• Title/Summary/Keyword: Source points

Search Result 704, Processing Time 0.027 seconds

Two Semantic Types of Korean Sluicing Constructions (슬루싱의 두 가지 의미 유형)

  • Wee, Hae-Kyung
    • Language and Information
    • /
    • v.19 no.2
    • /
    • pp.109-125
    • /
    • 2015
  • In this study, I attempt to show two points about Korean sluicing. First, the semantic source of the null subject of the copula phrase in Korean sluicing is a null pronoun. This null subject pronoun may refer to either the antecedent indefinite individual or the antecedent event of the preceding clause. Second, depending on the presence/absence of postpositions in the remant wh-phrase, sluicing constructions are classified into two different semantic types: i) an equative clause and ii) a predicational clause.

  • PDF

Development of a Numerical Analysis Method of Train/Track Interaction for Evaluation of Dynamic Track Design Load (궤도 설계 동하중 산정을 위한 차량/궤도 상호작용 해석기법 개발)

  • 양신추
    • Proceedings of the KSR Conference
    • /
    • 2002.10b
    • /
    • pp.1094-1099
    • /
    • 2002
  • In this paper, a numerical method for vehicle-track interaction analysis is developed to evaluate vertical dynamic force subjected to rail surface. A vehicle is modelled by lumped masses system and track by multi layered continuous beam system. The equation of motion of vehicle and track interaction system is derived by considering compatibility condition at the contact points between wheel and rail. The input vibration source is given by the empirical formula of power spectral density of track irregularity, which is suggested by FRA. Using this method, dynamic impact factors with the train speed are evaluated.

  • PDF

A study on the transient temperature distribution for spot welds (점용접에 있어서 온도분포의 변화에 관한 연구)

  • 왕지석;조용배
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.12 no.1
    • /
    • pp.37-45
    • /
    • 1988
  • A calculating method of transient temperature distribution due to spot welding of thin plates is studied in this paper. Considering the contact stress between upper and lower plate and temperature-dependence of specific resistance and elastic limit of base metal, the model of calorific density of heat source was decided. Using 2-dimensional polar coordinates system, the governing equation of heat transfer was developed. The thermal cycles of various points were recorded using C-A thermocouples during spot welding procedure for mild steel plates of 1mm thickness, and those results were compared with the results of calculations presented in this paper.

  • PDF

Experimental Study of flash point determination for Alcohols & Aromatic Compounds. (가연성 액체의 인화점 추정에 관한 실험적 연구)

  • 최세환;김광일
    • Fire Science and Engineering
    • /
    • v.7 no.2
    • /
    • pp.24-28
    • /
    • 1993
  • The flash point for flammable liquids (alcohol, aromatic compounds) were measured by Penskt-Martens's measuring apparatus with closed cup. As a result, it was observed that the flash points had the regular tendency according to the carbon number and the molecular structure. Consequently, the flash point for the alcohols were increased in proportion to the increase of the carbon number and branch number. The differences between the literature and experimental data are 14.6% for the relative error and 3.46$^{\circ}C$ in average for the measuring temperature.

  • PDF

Stellar Source Selections for Image Validation of Earth Observation Satellite

  • Yu, Ji-Woong;Park, Sang-Young;Lim, Dong-Wook;Lee, Dong-Han;Sohn, Young-Jong
    • Journal of Astronomy and Space Sciences
    • /
    • v.28 no.4
    • /
    • pp.273-284
    • /
    • 2011
  • A method of stellar source selection for validating the quality of image is investigated for a low Earth orbit optical remote sensing satellite. Image performance of the optical payload needs to be validated after its launch into orbit. The stellar sources are ideal source points that can be used to validate the quality of optical images. For the image validation, stellar sources should be the brightest as possible in the charge-coupled device dynamic range. The time delayed and integration technique, which is used to observe the ground, is also performed to observe the selected stars. The relations between the incident radiance at aperture and V magnitude of a star are established using Gunn & Stryker's star catalogue of spectrum. Applying this result, an appropriate image performance index is determined, and suitable stars and areas of the sky scene are selected for the optical payload on a remote sensing satellite to observe. The result of this research can be utilized to validate the quality of optical payload of a satellite in orbit.

On the Method of Rankine Source Distribution for Free Surface Flow Problem: Radiation Condition and Influence of Finite Distribution (자유표면문제해석(자유표면문제해석)을 위한 Rankine용출점(湧出點) 분포법(分布法) -방사조건(放射條件)과 유한분포(有限分布)의 영향-)

  • Chang-Sup,Lee;Seung-Il,Yang;Chang-Gu,Kang
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.19 no.2
    • /
    • pp.13-18
    • /
    • 1982
  • The method of Rankine source distribution is emerging as a powerful yet simple alternative for the solution of complicated free surface problems. But it has been uncertain whether the radiation condition could be satisfied exactly by distributing the simple sources on the free surface only. In this paper, it is proved rigorously that the Rankine sources, whose intensities are varying sinusoidally along the axis satisfying the free surface boundary condition, generate the radiation waves both in the infinite and finite-depth flows. A formula is derived to give the upper and lower bounds of the errors in the induced velocity computation that will be introduced by truncating the extent of source distribution on the free surface. Since the truncation is inevitable in the numerical analysis, this formula may be used as a criterion to limit the position of the field points, where velocity computation is made, away from the truncation boundary. A typical analysis shows that the maximum error will be 3.4 percent of the exact induced velocity when the field point is on the free surface two wave lengths away from the truncation boundary.

