• 전기전자학회논문지
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• 제7권2호
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• pp.210-217
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• 2003

본 논문에서는 수리형태학에 기반한 새로운 특징값 추출 방법을 제안하였다. 수리형태학적 패턴 분포함수에 의한 수리형태학적 공간주파수를 소개하고 이를 새로운 특징인 평균높이를 정의하는데 적용하였다. 평균높이는 내용기반 이미지 검색을 위한 인덱스 키를 생성하는데 사용되는 특징값을 정의하기 위하여 사용하였다. 제안한 방법의 우수성을 다양한 영상에 대한 실험을 통하여 증명하였다. 또한 기존의 검색방법은 검색하는 이미지 데이터마다 에지 검출단계에서 적절한 문턱값에 의한 이진화 처리가 요구되어 지나 제안한 방법은 이진화가 필요 없어서 그 효용성이 크다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.42-45
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• 2002

A novel characteristic value extraction method based on morphological spatial frequency is proposed. Morphological spatial frequency defined by morphological pattern distribution function is introduced. Superiority of the method was proved for various images by experiment. Furthermore the fact that the proposed method does not need threshold to obtain binary image provides its applicability to content-based image retrieval.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.325-329
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• 2003

In this paper. the stability and performance analysis of wave-based teleoperation system is presented. For stability and performance analysis with respect to the variation of characteristic impedance b, loop gains of communication channel and minimum value of trasmitted impedance from slave side to the master side are considered. The stability of slave side may be enhanced by increasing characteristic impedance b, whereas exssively high value of b may degrade the performance, which imply a tradeoff between stability and performance.

• 대한수학회논문집
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• 제37권3호
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• pp.635-648
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• 2022

In this paper, we establish an asymptotic formula for mean value of $L^{(k)}({\frac{1}{2}},\;{\chi}_P)$ averaging over ℙ_2g+1 and over ℙ_2g+2 as g → ∞ in odd characteristic. We also give an asymptotic formula for mean value of $L^{(k)}({\frac{1}{2}},\;{\chi}_u)$ averaging over 𝓘_g+1 and over 𝓕_g+1 as g → ∞ in even characteristic.

• 한국정보통신학회논문지
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• 제23권10호
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• pp.1282-1289
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• 2019

임피던스 변환회로의 신호 전달특성(S21)을 측정하기 위해서는 두 개의 임피던스 변환회로를 대칭 연결하여야 한다. 하지만 두 개의 임피던스 변환회로를 대칭 연결한 회로의 신호 전달특성은 중간 연결 선로의 길이에 의해 영향을 받는다. 본 논문에서는 임피던스 변화회로의 정확한 신호 전달특성을 얻기 위한 중간 연결 선로의 길이를 수식으로 유도하였다. 수식을 이용하여 계산하면 4:1(50-Ω:12.5-Ω) 임피던스 변환회로의 정확한 신호 전달특성을 얻기 위한 중간 연결 선로의 전기적 길이는 약 45°이다. 계산된 연결 선로의 길이를 적용하여 1GHz에서 λ/4-마이크로스트립 임피던스 변환회로를 제작하여 신호 전달특성을 측정하였다. 제작된 대칭 연결된 임피던스 변환회로의 신호 반사 특성(S11)은 0.980GHz에서 -40.64dB, 신호 전달 특성(S21)은 -0.154dB였다. 이는 제작 회로에 대해 이론적으로 살펴본 중심 주파수의 987MHz 변화, 마이크로스트립 선로의 신호 손실 -0.15dB 값과 거의 동일한 값이다.

• 산업경영시스템학회지
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• 제39권2호
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• pp.37-45
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• 2016

Control chart is representative tools of statistical process control (SPC). It is a graph that plotting the characteristic values from the process. It has two steps (or Phase). First step is a procedure for finding a process parameters. It is called Phase I. This step is to find the process parameters by using data obtained from in-controlled process. It is a step that the standard value was not determined. Another step is monitoring process by already known process parameters from Phase I. It is called Phase II. These control chart is the process quality characteristic value for management, which is plotted dot whether the existence within the control limit or not. But, this is not given information about the economic loss that occurs when a product characteristic value does not match the target value. In order to meet the customer needs, company not only consider stability of the process variation but also produce the product that is meet the target value. Taguchi's quadratic loss function is include information about economic loss that occurred by the mismatch the target value. However, Taguchi's quadratic loss function is very simple quadratic curve. It is difficult to realistically reflect the increased amount of loss that due to a deviation from the target value. Also, it can be well explained by only on condition that the normal process. Spiring proposed an alternative loss function that called reflected normal loss function (RNLF). In this paper, we design a new control chart for overcome these disadvantage by using the Spiring's RNLF. And we demonstrate effectiveness of new control chart by comparing its average run length (ARL) with ${\bar{x}}-R$ control chart and expected loss control chart (ELCC).

• 대한전자공학회논문지SP
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• 제37권4호
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• pp.20-28
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• 2000

오차확산 하프토닝 기법은 연속계조 영상을 이진영상으로 생성시 우수한 재현성을 보인다. 그러나 표시오차의 특성분석에서 경계정보의 재현성이 다소 떨어지는 특성을 보인다. 이러한 경계정보의 재현성 개선하기 위해 전처리 필터를 적용하는 오차확산 기법을 제안한다. 제안한 전처리 필터는 원영상의 수평 및 수직 방향의 미분값, 필터의 가중치 함수로 구성된다. 첫째, 원영상의 수평 및 수직 방향의 미분값은 현재 화소를 중심으로 하여 $3{\times}3$ 인접화소에 Sobel 연산자를 적용시켜 얻는다. 둘째, 필터의 가중치 함수는 미분값의 크기를 포함하는 함수와 미분값의 부호로 구성된다. 제안한 기법을 적용한 하프토닝 영상은 경계가 강조되어 시각적으로 선명한 결과를 보인다. 원영상과 오차확산된 하프토닝 영상과의 차이(표시오차)를 환상 평균 전력 스펙트럼 밀도를 이용하여 기존의 경계강조 오차확산 알고리즘과 비교한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.2203-2204
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• 2006

When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results. using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.571-572
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• 2006

When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results, using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1446-1448
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• 2002

The short-time permissible temperature of an overhead distribution line conductor is determined by the softening characteristics of ACSR-OC, ACSR AW/OC 160, typical conductors employed in the overhead distribution line. Transient heat transfer equation and Newton's cooling law were applied to analyze the heating and cooling effects of the insulating conductors, respectively, and the error of co-relation was calibrated after simulating the softening test to assess the short-time characteristic of the insulating conductor. In order to verify the softening characteristic, the conductors were tested with heat cycle. The test was totally carried out 200 cycles, and 1 cycle was to heat and cool at 1.1 times permissible current of the conductor, 1.15 times for 120 minutes, respectively. After heating, the tensile strength and surface of the conductor were observed. In case of ACSR-OC, as the result of 100 hour heating test, the tensile strength of the insulator was 0.8 times the initial value. This is equivalent to the value of the conductors which are used for 10 years at sites.