• Title/Summary/Keyword: D-S 이론

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An Analysis of Intake System using BEM and 1-D Solution (경계 요소법과 평면파 이론을 이용한 흡기계 해석)

  • Lee, C.M.;Kwon, O.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.89-96
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    • 1995
  • The application of the 4-pole parameter method with 1 - D theory is acceptable for intake system analysis. However, the limitaion appears during the analysis of complicated intake system since this method is developed based on the plane wave thoery. For the intake system analysis, the usage of BEM(Boundary Element Method) is introduced describing its disadvantage. To combine benefits of both method. a hybrid method is introduced. This hybrid method consists of the 4-pole parameter with I-D theory and BEM. The developed method is applied to an automobile intake system analysis to obtain the transmission loss.

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A Study on the Effects of Excessive Price Discounts etc. on Consumer Purchase Intention in Internet Shopping Mall (인터넷쇼핑몰의 과다한 가격할인 및 선착순경매가 소비자의 구매의도에 미치는 영향에 관한 연구)

  • Moon, Tae-Hyun;Park, Ju-Young
    • The KIPS Transactions:PartD
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    • v.14D no.4 s.114
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    • pp.395-406
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    • 2007
  • The development of e-commerce made a great effect on all the aspect of marketing mix. Especially, marketing stimuli of Halfplaza.com, excessive price discounts and auction by order of arrival, spread out gradually in internet shopping mall industry. The study showed that excessive price discounts combined with auction by order of arrival increased consumer's perceived value, but decreased perceived risk. In conclusion, legal protections must be established since consumers tend to be vulnerable to various marketing mix of deceptive e-commerce players.

Design of Optical Multimode Interference Couplers with Ultracompact Propagating Width (초소형 전송폭을 갖는 광 다중모드 간섭결합기의 설계)

  • Ho, Kwang-Chun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.1
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    • pp.47-52
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    • 2011
  • In this paper, to evaluate the design properties of 3D optical multimode interference (MMI) couplers with ultracompact width, modal transmission line theory and effective dielectric method are combined with together. A coupling efficiency based on the composed approach is defined, and the coupling length is numerically determined for the design of 3 dB coupler, cross coupler and bar coupler. The simulation result shows that the designed MMI coupler has a low insertion loss and a high splitting ratio.

Efficient Implementation of 4D GIS for Spatio-Temporal Analysis (시공간분석을 위한 4차원 GIS의 효율적인 구현)

  • 김성수;김경호;이성호;박종현
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04a
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    • pp.629-631
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    • 2003
  • 대부분의 상용 CIS 소프트웨어에서는 시공간분석 결과를 2 차원상에 가시화 하거나 해당 분석결과를 단순히 출력해 주는 형태이다. 3차원상의 질의 볼륨에 대한 3차원 공간분석 또한 이론 및 실험적으로 많은 연구가 이루어져 왔으나, 3 차원상의 공간분석 결과 가시화 기능을 통합한 시스템은 아직까지 미흡한 실정이다. 본 논문에서는 3 차원상의 공간연산 및 3 차원에 시간속성을 부가한 4 차원 시공간 연산을 처리할 있는 4 차원 CIS 시스템을 소개한다. 제안된 기법은 2차원 수치지도와 3 차원 부가속성을 가진 데이터베이스를 이용하여 2 차원, 3 차원, 미디어 데이터간의 상호연계 및 통합된 가시화 프레임워크를 제공한다. 또한 가상세계 매핑기법을 이용하여 수작업에 의존한 별도의 이미지 프로세싱 과정 없이도 비디오상의 특정 프레임의 건물에 대한 속성질의 및 2D/3D 간의 상호 연계 기능을 제공할 수 있다.

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Comparison Study of Experimental Neutron Room Scattering Corrections with Theoretical Corrections in RCL's Calibration Facility at KAERI (한국원자력연구소 중성자교정실에 대한 중성자산란보정인자 결정연구)

  • Yoon, Suk-Chul;Chang, Si-Young;Kim, Jong-Soo;Kim, Jang-Lyul;Kim, Bong-Hwan
    • Journal of Radiation Protection and Research
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    • v.22 no.1
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    • pp.29-33
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    • 1997
  • Neutron room scattering corrections that should be made when neutron detectors are calibrated with a $D_2O$ moderated $^{252}Cf$ neutron source in the center of a calibration room are considered. Such room scattering corrections are dependent on specific neutron source type, detector type, calibration distance, and calibration room configuration. Room scattering corrections for the responses of a thermoluminescence dosimeter and two different types of spherical detectors to neutron source in the Radiation Calibration Laboratory(RCL) neutron calibration facility at the Korea Atomic Energy Research Institute(KAERI) were experimentally determined and are presented. The measured room scattering results are then compared with theoretical results calculated by predicting room scattering effects in terms of parameters related to the specific configuration. Agreement between measured and calculated scattering correction is generally about 10% for three kinds of detectors in the calibration facility.

