• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권5호
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• pp.295-304
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• 2004

This paper deals with characteristic analysis method using d-q axis equivalent circuit considering iron loss in a single-phase line-start permanent magnet synchronous motor. The iron loss resistance to account for the iron loss is included in the equivalent circuit to improve the modeling accuracy. Furthermore, for the improved calculation of the iron loss, the iron loss is calculated from the magnetic flux density by 2-dimensional finite element method. The result is represented as the iron loss resistance and connected in parallel with the total induced voltage. Therefore, the currents can be expressed as the summation the output current with the current corresponding to the iron loss. Finally, the steady state characteristic analysis results are compared with the experimental results to verify this approach.

• 대한기계학회논문집B
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• 제32권11호
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• pp.817-823
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• 2008

A pin fin with variable fin base thickness is optimized based on the ratio of heat loss to the maximum heat loss using a two-dimensional analytic method. The temperature profile along the normalized radius position in the fin is presented. For fixed fin outer radius, the optimum heat loss, fin length and efficiency as a function of fin base thickness, outer radius, convection characteristic numbers ratio and ambient convection characteristic number are presented. One of the results shows that the effect of fin outer radius and ambient convection characteristic number on the optimum fin length is remarkable.

• 산업기술연구
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• 제27권B호
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• pp.71-75
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• 2007

A cylindrical pin fin with variable diameter is analyzed by using the one dimensional analytical method. Heat loss and fin efficiency are presented as a function of the fin diameter, length and convection characteristic numbers ratio. The relationship between the fin diameter and convection characteristic number over the fin for the same amount of heat loss is shown. One of the results indicates the fin efficiency increases as the fin diameter increases while that decreases as the fin length increases.

• 반도체디스플레이기술학회지
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• 제23권1호
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• pp.97-103
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• 2024

In this paper, the difference between the S-parameter and the characteristic impedance according to the structural change of the fine pitch coaxial socket was analyzed. A pitch of the probe pin was applied to 0.20mm, and ground pins of different conditions were placed on each of the five signal pins. Insertion loss and reflection loss were analyzed for the coaxial socket of normal structure and the two sockets of the proposed structure. In addition, the difference in characteristic impedance was analyzed using time domain reflectometry. Through the analysis, it was confirmed that the characteristic impedance was improved applying the new structures of the socket at the same pitch

• International Journal of Automotive Technology
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• 제8권6호
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• pp.705-711
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• 2007

A rectangular fin with a fluid in the inside wall is analyzed and optimized using a two-dimensional analytical method. The influence of the fluid convection characteristic number in the inside wall and the fin base thickness on the fin base temperature is listed. For the fixed fin volumes, the maximum heat loss and the corresponding optimum fin effectiveness and dimensions as a function of the fin base thickness, convection characteristic numbers ratio, convection characteristic number over the fin, fluid convection characteristic number in the inside wall, and the fin volume are represented. One of the results shows that both the optimum heat loss and the corresponding fin effectiveness increase as the fin base thickness decreases.

• 한국소음진동공학회논문집
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• 제11권9호
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• pp.391-397
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• 2001

The characteristic values of damping materials are variant on frequency and temperature. We measure the characteristic values(loss factor, young\\\\`s modulus) of damping materials in vibration test. We can not measure characteristic values of damping materials by themselves. So, we proposed a method, sticking damping material to thin steel beam and measuring of characteristic values of damping material on frequency and temperature. We didn\\\\`t use constraining layer but we measured characteristic values on conditioning temperature.

• 전기학회논문지
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• 제65권3호
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• pp.520-525
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• 2016

In this paper, Characteristic of power conversion unit of a railway vehicles according to contact loss in feeding system that applied impedance of rigid conductor is analyzed. It applied impedance of rigid bar in modeling of electric railway system. Railway vehicles are performed of modeling based on the performance of the electric railway vehicle. Effects of the contact loss in the power conversion unit were analyzed via main transformer of railway vehicle, the input and output voltage characteristics of the converter through contact loss was generated after linking the vehicle with feeding system.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제12권1호
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• pp.25-32
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• 2008

A pin fin is optimized based on the increasing rate of heat loss by using a two-dimensional analytic method. The optimum heat loss, corresponding optimum thermal resistance and fin length are presented as a function of the fin base thickness, convection characteristic numbers ratio, fin outer radius and ambient convection characteristic number. One of the results shows that both the optimum heat loss and fin length decrease linearly whereas the optimum thermal resistance increases very slightly with increase of the fin base thickness.

• 한국소프트웨어감정평가학회 논문지
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• 제15권1호
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• pp.109-114
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• 2019

본 논문은 프로브 핀에 대한 S-파라미터 시뮬레이션과 특성 임피던스 시뮬레이션을 수행하였고 이를 통해 프로브 핀의 고주파 성능을 분석하였다. 프로브 핀은 중앙의 한 개의 신호 핀과 상하좌우의 네 개의 접지 핀으로 배치하였다. 프로브 핀 사이의 간격을 0.35 mm, 0.40 mm, 0.50 mm으로 증가시키면서 프로브 핀의 삽입손실과 반사손실을 계산하였다. 반사손실의 주기적인 공진 현상으로 인해 프로브 핀은 서로 다른 삽입손실 특성을 가진다. 또한 프로브 핀의 배치와 피치 변화에 따른 특성 임피던스 분석을 수행하였다. 동일한 피치에서 특성 임피던스가 50 Ω에 근접하는 접지 핀 개수가 있음을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권9호
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• pp.3194-3210
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• 2022

Wall obstruction is the main factor leading to the non-line of sight (NLoS) error of indoor localization based on received signal strength indicator (RSSI). Modeling and correcting the path loss of the signals through the wall will improve the accuracy of RSSI localization. Based on electromagnetic wave propagation theory, the reflection and transmission process of wireless signals propagation through the wall is analyzed. The path loss of signals through wall is deduced based on power loss and RSSI definition, and the theoretical model of path loss of signals through wall is proposed. In view of electromagnetic characteristic parameters of the theoretical model usually cannot be accurately obtained, the statistical model of NLoS error caused by the signals through the wall is presented based on the log-distance path loss model to solve the parameters. Combining the statistical model and theoretical model, a hybrid model of path loss of signals through wall is proposed. Based on the empirical values of electromagnetic characteristic parameters of the concrete wall, the effect of each electromagnetic characteristic parameters on path loss is analyzed, and the theoretical model of regional path loss of signals through the wall is established. The statistical model and hybrid model of regional path loss of signals through wall are established by RSSI observation experiments, respectively. The hybrid model can solve the problem of path loss when the material of wall is unknown. The results show that the hybrid model can better express the actual trend of the regional path loss and maintain the pass loss continuity of adjacent areas. The validity of the hybrid model is verified by inverse computation of the RSSI of the extended region, and the calculated RSSI is basically consistent with the measured RSSI. The hybrid model can be used to forecast regional path loss of signals through the wall.