• 제목/요약/키워드: D-S 이론

검색결과 739건 처리시간 0.034초

A Study on the Construction of 3D Noisemap for Busan's Road Traffic Noise (부산시 도로교통소음의 3차원 소음지도제작에 관한 연구)

  • Kim, Hwa-Il;Han, Kyoung-Min
    • Journal of Environmental Policy
    • /
    • 제6권1호
    • /
    • pp.111-132
    • /
    • 2007
  • The traffic noise of Busan, the second largest city in Korea, is polluting the area. Noise map is a map that shows data on an existing or predicted noise condition in terms of a noise indicator, breaches of a limit value, the number of dwellings exposed to certain values of a noise indicator in a certain area, or on cost-benefit ratios or other economic data on mitigation methods or scenarios with Geographic Information System. With noise map, the effect of traffic noise and the efficiency of city development plan are exactly estimated. So making systematic counteroffer is possible with it. This study is aimed to the construction of basis for noise map construction method for domestic use and the area focus is Busan.

  • PDF

Development of Eddy Current Test Probe for Profilometry Inspection of Tube (원형튜브 단면형상검사용 와전류탐촉자 개발)

  • Lee, H.J.;Nam, M.W.;Lee, C.H.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • 제17권4호
    • /
    • pp.262-269
    • /
    • 1997
  • An eddy current probe ($8{\times}1$ multiple-element, surface scan) was successfully designed and fabricated at the KEPRI using the impedance equivalent circuit theory. The probe is intended for the detection of circumferential deformations (cross-section view) of the heat exchanger tubing that can occur due to corrosion, erosion, and denting. Optimum design parameters providing the highest sensitivity and signal-to-noise ratio, such as the coil dimensions, electrical characteristics, and test frequencies, were determined based on initial laboratory experiments conducted on the test specimen (SS304 tubing: OD : 9.68mm, wall-thickness : 0.47mm) containing artificial flaws (e.g., dents and corroded surface on tube OD) using the available Zetec-made probe. Using this parameters, a new probe was made and tested on an unknown specimen. The result indicated that the new probe is capable of detecting the circumferential deformation with the error of ${\pm}0.2%$ (0.022mm) of the tube O.D.

  • PDF

Linear Free Energy Relationship on the Phosphorylation of Acetylcholinesterase by Insecticidal O,O-Diethylphenylphosphate Derivatives (살충성(殺蟲性) O,O-Diethylphenylphosphate유도체(誘導體)들에 의(依)한 Acetylcholinesterase의 Phosphorylation에 미치는 자유(自由)에너지 관계(關係))

  • Sung, Nack-Do
    • Korean Journal of Agricultural Science
    • /
    • 제11권1호
    • /
    • pp.176-181
    • /
    • 1984
  • Linear free energy relation ship(LFER) on the insecticidal activity of O,O-diethylphenylphosphate (A) and 3,5-dimethylphenyl-O,O-diethylphosphate (B) derivatives were studied by EHT MO calculation method and regression analysis method. LFER between varying substituent constants and $pI_{50}$ constants of phosphates, (A) & (B) were calculated with applying Hammett, Okamoto-Brown, Taft and Swain-Lupton's DSP equations;percent resonance effect(R) and field effect(F) of (A) were %R=33.5 & %F=66.5 and also that of (B) were %R=2 & %F=98, respectively. On the basis of above findings, the insecticidal activities were similar for both (A) and (B), but (B) have larger field and inductive contribution than (A), due to the 3,5-dimethyl group of (B).

  • PDF

Study on Efficiency of Flat-Plate Solar Collector Using Nanofluids (나노유체를 이용한 평판형 태양열 집열기의 효율에 관한 연구)

  • Lee, Seung-Hyun;Jang, Seok Pil
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • 제37권9호
    • /
    • pp.799-805
    • /
    • 2013
  • An analytical study is conducted to assess the efficiency of a flat-plate solar collector using nanofluids. The nondimensionalized 2D heat diffusion equation is solved by assuming a wavelength-independent extinction coefficient and intensity to obtain the analytical solution of the temperature distribution in the flat-plate solar collector. The dimensionless temperature distribution is investigated as functions of the volume fraction of the nanofluids, magnitude of heat loss, and collector's depth based on the analytical solution when using water-based single-walled carbon nanohorn (SWCNH) nanofluids as a working fluid. Finally, the efficiency of the flat-plate solar collector using the nanofluids is predicted and compared with that of the conventional solar collector. The results indicate that the efficiency of the nanofluid solar collector is better than that of the conventional solar collector under specific geometrical conditions.

Thermopower Wave in Core-Shell Structures of Carbon Nanotube Chemical Fuels (나노튜브/화학연료의 동축 구조에서 생성되는 열동력 파도를 이용한 전기 에너지 생성)

  • Choi, Wonjoon;Strano, Michael S.
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • 제37권6호
    • /
    • pp.615-620
    • /
    • 2013
  • There is considerable interest in developing energy sources capable of larger power densities. In our previous works, we proved that by coupling an exothermic chemical reaction with 1D nanostructures, a self-propagating reactive wave can be driven along its length with a concomitant electrical pulse of high specific power, which we identified as a thermopower wave. Herein, we discuss details about many different aspects of a thermopower wave. Different alignment degree in vertically aligned CNT films is evaluated in the reactive wave speed and correlated with its thermal reaction that affects the change in the magnitude of energy generation. The effects of the temperature-dependent properties of chemical fuels and CNTs are evaluated. Furthermore, we explore the convection and radiation portions in this thermal wave as well as the synchronization between the thermal reaction transfer and the oscillation of the electrical signal.