  • PDF

Real Time Linux System Design (리얼 타임 리눅스 시스템 설계)

  • Lee, Ah Ri;Hong, Seon Hack
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.10 no.2
    • /
    • pp.13-20
    • /
    • 2014
  • In this paper, we implemented the object scanning with nxtOSEK which is an open source platform. nxtOSEK consists of device driver of leJOS NXJ C/Assembly source code, TOPPERS/ATK(Automotive real time Kernel) and TOPPERS/JSP Real-Time Operating System source code that includes ARM7 specific porting part, and glue code make them work together. nxtOSEK can provide ANSI C by using GCC tool chain and C API and apply for real-time multi tasking features. We experimented the 3D scanning with ultra sonic and laser sensor which are made directly by laser module diode and experimented the measurement of scanning the object by knowing x, y, and z coordinates for every points that it scans. In this paper, the laser module is the dimension of $6{\times}10[mm]$ requiring 5volts/5[mW], and used the laser light of wavelength in the 650[nm] range. For detecting the object, we used the beacon detection algorithm and as the laser light swept the objects, the photodiode monitored the ambient light at interval of 10[ms] which is called a real time. We communicated the 3D scanning platform via bluetooth protocol with host platform and the results are displayed via DPlot graphic tool. And therefore we enhanced the functionality of the 3D scanner for identifying the image scanning with laser sensor modules compared to ultra sonic sensor.

Analysis of Sources and Contribution for the Radiated Noise of Drum-type Washing Machine (드럼세탁기 방사소음의 소스 및 기여도 분석)

  • Kim, Ji Man;Jung, Byung Kyoo;Heo, So Jung;Ahn, Se Jin;Jeong, Weui Bong
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.24 no.8
    • /
    • pp.628-635
    • /
    • 2014
  • The procedure to estimate the sources of noise and vibrations in a typical drum-type washing machine was presented. The sources should be identified to predict the radiated noise with computational model of structure. Source identification techniques based on singular decomposition were implemented using the measured signals of accelerometers and microphones. The finite element analysis and indirect boundary element analysis were implemented to predict the structural vibrations and the acoustic pressures at the field points. The predicted results by only structural sources were compared with those by both structural and acoustical sources. It was verified that not only the structural-borne source but also air-borne source should be considered to predict the radiated noise with better accuracy. The contribution analysis with respect to the transfer path was also preformed.

Acoustic Investigation on BFP Piping System in a Power Plant (발전소 급수용 펌프 배관계의 음향학적 현상 고찰)

  • Yang, K.H.;Cho, C.H.;Bae, C.H.
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.21 no.11
    • /
    • pp.1029-1035
    • /
    • 2011
  • Pressure pulsation of exciting sources that generally occurs on the piping system connected to the discharge of BFP(boiler feed water pump) in power plants causes wave reflection, wave interference, resonance, standing wave and so on. But if the operating speed of the pump is changed, the state of the noise and vibration can be done because characteristics of the exciting source are changed. This paper is to investigate the cause of the noise and vibration occurring on the piping system when the operating speed of BFP is down in accordance with lowering of the power generation. It is approached to two points of view ; Firstly, it is examined whether the pulsation source impacts on the shell mode vibration that vibrates radially across the cross-section of the pipe. But it doesn't affect the shell mode as much as the resonance occurs. Secondly, to find the relation between the pulsation source and the acoustic mode of the piping system, analysis for the piping system by indirect BEM(boundary element method) is carried out. Therefore it is investigated that the mechanism of the noise and vibration relates with acoustic mode of the piping system.

Characteristics of Fire-induced Thermal-Flowfields in an Underground Utility Tunnel with Ventilation (화재 발생시 환기방식에 따른 지하공동구내 열유동 특성 연구)

  • Kim, Hong-Sik;Hwang, In-Ju;Kim, Yun-Je
    • Proceedings of the KSME Conference
    • /
    • 2003.04a
    • /
    • pp.1845-1850
    • /
    • 2003
  • The underground utility tunnels are important facility as a mainstay of country because of communication developments. The communication and electrical duct banks as well as various utility lines for urban life are installed in the underground utility tunnel systems. If a fire breaks out in this life-line tunnel, the function of the city will be discontinued and the huge damages are occurred. In order to improve the safety of life-line tunnel systems and the fire detection, the behaviors of the fire-induced smoke flow and temperature distribution are investigated. In this study we assumed that the fire is occurred at the contact or connection points of cable. Numerical calculations are carried out using different velocity of ventilation in utility tunnel. The fire source is modeled as a volumetric heat source. Three-dimensional flow and thermal characteristics in the underground tunnel are solved by means of FVM (Finite Volume Method) using SIMPLE algorithm and standard ${\kappa}-{\varepsilon}$ model for Reynolds stress terms. The numerical results of the fire-induced flow characteristics in an underground utility tunnel with different velocity of ventilation are graphically prepared and discussed.

  • PDF