• Title/Summary/Keyword: General Green Function

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한강 연안 경관 녹화 계획

  • 권오준
    • Proceedings of the Korean Professional Engineer Association Conference
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    • 1995.12b
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    • pp.23-29
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    • 1995
  • Green landscape plan to the riverfront area of the Han River The Han River, one of the symbolic elements in metropolitan Seoul, structures an axis of waterscape as the openspace crossing east to west of the city of Seoul. As riverside urban motorway(88 Olympic motorway) and riverside public park were constructed by the Han River Comprehensive Development Project in 1986, the necessity of general plan for the in-stallation of envirommental facility belt to conserve living enviroument is being required with relation to, dense residential areas closed to the river Therefore, the goal of the study is to provide better riverview and to increase environmental purifi-cation ability as a large scale waterscape axis by the preparation of landscape plan to the riverfront area of Han River, In order to achieve the goal, the study deals with sectional speciality, the introduction of landscape assessment techniques and ecological approach to given environment. As unity is kept through whole waterfront area, the area is divided into 9 zoning sections to study development methods for each section, and themes for speciality are given to each section, and the. sort of plants which can be symboliged to the area is selected. Also, the planting methods for harmony with the type of road structure and riverscape is offered. Though the study may give significane to the image and the function of riverside road, in con-clusion, the characteristic ecological approach to the river is so limited that has not been reflected enough on the plan. It is expected that the study should be continued, and long-term riverfront openspace plan, environmentally sustainable, should be arepared.

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Study on Sound Field Analysis in Near-Field using Boundary Collocation Method; Decision of Optimum Points of Measurement for Line Array Sound Source with Weighting Value (경계배치법에 의한 근거리 음장 해석 기법 연구; 가중치를 갖는 선배열 음원의 최적 측정점 개수의 결정)

  • Kim, Won-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1752-1761
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    • 2000
  • This paper describes the far-field estimation using the near-field measurement data. Measurement in far-field region gives us the acoustical characteristics of the source but in general measurement is made in near-field such as acoustic water tank or anechoic chamber, so far-field acoustical characteristics of the source should be predicted from near-field data. In this case, the number of measurement points in the near field which relates to the accuracy of the predicted field and the amount of data processing, should be optimized. Existing papers say that measurement points is proportional to kL and depends on geometry and directivity of the source. But they do not give us any definite criterion for the required number of measurement points. Boundary Collocation Method which is one of the far-field prediction methods, is analyzed based on Helmholtz integral equation and Green function and it has been found that the number of measurement points is optimized as 0.54kL which is about one half of the existing results.

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On the Surge Motion of a Freely-Floating Sphere in a Plane Progressive Wave (규칙파(規則波)에 놓인 구(球)의 수평운동(水平運動)에 대(對)한 해석(解析))

  • Chan-Wook,Park;Hang-Shoon,Choi
    • Bulletin of the Society of Naval Architects of Korea
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    • v.18 no.1
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    • pp.19-27
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    • 1981
  • The surge motion of a freely-floating sphere in a regular wave is studied within the framework of a linear potential theory. The fluid is assumed to be perfect and only the steady-state harmonic motion in a water of infinite depth is considered. A velocity potential describing the fluid motion is decomposed into three parts; the incident wave potential, the diffraction potential and the radiation potential. In this paper the diffraction potential and the radiation potential are analysed by using multipole expansion method. Upon calculating pressures over the immersed surface of the sphere, the hydrodynamic forces are evaluated in terms of Froude-Krylov, diffraction, added mass and damping forces as functions of the frequency of the incident wave. Finally the frequency dependence of two pertinent parameters, the amplitude ratio and the phase lag between the motion of the sphere and that of the incident wave is derived from the equation of motion. As for numerical results the general tendency of the present calculation shows good agreement with Kim's work who also treated this problem utilizing the Green's function method.