A Study on the Behavior of stress path subject to the gap size of metal touch connection (메탈터치 이음부의 틈의 크기에 따른 응력전달 거동에 대한 연구)

  • Hong, Kappyo;Kim, Seok Koo
    • Journal of Korean Society of Steel Construction
    • /
    • 제16권5호통권72호
    • /
    • pp.599-607
    • /
    • 2004
  • As buildings become more high-rise and lightweight in recent years, steel has been utilized more frequently. Based on the American AISC standard, all axial loads could be carried through a bearing load in a column splice, but according to Korean codes, the bearing load has constrained the stress that could be carried by only 25% of all axial loads. Thus, new column splice methods that use metal touch have been examined. In this study, the stress path mechanism, as an intermediation parameter in the gap's magnitude, must be determined. Similarly, the behavioral aspect of the metal touch connection must be sought after comparing and analyzing the results of the test.

A Comparative Study of Graduate Archival Programs in Korea and North America (기록학 대학원 교육 프로그램에 관한 비교 연구 - 한국과 북미를 중심으로 -)

  • Chung, Yeon-Kyoung
    • Journal of the Korean Society for Library and Information Science
    • /
    • 제37권1호
    • /
    • pp.81-100
    • /
    • 2003
  • The purpose of this study is to find necessary factors and to suggest the future directions for the successful graduate archival education in Korea by comparing current programs hi Korea and North America. Name of the schools, credits, required and elective courses, practice, research and thesis are compared by analyzing web sites and literature review. Development of more various Master's programs, a separate degree in Master of Archival Studies, more credits for the degree, standardization of curriculum, and the working environments for practicum, internship and research are found as important elements for the program. In the end, more collaborations with other disciplines, more faculties with working experiences and Ph. D. degree in archival studies, communications among the universities, archival institutions and professional societies/associations, continuous research on the programs, improvement of the quality of archivists, strong national supports for archives and records and establishment of the strong quality control for being archivists are suggested for the future directions.

The Effects of a Staged Smoking Prevention Program for Primary School Children (초등학생을 위한 단계별 흡연예방 프로그램의 효과)

  • Kim, Jae-Hee;Lee, Yu-Jeong;Kang, Seong-Mi;Oh, Yu-Mi
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • 제15권8호
    • /
    • pp.5131-5139
    • /
    • 2014
  • The subjects of this study were 415 children in the first to third grade selected from 4 primary schools. Among them, 212 children belong to the experimental group, and 203 children were in the control group. The program was provided respectively to first, third and fifth grade children for 2, 4 and 6 teaching-hours from 2013.1.1 to 2013.12.19. To measure the effects of the program, the knowledge and attitudes on/toward smoking, self-concept were used as the research tools. Before and after program-implementation, there were significant differences in knowledge of smoking, but no differences in attitudes and self-concept. A smoking prevention program for primary school children should be applied step-by-step in conjunction with the regular education curriculum. In addition, the program should aim for long-term effects rather than short-term effects.

Investigation and Theoretical Analysis of a Fire Accident Caused by Smoldering Combustion (Smoldering 연소로 인한 화재사고 조사보고 소개 및 이론적 해석)

  • 김연승;변영철;황정호
    • Fire Science and Engineering
    • /
    • 제13권3호
    • /
    • pp.3-17
    • /
    • 1999
  • Smoldering is a non-flaming combustion mode, characterized by thermal degradation and c charring of the virgin material, evolution of smoke and emission of visible glow. A big fire may @ occur even in a confined environment having a limited amount of oxygen, due to smoldering c combustion through a porous solid material. This paper presents a theoretical analysis on the effect of smoldering combustion on fire occurrence based on a report about fire investigation of a real f fire accident. It is assumed that the propagation of the smolder wave is one-dimensional, d downward, opposing an upward forced flow and steady in a frame of reference moving with the s smolder wave. Smoldering combustion is modeled by a one-step reaction mechanism, without c considering pyrolysis. It is found that dominant parameters controlling smoldering combustion i include mass flux of oxidizer entering the reaction zone and void fraction of solid fuel. It is also found that the mechanism of transition to flaming is critically influenced by these two parameters.

  • PDF

A Development of Whipping Analysis Program for Ship Hulls (선체 휘핑 해석 전용 프로그램의 개발)

  • Seong-Whan Park;Jai-Kyung Lee;Sang-Heon Oh;Myung-Jae Song;Seung-Min Kwon
    • Journal of the Society of Naval Architects of Korea
    • /
    • 제39권3호
    • /
    • pp.64-74
    • /
    • 2002
  • A special purposed program for ship hull strength analysis considering whipping phenomena is developed. In this program, the non-linear hydrodynamic impact force is considered using the momentum slamming theory and the hull girder is modeled as elastic body on the base of Timoshenko's beam theory. The numerical verifications are conducted in the view points that the effect of slamming impact force, the effect of hydro-elastic formulation, and the effect of various design parameters such as ship speed, wave amplitude, wave length and others. By the application of a real ship design process, the availability of the program is proved. This program has a GUI function for many I/O data process as well as the function to show the 2-D ship motion in the graphic window, and has other available functions for the whipping analysis.