• 수산해양교육연구
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• 제7권1호
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• pp.127-132
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• 1995

In this paper, a new speed estimation method of induction motors based on the very quick torque control is proposed to realize speed sensorless control. The proposed method can be realized very simply by detecting primary motor current and voltage command at every sampling time. As the method need not the differential value of primary current in a arithmetic of voltage command, it can be expected to promote the precision of speed estimation in low speed area, especially. Through the numerical simulation, the validity of the proposed method was successfully confirmed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.192-193
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• 2015

Construction Cycle Trend Survey, which survey total value of orders and realized amounts monthly, is a valuable statistics that used to quick grasp or forecast the trend of domestic construction business. In recent periodical survey quality diagnoses, few professional users named a problem that Construction Cycle Trend Survey could not get together with the current state of the construction industry. This study examined weather Construction Cycle Trend Survey reflects the economic sentiment of construction business or not. Paired t test was performed between Construction Cycle Trend Survey and Construction Business Survey Index (CBSI), and significant differences were verified.

• 전기학회논문지
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• 제59권4호
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• pp.722-727
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• 2010

This paper presents Dynamic-Simulation to estimate the inductance of a permanent magnet type transverse flux rotating motor by applying the real-time parameter estimation theory. As transverse flux rotating motor has the complex structure, it can be happen to some errors between real value and designed one with respect to the inductance. To reduce this kinds of errors, the real-time parameter estimation theory was applied to dynamic-simulation. And then, By comparing the estimated inductance and designed one, it is realized that the real-time parameter estimation theory can be applied in the permanent magnet type transverse flux rotating motor.

• 대한전자공학회논문지
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• 제20권2호
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• pp.29-34
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• 1983

의사 인덕턴스는 두 개의 저항과 한 개의 연산증폭기만으로 구성된 위상 파라미터 제어회로에 의해 이단자회로망으로 구현될 수 있었다. 제안된 회로를 해석한 결과 주파수에 관계없이 등가 인덕턴스가 일정함을 알았고 이를 약 100KHz의 각파수 범위에 걸쳐 실험으로 확인하였다. 등가 인덕턴스의 실험치와 이론치의 오차는 최대 4% 미만이었다.

• 한국지능시스템학회논문지
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• 제11권4호
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• pp.325-330
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• 2001

최적화문제에 사용되는 신경회로망을 회로레벨에서 시뮬레이션을 해보면, 알고리즘레벨에서 시뮬레이션한 결과와 많이 다름을 체험한다. 즉, 이런 신경회로망의 출력값들은 시간이 흐름에 따라 점근적으로 수렴하나, 입력단의 값들은 입력단에 부수적으로 연결되어 있는 컨덕턴스의 값에 따라 수렴여부도 달라지고, 또한 시스템의 성능도 변함을 안다. 이 논문에서는 입력단에 시스템의 안정도를 위해 부수적으로 연결된 컨덕턴스의 값에 따라 시스템의 수렴여부를 입력단과 출력단에서 분석하였으며, 에너지함수의 수렴점들이 이들 컨덕턴스의 값에 따라 성분이 변함을 분석하였다.

• Journal of electromagnetic engineering and science
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• 제5권1호
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• pp.26-30
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• 2005

It is important to know phase offsets of PN(Pseudo Noise) sequences in spread spectrum communications since the acquisition is equivalent to making a phase offset between a receiving PN sequence and a PN sequence of local PN generator be identical. In this paper, a phase offset enumeration method for PN sequences with error detection, and its application to the synchronization are proposed. The phase offset enumeration for an n-tuple PN sequence and its error detection are performed when one period of the sequence is received. Once the phase offset of the receiving sequence is calculated, we can easily accomplish the synchronization by initializing shift registers of a local PN generator according to the phase offset value. The mean acquisition time performance of the proposed scheme was derived analytically. Since this synchronization scheme can be realized by using simple circuit and acquires very rapid acquisition in high SNR but shows performance degradation in low SNR, it can be especially useful in indoor and office environments.

• 한국소음진동공학회논문집
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• 제22권4호
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• pp.365-371
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• 2012

This paper presents robust control performance of a direct current(DC) motor with brake system adopting a giant electrorheological(GER) fluid, whose distinguished feature is an extremely high value of yield stress. As a first step, Bingham characteristics of the GER fluid is experimentally investigated using the Couette type electroviscometer. A cylindrical type of ER brake is then devised based on the Bingham model, and its braking torque is evaluated. Structural analysis of ER break is performed using ANSYS. After formulating the governing equation of motion for the DC motor with ER brake system, a sliding mode control algorithm, which is very robust to external disturbances and parameter uncertainties, is synthesized and experimentally realized in order to achieve desired rotational speed trajectories. The tracking responses of the control system are then evaluated and verified by presenting speed control performance.

• 기술혁신연구
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• 제16권1호
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• pp.47-79
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• 2008

RFID(Radio Frequency Identification) technologies enjoy an enormous interest in all throughout the world, not only from the research but also from corporate practice. Although bar code is gradually substituted with RFID technology, the use of RFID technology in the companies is at the early stages and it's potential value isn't fully realized yet. RFID-related-trust is needed to solve these problems because these phenomena are related to uncertainties or risks disturbing RFID diffusion. This paper focuses on trust in the adoption of RFID and analyzes the effect to RFID technology acceptance of trust. This paper proposes 5 second constructs of trust; institutional trust, trust between companies, trust within company, technology trust, and service provider trust. In order to analyze some relationships between trust variable and 4 variables in TAM, structural equation modeling(SEM) is developed and SPSS 12.0 and AMOS 7.0 are used for analyses.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 1996년도 정기학술강연회 발표논문 초록집
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• pp.10-13
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• 1996

Satellite-borne altimeters are one of the most important global ocean measurement and monitoring techniques available to modern oceanographers. While the U.S. Navy's GEOdetic SATellite (GEOSAT) mission in the mid-eighties firmly established its value, the full potential of satellite altimetry was not realized until the launch of the NASA/CNES TOPEX/Poseidon precision altimeter in 1992. (omitted)

• 한국실내디자인학회논문집
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• 제15권5호
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• pp.104-111
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• 2006

Digital media changed not only our lifestyle and sense of value but also art and space design, and development of technology will accelerate the alteration. It provided limitless possibility and inspiration to art, architecture and design. In this 'image' era, media communicate with us mostly in visual method, which gets to he realized by visual interface. The purpose of this study is to analyze the tendency of visual interface of contemporary interior design cases in the standpoint of digital media characteristics and suggest directions for future space design. The characteristics of digital media and interface are defined, and how the concept unfolded in art, design is also discussed. In interior design, the concepts come out as various types of visual interface, showing the characteristics of composition of material and immaterial, interaction between visual information and space users and among users, realization of cyberspace and simultaneous coexistence of multiple space-time multi-layer.