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Effect of Reverse Feeding on the Reproductive System in Male Rats

  • Jeon, Eun-Young;Lee, Sung-Ho
    • Development and Reproduction
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    • v.16 no.3
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    • pp.227-233
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    • 2012
  • Circadian timing system plays a major role in a wide range of reproductive function. However it is plausible idea that other environmental and/or internal cue might be simultaneously participated in the optimal regulation of reproductive system. In the present study we extended the reverse feeding (RF) time regimen up to 8 weeks, then measured the general and reproductive indices of the animals. The animals of ad libitum feeding group (Control, CON) have free access to food for 4, 6 and 8 weeks, respectively. The day feeding animals (reverse feeding, RF group) have restricted access to food during daytime (09:00-18:00) for 4, 6 and 8 weeks, respectively. When the feeding schedules were over, key indices were measured. After 4 weeks and 8 weeks of feeding, body weights of animals were not significantly different. However, body weights of 6 weeks RF animals were significantly smaller than those of control animals (CON : RF = $333.46{\pm}12.71$ g : $289.91{\pm}8.31$ g, p<0.01). The blood glucose levels of 4 weeks RF animals were significantly decreased compared to the levels of control animals (CON : RF = $161.4{\pm}2.7$ mg/dL : $176.7{\pm}5$ mg/dL, p<0.01) while the levels of 6 weeks RF and 8 weeks RF animals were not different form those of control animals. Reproductive and non-reproductive tissue weights from 6 weeks RF group were significantly lowered than those from CON group (testis, CON : RF = $1.4714{\pm}0.0174$ g : $1.3724{\pm}0.0168$ g, p<0.001; epididymis, CON : RF = $0.3574{\pm}0.0059$ g : $0.3243{\pm}0.0068$ g, p<0.001; seminal vesicle, CON : RF = $0.1655{\pm}0.0068$ g : $0.1328{\pm}0.0054$ g, p<0.001; prostate, CON : RF = $0.3350{\pm}0.0231$ g : $0.2528{\pm}0.0143$ g, p<0.01). After 4 weeks and 8 weeks of reverse feeding, sperm counts in RF animals were markedly reduced than those in control animals[CON 4W : RF 4W = $121.17{\pm}9.96\;({\times}10^6)$ : $50.86{\pm}9\;({\times}10^6)$, p<0.001; CON 8W : RF 8W= $138.69{\pm}9.8\;({\times}10^6)$ : $108.94{\pm}4.22\;({\times}10^6)$, p<0.001]. Present study indicates that RF may induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. On-going longitudinal studies will allow a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.

Trend and Development Direction of Restoration Technology Utilization in Ecosystem Conservation Charge Project - Focusing on Implementation Cases from 2014 to 2020 - (생태계보전부담금 반환사업의 복원기술 활용 경향과 방향 - 2014년부터 2020년까지 시행 사례를 중심으로 -)

  • Yoon, Young-Kwan;Lee, Ho-Woo;Koo, Bon-Hak
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.5
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    • pp.1-18
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    • 2023
  • The Ecosystem Conservation Levy (formerly known as the Ecosystem Conservation Cooperation Fund) system has been in place for 20 years, and it can be said that it has now entered the settlement stage. Based on an analysis of publicly available project implementation data from 2014 to 2020, we found that: 1) As the number of return projects increases, the targets of restoration technologies are also strengthening, and it is necessary to frame a series of processes from application, creation, and monitoring for some detailed projects to improve the effectiveness and efficiency of utilizing the levy. 2) Most of the implemented projects are applied as micro-ecosystem creation, but there are many cases where the contents of the project can be seen as other project categories. This shows that the purpose of the return project needs to be approached more clearly and suggests that institutional complementation is needed from the project application stage. 3) The detailed technologies applied tend to be gradually expanding, but most of them are technologies that are not differentiated from general development projects. It is urgent to secure a more technical identity, such as a range and list of utilized technologies suitable for the characteristics and purposes of return projects. 4) It is necessary to establish a relevant evaluation system or framework to utilize the monitoring results of restoration projects. 5) There have been few cases of application of single restoration technologies since the beginning, but the content and scope of the complexity tend to expand in recent years. Even if the objectives are not comprehensive and diverse, it can be seen that many parts of the projects are oriented toward convergence, so it is necessary to conduct separate research on this. 6) As for the direction of improvement of the return project, it is possible to consider expanding the restoration and conservation focus to partially accommodate the complexity of the natural environment and human ecology. It seems that the expansion of restoration technologies that consider the role and function of humans in the natural environment should be explored.

