 기생 소자 값들을 추출하였다. Strip line 으로 구성된 short, open, MIM 구조들의 산란 파라미터 행렬들은 전자기 시뮬레이터 및 벡터 네트웍 분석기를 이용하여 측정되었다. 전자기 시뮬레이션들은 3차원 구조 해석에 적합해왔던 유한 유소법 (FEM)을 이용하여 수행되었다. 적층 구조 내부에 형성된 MIM 커패시터의 전자기 영향들은 집중 소자들로 구성된 II 형 등가 회로로 제안되었고, 2 포트 네트웍 해석을 수행함으로써, 측정된 산란 파라미터들과 등가회로 소자들 간의 관계를 보였다. 제안된 SOC 방법을 이용하여 추출된 집중 소자들은 주파수 독립적인 결과를 나타낸다.