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Measurements of X-Ray Production Cross-Sections for 0.5¡­1.2-MeV Proton Beam (0.5~l.2-MeV 양성자빔에 대한 X-선 발생단면적의 측정)

  • Hae-ill BAK;Jun-Gyo BAK
    • Nuclear Engineering and Technology
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    • v.22 no.2
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    • pp.108-115
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    • 1990
  • The measurements of X-ray production cross-sections for 0.5~1.2-MeV proton beam are carried out on Cu and Au. For this experiment, the proton tram generated from the SNU 1.5-MV Tandem Van do Graaff accelerator is Incident on the target. The X-rays and the backscattered protons from the irradiated target are detected simultaneously by the Si(Li) X-ray detector and the SSB (Silicone Surface Barrier) charged particle detector The measured values of X-ray production cross-sections are compared with other experimental values and theoretical values such as the PWBA (Plane Wave Born Approximation) and the ECPSSR(Perturbed Stationary State corrected Energy loss, Coulomb deflection, Relativistic effects) values. For measured cross-sections near 1.0- MeV proton energy, the ECPSSR (D.D. Cohenet al., 1985) shows better agreement than the PWBA. Particularly, that of Au for 1.2 MeV proton beam is 9.69$\pm$ 0.39 barns which deviates from the ECPSSR by less than 5%. and the experimental data for 0.5~1.2- MeV proton agree with most of other experimental values within 30%.

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A Study on the Development of Level Sensor using Frequency Modulated Continuous Wave (주파수 변조 연속파를 이용한 레벨 측정 시스템 개발에 관한 연구)

  • Park, Dong-Kook;Han, Tae-Kyoung;Park, In-Yong;Yoon, Chun-Su
    • Journal of Navigation and Port Research
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    • v.28 no.6
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    • pp.497-501
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    • 2004
  • In this paper, it is presented a level sensor for measuring a level of the contents of cargo tank using frequency modulated continuous wave(FMCW). The frequency range is 10∼11 GHz, the radar cross section(RCS) of test target is $0.8\textrm{m}^2$ of metal plate. The experiment is performed in laboratory and open ground, the sweep time of the signal is 100 ms, the pyramidal horn antenna of about 22 dBi gain is used, and input power of antenna is about 8 dBm The beat frequency according to the target moving to 40 m is measured. There is a good agreement between measured and calculated results. But the resolution of the FMCW radar is measured about 10 cm due to nonlinear of voltage controlled oscillator(VCO).

A Study on Big data Utilization Policy by the Complex System Theory: Focused on 2030 Seoul City Comprehensive Plan (복잡계이론에서의 빅데이터 활용방안에 관한 연구 (『2030 서울도시기본계획』을 중심으로))

  • Eum, Hee-Kyoung;Choi, Doo-Jin;Park, Sung-Chan;Chang, Hye-Jung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.4
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    • pp.281-298
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    • 2015
  • From the complexity system theory, City is dynamic system which has evolved through evolution and adaptation in initial conditions and different situation. So people's active should involve in decision-making processes in the urban planning. And this suggests that responding to the demands of its citizens are important factors influencing the process of urban planning. The implications of this study are following: using big data helps people understand current social phenomena. Specifically, it figured out latent needs of citizens that traditional survey methods could not before. we can make the most of new opportunities given by digital data and prevent potential dangers in advance. They are complementary and do not replace one another.

A Theoretical Study on the Inter-molecular Hydrogen Bond Between Nitromethanes and the Stabilization of Nitromethane Dimer (니트로메탄의 분자 간 수소결합과 니트로메탄 이합체의 안정화에 관한 이론적 연구)

  • Lee, Min-Joo;Kim, Ji-Young
    • Journal of the Korean Chemical Society
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    • v.48 no.3
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    • pp.229-235
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    • 2004
  • For the study of hydrogen bonding phenomenon of high energetic compounds, we have been carried out a theoretical calculations for the nitromethane with the program Gaussian-98. The calculations at levels of restricted BLYP/6-311++G(d,p), B3LYP/6-311++G(d,p) and MP2/6-311++G have been performed to obtain molecular structures, hydrogen bonding effects and vibrational spectra of nitromethane monomer and dimer. The results show nitromethane is favored to make two hydrogen bonds between molecules and the nitromethane dimer is more stable than the monomer about 15.2, 19.4 and 32.6 kJ/mol for the BLYP, B3LYP, and MP2 level calculations, respectively.

Analysis of the Theoretical Performance Characteristics for Methane-fuel Bipropellant Rocket Engine (메탄을 연료로 하는 이원추진제 로켓엔진의 이론성능특성 분석)

  • Kim, Jong Hyun;Jung, Hun;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.3
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    • pp.1-7
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    • 2014
  • A set of preliminary design parameters for the bipropellant rocket engine using liquid methane-fuel as green propellant were derived through a theoretical performance analysis. Chemical equilibrium analysis utilizing CEA was conducted for the prediction of combustion performance: combustion characteristics according to the O/F ratio and chamber pressure variation were investigated. For a determination of chamber-characteristic length, the vaporization time of fuel-droplet with various performance parameters was calculated by applying Spalding's 1-D droplet vaporization model. Finally, the preliminary design specification of methane-bipropellant rocket engine, which is to be performance-tested under the ground firing condition, was proposed.