• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.167-168
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• 2005

The operational characteristics of the integrated three-phase flux-lock type superconducting fault current limiter (SFCL) were analyzed. The suggested three-phase SFCL consisted of a three-phase flux-lock reactor and three high-Tc superconducting (HTSC) elements. The former has three windings wound on an iron core, each of which has the same turn's ratio between coil 1 and coil 2. The latter are connected in series with coil 2 of each phase. The integrated three-phase flux-lock type SFCL showed the operational characteristics that the fault phase could affect the sound phase, which resulted in quenching the HTSC element in the sound phase. Through the computer simulation applying numerical analysis for its three-phase equivalent circuit, the fault current limiting characteristics of the integrated three-phase flux-lock type SFCL according to the ground fault types were compared.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.112-113
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• 2006

The operational characteristics of the integrated three-phase flux-lock type superconducting fault current limiter (SFCL) were analyzed. The suggested three-phase SFCL consisted of a three-phase flux-lock reactor and three high-$T_c$ superconducting (HTSC) elements. The former has three windings wound on an iron core, each of which has the same turn's ratio between coil 1 and coil 2. The latter are connected in series with coil 2 of each phase. The integrated three-phase flux-lock type SFCL showed the operational characteristics that the fault phase could affect the sound phase, which resulted in quenching the HTSC element in the sound phase. Through the computer simulation applying numerical analysis for its three-phase equivalent circuit, the fault current limiting characteristics of the integrated three-phase flux-lock type SFCL according to the ground fault types were compared.

• Communications for Statistical Applications and Methods
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• 제22권5호
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• pp.435-443
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• 2015

Two phase sampling design is useful to increase estimation efficiency using deep stratification, improved non-response adjustment and reduced coverage bias. The same sampling units are commonly used for the first and the second phases in complex two-phase sampling design. In this paper we consider a sampling scheme where the first phase sampling units are clusters and the second phase sampling units are list samples. Using selected clusters in first phase requires that we list up elements in the selected clusters from the first phase and then use the list as a secondary sampling frame for the second phase sampling design. Then we select second phase samples from the listed sampling frame. We suggest an estimator based on the complex two-phase sampling design with different sampling units of each phase. Also the estimated variances of the estimator obtained by using classic and replication variance methods are considered and compared using simulation studies. For real data analysis, 2010 Korea Farm Household Economy Survey (KFHES) and 2011 Korea Agriculture Survey (KAS) are used.

• 한국정보통신학회논문지
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• 제9권8호
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• pp.1780-1786
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• 2005

디지털 신호의 전송 성능은 전송 시스템의 위상 에러에 지배적으로 영향을 받고 있으며, 위상 에러는 랜덤 특성을 갖는 위상 잡음과 도플러에 의한 추적 위상 에러에 의해 발생된다. 도플러 현상이 나타나는 움직임을 갖는 이동형 위성통신 시스템에서는 랜덤 위상 잡음과 추적 위상 오차에 의한 전송 신호의 영향을 해석하여 이동형 위성통신 시스템에 적합한 시스템 요구 위상 잡음 스펙트럼을 설계해야 한다. 본 논문에서는 이동형 양방향 위성통신 시스템의 비대칭 이동 서비스에 대한 도플러 영향과 위상 에러를 해석하여 요구되는 전송 시스템의 위상 잡음 스펙트럼을 설계하고, 움직임을 갖는 단말국의 도플러 영향을 최소화하는 전송서비스를 해석한다. 제안한 위상 잡음 스펙트럼은 요구 전송 시스템에 대한 주파수 발생 부 주파수 특성으로 설계할 수 있다.

• 한국운동역학회지
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• 제30권1호
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• pp.7-16
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• 2020

Objective: It is to find factors related to stability through analysis of plantar pressure factors according to the level of instability when performing Snatch. Method: Foot pressure analysis was performed while 10 weightlifters performed 80% of the highest level of Snatch, and motion was classified and analyzed in 3 grades according to the level of instability. Results: First, in Bad Motion, the movement distance of the pressure center in the direction of ML and AP was larger significantly in Phase 2. Second, in Phase 2, the number of zero-crossing in the AP direction was larger statistically significantly in Good Motion. Third, in the bad motion in Phase 3, the number of zero-crossing in the ML direction showed a significantly larger value. Fourth, in Phase 4, it was found that the more stable the lock out motion, the greater the activity of foot controlling in the left and right directions. Fifth, Phase 3, the greater the Maximum/Mean foot pressure value, the more stable the pulling action. Sixth, in Phase 2, the foot pressure was concentrated with a wide distribution in the midfoot and rearfoot. Seventh, the triggering number of the forefoot region was small in the last pull phase. Eighth, the number of triggers in the toe area was significantly higher during Good Motion in Phase 4. Conclusion: Summarizing the factors of instability in Snatch, there was no significant difference in Phase 1 for each condition. In order to enhance the stability in Phase 2, the sensory control ability in the AP direction is required, and focusing the foot pressing motion with a wide distribution in the middle and rear parts increases the instability. In Phase 3, it was found that the more unstable, the more sensory control activity was performed in the ML direction, the stronger the forefoot pressing action should be performed for a stable Snatch. In Phase 4, It is important that the feet sensory control activity in ML directions and the control ability of the toes in order to have stable Lock out motion.

