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      • 도시공원의 이용후 평가에 기초한 공원의 개발지표 설정 : 부산광역시 암남공원을 사례로 Case Study of Amnam Park in Busan City

        박승범,김승환,남정칠,강영조,이기철,김석규 동아대학교 환경문제연구소 1999 硏究報告 Vol.22 No.2

        The purpose of this study is to investigate the prime factors that affect to user postoccupancy evaluation of activities and facilities in urban parks, to classify those factors, to find out factors about them, and then to suggest important indicators in the urban park planning, design, and development. The survey research was done using the self-administered questionnaire method by 435 peoples in the Busan City who participated in recreational activities in the Amnam Park. The Analysis of the data primarily consists of two phase: The first analysis was dealt an exploratory factor analysis which identified major factors involved in user postoccupancy evaluation with reacreational activities and facilities in Amnam Park by the SPSS(Ver.6.0) program and the second analysis was used to investigate the factors affected to user postoccupancy evaluation in the urban park by the Regression Analysis. According to the factor analysis, user postoccupancy evaluation of facilities in urban parks concerning the 20 variables, 5 prime factors by the staistical values were considered. The factor analysis showed that user postoccupancy evaluation of activities in urban parks concerning the 11 variables, 3 prime factors by the staistical values were analysed. Postoccupancy evaluation in the urban park by the Regression Analysis suggested that the two varlables as 'the directions of park development' and 'companies with the personal specific characteristics' are significant in addition to the some variables presented in user postoccupancy evaluation with reacreational activities and facilities in Amnam Park by the factor analysis. Furthomore the analysis models were identified as having significant effects on the factor and regression analysis. Overall fits of both models were very good. These significant relationships indicate important factors and variables that should be considered in planning, design, and development of the urban parks. Therefore, development direction of the h a m park has to be analyzed as significant factors concerning user postoccupancy evaluation in a systematic way, recognized as important variables for planning process. The urban park has to be fully designed and established in the planning process not by the decision-maker's subjective evaluation but by user postoccupancy evaluation.

      • KCI등재

        SAW Filter Transmission Characteristics Design with Genetic Algorithm

        Park, Kyu­-Chil,Kim, Seok­-Jae The Korea Institute of Information and Commucation 2003 한국정보통신학회논문지 Vol.7 No.8

        SAW(Surface Acoustic Wave) 필터는 탄성표면파를 응용한 신호처리 기능 소자로, 각종 통신 기기의 고주파 회로의 대역 통과 필터로 이용된다. 기본적인 구성은 압전체 기판의 표면에 전기 신호와 표면파를 서로 교환하기 위한 입/출력 IDT(interdigital transducer) 한 쌍으로 이루어진다. 그 주파수 특성은 입/출력 IDT의 간격과 각각의 길이에 의해 결정되어지며, 대역 통과 필터의 특성을 지닌다. 본 논문은 이런 SAW 필터의 수치 설계 방법론에 관한 것이다. 입력 IDT의 전극의 길이를 변수로 정하고, 중심 주파수, 통과 대역의 폭과 정지 대역의 감소치가 주어졌을 때 적응/최적화 알고리즘을 이용하며 필터를 설계한다. 설계하고자 하는 필터 특성과 임의의 시간에 만들어진 필터와의 오차를 목적 함수로 정하고, 이 목적 함수를 최소화하는 것으로 필터의 설계가 가능하게 된다. SAW 필터의 계산 모델로는 델타 함수 모델과 등가 회로 모델을 사용하였으며, 최적화 알고리즘으로는 유전자 알고리즘을 사용하였다. The SAW device is extensively used as a electro$.$mechanical band­pass filter in which a two­pairs of interdigital transducers are provided over the surface of the piezoelectric substrate. For the design requirement, the central frequency and the bandwidth of the passband, and the attenuation level of the stopband region are specified. The configuration is made so as to satisfy the specification given. The central frequency is mainly determined by the distance between the pair of the finger electrodes. The design is considered as an optimization problem with which the error norm, the distance between the desired characteristics and the calculated for a given model is to be minimized. The delta function model and the electrical equivalent circuit model are utilized to represent the SAW filter characteristics. Genetic algorithm is used for optimization in which apodization of the transducer fingers is chosen as a design variable.

