• 전자통신동향분석
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• 제29권6호
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• pp.113-125
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• 2014

최근 모바일 단말 기술의 발전과 무선망의 성능 향상에 따른 다양한 서비스가 제공되고 있는 추세이며, 위치정보인식시스템과 결합된 서비스에 많은 관심이 높아졌다. 본고에서는 GPS(Global Positioning System)의 신호가 미치지 못하는 건물의 실내환경에 적합한 경로 안내서비스 및 지하시설물 안내 등 초정밀 실내 측위 서비스를 제공하기 위한 융합 측위 방안을 제안한다. 융합 측위 방안은 실내외 연속 측위를 위해 실외에서는 GPS를 이용하고 실내환경에서는 WLAN 기반의 측위 전용 AP(Access Point)를 이용, 전파신호의 LoS(Line of Sight)를 확보하여 측위하고 전파음영지역에서는 스마트폰의 가속도, 자이로센서 등 여러 가지 관성센서를 활용하여 PDR(Pedestrian Dead Reckoning) 알고리즘 등을 적용하여 측위한다. 또한 측위 정확도 향상 및 오차를 줄이기 위한 방법으로 LSE(Least Squire Estimation) 및 EKF(Extended Kalman Filter), KNN(K-Neighbor Node)/MSSM(Maximum Signal Strength Model) Algorithm 등 다양한 융합 측위 알고리즘을 적용하여 실내환경에 적합한 최적의 초정밀 실내 측위 서비스를 제공한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1829-1831
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• 2001

A novel multi-section power divider configuration is proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a planar multi-section three-ports hybrid and a waveguide transformer design procedures. The multi-section power divider is based on design theory of the optimum quarter-wave transformer. Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Simulation and experiment show excellent performance of multi section power divider.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.161-164
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• 2002

In this paper, a design technique is introduced for designing a 360-degree linear analog phase shifter at 1.8㎓. Using tunable short-circuit terminated comb-line filters as reactive loads, the circuit gives a very small insertion loss(less than 0.1㏈) and an almost linear phase shifter over the filter bandwidth for the full 360-degree range. We were showed large phase variation with small capacitance variation in the quadrature hybrid coupler using tunable shorted terminated combline filters.

• Journal of Advanced Marine Engineering and Technology
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• 제38권8호
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• pp.995-999
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• 2014

In this paper, a new size-reduction approach for branch-line coupler is introduced which uses parallel end-shorted coupled lines with lumped capacitors. The characteristic of the new design was analyzed using even-odd mode method, and simulated on HFSS before fabricated on the FR4 epoxy glass cloth copper-clad plat (CCL) PCB substrate at center frequency of 1 GHz. The electrical length of transmission line was reduced to 15 degrees, therefore the size of branch-line coupler was largely reduced approximately maintaining the same characteristic around the stable center frequency. The insertion loss of the branch-line coupler filter was -4.39 dB. The size of the overall hybrid is $20mm{\times}20mm$. Measurements results were well agreed with the simulated ones.

• 전자공학회논문지B
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• 제32B권12호
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• pp.1591-1602
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• 1995

A hybrid approach which includes edge- and region-based methods is considered. The modified non-linear Laplacian(MNL) filter is used for feature extraction. The matching algorithm has three steps which are edge, signed region, and residual region matching. At first, the edge points are matched using the sign and direction of edges. Then, the disparity is propagated from edge to inside region. A variable window is used to consider the local method which give accurate matched points and area-based method which can obtain full-resolution disparity map. In addition, a new relaxation algorithm for considering matching possibility derived from normalized error and regional continuity constraint is proposed to reduce the mismatched points. By the result of simulation for various images, this algorithm is insensitive to noise and gives full- resolution disparity map.

• 대한전자공학회논문지TE
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• 제37권5호
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• pp.56-61
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• 2000

반도체 공정 기술의 발달은 기하 급수적인 집적도의 증가를 가져오고, 이는 한 칩에 시스템을 모두 집적시키는 시스템 온 칩(SoC : System on Chip) 설계가 가능해지고, 이에 따른 설계 방법의 변화를 요구하고 있다. Soc 설계는 시스템에서 설계 사양(Specification)의 정의가 중요한 요소가 되고 있다. 본 논문에서는 MPEG 오디오 복호기에서 사용되는 IMDCT를 시스템 수준의 실행 가능한 설계 사양(Executable Specification)에 의해 설계하였다.

• 전기학회논문지
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• 제58권1호
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• pp.35-41
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• 2009

This paper proposes a stand alone type single-phase fuel cells micro-source with a voltage sag compensator for compensating the ac output voltage variations (sag or swell) of micro-source. The proposed micro-source is consist of a PEM(polymer electrolyte membrane) fuel cells simulator, a full bridge de converter, a 60Hz PWM(pulse width modulation) VSI(voltage source inverter), and a voltage sag compensator. Voltage sag compensator is similar to the configuration of hybrid series active power filter, and it is directly connected to micro-source through the injection transformer. Compensation algorithm of a voltage sag compensator adopts a single phase p-q theory. Effectiveness of the proposed the system is verified by the PSIM(power electronics simulation tool) simulation in the steady state and transient state which the proposed system is able to simultaneously compensate the harmonic current and source voltage sag or swell.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2003년도 추계학술대회 논문집
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• pp.63-64
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• 2003

원심력집진기는 장치가 간단하지만 집진효율이 낮아 주로 여과포집진장치 및 전기집진장치의 전단에만 사용되는 단점을 가지고 있다. 여과포집진장치는 고효율의 집진성능을 가지고 있지만 유입되는 먼지의 농도를 감소시키기 위하여 전단에 원심력집진기를 설치하게 되므로 설치공간 및 동력비가 과다하게 소요되고 있으며, 높은 압력손실, 낮은 여과속도에 의한 장치면적 증가, 균일한 집진이 어려워 일부 여과포에 집중적인 부하가 걸리게 되는 단점 등을 가지고 있다. 전기집진장치의 경우 압력손실이 적고 대용량에 적용 가능하지만, 여과집진장치에 비해 집진효율이 낮고, 먼지의 종류 및 연료연소조건에 따라 집진효율이 크게 영향을 받는 단점을 가지고 있다. (중략)

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.287-292
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• 1998

This paper presents some results of performance evaluation test via actual machines of a new hybrid vector control utilizing a new indirect orientation scheme and stable filter embedded direct orientation scheme for induction motors without speed or position sensor. It is shown through the test by 0.3(kW) and 3.7(kW) motors that the proposed sensorless vector control has the following high potentialities: 1) speed range is 0 to 600(rad/s) or more, 2) zero-speed command is accepted and settles the machines at a stable standstill with no vibration 3) it can make machines to track variable command of acceleration and deceleration $\pm$6,000(rad/s2), 4) it can make machines to drive directly load of at least 26 times larger inertia than that of the machine, 5) it can make machines to produce much larger torque than the rating in torque control mode even at standstill. The performance confirmed by the test is far away for previous schemes or sensorless drive apparatuses.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2012년도 하계학술대회
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• pp.262-265
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• 2012

In this paper we propose a new deinterlacing method with block classification and motion vector smoothing. The proposed method classifies a block, then depending on the region it belongs to, the motion estimation or line averaging is applied. To classify a block its variance is calculated. Then, for those blocks that belong to simple non-texture region the line averaging is done while motion estimation is applied to complex region. The motion vector field is smoothed using median filter what yields more accurate interpolation. In the experiments for the subjective evaluation, the proposed method bas shown satisfying results in terms of computation time consumption and peak signal-to-noise ratio. Due to the simplicity of the algorithm computation time was drastically decreased.