• 한국화재소방학회논문지
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• 제26권5호
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• pp.1-7
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• 2012

현재 국내에서 수계소화설비의 배관부속류와 밸브류의 마찰손실 계산에 사용되고 있는 등가길이표에 대하여 비교 연구하였다. 3가지 종류의 등가길이표가 주로 사용되고 있으며 안타깝게도, 가장 광범위하게 사용되고 있는 등가길이표에 대한 근거를 찾을 수 없었다. 세 개의 등가길이표를 비교했을 때 각 등가길이표간 동일 항목의 등가길이에 있어 최대 2.4배까지 차이가 있었다. 많은 해외 Project들을 수행하고 있는 국제화시대에 부응할 수 있도록 공학적으로 합리적이며 단일화된 등가길이표를 사용하여야 한다. 이에 합리적인 등가길이표를 제시한다.

• 한국인터넷방송통신학회논문지
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• 제19권1호
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• pp.261-264
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• 2019

경계선 추적을 통해서 결정된 영역의 내부를 래스터 스캔하면서 내부를 일정한 값으로 채워 넣는데 이를 '색칠하기(blob coloring)'라고 하며 보통은 '연결 성분 라벨링(Connected Region labeling)'라 부른다. 이 과정은 각 독립적인 영역들을 고유의 라벨 값으로 구분하여 표시하게 된다. 본 논문에서는 래스터 스캔 결과로 산출된 동치테이블을 동일한 라벨끼리 그룹화 하는데 수많은 그룹이 서로 얽혀서 복잡하므로 신속하고 간단하게 처리할 수 있는 개선된 알고리즘을 제안하고자 한다. 동치테이블 내에서 동일한 그룹으로 묶기 위한 이동 절차를 8단계 알고리즘으로 제시하고 이에 따른 수행 결과를 보여준다.

• 한국정밀공학회지
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• 제19권1호
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• pp.65-70
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• 2002

An analysis method for calculating motion accuarcy of double sides hydrostatic table is proposed in this paper. In this method, profiles of each rails are assumed as periodic function, therefore it is represented as the sum of spacial frequencies. Bearing clearance at any position rail is depended on the variation of linear, angular motion error of table and the form errors of both sides of a rail. Finite element method is applied to calculate pressure distributions in bearing clearance. In order to simplify the analyzing process, double sides table model is converted into equivalent single side table model. Results calculated by the proposed modeling method agree well with the results directly caculated by double sides modeling method, and also agree well with experimental results. From the theoretical and experimental analysis, it is verified that the proposed analysis method is very effective to analyze the motion accuracy of double sides hydrostatic table.

• Journal of Yeungnam Medical Science
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• 제4권2호
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• pp.83-88
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• 1987

본 병원 18MeV 선형가속기에 대한 equivalent square field를 측정하여 다음과 같은 결과를 얻었다. 1. $10{\times}10cm$ 이하의 작은 면적에서 매우 가늘고 긴 조사에서는 실제 측정치와 약 0.5%의 차이를 나타내고 있다. 2. $10{\times}10cm$보다 크며 $15{\times}15cm$보다 작은 중간 면적에서는 실제 측정치와 약 0.64 %의 차이를 나타내고 있다. 3. $15{\times}15cm$보다 큰 면적에서는 실제 측정치와 약 0.24%의 차이를 나타내고 있다. 위와 같은 측정결과로 (6)식에 의해서 구해진 Table 1의 equivalent square field는 매우 바람직함을 알 수 있으며, 특히 매우 가늘고 긴 작은 면적에 대해서는 BJR table보다 오차를 훨씬 줄이고 있어서 식도암 등을 조사할 시에는 매우 유용함을 알 수 있다. 더 나아가 전 영역을 포함하는 더욱 더 근시적인 equivalent square field method가 연구되어야 할 것이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.842-849
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• 2009

The objective of this study is to investigate design parameters of a tuned liquid column damper(TLCD), which is affected by various excitation amplitudes, through shaking table test. Design parameters of a TLCD are examined based on the equivalent tuned mass damper(TMD) model of a TLCD, in which the nonlinear damping of a TLCD is transposed to equivalent viscous damping. Shaking table test is carried out for a TLCD specimen subjected to harmonic waves with various amplitudes. Transfer functions are ratios of liquid displacement of TLCD and control force produced by a TLCD, respectively, with respect to the acceleration excited by a shaking table. They are derived based on the equivalent TMD model of a TLCD. Then, the variation of design parameters according to the excitation amplitude is examined by comparing analytical transfer functions with experimental ones. Finally, the dissipation energy due to the damping of a TLCD, which is experimentally observed from the shaking table test, is examined according to the excitation amplitude. Comparisons between test results and analytical transfer functions showed that natural frequencies of TLCD and the ratio of the liquid mass in a horizontal column to the total liquid mass does not depend on the excitation amplitude, while the damping ratio of a TLCD increases with larger excitation amplitudes.

