• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.538-542
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• 2005

본 연구에서는 Penney와 Price(1952)의 해석 해를 사용하여 반무한방파제, 양익방파제등에서 발생하는 회절현상에 대한 해석 해를 구하였다. 양익방파제가 경사지게 위치한 경우에도 중첩을 통하여 해석 해를 구할 수 있었으며, 이를 바탕으로 방파제의 위치와 입사파랑의 각도에 따른 각각의 경우에 대하여 해석 해를 구할 수 있다. 또한, 구조물에 입사된 파랑성분과 구조물의 폭만큼의 개구부를 갖는 양익방파제를 통과하는 회절파성분과 같게 표현될 수 있는 반사파성분을 서로 중첩시켜 구조물 전면부에서 발생되는 완전반사 및 부분반사현상에 대한 해석 해를 제시하였다. 국내의 실무에서 해안 및 항만 구조물 설계에 사용되는 수치프로그램들의 정확도를 간단히 판단할 수 있는 비교 대상으로 이러한 해석해가 이용될 수 있으리라 판단된다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제19권1호
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• pp.50-55
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• 2009

The monitoring efficiency of the aircraft noise monitoring stations is decided to the reference noise level and the infringement of each monitoring stations. We calcurates the monitoring efficiency of three noise monitoring station among twelve in the vicinity of Gimpo Int'l Airport. As a result, the monitoring efficiency shows that the noise monitoring stations No#3, No#5 and No#6 are 14.3%, 18.5% and 29.3% respectively, Among them No#6 staion looks higher efficiency than another two stations because of underneath the flight trackas.

• Proceedings of the Korean Society of Life Science Conference
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• 한국생명과학회 2002년도 제36회 학술심포지움
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• pp.9-16
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• 2002

농산부산물 중 식품화 요건이 비교적 적합한 곶감부산물을 기능성 소재로 활용하고자 전처리에 따른 유용성분인 카로티노이드의 함량변화를 조사하였다. 조추출물의 항고혈압활성 및 동물실험에 의한 항당뇨 및 지질대사 개선 효과를 조사하였다. 1. 농산부산물의 기능성 식품화에는, 함유 성분의 특정 생체 기능성, 수집성, 함수율, 안전성 등의 요건이 만족될 필요가 있다. 2. 입도와 건조온도에 따라 보존기간 중 감피의 총카로티노이드와 베타카로틴의 함량은 60일 후에 80% 정도 감소하였으며 입도가 적을수록 감소폭이 컸다. 3. 감과피의 메탄올 조추출물에 대한 항고혈압성은 $11.76{sim}58.61%$의 저해활성을 보여 품종별로 다소 차이를 보였다. 4. Streptozotocin으로 당뇨를 유도한 실험쥐에 대하여 감껍질 분말의 혈당강화 및 지질대사의 개선능력을 검정한 결과 혈당치, 총지질 및 중성지질, 총콜레스테롤의 함량이 대조구에 비하여 유의적으로 낮았다.

• Journal of the Korean Association of Geographic Information Studies
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• 제4권4호
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• pp.39-50
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• 2001

There has been considerable controversy over the changes in the size of the beaches in the Pusan area; any loss of beach area will have an immense effect on the tourism industry, which is an important source of income for the local economy. The best beaches in Korea are in the Pusan area and were visited by more than 8 million persons in 2000. It is expected that the number of visitors, drawn to the scenic vistas and convenient facilities of this area, will increase annually. Any loss in the size of these swimming beaches will have an important negative effect on tourism income. Therefore, the local governments have gone to great lengths to preserve these beaches, transporting tens of thousands of tons of sand to the beaches before they open each year at a cost of billions of won annually. In this study, we analyzed aerial photographs and tide data for the past 50 years using digital aerial photo analysis and GIS techniques for each 3-year interval. We abstracted beach DEM (digital elevation model) and ortho aerial photographs, and conducted a space analysis. As a result, we were able to identify changes in the area and width of sections of Haeundae Beach.

• Journal of the Korean Society for Library and Information Science
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• 제47권1호
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• pp.249-268
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• 2013

Public Performance in Copyright Law is a wider concept, which people generally think. It includes the presentation of a work to the public by acting, musical playing, singing, narrating as well as even the act of mechanical playing phonogram and cinematographic work. Article 29 in Korean Copyright Act is the restriction of an author's public performance right. It shall be permissible to perform publicly or broadcast a work already made public for nonprofit purposes and without charging any fees to audience, spectators, or third parties, provided that the performers concerned are not paid any remuneration for such performances. Commercial phonograms or cinematographic works may be played back for the public, if no fee is charged to the audience or spectators, except in cases as set forth by Presidential Decree. In recent year, public performance in libraries became a major issue of the Copyright Law. It is a claim that watching cinematographic works in libraries is one of the act that should apply public performance right, thus to use commercial cinematographic works before six months, which was published, need permission to copyright owners. But this claim is unfair because it can make impossible normal library service. Thus there is a need to revise the Copyright Law to understand the difference between act of viewing and public performance in libraries.