      • Cd(Ⅱ) 폴라로그람의 異常波에 關한 硏究

        崔七男,朴聖珪,丁梧鎭,문경국 조선대학교 기초과학연구소 1984 自然科學硏究 Vol.7 No.1

        pH 6.0∼12.0 範圍에서 0.15M 타르타르 酸鹽支持溶液 속에서 Cd(Ⅱ) Polarogram을 25℃에서 二段還元波를 調査한 결과 pH8.2部分 까지는 限界電流 및 半波電位값이 一定하며 한편 같은 濃度의 窒酸鹽 支持溶液을 사용하였을 때에 比하여 一段還元波의 半波電位값은 0.03volt 陰의 電位값으로 移動하고, 限界電流 값은 21% 減少되었다. pH8.2 部分 以上부터 限界電流 값이 急激하게 增加하다가 pH8.9 以上부터는 다시 急激하게 減少하는 現象을 보여 주었다. 한편 pH8.2 以上부터는 半波電位가 pH11.0에서는 -1.37volt로 되었다. 可能한 電極反應을 假定하여, pH11.0에 이르기까지의 還元波移動의 原因을 檢討하였다. The second reduction waves of the polarogram of Cd(Ⅱ) in 0.15M sodium tartrate solution were investigated in the range of pH from 6.0 to 12.0 at 25 C. Up to pH 8.2, the limiting current and the half wave potential were found to be constant, and when compared with the nitrate solution equal to the concentration of sodium tartrate, the limiting current of the first reduction wave has been decrease 21% and the half wave potential of the first reduction wave shifted by -0.03 volt. The values of limiting current were sharply increased above pH 8.2, and maximum value was obtained at pH 9.8. The half wave potentials were gradually proceeded in negative direction with increasing pH and the half wave potential of -1.37 volt was obtained at the pH 11.0. Suggesting possible mechanisms of electrode reactions, the anomalous behavior of reduction waves of Cd(Ⅱ) in sodium tartrate solution up to pH 11.0 was discussed.

      • 水稻의 穗發芽에 關한 硏究 (Ⅰ) 收穫 및 置床時期의 影響

        趙東三,金仁培,尹汰,朴成圭,權圭七 충북대학교 농업과학기술연구소 1987 農業科學硏究 Vol.5 No.1

        This study was conducted in 1986 to investigate the vivaparous germination in rice. Two varieties, Daeseongbyeo and Chilseongbyeo, were transplanted on May 25 and June 5 and panicles were harvested 5 times with the interval of 5 days beginning 30 days after heading. Panicles were seeded in incubator at 20℃ right after harvest and after drying and storage to observe the germination. Rate of viviparous germination of Daeseongbyeo was higher than that of Chilseongbyeo regardless of the seeding time. Rate of vivaparous germination of May 25 transplanting was higher than that of June 5 transplanting. Germination of Daeseongbyeo was not afftected by seeding time. Viviparous germination rate of Daeseongbyeo appeared to be increased as the harvesting was posponded. On the other hand, Chilseongbyeo did'nt germinate when seeded right after harvesting and rate of vivaparous germination was decreased as the harvesting was postponded. Vivaparous germination was higher in the order of top > middle > bottom part on a panicle, while grains on the primary branches showed higher vivaparous germination than those on the secondary branches.

