• 한국음향학회지
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• 제40권6호
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• pp.546-554
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• 2021

수중 탐지를 위한 합성개구소나(Synthetic Aperture Sonar, SAS) 신호처리에서는 탑재플랫폼이 직선경로를 따라 주행한다고 가정한다. 그러나 실제로는 플랫폼의 복잡한 운동에 따른 궤적 교란으로 인해 SAS 영상에 번짐과 같은 왜곡이 발생한다. 본 연구에서는 예인형 SAS 개발을 위해 궤적 교란에 의한 SAS 영상 왜곡을 개선하기 위한 방법으로서, Redundant Phase Center (RPC)을 이용한 예인체 운동 추정 및 영상 보정, 그리고 자동 초점 기법인 Phase Gradient Autofocus (PGA) 기법에 대해 검토하였다. 그리고 시뮬레이션을 통해, sway로 인해 왜곡된 SAS 영상에 이 기법들을 적용하고 그 성능 및 유효성에 대해 살펴보았다.

• 대한교통학회지
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• 제14권2호
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• pp.45-58
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• 1996

In a large signal intersection, it is the most important to set phase sequences and phase intervals of traffic signal in order to improve the efficiency of the capacity as well as safety. These setting allows to select the best sequence of signal phase among several alternatives, and thus to rearrange the starting and ending points of the individual phase using an effective interphase periods (EIP). The EIP is a gap between previous and current traffic movements at a potential collision point in an intersection. Each of traffic movements has an equality for safety and efficiency at the balanced condition of EIP. This paper presents how to set optimally the phase sequences and intervals of traffic signal in an intersection using phase based approach. And in the second part, we applied the theory developed in the first part. In particular, a numerical example of phase base signal setting is presented using a matrix computation method in order to select the best sequence among several alternatives, and thus to rearrange the starting and ending points of the individual phase using the EIP. This method also allows to apply to optimum signal setting even in five-lag or staggered-type intersection.

• 한국통신학회논문지
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• 제37권5A호
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• pp.290-297
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• 2012

본 논문에서는 의료용 In-Body Wireless Body Area Network (WBAN) 시스템을 위한 Offset Phase Rotation Shift Keying (OPRSK) 및 Phase Silence Rotation Shift Keying (PSRSK) 변조 방식을 제안한다. 현재 IEEE에서는 인체통신을 위한 WBAN 시스템을 802.15. Task Group (TG) 6로 지정하고 이에 관한 표준화를 진행하고 있다. 최근에는 WBAN 시스템의 전력 효율 향상을 위해 Phase Silence Shift Keying (PSSK), Phase Silence Position Keying (PSPK), 및 Phase Rotation Shift Keying (PRSK) 등의 변조 방식들이 제안되었으나, 기존의 방식들은 비선형 증폭기에 의한 왜곡에 취약한 단점이 있다. 따라서 본 논문에서는 심볼 구간의 전력 분산 및 성상도의 위상 옵셋을 통해 최대 위상 전이 범위를 제한함으로써 비선형 왜곡에 강인한 OPRSK 및 PSRSK 방식을 제안하며, 다양한 성능 분석을 통해 제안된 방식의 우수성을 입증하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.124-128
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• 2000

The high Tc phase disappeared and low Tc phase increased in the substitution of transistion elements for Bi ions. The high Tc phase decreased in the substitution of Si and Sn for Bi ions. The high Tc phase increased in the substitution of Sb, As and P Which Were the same group of Bi for Bi ions. The substitution of P ions was the most effective and then the high Tc phase was formed in large quantity by replacing Bi ions with 30%of P ions.

• 한국세라믹학회지
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• 제34권8호
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• pp.886-896
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• 1997

To investigate an effect of phase separation on precipitation characteristics of CuCl nanocrystals in CuCl doped nonlinear optical glasses, borosilicate glass systems with 9 different compositions with ~2wt% of CuCl were selected and CuCl doped glasses were prepared by melting and precipitation method. Microstructural properties of the CuCl doped glasses were analyzed by optical absorption spectroscopy, acid elution test, TEM, and EDXS. While phase separation did not occur in Glass A~D, interconnected and droplet microstructures due to phase separation were found in Glass E, F and Glass G~I, respectively. In the particular composition of the matrix glasses in this study, the precipitation of the CuCl particles was observed in the phase separable glasses, not in phase non-separable glasses. The CuCl particles were precipitated in both silica-rich phase region and boronrich phase region of the glass matrix. In the case of 7.7Na2O-36.6B2O3-52.7SiO2(mole%) glass, the larger CuCl particles than those in the silica-rich phase region were observed in the boron-rich phase region.