• Journal of IKEEE
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• 제1권1호
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• pp.11-18
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• 1997

By utilizing the technique to monitor the DC cell node voltages through circuit simulation, degradation of the static read operating margin In high load-resistor SRAM cell was examined, which is caused by parasitic resistances and transistor asymmetries in this cell structure. By selectively adding the parasitic resistances to an ideal cell, the influence of each parasitic resistance on the operating margin was examined, and then the cases with parasitic resistances in pairs were also examined. By selectively changing the channel width of cell transistors to generate cell asymmetry, the influence of cell asymmetry on the operating margin was also examined. Analyses on the operating margins were performed by comparing the supply voltage values at which two cell node voltages merge to a single value and the differences of cell node voltages at VDD=5V in the simulated node voltage characteristics. By determining the parasitic resistances and the transistor asymmetries which give the most serious effect on the static read-operation of SRAM cell from this analysis based on circuit simulated, a criteria was provided, which can be referred in the design of new SRAM cell structures.

• 한국해양학회지
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• 제4권1호
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• pp.9-16
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• 1969

The sand drift movement at Young Il Bay area was tentatively investigated using Co-60 glass sand. Grain size and specific gravity of the glass sand which has originally contained natural cobalt, Co-59, was made similar to those of the real coastal sand, and was irradiated in a beam port of the reactor Triga Mark II to make the glass sand radioactive by the reaction of 59Co(n, r)60Co. The radioactive cobalt glass sand was deposited on the preselected point of sea bed, and, after a couple of weeks, the drift of sand was traced by means of specially designed water-proof G-M detector. Net counts at each point were plotted to figure out equicount lines and consequently such aspects as the direction of sand drift movement, the scope of distribution and the relative drift velocity etc. were indicated.

• Journal of the Society of Naval Architects of Korea
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• 제28권1호
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• pp.53-59
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• 1991

By employing multiple-scale expansion techniques, the diffraction of sinusoidally-modulated nonlinear Stokes waves by a stationary thin wedge has been studied within the framework of potential theory. It is found that the evolution of diffracted waves can be described by the Zakharov equation to the leading order and it can be replaced by the cubic $Schr\ddot{o}dinger$ equation with an additional linear term for stable modulations. Computations are made for the cubic $Schr\ddot{o}dinger$ equation with different values of nonlinear and dispersion parameters. Numerical results well reflect the experimental findings in the amplitude and width of generated stem waves. It is numerically confirmed that the nonlinearity dominates the wave field, while the dispersion hardly affects the wave evolution, and stem waves are likely to be formed for steep incident waves in the case of stable sinusoidal modulations.

• Journal of Navigation and Port Research
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• 제46권4호
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• pp.344-350
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• 2022

Due to the increase in container cargo volume, the congestion of container terminals is increasing and the waiting time of gate in-out trucks has significantly lengthened at container yards and gates, resulting in severe inefficiency in gate in-out truck operations as well as port operations. To resolve this problem, the Busan Port Authority and terminal operator provide services such VBS, terminal congestion information, and expected operation processing time information. However, the visible effect remains insufficient, as it may differ from actual waiting time.. Thus, as basic data to resolve this problem, this study presents deep learning based average gate in-out truck waiting time prediction models, using container gate in-out information at Busan New Port. As a result of verifying the predictive rate through comparison with the actual average waiting time, it was confirmed that the proposed predictive models showed high predictive rate.

• Transactions of the Korean Society of Mechanical Engineers
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• 제16권10호
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• pp.1940-1954
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• 1992

Fine grid computations were attempted to analyze the turbulent flows in the near wall low Reynolds number region and the numerical analyses were incorporated by a finite-volume discretization with full find grid system and low Reynolds number k-.epsilon. model was employed in this region. For the improvement of low Reynolds number k-.epsilon. model, modification coefficient of eddy viscosity $f_{\mu}$ was derived as a function of turbulent Reynolds number $R_{+}$ and nondimensional length $y^{+}$ from the concept of two length scales of dissipation rate of turbulent kinetic energy. The modification coefficient $f_{\epsilon}$ in .epsilon. transport equation was also derived theoretically. In the turbulent kinetic energy equation, pressure diffusion term was added in order to consider low Reynolds number region effect. The main characteristics of this low Reynolds number k-.epsilon. model were founded as : (1) In high Reynolds number region, the present model has limiting behavior which approaches to the high Reynolds number model. (2) Present low Reynolds number k-.epsilon. model dose not need additional empirical constants for the transport equations of turbulent kinetic energy and dissipation of turbulent kinetic energy in order to consider wall effect. Present low Reynolds number turbulence model was tested in the pipe flow and obtained improved results in velocity profiles and Reynolds stress distributions compared with those from other k-.epsilon. models.s.s.