      • 水稻의 穗發芽性에 關한 硏究 (Ⅱ) 栽培時期 移動에 따른 穗發芽性

        趙東三,孫錫龍,金鍾煥,尹太,朴成圭,權圭七 충북대학교 농업과학기술연구소 1988 農業科學硏究 Vol.6 No.1

        This study was conducted in 1987 to investigate the viviparous germination in rice. Six varieties, i. e., Daeseongbyeo, Sangpungbyeo Hwaseongbyeo, Taebagbyeo, Chilseongbyeo and Samgangbyeo were used for this experiment. Seedlings were transplanted on May 25 and dune 5 and panicles were harvested 5 times with 5 days interval beginning 25 days after heading. Panicles were incubated at normal temperature right after harvest to observe the germination. Rate of viviparous germination of Japonica type was higher than that of Indica type. The early varieties such as Daeseongbyeo, showed high viviparous germination. Rate of viviparous germination of May 25 transplanting was higher than that of June 5 transplanting. Viviparous germination rate of Japonica type appeared to be increased as the harvesting was postponed. On the other hand, Indica type didn't show viviparous germinate. Based on this study the optimum harvesting time of tested varieties appeared to be between 40 to 45 days after heading.

      • SCOPUSKCI등재

        A Study on the Acoustic Fault Detection System of Insulators from Their Radiation Noises

        Park, Kyu-Chil,Yoon, Jong-Rak The Korea Institute of Information and Commucation 2011 Journal of information and communication convergen Vol.9 No.5

        To detect the insulator in the fault state on the electric poles, we first measured radiation sounds from normal state insulators and error state insulators in the anechoic chamber. We processed the signals in frequency domain to find the features with filter bank, narrow band and wide band analysis. So we could found two apparent results from their frequency spectrums - one was 120Hz harmonic components, the other was high average noise level than normal state ones. Then we also introduced a technique for the direction detection of the fault state insulator using the cross correlation from the three dimensional array microphones. To eliminate the noise signal from unexpected directions, we suggested the zero padding technique in cross correlation function. From these, we could conclude that acoustic fault detection techniques are useful of the detection of insulators' faults and the estimation of the direction of the fault state insulators.

      • SCOPUSKCI등재

        An Approach for Implementation of Underwater Acoustic Communication Channel using 2-D TLM Modeling and Cross-Correlation Function

        Park, Kyu-Chil,Yoon, Jong-Rak The Korea Institute of Information and Commucation 2010 Journal of information and communication convergen Vol.8 No.2

        In underwater acoustic communication, acoustic signals from transducers or hydrophones are used. And the underwater acoustic communication channels are very complicated, because of vertical distribution of acoustic velocity according depths, and reflections from boundaries like as surface or bottom. For the implementation of the underwater acoustic communication channel, the image method or ray tracing method have been used. In this paper, we introduce a new approach for implementation of underwater acoustic communication channel using the simulation of the Transmission Line Matrix Modeling and cross-correlations from the input and output signals.

      • SCOPUSKCI등재

        Performance Evaluation of the Complex-Coefficient Adaptive Equalizer Using the Hilbert Transform

        Park, Kyu-Chil,Yoon, Jong Rak The Korea Institute of Information and Commucation 2016 Journal of information and communication convergen Vol.14 No.2

        In underwater acoustic communication, the transmitted signals are severely influenced by the reflections from both the sea surface and the sea bottom. As very large reflection signals from these boundaries cause an inter-symbol interference (ISI) effect, the communication quality worsens. A channel estimation-based equalizer is usually adopted to compensate for the reflected signals under the acoustic communication channel. In this study, a feed-forward equalizer (FFE) with the least mean squares (LMS) algorithm was applied to a quadrature phase-shift keying (QPSK) transmission system. Two different types of equalizers were adopted in the QPSK system, namely a real-coefficient equalizer and a complex-coefficient equalizer. The performance of the complex-coefficient equalizer was better than that of two real-coefficient equalizers. Therefore, a Hilbert transform was applied to the real-coefficient binary phase-shift keying (BPSK) system to obtain a complex-coefficient BPSK system. Consequently, we obtained better results than those of a real-coefficient equalizer.

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