• 제목/요약/키워드: Park Kil Yong

검색결과 394건 처리시간 0.031초

ON NEARLY CONVERTIBLE (0,1) MATRICES

  • Kim, Si-Ju;Park, Yong-Kil
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제8권1호
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    • pp.25-32
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    • 2001

  • Let A be a nonnegative matrix of size $n \times n$. A is said to be nearly convertible if A(i│j) is convertible for all integers i, j$\in${1,2,…, n} where A(i│j) denote the submatrix obtained from A by deleting the i-th row and the j-th col-umn. We investigate some properties of nearly convertible matrices and existence of (maximal)nearly convertible matrices of size n is proved for any integers $n(\geq 3)$.

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600kJ급 SMES용 전도냉각시스템 열해석 (Thermal analysis of the conduction cooling system for HTS SMES system of 600 kJ class)

  • 홍용주;염한길;박성제;김효봉;고득용
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.1959-1963
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    • 2007

  • SMES systems need cryogenic cooling systems. Conduction cooling system has more effective, compact structure than cryogen. In general, 2 stage GM cryocoolers are used for conduction cooling of HTS SMES system. 1st stages of cryocoolers are used for the cooling of current leads and radiation shields, and 2nd stages of cryocoolers for HTS coil. For the effective conduction cooling of the HTS SMES system, the temperature difference between the cryocooler and HTS coil should be minimized. In this paper, a cryogenic conduction cooling system for HTS SMES is analyzed to evaluate the performance of the cooling system. The analysis is carried out for the steady state with the heat generation of the HTS coil and effects of the thermal contact resistance. The results show the effects of the heat generation and thermal contact resistance on the temperature distribution.

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지형고도자료 해상도가 가시선분석에 미치는 영향 (The Effect of Digital Elevation Resolution on LOS Analysis)

  • 어양담;박완용;이용웅;이병길;편무욱
    • 한국군사과학기술학회지
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    • 제11권3호
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    • pp.99-105
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    • 2008

  • The analysis of LOS(Line-Of-Sight) is defined as an "unobstructed view between two points". The LOS results may be influenced by terrain source, algorithm/interpolation method, etc. In the area denies any access and flight over, LOS results would be doubtful because of low precision of terrain data therefore have limitations of referring to many military applications. Using LIDAR data, LOS Analysis was performed by changing DTED resolution(1$\sim$30m) and LOS distance(50$\sim$2000m). The results of experiment shows that LOS analysis for small area, such as DMZ surveillance, were heavily influenced by DTED resolution.

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