• 한국음향학회지
• /
• 제28권1호
• /
• pp.51-60
• /
• 2009

본 논문에서는 warped common acoustical pole and zero (WCAPZ) 모델링 방법을 이용한 새로운 공간 등화 방법을 제안한다. 제안한 방법은 저주파 영역의 등화 성능을 감소시키지 않으면서 등화 필터의 차수를 줄일 수 있는 장점을 가진다. 따라서 제안된 공간 등화 시스템은 기존의 블록 변환 방법에 비해 연산량은 비슷하면서도 적은 입출력 지연을 가지게 된다. 컴퓨터 모의실험을 통해 제안된 방법이 기존의 기법에 비해 저주파 영역에서 좋은 공간 등화 성능을 보임을 검증하였다.

• 동력기계공학회지
• /
• 제5권3호
• /
• pp.11-16
• /
• 2001

In the DI diesel engine of passenger cars, common rail injection system have been used to improve the engine performance and reduce the exhaust emission by controlling injection timing, injection pattern, and injection duration. In case that common rail injection system is applied to high speed DI diesel engine, it is necessary to have high response and good repetition characteristics. These characteristics of injector depend on the characteristics of solenoid. Thus, to apply the common rail injection system in the high speed diesel engine, we had designed and made a multi-pole solenoid, and carried out repetition, response test to compare the multi-pole solenoid with the gasoline Injector solenoid. The result shows that repetition and response characteristics of multi-pole solenoid have better characteristics than the gasoline injector solenoid.

• 전기학회논문지
• /
• 제67권6호
• /
• pp.702-707
• /
• 2018

In case of Lighting occurs in Domestic combined distribution line, normally the voltage for the neutral line increase dramatically. General connection for underground cable is bundled common earth type so the lightning over voltage increase at the concentric-neutral line is not big enough to give impact on cable sheath. But in case of Non bundled common earth type it is necessary to analyze the phenomena on cable sheath caused by lightening overvoltage. Especially pole and cable joint are the core factor to consider. In this paper concrete pole and cable joint were evaluated in case of Non bundled common earth type combined distribution Line. EMTP simulation model has been designed and several case study were made. Also several experimental test were made to verify the simulation result.

• 전력전자학회논문지
• /
• 제19권6호
• /
• pp.488-493
• /
• 2014

This paper presents a carrier-based pulse-width modulation(PWM) method for reducing the common-mode voltage of a three-level four-leg converter. The idea of the proposed PWM method is intuitive and easy to be implemented in digital signal processor-based converter control systems. On the basis of the analysis of space-vector PWM(SVPWM) and sinusoidal PWM(SPWM) switching patterns, the fourth leg pole voltage of the three-phase converter called "f leg pole voltage" is manipulated to reduce the common-mode voltage. To synthesize f leg pole voltage for the suppression of the common-mode voltage, positive and negative pole voltage references of f leg are calculated. An offset voltage is also deduced to prevent the distortion of a, b, and c phase voltages. The feasibility of the proposed PWM method is verified by simulation and experimental results. The common-mode voltage of the proposed PWM method in peak-to-peak value is 33% in comparison with that of the conventional SVPWM method. The transition number of the common-mode voltage is also reduced to 25%.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.433-435
• /
• 2003

As the nation's standard of living rises lately, the common interest in the environmental issue is raised and the environmental design of a transmission line is needed. When the environmental design is needed, KEPCO used a steel pole instead of a rectangular tower. A steel pole has many advantages such as simplification of a tower and less damage to the forest according to less demand of site. But the weak withstand weight of a mono type steel pole is a problem. This paper introduces an H type steel pole which improves its withstand weight, reduces a diameter of a pole from 2.6m to 1.3m and decreases joining points according to the increase of unit length of a pole from 6m to 9m.

