• 대한임베디드공학회논문지
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• 제1권1호
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• pp.1-7
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• 2006

In this paper, a novel power management structure for an energy harvesting pervasive system is proposed. The system considers the power state of each subsystem to assign proper power sources. The switch matrix structure utilizes each power source to reduce the peak current of the battery. The power management structure can be interfaced to an embedded system power supply without significant design change.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권6호
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• pp.760-767
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• 2014

This paper describes a high-radix crossbar switch design with low latency and power dissipation for Network-on-Chip (NoC) applications. The reduction in latency and power is achieved by employing a folded-clos topology, implementing the switch organized as three stages of low-radix switches connected in cascade. In addition, to facilitate the uniform placement of wires among the sub-switch stages, this paper proposes a Mux-Matrix-Mux structure, which implements the first and third switch stages as multiplexer-based crossbars and the second stage as a matrix-type crossbar. The proposed 256-radix, 8-bit crossbar switch designed in a 65nm CMOS has the simulated power dissipation of 1.92-W and worst-case propagation delay of 0.991-ns while operating at 1.2-V supply and 500-MHz frequency. Compared with the state-of-the-art designs in literature, the proposed crossbar switch achieves the best energy-delay-area efficiency of $0.73-fJ/cycle{\cdot}ns{\cdot}{\lambda}^2$.

• 한국재료학회지
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• 제12권4호
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• pp.254-258
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• 2002

To realize channel cross-connecting in optical communications systems, a high speed optical matrix switch was fabricated using z-cut $LiNbO_3$. For switch fabrication was design bending structure and coupling length and four $2{\times}2$ directional couplers were integrated on one substrate far construction of a $4{\times}4$ switch. Single-mode optical waveguides were formed by Ti-diffusion at a wet $O_2$ atmosphere. Ti-diffusion profile, refractive index variation and waveguide morphology were analyzed by Prism coupler and optical microscopy, respectively.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1552-1557
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• 2015

The paper unleashes a new idea to arrive at reduced switch count topological structures configured in the form of a matrix for a cascaded Multi level inverter (CMLI). The theory encircles to minimize the number of switches involved in the conduction path and there from acclaim reduced input current distortion, lower switching losses and electromagnetic interference. The focus extends to standardize the number of power devices required for reaching different levels of output voltage from the same architecture. It includes appropriate pulse width modulation (PWM) strategy to generate firing pulses and ensure the desired operation of the power modules. The investigative study carries with it MATLAB based simulation and experimental results obtained using suitable prototypes to illustrate the viability of the proposed concept. The promising nature of the performance projects a new dimension in the use of single phase MLIs for renewable energy related applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.243-246
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• 1998

This paper presents a 6-bit self-calibrated D/A converter designed with current cell matrix structure. This structure is based on the current-cell matrix configuration using a regulated gate cascode current cell with 3-way switch. using from CMOS process and 5V power supply, the simulated conversion rate is 45.78MHz and the average mismatching properties among current sources are reduced to 0.02% and 0.005%, respectively when 1% and 0.5% errors of current sources are considered.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.208-210
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• 2007

As a renewable power source, wind power generation has been research interest for many years. And power electronic converters have been developed and applied in variable speed wind turbines. This paper presents the basic development and implementation of space-vector modulated three phase AC-AC matrix converter for variable speed wind power system. Basic matrix converter operation is described, where a new bidirectional switch structure with commutation circuit is used. Finally, experiment results of basic converter operation are shown.

• Smart Structures and Systems
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• 제5권6호
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• pp.645-662
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• 2009

Adaptive wings are capable of properly modifying their shape depending on the current aerodynamic conditions, in order to improve the overall performance of a flying vehicle. In this paper is presented the concept design of a small-scale compliant wing rib whose outline may be distorted in order to switch from an aerodynamic profile to another. The distortion loads are induced by shape memory alloy actuators placed within the frame of a wing section whose elastic response is predicted by the matrix method with beam formulation. Genetic optimization is used to find a wing rib structure (corresponding to the first airfoil) able to properly deforms itself when loaded by the SMA-induced forces, becoming as close as possible to the desired target shape (second airfoil). An experimental validation of the design procedure is also carried out with reference to a simplified structure layout.

