• 대한수학교육학회지:학교수학
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• 제7권4호
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• pp.353-373
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• 2005

최근의 급속한 정보화 사회로의 전환에 편승하여 이산수학에 대한 관심과 이에 따른 연구가 활발해지고 있으며, 제 7차 교육과정에서 이산수학을 선택과목으로 지정할 만큼 그 중요성이 인정되고 있다. 본 연구는 네트워크문제와 관련된 이중계수 문제, 한붓그리기, 그리고 도로망문제를 중심으로, 초등 수학영재학생을 위한 학습프로그램을 구성하는 문제와 관련된 교수학적 변환에 대하여 논의하였다.

• 보건의료생명과학 논문지
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• 제8권2호
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• pp.121-125
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• 2020

인원계수는 특정 시설의 혼잡도나 이용량을 파악하여 시설을 효율적으로 관리하거나 화장실 등 특정 장소의 출입인원을 파악하여 자동으로 절전기능을 구현함으로써 에너지 절약을 최대화하기 위한 용도로 늘 관심있는 방법이었다. 영상처리에 의한 인원계수 방법은 매우 비용이 비싸며 조명의 주위환경에 심하게 영향을 받는 단점이 있고 area sensor의 경우 인원이 팔짱을 끼고 근접하여 통과할 경우 1명의 인원으로 계수하는 단점이 있다. 비용이 비싸고 조명에 영향을 받거나 특정한 경우 인원계수가 부정확한 기존의 방법을 해결하기 위하여 본 논문에서는 라이다(LIADAR)의 원리를 이용한 새로운 인원계수 방법을 제안한다. 병원 출입인원을 정확하기 계수하는 것은 병원시설을 관리하는 데도 도움이 되겠지만 코로나19가 만연한 현시점에서 효율적인 방역대책을 세우는 데도 도움이 될 것이다.

• 한국입자에어로졸학회지
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• 제10권4호
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• pp.163-167
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• 2014

Particle number portable emission measurement system (PN-PEMS) is an instrument for measuring number concentration of automobile exhaust. The principle of some pre-existing commercial PN-PEMS is to charge particles and display the number of particles by measuring current. However, this method has some problems for measuring exhaust. In this study, to solve these issues, we have developed a single particle counting PN-PEMS based condensation particle counter (CPC). The PN-PEMS based CPC does not affect driving conditions and it is convenient for mobile because the instrument is small and light in structure. We evaluated counting efficiency of PN-PEMS based CPC by using electrostatic method (electrometer and Faraday cup).

• 전력전자학회논문지
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• 제23권2호
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• pp.106-111
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• 2018

In this work, we propose techniques for estimating the SOC of Li-air battery. First, we describe and explain the operation principle of the Li-air battery. Energy density of the Li-air battery was compared with that of the Li-ion battery. The capacity and impedance value of the fully discharged voltage is analyzed, and the OCV value for SOC estimation is measured through the electrochemical characterization of the Li-air battery. Estimation value is obtained by SOC modeling through extended Kaman filter and is compared with the measurement value from the Coulomb counting method. Moreover, the performance of SOC estimation circuit is evaluated.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1259-1265
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• 2020

A beta ray scanner was proposed for in-situ discrimination of beta and gamma ray radioactivity. This scanner is based on the principle that gamma and beta rays experience different changes in detection efficiency in scintillators with different geometries, especially with regard to the scintillator thickness. The ratios of the counting rates of gamma rays (R_gamma), beta rays (R_beta), and sample measurements (R_total) in a thick scintillator to those in a thin one are reported. The parameter X_thick, which represents the counting rate contributed by beta rays to the total counting rate in the thick scintillator, was derived as a function of those ratios. The values of R_gamma and R_beta for ⁶⁰Co and ⁹⁰Sr sources were estimated as 3.2 ± 0.057 and 0.99 ± 0.0049, respectively. The estimated beta ray contributions had relative standard deviations of 2.05-4.96%. The estimated range of the beta rays emitted from ⁹⁰Sr was 19 mm as per the Monte Carlo N-Particle simulation, and this value was experimentally verified. Homogeneous and surface contaminations of ⁶⁰Co and ⁹⁰Sr-⁹⁰Y were simulated for application of the proposed method. The counting rate contributed by the beta rays was derived and found to be proportional to the concentration of ⁹⁰Sr-⁹⁰Y contamination.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.755-767
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• 2020

A significant development has been made on a new fatigue damage model applicable to Gaussian wide band stress response spectra using numerical approximation methods such as data processing, time simulation, and regression analysis. So far, most of the alternative approximate models provide slightly underestimated or overestimated damage results compared with the rain-flow counting distribution. A more reliable approximate model that can minimize the damage differences between exact and approximate solutions is required for the practical design of ships and offshore structures. The present paper provides a detailed description of the development process of a new fatigue damage model. Based on the principle of the Gaussian wide band model, this study aims to develop the best approximate fatigue damage model. To obtain highly accurate damage distributions, this study deals with some prominent research findings, i.e., the moment of rain-flow range distribution MRR(n), the special bandwidth parameter μk, the empirical closed form model consisting of four probability density functions, and the correction factor QC. Sequential prerequisite data processes, such as creation of various stress spectra, extraction of stress time history, and the rain-flow counting stress process, are conducted so that these research findings provide much better results. Through comparison studies, the proposed model shows more reliable and accurate damage distributions, very close to those of the rain-flow counting solution. Several significant achievements and findings obtained from this study are suggested. Further work is needed to apply the new developed model to crack growth prediction under a random stress process in view of the engineering critical assessment of offshore structures. The present developed formulation and procedure also need to be extended to non-Gaussian wide band processes.

• 한국정보처리학회논문지
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• 제3권1호
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• pp.167-180
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• 1996

스칼라 처리지향의 기계에서 벡터 처리를 위해서는 스칼라 처리가 벡터 요소 수 만큼 수행되어야 한다. 소위 von Neumann원리에 의한 벡터 처리기법이다. 메모리를 악세스 하는 장치로는 명령어의 순차적 계수를 위한 프로그램 계수기 뿐이기 때문에 벡터 데이터의 악세스는 명령어의 지시나 또는 ALU 의 주소 계산에 의해 수행되어 야 한다. 여기서는 재래식 개념의 하드웨어적 결합을 보충하기 위해 벡터 요소들을 입체적으로 악세스하기 위한 악세스 장치의 설계를 제안한다. 벡터의 구조 처리를 위한 필요성은 명령어군에 포함되었고 그들 명령어들은 데이터 처리와 동시에 데이터 악세스 안에 처리되도록 한다.

• Journal of Mechanical Science and Technology
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• 제18권6호
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• pp.879-894
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• 2004

The image processing technique is simple and, in principle, can handle particles with various shapes since it is based on direct visualization. Moreover, a wide measurement area can be covered with appropriate optical arrangement. In the present paper, various techniques of image processing for sizing and counting particles are reviewed and recent developments are introduced. Two major subjects are discussed in detail: identification of particles (i.e., boundary detection and pattern recognition) and determination of in-focus criteria. Finally, an overall procedure for image processing of spray particles is suggested.

• 소음진동
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• 제10권4호
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• pp.686-691
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• 2000

In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1883-1888
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• 2000

In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.