• Applied Microscopy
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• 제45권2호
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• pp.58-62
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• 2015

Formation of an icosahedral phase in the bulk glass forming $Ti_{40}Zr_{29}Be_{14}Cu_9Ni_8$ alloy during crystallization from amorphous phase and solidification from melt is investigated. The icosahedral phase with a size of 10 to 15 nm forms as a thermodynamically stable phase at intermediate temperature during the transformation from amorphous to crystalline phases such as Laves and ${\beta}$-(Ti-Zr) phases, indicating that the existence of the icosahedral cluster in the undercooled liquid. On the other hand, the icosahedral phase forms as a primary solidification phase even though the Laves phase is stable at high temperature, which is can be explained based on the high nucleation rate of icosahedral phase relative to that of competing crystalline Laves phase due to lower interfacial energy between icosahedral and liquid phases.

• Asian-Australasian Journal of Animal Sciences
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• 제23권2호
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• pp.169-174
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• 2010

A meta-analysis was conducted to summarize the results of studies which have described the profiles of hormones during the oestrous cycle in buffalo using a fixed effect model and a random effect model. Plasma progesterone concentrations were lowest (0.30${\pm}$0.06 ng/ml) during the peri-oestrous phase and increased (p = 0.067) through the early luteal phase to a maximum concentration (1.94${\pm}$0.03 ng/ml) during the mid-luteal phase. Circulating plasma inhibin and estradiol concentrations were lowest (0.31${\pm}$0.01 and 11.04${\pm}$0.13 ng/ml) during the mid-luteal phase, increased through the late luteal phase to maximum concentrations (0.44${\pm}$0.02 and 22.48${\pm}$0.32 ng/ml) during the peri-oestrous phase. Plasma FSH concentrations were lowest during the early luteal phase and increased through the mid-luteal phase to a maximum concentration during the peri-oestrous phase. Peripheral prolactin concentrations were lowest during the late luteal phase and increased to a maximum concentration during the peri-oestrous phase which then declined (p = 0.716) during the early luteal phase. Peripheral plasma cortisol concentrations decreased from 2.68${\pm}$0.14 ng/ml during the early luteal phase to 1.43${\pm}$0.27 ng/ml during the mid-luteal phase (p<0.001) which then increased to 2.06${\pm}$0.17 ng/ml during the late luteal phase. Plasma $T_{5}$ concentrations decreased from the late luteal phase to the peri-oestrous phase (p<0.001) which then increased during the early luteal phase. $T_{4}$ concentrations increased from the late luteal phase to the peri-oestrous phase which then decreased during the early luteal phase.

• 대한방사선치료학회지
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• 제34권
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• pp.61-72
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• 2022