• 한국소음진동공학회논문집
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• 제19권11호
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• pp.1167-1176
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• 2009

The objective of this study is to investigate design parameters of a tuned liquid column damper(TLCD), which is affected by various excitation amplitude, through shaking table test. Design parameters of a TLCD are examined based on the equivalent tuned mass damper(TMD) model of a TLCD, in which the nonlinear damping of a TLCD is transposed to equivalent viscous damping. Shaking table test is carried out for a TLCD specimen subjected to harmonic waves with various amplitude. Transfer functions are ratios of liquid displacement of TLCD and control force produced by a TLCD, respectively, with respect to the acceleration excited by a shaking table. They are derived based on the equivalent TMD model of a TLCD. Then, the variation of design parameters according to the excitation amplitude is examined by comparing analytical transfer functions with experimental ones. Finally, the dissipation energy due to the damping of a TLCD, which is experimentally observed from the shaking table test, is examined according to the excitation amplitude. Comparisons between test results and analytical transfer functions showed that natural frequencies of TLCD and the ratio of the liquid mass in a horizontal column to the total liquid mass do not depend on the excitation amplitude, while the damping ratio of a TLCD increases with larger excitation amplitude.

• 한국결정학회지
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• 제1권1호
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• pp.57-59
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• 1990

International Tables of X-Ray Crystallography Vol.IV(1974) Table 2.3.2에 오자가 있다. 점군 422의 등가반사면들은 hkl=hkl=hkl=hkl=hkl=khl=khl=khl이다.

• Structural Engineering and Mechanics
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• 제56권1호
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• pp.27-47
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• 2015

In this study, the accuracy and reliability of fully nonlinear method against equivalent linear method for dynamic analysis of soil-structure interaction is investigated comparing the predicted results of both numerical procedures with the results of experimental shaking table tests. An enhanced numerical soil-structure model has been developed which treats the behaviour of the soil and the structure with equal rigour. The soil-structural model comprises a 15 storey structural model resting on a soft soil inside a laminar soil container. The structural model was analysed under three different conditions: (i) fixed base model performing conventional time history dynamic analysis, (ii) flexible base model (considering full soil-structure interaction) conducting equivalent linear dynamic analysis, and (iii) flexible base model performing fully nonlinear dynamic analysis. The results of the above mentioned three cases in terms of lateral storey deflections and inter-storey drifts are determined and compared with the experimental results of shaking table tests. Comparing the experimental results with the numerical analysis predictions, it is noted that equivalent linear method of dynamic analysis underestimates the inelastic seismic response of mid-rise moment resisting building frames resting on soft soils in comparison to the fully nonlinear dynamic analysis method. Thus, inelastic design procedure, using equivalent linear method, cannot adequately guarantee the structural safety for mid-rise building frames resting on soft soils. However, results obtained from the fully nonlinear method of analysis fit the experimental results reasonably well. Therefore, this method is recommended to be used by practicing engineers.

• 대한전기학회논문지
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• 제32권7호
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• pp.247-253
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• 1983

Cauer and Foster type LC networks being examined, table for illustration is presented. This paper presents a thoerem to determine and generate the exact number of LC equivalent networks obtained by combining Cauer and Foster type. By combining Cauer and foster type, one can construct greater number of canonic equivalent networks than is obtainable through use of Cauer type alone. Furthermore, the number of equivalent networks is rapidly increased with increased with increasing the order. An illustrative example is provided to confirm the proposed theorem. This theouem is easily applied to RC and RL cases.

• 한국군사과학기술학회지
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• 제12권3호
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• pp.368-377
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• 2009

In this paper we study the gyro bias calibration method of SDINS(Strap-Down Inertial Navigation System). Generally, SDINS's calibration is performed in 2-axis(or 3-axis) rate table with chamber for varying ambient temperature. We assumed that the majority of calibration-parameter except for gyro bias is knowned. During gyrobias calibration procedure, it can be induced some disturbances(accelerometer's short-term error induced rate table rotation and anti-vibration mount's rotation). In these cases, old gyro-bias calibration methods(using velocity error or attitude error) have an error, because these disturbances are not detectable at the same time. So that, we propose a new gyro-bias calibration method(heading error minimizing using equivalent linear transformation) that can detect anti-vibration mount's rotation. And we confirm efficiency of the new gyro-bias calibration method by simulation.