CO₂ 배출량을 감안한 화력발전소의 생산성 변화 분석: Luenberger지수 접근법

권오상,Kwon, Oh-Sang 한국자원경제학회 2010 자원·환경경제연구 Vol.19 No.4

This study applies the Luenberger indicator approach to estimate productivity of the Korean fossil-fueled power plants. A panel data set of 25 power plants was used. The method incorporates $CO_2$ emission as an undesirable output and shows that ignoring $CO_2$ emission overestimates the productivity change. There are two sources of overestimation. First, the usual method estimates productivity change ignoring the increase in $CO_2$ emission that occurred during the study period. Second, the productivity change estimated by the usual method that does not incorporate $CO_2$ emission is very sensitively affected by the change in operation rate. The paper decomposes the productivity change into the efficiency change and the technical change. The results show that the two sources contribute to the productivity change almost equally. It is also shown that the size and the pattern of productivity change are dependent on the plants' fuel types. Non-LNG power plants which saved their energy consumption and thereby reduced their $CO_2$ emission have achieved relatively high rate of productivity improvement.

자동차 실내에서의 엔진 소음 감쇠를 위한 실시간 능동 소음 제어 시스템의 구현

권오상,차일환,Kwon, Oh-Sang,Cha, Il-Whan 한국음향학회 1997 韓國音響學會誌 Vol.16 No.4

The passive noise control techniques used until now cancel the noise in terms of the characteristics of materials, which increase the mass and the dimension and have a limit that is effective only to attenuate the high frequency components of the noise. But the active noise control techniques developed in recent years have merits that they decrease the mass and the dimension and are effective to attenuating the low frequency noises. In this paper, the real-time active noise control system attenuating the engine booming noise in a car using the digital signal processing(DSP) techniques in terms of the principle of active noise control. The multiple-error filtered-x LMS(Least-Mean Square) algorithm is used as the adaptive algorithm for active noise control and is implemented using the DSP processor Motorola DSP56001 as a controller. According to the result that the experiments are performed for the engine as the RPM changes in a car, the noise attenuating performances are achieved in an overall car interior and is verified to be 20 dB higher for pure-tone and globally, 15 dB.

화상 정보를 이용한 이동 로봇의 장애물 회피 알고리즘

권오상,이응혁,한영환,홍승홍,Kwon, O-Sang,Lee, Eung-Hyuk,Han, Yong-Hwan,Hong, Seung-Hong 한국전기전자학회 1998 전기전자학회논문지 Vol.2 No.1

There are some problems in robot navigations with a single kind of sensor. We propose a system that takes advantages of both CCD camera and ultrasonic sensors for the concerning matter. A coordinate extraction algorithm to avoid obstacles during the navigation is also proposed. We implemented a CCD based vision system at the front part of the vehicle and did experiments to verify the suggested algorithm's availability. From experimental results, the error rate was reduced when a CCD camera was used rather than when only ultrasonic sensors were used. Also we can generate path to avoid those obstacles using the measured values.

미래전투에 대비한 로봇 요구분석과 개발방향에 대한 연구

권오상,Kwon, Oh-Sang 한국군사과학기술학회 2005 한국군사과학기술학회지 Vol.8 No.2

The use of robot is no longer limited in the industrial scene, and becoming expanded toward many aspects of human life. Especially, military robot closely concerned with our lives seems to advance more and more in the future. As a need analysis for developing military robot, this project conducted a poll about Unmanned Reconnaissance Robot, and on the basis of the result, I suggested 3 directions of developing UGV(Unmanned Ground Vehicle) suitable to strategic environment of Korea.

부 모드 억제율이 향상된 소형 이중 링 공진 반사기 기반 하이브리드 집적 파장 가변 레이저

권오상,정영철,Kwon, Oh-Sang,Chung, Young-Chul 한국광학회 2011 한국광학회지 Vol.22 No.2

In this paper, a small double ring resonator reflector was designed and fabricated using a polymer waveguide, and the measurement result was discussed. A widely tunable characteristic of the small double ring resonator caused by the Vernier effect, which results from the difference of the ring radii, was observed. The insertion loss of the double ring reflector was reduced by minimizing the device length to be as short as possible, and thus the output power and the SMSR (side mode suppression ratio) was greatly enhanced. The hybrid integrated laser based on the small double ring resonator reflector lased with the SMSR of 45 dB. In addition, the wide tuning range of 40 nm could be obtained by injecting a current of 30 mA to an electrode on top of the reflector.