• 대한전자공학회논문지
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• 제12권1호
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• pp.27-33
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• 1975

한글의 기하학적 배조상의 복잡도로 부터 한글 각 자소의 character generator용 diode matrix의 size를 추산하고 이자소 matrix 3성(초성, 중성, 종성)의 OR동작으로시 모아쓰기 한글의 모든 조합이 가능합을 보였고 수평각음순가성과 수직모음용초성의 자판 선택자, 종성이 있을 때와 없을때의 중용길이의 변경등이 비교적 간단한 논리회로로서 switch될 수 있음을 보였다. 새로 15bit내부 code를 제안하였는데 이는 86개의 sparse diode matrix로시 모든 조합을 다 카버하고 그러면서도 decodig기구의 규모를 줄여준다. The required minimum size of character diode matrix of Korean letters is estimated from the topological complexity of letter structure. The OR aombination of three letter boards (diode matrice) gives all possible Hangout whole letters in proper traditional combined form with minimum required discernibility. Two forms of first consonants (centre located ones for horizontal vowels and leftward displaced ones for vertical and composed vowels) are switched by only 1 bit of the vowel code. The vowel pattern length is modified by again the last four bits of the code. A new 15bit sized inner code is proposed which permits considerably small sized decoding mechanism.

• 전자공학회논문지C
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• 제36C권8호
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• pp.10-21
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• 1999

본 논문에서는 12비트의 해상도와 65MHz의 변환속도를 가지면서 단일 3.3V의 공급전압으로 동작하는 전류 셀 매트릭스 구조의 CMOS D/A 변환기를 제안하였다. 설계된 CMOS D/A 변환기는 우수한 단조증가성과 빠른 정착시간을 가지는 전류 셀 매트릭스 구조의 장점을 이용하면서 기존의 D/A 변환기의 전류셀 간의 문턱전압의 부정합과 접지선의 전압 강하에 의한 오차를 감소시키기 위해 트리 구조 바이어스 회로, 대칭적 접지선 연결, 캐스코드 전류 스위치를 사용하여 구현되었다. 설계된 전류 셀 매트릭스 12비트 D/A 변환기를 $0.6{\mu}m$ CMOS n-well 공정을 이용하여 제작하였다. 제작된 DAC칩을 +3.3V 단일 공급전원을 이용하여 측정한 결과, 정착시간이 20nsec로써 50MHz의 변환속도와 35.6mW의 전력소모를 나타내었다. 또한 측정된 SNR, DNL은 각각 55 dB, ${\pm}0.5LSB$,${\pm}2LSB$를 나타내었다.

• 한국콘텐츠학회논문지
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• 제14권6호
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• pp.385-396
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• 2014

한국의 이동통신시장은 이미 경쟁이 치열한 성숙기에 진입했으며, 최근 LTE서비스가 출시되면서 여러요인으로 인해 이동통신 시장구조가 급격히 변동하고 있다. 따라서 본 연구의 목적은 이러한 시장상황에서 이동통신서비스 이용고객의 상표전환의향 및 상표전환행동이 어떠한 영향이 있는지를 증명하고, 그 시사점을 제시하고자 하였다. 연구결과, 미래창조과학부가 제공하는 전체 스마트폰 가입자 비율과 본 연구가 제시하는 현재 시장점유율은 일치하는 것으로 나타났다. 스마트폰 이용고객의 잠재고객유지율은 SKT > KT > LGU+순으로 높게 나타났으며, 이용통신사 전환 선호도도 SKT, KT, LGU+ 순으로 조사 되었다. 본 연구에서 조사된 자료와 상표전환행렬을 활용한 향후 스마트폰 시장의 최종 시장점유율은 SKT 63.65%, KT 21.99%, LGU+ 14.36%로 추정 되었다. 또한 잠재고객유지율이 1년 전에 비하여 큰 폭으로 하락한 것으로 나타나, 스마트폰 시장은 당분간 변동이 심할 것으로 예측되었다.