• 한국정보통신학회논문지
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• 제13권9호
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• pp.1745-1752
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• 2009

본 논문은 쉬프만 위상 천이기의 소형화 설계를 위하여 마이크로스트립 선로의 접지면에 결함 접지면 구조를 이용하는 새로운 방법을 제시한다. DGS에 의하여 발생하는 부가적인 인덕턴스와 캐패시턴스 성분에 의하여 전파 지연 특성이 표준형 선로보다 크게 나타나는데, 이로 인하여 DGS를 포함한 전송선로의 전기적 길이가 DGS가 없는 표준 전송선로 전기적 길이보다 길게 나타난다. 표준 쉬프만 위상 천이기에 DGS를 삽입하여 전체적으로 15% 정도의 사이즈를 축소할 수 있었다.

• 천문학회보
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• 제40권1호
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• pp.61.3-62
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• 2015

Remote-sensing observation is one of the observation methods that provide valuable information, such as composition and surface physical conditions of solar system objects. The Hayabusa spacecraft succeeded in the first sample returning from a near-Earth asteroid, (25143) Itokawa. It has established a ground truth technique to connect between ordinary chondrite meteorites and S-type asteroids. One of the scientific observation instruments that Hayabusa carried, Asteroid Multi-band Imaging Camera(AMICA) has seven optical-near infrared filters (ul, b, v, w, x, p, and zs), taking more than 1400 images of Itokawa during the rendezvous phase. The reflectance of planetary body can provide valuable information of the surface properties, such as the optical aspect of asteroid surface at near zero phase angle (i.e. Sun-asteroid-observer's angle is nearly zero), light scattering on the surface, and surface roughness. However, only little information of the phase angle dependences of the reflectance of the asteroid is known so far. In this study, we investigated the phase angle dependences of Itokawa's surface to understand the surface properties in the solar phase angle of $0^{\circ}-40^{\circ}$ using AMICA images. About 700 images at the Hayabusa rendezvous phase were used for this study. In addition, we compared our result with those of several photometry models, Minnaert model, Lommel-Seeliger model, and Hapke model. At this conference, we focus on the AMICA's v-band data to compare with previous ground-based observation researches.

• Nuclear Engineering and Technology
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• 제16권1호
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• pp.1-10
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• 1984

2상 유동에 대한 일반적인 시간과 공간에 대해 평균된 보존방정식과 jump condition을 유도했다. 단상난류 유동 방정식에 사용되는 방법을 써서, 한부분에서 순간적으로 이루어지는 평형 방정식 (local instant balance eq.)으로부터 2상유동내 단상영역에 관한 시간에 대해 평균된 방정식을 유체체적에 대해 적분하여 얻어진 결과는 공간적으로 두차례에 걸쳐 평균된다. 즉, 한 유체체적내에서 일차적으로 k번째 상의 단상영역에 대해 평균하고 다음에 k번째 상 전체체적에 대해 평균한다. 질량, 운동량 그리고 에너지 보존 방정식은 일반적인 시간과 공간에 대해 평균된 방정식으로부터 얻어진다. 이 모델의 장점은 Ishii모델, 그리고 Banerjee의 model과 비교하여 설명된다. 마지막으로, THERMIT-6S의 방정식에 포함된 가정과 근사항들에 대해 박혀둔다.

• 한국전기전자재료학회논문지
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• 제17권6호
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• pp.641-646
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• 2004

We report the changes of the microwave reflection coefficients S$_{11}$ of copper(II)-phthalocyanine (CuPc) thin films by using a near-field microwave microscope(NSMM) in order to understand the phase transition of CuPc. For a NSMM system, a high-quality microstrip resonator coupled with a dielectric resonator was used. CuPc thin films were prepared on the pre-heated glass substrates using a thermal evaporation method. The reflection coefficients S$_{11}$ of CuPc thin films were changed by the dependence on the substrate pre-heating temperatures. By comparing reflection coefficient S$_{11}$ and crystal structures, we found the phase transition of CuPc thin films from $\alpha$-phase to $\beta$-phase at the substrate heating temperature 200 $^{\circ}C$./TEX>.

• 전기의세계
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• 제21권3호
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• pp.7-18
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• 1972

An analysis is made for the performance of twin stator single-phase induction machine having any movable asymmetrical angle of stator windings, with any symmetrical or asymmetrical magnetizing reactance and winding turn-ratio between two stators, provided that asymmetrical common squirrel cage rotor is utilized. This mechanism is a new type, which has the advantage of mading only not the performance prediction in applications as a single-phase electromagnetic driving mechanism but also the analysis prediction of single-phase induction motor with not in quadrature axis. The basis of the analyses are lead by Kron's primitive machine matrix and Morrill's double-revolving field concept. All the performances can be calculated from the test values and design details of the asymmetrical magnetizing reactance twin stator single-phase induction machine and verified by test. And its validity is still demonstrated to the pure twin stator single-phase induction machine.