능동 소음 제어를 위한 선택적 결합 알고리듬

권오상,차일환,Kwon, Oh-Sang,Cha, Il-Whan 한국음향학회 1997 韓國音響學會誌 Vol.16 No.5

The feedforward control algorithm for active noise control exhibits high stability and performance robustness. But it has a slow convergence speed and requires a correlated reference signal. Broadband active control systems typically use feedback control in order to increase the convergence speed and to avoid the problems associated with obtaining and decoupling a suitable reference signal. However, it is well known that conventional feedback control systems have a gain-bandwidth limitation and stability problem. This paper presents the new system based on the combination of both feedforward and feedback system in order to increase the convergence speed. The proposed system uses a proposed control algorithm termed "optional-summed" algorithm in which the "optional summed reference signal" comprised of weighted sum of an original reference signal and a eror signal, is used as an input to an adaptive system. Thus, the proposed system can have faster convergence speed and better performance than either feedforward or feedback system using the Filtered-x LMS algorithm as almost equivalent complexity of computation as it. Several simulation results demonstrating the good properties of the proposed adaptive system as well as verifying the analytical results are also presented in the paper.

폴리머 결합 링 공진기 기반 가변 광신호 지연기의 설계 및 제작

권오상,김재성,정영철,Kwon, Oh-Sang,Kim, Jae-Seong,Chung, Young-Chul 한국광학회 2011 한국광학회지 Vol.22 No.6

In this paper, a variable optical signal delay line based on coupled ring resonators is designed and fabricated in high-index contrast polymer material. The free spectral ranges (FSR) of the rings are designed to be 100 GHz, and 8 coupled rings are used. When two rings near a bus waveguide are in resonance, the optical delay is measured to be about 100 ps. When four rings are in resonance, the measured delay is about 180 ps. Both are close to the theoretical calculations.

디지털 신호처리 칩(GCD4101)을 사용한 컬러 CCD 카메라 구현

권오상,이응혁,민홍기,정정석,홍승홍,Kwon, O-Sang,Lee, Eung-Hyuk,Min, Hong-Ki,Chung, Jung-Seok,Hong, Seung-Hong 한국센서학회 1999 센서학회지 Vol.8 No.1

The research and implementation was preformed on high-resolution CCTV camera with CCD exclusive DSP conventional analog signal processor CCTV camera has its limit on auto exposure(AE), auto white balance(AWB), back light compensation(BLC) processing, severe distortion and noise of image, manual control parameter setting, etc. In our study, to resolve the problems in conventional CCTV camera, we made it possible to control AE, AWB, BLC automatically by the use of the DSP, which are used exclusively in the CCD camera produced domestically, and the microcontroller. And we utilized the function of screen display of microcontroller for the user-friendly interface to control CCD camera. And the electronic variable resister(EVR) was used to avoid setting parameters manually in the level of manufacturing process. As the result, It became possible to control parameters of the camera by program. And the cost-down effect was accomplished by improving the reliability of parameter values and reducing the efforts in setting parameters.

Enhanced Multi-Channel Adaptive Noise Control Compensating Nonlinear Distortions

권오상,Kwon, Oh Sang The Acoustical Society of Korea 2015 한국음향학회지 Vol.34 No.1

In fields of controlling acoustical noises, the overall adaptive control system is nonlinear due to the loudspeaker, amplifiers, converters, and microphones, etc. and the performance of noise control is decreased by the extent of nonlinearities, so an adaptive control system compensating nonlinear distortions is needed. In this paper, a new multi-channel adaptive noise controller was proposed, which was combined with the adaptive compensator to effectively linearize nonlinear distortions in the overall adaptive control system. Through computer simulations, the proposed adaptive compensator could linearize the nonlinear distortions and the proposed noise controller had better capability of controlling the noises than the conventional LMS controller.

자동차의 엔진소음 감쇠를 위한 효율적인 적응제어기에 대한 연구

권오상,Kwon, Oh-Sang 한국전자통신학회 2014 한국전자통신학회 논문지 Vol.9 No.9

본 논문에서는 자동차의 무게 감소, 탑승자의 안락함과 정숙함, 그리고 연비의 향상 등을 위해 소음을 저감하는데 있어 흡음재와 차음재를 사용하는 기존의 수동적인 방법을 사용하지 않고 능동적으로 감소시키는 방법을 제안하였다. 제안한 방법은 기존의 능동소음 제어기를 향상시킨 것으로서 양방향 제어 알고리듬을 사용하는 새로운 제어기이다. 제안한 알고리듬은 계산양의 증가가 거의 없고, 구현이 간단하고 안정적이며, 수학적으로도 해석이 용이한 장점이 있다. 자동차 엔진소음에 대한 모의실험을 통해 양방향 제어기의 소음감쇠 성능을 순방향제어기와 역방향제어기의 성능에 대해 비교한 결과 시간영역과 주파수영역에서 양방향제어기의 소음감쇠 성능이 우수함을 확인하였으며, 임펄스성의 간섭이 유입되거나 2차 경로의 응답이 변화하는 경우에도 가장 좋은 성능을 보여주었다.