• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.10-18
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• 2014

In this paper, we propose a new frequency reconfigurable dual-band antenna. By using an electronically compact eighth-mode substrate-integrated-waveguide(EMSIW) resonator, we have designed a compact antenna, which performs dual-band movement by additionally loading a complementary split ring resonator(CSRR) structure. The EMSIW and CSRR structures are designed to satisfy the bandwidths of 1.575 GHz(GPS) and 2.4 GHz(WLAN), respectively. We load the CSRR with a varactor diode to allow a narrow bandwidth and to enable the resonance frequency to continuously vary from 2.4 GHz to 2.5 GHz. Thus, we realize a channel selection function that is used in the WLAN standards. Irrespective of how a varactor diode moves, the EMSIW independently resonates so that the antenna maintains a fixed frequency of the GPS bandwidth even at different voltages. Consequently, as the DC bias voltage changes from 11.4 V to 30 V, the resonance frequency of the WLAN bandwidth continuously changes between 2.38 GHz and 2.5 GHz, when the DC bias voltage changes from 11.4 V to 30 V. We observe that the simulated and the measured S-parameter values and radiation patterns are in good agreement with each other.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.307-314
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• 2011

A new predistortion technique for dynamic spectrum allocation systems such as cognitive radio (CR) is proposed. The system model considered in this paper occupies a small band at a time, but the center frequency can be changed in the wide range of frequency. In this scenario. the front-end filter may not eliminate the harmonics of the power amplifier (PA) output. The proposed PD reduces the spectral regrowth of the fundamental signal at the carrier frequency (${\omega}_0$) and removes the harmonics ($2{\omega}_0$, $3{\omega}_0$, ...) at the same time. The proposed PD structure is composed of multiple predistorters (PDs) centered at integer multiples of ${\omega}_0$. The PD at ${\omega}_0$ is for removing spectral regrowth of the fundamental signal, and the others are for harmonic reduction. In the proposed PD structure, parameters of PDs are found jointly. Simulation results show that the spectral regrowth can be reduced by 20dB, and the 2nd and 3rd harmonics can be reduced down to -70dB from the power of the fundamental signal.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.235-241
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• 2008

If the target volume cannot be included with one field at head and neck cancer, we commonly used two or more field. It is very important to irradiate uniform dose at junction area of the fields. However, according to body shape of patient or general condition of patient, skin junction area can be matched incorrect, So overdose area or underdose area can be appeared in the junction area. This study researched therapy technique which can give uniform dose at skin junction owing to applying the edge block of lateral field at head and neck cancer. We measured the changed distance and rotational angle between central line of anterior supraclavicle lymph node and low margin of right lateral field on simulation process using the shielding block of variable rotation. As a result, the changed distance between central line of anterior supraclavicle lymph node and low margin of right lateral field was below 2mm to ${\pm}$10cm distance at central line of Y axis, changed angle was average 1.28 degree. But by using it the shielding block of variable rotation, the incorrect match at junction can be minimized. We think that this technique is very efficient one to apply this technique at head and neck cancered by the movement of organs can be not included, Therefore we have to pay attention on the process to imput MLC layer

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.495-520
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• 2018

Because of structural changes in the international oil market and the economy, it is widely recognized that the impact of oil shocks on the economy has weaken since the mid-1980s. This study tries to examine the validity of the recent perception about the relationship between oils shocks and the economy, estimating the time-varying effects of oil shocks on the Korean economy. The results show that the dynamic effects of oil shocks normalized to a one standard deviation has been relatively constant, in contrast to the recent perception and a number of existing studies. In addition, because the shape of impulse response functions at each point in time spanning from 1984:II to 2017:IV has not been changed significantly, it seems that the propagation mechanism of oil shocks also has not been substantially altered. These findings indicate that even though structural changes of the economy, such as the reduction in the share of oil consumption and the spread of high-efficiency energy technologies, have been rapidly progressed, it is not still enough to offset the negative effects of oil shocks. Rather, it seems that the recent perception about the shrinking effects of oil shocks is mainly due to the assumptions that do not reflect changes in the size of oil shocks. In particular, this problem appears more pronounced in the case of the typical a one standard deviation increase oil shock under homoskedasticity assumption, which is widely adopted in the most VAR analyses. Therefore, in estimating the effects of oil shocks on the economy, it is important to specify the correct model and normalization method, to reflect changes in the size of oil shocks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2339-2344
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• 2014

of a microstrip transmission line, this transmission line can operate as the microstrip line or the coplanar line according to open or short connection between the ungrounded copper plane and grounded plane on the base plane. Two different type operation of the transmission line means that one transmission line can have two different characteristic impedances. This paper proposes and fabricates the circuit to be operated 2-ports power transmission line or 2-way power divider with the stable input matching characteristic by using this dual-impedance transmission line. The proposed circuit operates 2-ports power transmission line in case of the coplanar line or 2-way power divider line in case of the microstrip line. The fabricated circuit shows $S_{21}$ > -0.2 dB and $S_{11}$ < -15 dB above 700 MHz when the circuit operates 2-ports power transmission line. And, it is $S_{21}$ > -3.8 dB, $S_{11}$ < -10 dB and $S_{21}/S_{31}$ < ${\pm}0.3dB$ above 700 MHz when the circuit operates 2-way power divider.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.25-29
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• 1998