목 적: 기존의 CBCT(Cone-beam Computed-tomography)는 호흡에 의한 움직임의 영향을 받는 부위에서 장기의 움직임으로 표적용적에 오차가 발생했다. 본 논문의 목적은 호흡동조방사선치료를 시행할 때 오차를 감소시켜주는 Gated CBCT(Gated Cone-beam Computed-Tomography)기능을 이용하여 정확성과 소요시간의 각각 유용성을 평가하고 위상에 따른 적절성에 대해 고찰하고자 한다. 대상 및 방법: Gated CBCT의 유용성을 평가하기 위해 Truebeam STx^TM에서 QUASAR^TM 호흡 움직임 팬텀과 납 표지자 삽입물(lead marker inserts)을 이용하여 전체 위상(Full Phase), 20~80% 위상, 30~70% 위상, 40~60% 위상마다 5회씩 Gated CBCT를 촬영하여 납 표지자의 번짐(Blurring) 길이를 측정하고 투시 촬영(fluoroscopy)의 Trigger mode를 사용하여 최고 위상(Top Phase)에서 구간이 끝나는 지점까지 납 표지자가 움직이는 거리를 5회씩 측정하여 비교하였다. 삼나무 고체 종양 삽입물(Cedar Solid Tumor Inserts)을 이용하여 4차원 전산화단층촬영(4-Dimentional Computed-tomography, 4DCT)을 촬영하여 전체 위상, 20~80% 위상, 30~70% 위상, 40~60% 위상마다 표적 용적을 설정하고 축 방향(S-I방향)으로 5회씩 길이를 측정하였고 동일하게 Gated CBCT를 5회씩 촬영하고 영상의 CT 값(CT number)을 분석하여 표적이 움직인 거리를 측정하여 비교하였다. 결 과: 납 표지자 삽입물을 이용하여 촬영한 Gated CBCT에서 전체 위상은 평균 4.46 cm, 20~80% 위상은 평균 3.11 cm, 30~70% 위상은 평균 1.94 cm, 40~60% 위상은 평균 0.90 cm가 측정되었다. 투시 촬영에서 납 표지자의 축방향 움직임 거리는 평균 4.38 cm였고 Trigger mode를 이용하여 최고 위상부터 Beam off 구간까지의 거리는 20~80% 위상은 평균 3.342 cm, 30~70% 위상은 평균 2.04 cm, 40~60% 위상은 평균 0.84 cm가 측정되었다. 두 결과를 비교하였을 때 전체 위상은 0.08 cm, 20~80% 위상은 0.23 cm, 30~70% 위상은 0.10 cm, 40~60% 위상은 0.07 cm의 차이가 확인되었다. 삼나무 고체 종양 삽입물을 이용하여 촬영한 4차원 전산화단층촬영 영상으로 윤곽 묘사(contouring)한 내부표적용적(Internal Target Volume, ITV)과 치료계획용적(Planning Target Volume, PTV) 윤곽의 길이는 전체 위상에서 6.40 cm, 7.40 cm, 20~80% 위상에서 4.96 cm, 5.96 cm, 30~70% 위상에서 4.42 cm, 5.42 cm, 40~60% 위상에서 2.95 cm, 3.95 cm가 측정되었고 촬영한 Gated CBCT에서 Full 위상은 평균 6.35 cm, 20~80% 위상은 평균 5.25 cm, 30~70% 위상은 평균 4.04 cm, 40~60% 위상은 평균 3.08 cm가 측정되었다. 두 결과를 비교하였을 때 내부표적용적에서 ±8.5% 이내의 오차로 일치하는 것을 확인하였다. 결 론: 기존의 CBCT는 호흡에 의한 움직임의 영향을 받는 부위에서 장기의 움직임으로 오차가 발생하는 문제가 있었지만 본 연구를 통해서 Gated CBCT를 이용하여 설정한 위상의 표적 용적과 비슷한 영상을 얻어 정확한 영상유도를 시행하여 유용성을 확인하였다. 하지만 설정한 위상이 줄어들수록 영상 촬영소요시간이 길어진다. 따라서, 촬영소요시간과 위상의 오차를 고려했을 때 30~70% 위상 이상의 넓은 위상을 사용하는 호흡동조 정위체부방사선치료 환자에게 적용하는 것이 적절하다고 생각한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.193-197
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• 2004

The effect of the temperature dependence of the smectic layer spacing in the smectic-A (SmA) phase on the formation of defects in the ferroelectric smectic-$C^{\ast}$ ($SmC^{\ast}$) phase is investigated with x-ray scattering technique. The study is based on thin parallel-aligned surface stabilized ferroelectric liquid crystal cells with two different alignment conditions, high pretilt $SiO_x$, alignment and low pretilt polyimide films. It is found that defects observed in the $SmC^{\ast}$ phase have much more profound dependence on the layer changes and chevron formation in the SmA phase than in the $SmC^{\ast}$ phase. We find that thermal layer expansion with decreasing temperature in the SmA phase suppresses the formation of defects observed in the SmC phase.

• 한국멀티미디어학회논문지
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• 제19권6호
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• pp.1043-1051
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• 2016

In this paper, double encryption technique of binary image using random phase mask and 2-step phase-shifting digital holography is proposed. After phase modulating of binary image, firstly, random phase mask to be used as key image is generated through the XOR operation with the binary phase image. And the first encrypted image is encrypted again through the fresnel transform and 2-step phase-shifting digital holography. In the decryption, simple arithmetic operation and inverse Fresnel transform are used to get the first decryption image, and second decryption image is generated through XOR operation between first decryption image and key image. Finally, the original binary image is recovered through phase modulation.