• 전기학회논문지
• /
• 제59권11호
• /
• pp.1986-1989
• /
• 2010

The modification of magnetic structures for an E-core switched reluctance machine (SRM) comprising two segmented stator cores or a monolithic stator core is presented for ease of assembly, good manufacturability, mechanical robustness, and electromagnetic performance improvement. The E-core stator has four small poles with phase windings and two or four large poles (hereafter referred to as common poles), in between. The common poles are shared by both phases for positive torque generation during the entire operation. The E-core SRMs are compared to a conventional two-phase SRM. The comparison includes cost savings, torque, copper and core losses, and efficiency in order to validate the distinct features of the E-core SRMs. Magnetic equivalent circuit (MEC) technique is employed for proving the benefits of the E-core common-pole structure.

• 대한정형외과스포츠의학회지
• /
• 제8권2호
• /
• pp.121-124
• /
• 2009

소아에서의 슬개골 골절은 성인을 포함한 전체 슬개골 골절의 약 2% 미만에서 발생하고, 모든 소아 골절의 약 1% 정도로 매우 드물게 발생한다. 성장중인 슬개골은 성인에서의 슬개골 골절과는 달리 골연골 골절 또는 견열 골절의 형태로 흔히 발생하며, 그 형태는 주로 소매형 골절로 나타난다. 소아 슬개골의 견열 골절 또는 소매형 골절은 슬개골의 상단부 혹은 하단부에서 발생하나, 대부분 슬개골 하단부가 주를 이루며, 상단부에 생긴 경우는 드물다. 저자들은 16세 소아에서 슬개골 상단부의 소매형 골절 1례를 경험하여 이를 문헌고찰과 함께 보고하는 바이다.

• 대한전기학회논문지
• /
• 제40권2호
• /
• pp.217-223
• /
• 1991

Most common applications of neural networks to control problems are the automatic motor controls using the artificial perceptual function. These control mechanisms are similar to those of the intelligent and pattern recognition control of an adaptive method frequently performed by the animate nature. In this paper, the pole-balancing problem is selected as the control object and an actual cart-pole controller is implemented by a computer interfacing and demonstrated as motor control using the reinforcement learning rule. In the experiment, given a change of the main parameters of cart-pole dynamics, a comparison is made between the LQR scheme and neural network method. The neural network method exhibits a more effecftive control action in a real situation having a large uncertainty than the LQR scheme.

• 한국음향학회지
• /
• 제29권5호
• /
• pp.339-346
• /
• 2010

음향 간섭제거기는 머리전달함수 (head-related impulse response; HRIR)의 길이에 큰 영향을 받게 되어, 일반적으로 큰 차수의 필터를 필요로 한다. 간섭제거필터의 길이를 줄이기 위한 방법으로 주파수 워핑, 공통 극점과 영점 (common acoustical pole and zero; CAPZ) 모델링 등의 방법들이 제안되었는데, 본 논문에서는 이 두 가지 방법을 결합한 방법을 제안한다. 이를 위해, 주파수 워핑 영역에서 공통 극점과 영점 모델링을 통해 필터를 설계하며, 디워핑 과정을 통해 종래의 선형 영역에서 안정된 필터를 구현한다. 제안된 방법은 주파수 워핑을 통한 간섭제거 성능 향상과 공통 극점 모델링을 통한 필터 계수 감소를 함께 제공할 수 있다. 이러한 성능을 검증하기 위해 다양한 컴퓨터 모의 실험을 진행하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제49권11호
• /
• pp.627-634
• /
• 2000

In this paper, new micromachined tunble bandpass filters for multi-band millimeter-wave telecommunication systems are proposed. Two types of mm-wave tunable filters are fabricated using micromachning technology and the responses of the filters are measured. One is two-pole lumped elements filter and the other two-pole resonators filter. Frequency tunability of the filter is achieved by changing the gap between a common CPW ground plate and the movable cantilever beam connected to the transmission line with the controllable renge of 2.5${\mu}m$. The deflection of cantilever beam is measured with the applied DC voltage. With the applied bias voltage from 0 to 50 V, the fabricated filters show 0.6 GHz(2.3%) at 26.6 GHz, and 0.8 GHz(2.5%) at 32 GHz center frequency shift for the lumped elements and resonators filter, respectively. The life time of the fabricated gold cantilever structure are tested.