• 미생물학회지
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• 제9권4호
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• pp.169-174
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• 1971

Ultrastructural observations of mycelial and tissue phase with dimorphic fungal pathogen Coccidioides immitis were studied by electron microscopy of thin sections. 1. In mycelial phase of C.immitis contains normal cell components such as nucleus, mitochondria, endoplamsic reticulum, intracytoplasmic membrane system, cell wall and cell membrane as observed in the other encaryotic cells. 2. In tissue phase of C. immitis was larger than mycelial phase in cell size and observed much more vacuoles than mycelial phase. 3. In the contrast of mycelial phase of C. immitis, the tissue phase of cells were observed fibril form of capsular layer.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.233-236
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• 2005

Phase noise in a phase-locked-loop (PLL) is unwanted and unavoidable. It is a main concern in oscillation system especially PLL. The phase noise is derived in term of power spectrum density by using a reliable phase noise model. There are four noise sources being considered in this paper, which are generated by reference oscillator, voltage controlled oscillator, filter, and main divider. The major concern for this paper is the noise from the filter. Two types of second order low pass filter are used in the PLL system. Applying the mathematical phase noise model, the output noises are compared. The total noise from the passive filter is lower than the active filter at the offset frequency range between 1 Hz to 33 kHz.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2317-2322
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• 2011

In three-phase power, when the power is supplied to the single phase load, there is the unbalance of load in the three-phase power. So the scott transformer is used in the power system to supply a single phase load in three-phase power without the unbalance of loads. Especially, the scott transformer is used in the AC substation of electric railroad. Two single phase transformers are combined by T-wiring in the scott transformer. So, two single phase voltage is provided by differing $90^{\circ}$ phase in three-phase power. The selection of related equipment and correction of protective relay are not easy from characteristic of the scott transformer when shunt and ground faults occur. In this paper, electric model of the scott transformer is suggested and the current of the scott transformer in shunt and ground faults is analyzed. Also, the scott transformer model is demonstrated by using Sinulink.

• The Journal of Korean Physical Therapy
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• 제23권6호
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• pp.85-92
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• 2011

Purpose: This study is executed to examine the effects of Korean somatotype on energy consumption and hormone changes during treadmill gait. Methods: The objects of study were a total of 70 university students in their 20s and 30s divided into 7 groups according to somatotype with 10 members each, 4 groups of male (M1, M2, M3, M4) and 3 groups of female (F1, F2, F3). Results: In case of male groups, there was a significant difference in VO2 and VCO2 between group M1, M2 and M3 (p<0.05). There was also a meaningful difference between Phase1 and Phase2, Phase3 and Phase4 in a phase (p<0.01). In case of female groups, there was a meaningful difference in VO2 between F1 and F2, F3 (p<0.01). There was also a significant difference between Phase1 and Phase2, Phase3 and Phase4 in a phase (p<0.01). There was no significant difference in VCO2 among them, but there was a significant difference in it between Phase1 and Phase2, Phase3 and Phase4 (p<0.01). There was equally no significant difference in the concentration of adrenaline and nor-adrenaline among both male and female groups, but such concentration showed meaningful difference before and after exercise (p<0.01). Conclusion: Energy consumption differs according to somatotype. There is a difference in hormone change, indicating that somatotype has effects on the physiological change. Therefore, in future exercise should be executed in more diverse conditions to further study somatotype with energy consumption and the correlations of hormone change.

• 조명전기설비학회논문지
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• 제27권2호
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• pp.45-53
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• 2013

In this paper, we analyze the typical phase voltage and line current waveform characteristics of the distribution system with 3 phase small synchronous generation source in case with load and non-load group, in order to investigate the power quality for end load connected of generation source. As demonstrated by our experimental results, the distortion and power quality of phase voltage and line current waveform were relatively good for low voltage 3 phase model grids connected of 3 phase small synchronous generation source in case with non-load group. However, distortion and power quality of voltage and current waveform was poor for low voltage 3 phase model grids connected to 3 phase small synchronous generation source in the load group with some phase voltage and frequency difference. From the above results, we conclude that the phase voltage and frequency of 3 phase generation source must be identical to that of distribution system source to maximize the power quality. Also, special attention is required in case of having load group or non-load group to 3 phase generation source.