본 논문은 얼굴 인식 또는 표정 인식 분야에 있어서 중요한 특징을 나타내는 얼굴과 얼굴의 주요소인 눈과 입, 눈썹의 영역 추출 및 그의 윤곽선·추출에 관한 방법을 제시한다. 얼굴요소의 영역 추출은 엣지 정보와 이진화 영상을 병합하여 이용한 프로젝션 분석을 통하여 얼굴 및 각 얼굴요소를 포함하는 최소포함사각형(MER: Minimum Enclosing Rectangle)을 추출하였다. 얼굴 영상에 관련된 윤곽선 연구에는 가변 템플릿(Deformable Template), 스네이크(Snakes: Active Contour Model)를 이용하는 연구들이 이루어지고 있는데 가변 템플릿 방법은 수행시간이 느리고 추출된 윤곽선의 모양이 획일 된 모양을 갖는 특성이 있다. 본 논문에서는 사람마다 얼굴요소의 모양의 개인차가 반영되고 빠른 수렴을 할 수 있는 스네이크 모델을 정의하여 눈, 입, 눈썹, 얼굴의 윤곽선 추출 실험을 하였다. 또한 스네이크는 초기 윤곽선의 설정이 윤곽선의 추출 곁과에 큰 영향을 미치므로, 초기 윤곽선의 설정 과정이 매우 중요하다. 본 논문에서는 얼굴 및 각 얼굴요소를 포함하는 각각의 최소 포함 사각형(MER)을 추출하고, 이 추출된 MER 내에서 얼굴 및 각 얼굴요소의 일반적인 모양을 초기 윤곽선으로 설정하는 방법을 사용하였다. 실험결과 눈, 입, 얼굴의 MER의 추출은 모두 성공하였고, 눈썹이 흐린 사람들의 경우에만 눈썹의 MER추출이 졸지 않았다. 추출된 MER을 기반으로 하여 스네이크 모델을 적용한 결과, 눈, 입, 눈썹, 얼굴의 다양한 모양을 반영한 윤곽선 추출 결과를 보였다. 특히 눈의 경우는 1차 유도 엣지 연산자에 의한 엣지 와 2차 유도 연산자를 이용한 영점 교차점(Zero Crossing)과 병합한 에너지 함수를 설정하여 보다 더 나은 윤곽선 추출 결과를 보였다. 얼굴의 윤곽선의 경우도 엣지 값과 명도 값을 병합한 에너지 함수에 의해 비교적 정확한 결과를 얻을 수 있었다.잘 동작하였다.되는 데이타를 입력한후 마우스로 원하는 작업의 메뉴를 선택하면 된다. 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Japanese Letter Jobcheso." Therefore, the purpose of this study is to look into the origin of the letter designs in the Chinese character culture

• Journal of IKEEE
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• v.12 no.4
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• pp.246-254
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• 2008

This paper represents a design of a 4 way SIMD processor with multi-thread and dual phase instruction pipeline. 8 threads can be performing in round-robin order, so any hazards can’t occur. The dual phase pipeline makes a pipeline operate as two pipelines, and it can fetch maximum 4 unit instructions at once. This variable length instruction set divide into first phase and second phase instructions, and with this function, complex branch and addressing can be executed at one clock cycle. This processor reduces the code size to quarter, pull out the doubled performance improvement than normal SIMD architecture.

• Journal of Korea Multimedia Society
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• v.7 no.9
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• pp.1246-1254
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• 2004

This paper presents a image coding method that is well adaptive to close-range video transmission because of its low titrate and simple coding procedure. At first, it reduces temporal redundancies by performing image DPCM between previous frame and current frame, and makes wavelet transformed image of this difference image. Then, the coefficients are quantized selectively by using the coefficient values of base level and mid-frequency level because inter-level redundancies are widely exists in multi-resolution images. Finally quantized coefficients are made iron the function that implies the target bitrate, the average coefficient energy, and the value of the level. The proposed method shows the effective Performance in the experiments using the continuous motion images and transition images.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.245-249
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• 2010

Now normally using a contact method of vehicle Inhibitor Switch that is use direct voltage level signal. This method is good solution for signal deliverly. but The contacted method have a short lifetime because of deterioration of contact surface. so we suggest to non-contacted method using magnetic sensor. The magnetic sensor is used to non-contacted method that is solution for problem of contacted method. In this paper using that of magnetic sensor feature, so we applied to Vehicle Transmitter switch that of non-contacting method. Sensor voltage outputs have variable electric potential that normally 0 mV to 150 mV, and it is depend on Switch Angle. we used two differential sin wave for switching of 5 state signal.

• Journal of IKEEE
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• v.24 no.2
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• pp.570-578
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• 2020

In this paper, we propose an efficient method for implementing the adaptive second-order Volterra filter. To reduce computational load, the UCFD-SVF has been proposed. The UCFD-SVF, however, shows deteriorated convergence performance. We propose a new method that initializes the adaptive filter weights periodically on the fact that the energy of the filter weights is slowly increased. Furthermore, we propose another method that the interval for the weight initialization is variable to guarantee the performance and we shows the method gives the better performance under the non-stationary environment through the computer simulation for the adaptive system identification.