• 대한한의학회지
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• 제21권4호
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• pp.9-15
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• 2000

Objective : The aim of this study was to investigate the neuroprotection effect of estrogen on brain atrophy following cerebral infarction. Method : All animals in this study were classified into 4 groups; ovariectomy group (OVXgroup), cerebral infarction group (INF group), combination ovariectomy and cerebral infarction group (OVX + INF group), and naturally intact group for control data (NOR group). Cerebral infarction was made by Chen's method with some modification. Ovariectomy was performed by Wayforth's method. Experimental data for each group was collected at 15 days, month, 3 months, and 6 months after starting observation. Serum $17{\beta}-estradiol(E2)$ was determined by radioimmunoassay. Brain volume was measured and calculated with image analysis. Each brain was sliced at intervals of 2mm in chamber after 30 min of freezing in refregerater. Cerebral volume was obtained by sum of volume of each slice level, which was mean $area{\;}{\times}{\;}2mm$. Results : Cerebral ischemia was found to decrease the serum concentration of $17{\beta}-{\;}estradiol(E2)$ and to inhibit the physiologically conpensatary function of the ovariectomized rats. Also we found that deprivation of estrogen have resulted in more severe cerebral atrophy followed by cerebral infarction. Conclusion : It is suggested that estrogen has a neuroprotection effect on cerebral atrophy following cerebral infarction.

• 한국생활과학회지
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• 제16권6호
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• pp.1119-1130
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• 2007

The purposes of this current study were to develop a pre-parent education class for university students and to examine the difference in their beliefs after the program. The subjects of this study were 86 students who were selected from one university in Kyunggido, South Korea. Students had pre-test and post-test to measure the changes caused by the program. Two instruments were used: Beliefs of Appropriate Education and Child Rearing Attitudes. The results of this study were as following: In the post-test, students showed higher scores on affectionate child rearing attitudes. More specifically, students endorsed expression of affection toward a child, positive mother-child relationship, emotional involvement, giving a child equal right after having pre-parent education class. In terms of beliefs on appropriate education, in the post-test students became put more value on process, child, play, experience- oriented learning compared to their pre-test scores. In sum, this pre-parent education class is an effective one, which improve future parents' beliefs and attitudes on appropriate education and child rearing practices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.391-393
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• 2000

This paper presents an new algorithm for the economic load dispatch considering the reliability level constraints of composite power system under deregulated electricity market. It is the traditional ELD problem that generation powers have been dispatched In order to minimize total fuel cost subjected to constraints which sum of powers generated must equal the received load and no violating lower and upper limit constraints on generation. Under deregulated electricity market, however, generation powers of a pool have to be reallocated newly in order to satisfy the reliability differentiated level required at a load point because of a reliability differentiated electricity service which is a part of the priority service. In this study, new economic load dispatch algorithm for reallocating the generation powers of a pool in order to satisfy the reliability differentiated level under deregulated competitive electricity market is proposed. The uncertainties of not only generators but also transmission lines are considered fer the reliability evaluation. The characteristics and effectiveness of this methodology are illustrated by the case studies on MRBTS and IEEE-RTS.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.80-83
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• 2010

IEEE 802.11n 표준에 제시된 3가지 블록길이(648, 1294, 1944)와 4가지 부호율(1/2, 2/3, 3/4, 5/6)을 지원하는 다중모드 LDPC(Low Density Parity Check) 복호기의 성능을 분석하였다. 최소합 알고 리듬과 layered 복호방식이 적용된 LDPC 복호기의 고정소수점(fixed-point) 시뮬레이션 모델을 Matlab으로 개발하였다. 고정소수점 시뮬레이션을 통해 복호기 내부 비트 수와 정수부 및 소수부의 비트 수에 따른 복호 수렴속도를 분석하여 다중모드 LDPC 복호기의 하드웨어 구현을 위한 최적의 설계조건을 탐색하였으며, 블록길이와 부호율에 따른 복호성능을 분석하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.444-444
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• 2008

For the polymer tandem cell, simple and advantaged solution-based method to electron transport intermediate layer is presented which are composed $TiO_2$ nanoparticles. Device were based on a regioregular Poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl $C_{61}$ butyric acid methyl ester($PC_{60}BM$) blend as a donor and acceptor bulk-heterojunction. For the middle electrode interlayer, the $TiO_2$ nanoparticles were well dispersed in ethanol solution and formed thin layer on the P3HT:PCBM charge separation layer by spin coating. The layer serves as the electron transport layer and divides the polymer tandem solar cell. The open-circuit voltage (Voc) for the polymer tandem solar cells was closed to the sum of those of individual cells.