• Structural Engineering and Mechanics
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• 제25권2호
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• pp.181-200
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• 2007

A decoupling technique for simulating near-field wave motions in two-phase media is introduced in this paper. First, an equivalent but direct weighted residual method is presented in this paper to solve boundary value problems more explicitly. We applied the Green's theorem for integration by parts on the equivalent integral statement of the field governing equations and then introduced the Neumann conditions directly. Using this method and considering the precision requirement in wave motion simulation, a lumped-mass FEM for two-phase media with clear physical concepts and convenient implementation is derived. Then, considering the innate attenuation character of the wave in two-phase media, an attenuation parameter is introduced into Liao's Multi-Transmitting Formula (MTF) to simulate the attenuating outgoing wave in two-phase media. At last, two numerical experiments are presented and the numerical results are compared with the analytical ones demonstrating that the lumped-mass FEM and the generalized MTF introduced in this paper have good precision.

• 전기의세계
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• 제24권1호
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• pp.55-62
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• 1975

A single-phase induction motor with it's stator winding splitted into two series windings, of which the terminals of one winding is switched pulsationally by a thyristor type ON-OFF device so that the motor may operate as a pulsational shaded-pole motor, can modulate current waveforms of it's two series windings. In view of current waveform modulation method, a single-phase single-winding motor operates as a two-phase induction motor with asymmetrical axis windings where the starting torque can be obtained effectively without an auxiliary capacitor attached and it's running speed controlled by shifting phase between current waveforms differently. Equivalent circuit for analysis is modified from a double revolving field equivalent circuit of a single-phase induction motor with asymmetrical windings whose angle is 45.deg.C elet. degrees. Analysis and test results show that ON-OFF action of the pulsational shaded-pole winding has the same effect of a series capacitor, and then at heavy loads this motor operates with a small amonut of the input current than that having the fixed shaded-pole winding.

• 전자공학회논문지A
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• 제30A권12호
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• pp.108-116
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• 1993

When realizing a multiple-output function by a PLA, there is often the flexibility to choose either uncomplementary or complementary phase for each output. In this case, it is possible to significantly reduce the number of product terms by fully exploiting the freedom. This paper presents a PLA phase for each output of a multiple-output function so that the product terms for each output are maximally shared with the other outputs. and then minimizes the multiple-output function with the assigned output phase assignment. The algorithm has been implemented on Sun4/330 in C language and compared with the previous approaches for 56 example PLA`s. The proposed algorithm has obtained better results for 18-32 PLA's, worse results for 1-5 PLA`s, and the same results for 23-33 PLA's. Moreover, the computation time is much less than for the previous approaches.

• Journal of Chest Surgery
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• 제50권3호
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• pp.177-183
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• 2017

Background: To improve postoperative outcomes associated with interstitial pneumonia (IP) in patients with lung cancer, the management of the postoperative acute exacerbation of IP (PAEIP) was investigated. Methods: Patients with primary lung cancer were considered to be at risk for PAEIP (possible PAEIP) based on a preoperative evaluation. The early phase of this study was from January 2001 to December 2008, and the late phase was from January 2009 to December 2014. In the early phase, chest computed tomography (CT) was performed for patients for whom PAEIP was suspected based on their symptoms, whereas in the late phase, chest CT was routinely performed within a few days postoperatively. The numbers of possible PAEIP cases, actual PAEIP cases, and deaths within 90 days due to PAEIP were compared between both phases. Results: In the early and late phases, surgery was performed in 712 and 617 patients, 31 and 72 possible PAEIP cases were observed, nine and 12 actual PAEIP cases occurred, and the mean interval from the detection of PAEIP to starting treatment was $7.3{\pm}2.3$ and $5.0{\pm}1.8$ days, respectively. Five patients died in the early phase, and one patient died in the late phase. Significantly fewer PAEIP-related deaths were observed in the late phase (p<0.05). Conclusion: Identifying patients at risk for PAEIP by routine postoperative CT examinations led to the early diagnosis and treatment of PAEIP, resulting in the reduction of PAEIP-related mortality.

• 접착 및 계면
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• 제2권2호
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• pp.11-19
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• 2001

트리카프릴메틸 암모니움 클로라이드를 상이동촉매로 사용하여 $Na_2S_2O_8$의 수용액과 톨루엔의 이상계에서 질소분위기하에 $60^{\circ}C$에서 스티렌의 라디칼중합을 행하였다. 중합시의 초기 중합속도는 촉매와 $Na_2S_2O_8$의 초기공급 농도보다는 수용액 상에서의 4급 암모늄양이온과 퍼록시디슬페이트 음이온의 농도로 나타낼 수 있었다. 관찰된 초기중합속도를 사용하여 분균일 액-액계에서의 순환 상이동에 의한 개시과정을 포함한 중함메카니즘을 밝힐 수 있었다. 폴리스티렌의 점도평균분자량은 $Na_2S_2O_8$의 농도에 역비례하였는데, 라디칼 중합메카니즘에 의하여 $[Q^+]([S_2O{_8}^{2-}]{\alpha}_2)^{1/2}$로 나타내어졌다.