• 전자공학회논문지
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• 제51권10호
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• pp.72-79
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• 2014

본 논문은 PIPELINE-AWARE QC-IRA-LDPC (PA-QC-IRA-LDPC) 코드 생성 방법과 Rate-1/2 (2016,1008) PA-QC-IRA-LDPC 코드에 대한 효율적인 고속 복호기 구조를 제안한다. 제안한 방법은 비트 오류율 (BER) 성능 저하 없이 파이프라인 기법을 사용하여 임계경로를 나눌 수 있다. 또한 제안한 복호기 구조는 데이터 처리량, 하드웨어 효율 및 에너지 효율을 크게 향상시킬 수 있다. 제안한 복호기 구조는 90-nm CMOS 기술을 사용하여 합성 및 레이아웃이 수행되었으며, 이전에 보고된 복호기 구조들에 비해서 하드웨어 효율성이 53%이상 향상되었고, 훨씬 좋은 에너지 효율성을 보여준다.

• 전자공학회논문지
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• 제53권12호
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• pp.36-41
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• 2016

LDPC 부호는 최근 Wi-Fi, WiGig, 10GBased-T Ethernet과 같은 최신 통신 표준들에서 순방향 오류 정정 부호로 적용되고 있다. 그러나 LDPC 부호는 우수한 성능을 위해 큰 블록 크기와 많은 반복 복호 횟수를 요구되어 많은 연산량을 필요로 한다. 이러한 문제를 해결하기 위해서 오류 정정 성능을 크게 저하시키지 않고 연산량을 감소시키기 위한 다양한 연구가 지속적으로 수행되고 있다. 본 논문에서는 특정 조건식을 만족하는 변수 노드나 체크 노드에 대하여 메시지 갱신 연산을 중지시켜 연산 복잡도를 감소시키는 AFC 알고리즘을 제안한다.

• 대한임베디드공학회논문지
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• 제4권4호
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• pp.195-200
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• 2009

As 4G mobile communication systems require high transmission rates with reliability, the need for efficient error correcting code is increasing. In this paper, a novel LDPC (Low Density Parity Check) decoder is introduced. The LDPC code is one of the most popular error correcting codes. In order to improve performance of the LDPC decoder, we use SNR (Signal-to-Noise Ratio) estimation results to adjust coefficients of modified UMP-BP (Uniformly Most Probable Belief Propagation) algorithm which is one of widely-used LDPC decoding algorithms. An advantage of Modified UMP-BP is that it is amenable to implement in hardware. We generate the optimal values by simulation for various SNRs and coefficients, and the values are stored in a look-up table. The proposed decoder decides coefficients of the modified UMP-BP based on SNR information. The simulation results show that the BER (Bit Error Rate) performance of the proposed LDPC decoder is better than an LDPC decoder using a conventional modified UMP-BP.

• 제어로봇시스템학회논문지
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• 제3권5호
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• pp.526-531
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• 1997

To control nonlinear chemical processes, a new neural linearizing control scheme is proposed. This is a hybrid of a radial basis function(RBF) network and a linear controller, thus the control action applied to the process is the sum of both control actions. Firstly, to train the RBF newtork a linear reference model is determined by analyzing the past operating data of the process. Then, the training of the RBF newtork is iteratively performed to minimize the difference between outputs of the process and the linear reference model. As a result, the apparent dynamics of the process added by the RBF newtork becomes similar to that of the linear reference model. After training, the original nonlinear control problem changes to a linear one, and the closed-loop control performance is improved by using the optimum tuning parameters of the linear controller for the linear dynamics. The proposed control scheme performs control and training simultaneously, and shows a good control performance for nonlinear chemical processes.

• 대한기계학회논문집A
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• 제33권11호
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• pp.1332-1340
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• 2009

The front end wheel loader is widely used for the loading of materials in mining and construction fields. It has repetitive digging, loading and dumping procedures. The bucket is subjected to large resistance force from the soil during scooping. We considered the soil reaction force characteristics from scooping procedure, the protection by overload and automatic scooping mode algorithm. The main topic of this paper is the analysis of the soil reaction force characteristics. The analysis of soil mechanics is carried out and the developed soil model is verified by experimental results from the simplified experimental equipment. A simplified model of the soil shape and bucket trajectory is used to determine the scooping direction based on an estimation of the resistance force applied on the bucket during the scooping motion. In the future, this model will be used for the generation of an appropriate path for the wheel loader automation.