A Study on the Environmental Effects of Improvement of Activated Carbon Adsorption Tower for the Application of Activated Carbon Co-Regenerated System in Sihwa/Banwal Industrial Complex (시화반월산업단지 활성탄 공동재생시스템 적용을 위한 활성탄 흡착탑 개선에 따른 환경적 효과분석)

  • Choi, Ye Jin;Rhee, Young Woo;Chung, Gu Hoi;Kim, Duk Hyun;Park, Seung Joon
    • Clean Technology
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    • v.27 no.2
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    • pp.160-167
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    • 2021
  • This study investigated the environmental effects of improving the general-type activated carbon adsorption tower used at the Sihwa/Banwol Industrial Complex with use of a cartridge-type activated carbon adsorption tower for the application of an activated carbon co-regenerated system. Four general-type activated carbon adsorption towers and two cartridge-type activated carbon adsorption towers were selected to analyze the properties of activated carbon and to compare the efficiency of reducing environmental pollutants. The results showed that the activated carbon used in the cartridge-type activated carbon adsorption towers was high quality activated carbon with an iodine adsorption force of more than 800 mg/g and that a good adsorption performance was maintained within the replacement cycle. From an analysis of the environmental pollutant reduction efficiency, it was confirmed that the cartridge-type activated carbon adsorption tower functioned properly as a prevention facility for handling emissions pollutants with a treatment efficiency of total hydrocarbons (THC), toluene, and methylethylketone (MEK) components of 71%, 77%, and 80%, respectively. The general activated carbon adsorption tower, which was confirmed to use low-performance activated carbon, had a very low treatment efficiency and did not function properly as a prevention facility for dealing with emission pollutants. It is believed that it is possible to reduce pollutants during operations by changing from the general-type activated carbon adsorption tower to a cartridge-type activated carbon adsorption tower.

The Visual Characteristics of an Outdoor Brand Logo Design (아웃도어 브랜드 로고의 시각적 특성)

  • Rha, Soo-Im
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.1
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    • pp.141-154
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    • 2015
  • The purpose of this study is to look for a development plan for strategic brand logo by a means of scrutinizing general characteristics and trend in the visual properties of outdoor logo brands. In this study, data research and analysis were conducted over the 68 outdoor brands in circulation in the domestic market based on the information on the website of each brand in order to examine the visual characteristics of an outdoor brand logo. For this, it was performed to examine the desired brand concept of each brand and to analyze the visual characteristics of typeface, color, and type of logo. The results of this research are the followings: First, it was found that the most popular typeface in outdoor brand logos is a capitalized Gothic type. It seems that the logo type is designed to symbolize power, toughness, and masculinity and to express the concept of sportswear brand. Second, when it comes to color, black color tone appeared most frequently, and also reddish colors among chromatic colors were prevailing over others like green, blue, or yellow. It is believed that reddish colors were used to express passion, power, youthfulness, and energy; black color tone for tough, masculine power. Third, the logo symbol of outdoor brands mostly contains mountain, the heads of powerful animals, spherical shape/abstract image that embodies outdoor sports activities. It was analyzed that these resulting symbols were chosen to convey the images of nature, conquest, challenge, future, and passion that are the brand concept of most outdoor brands. Today, in our country, the logo of an outdoor brand is the important factor that symbolizes the brand concept, function, or characteristics. Therefore, the necessity of constant follow-up researches is required to devise the way of designing the brand logo that can build brand power and enhance brand image.

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Measurements of Thermal Diffusivity of Heavy Rolled Low Carbon Steel Plate With Laser Flash Technique (레이저 섬광법에 의한 압연된 저탄소강 판재의 열확산계수 측정)

  • 배신철;임동주
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.1
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    • pp.157-171
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    • 1990
  • The heat transfer problem associated with pulse technique for measuring thermal diffusivity was solved by means of Green function. The obtained general solution was discussed so as to apply for all possible cases; kinds of boundary condition and heat source, irradiation positions of heat pulse, radius of heat pulse, one-and two-dimensional heat flow, finite pulse time effects and radiation heat loss systems. Experimentally, the laser flash lamp was used as heat source for measuring thermal diffusivity of low carbon, aluminium chilled steel plate, which was heavily rolled in order to measure the variation of thermal diffusivity in the temperature range from room temperature through 500.deg. C. The derived results are (1) materials produced from same furnace showed a somewhat different thermal diffusivity values. (2) the thermal diffusivity value of rolled material was smaller than unrolled material and the difference decreased as increasing temperature. (3) the thermal diffusivity value of an annealed and temper rolled material was larger than the value of a cold rolled material, even thought smaller than unrolled material. (4) In case of heavy rolled material, there was no consistent relationships between the thermal diffusivity and the reduction in thickness.

An Analysis of the Hydroelastic Response of Large Floating Structures in Oblique Waves (사파중에 놓인 거대 부유체의 응답에 대한 유탄성 해석)

  • In-H. Sim;Jae-D. Yoon;Hang-S. Choi
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.3
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    • pp.83-92
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    • 1999
  • In this paper, the fluid-structure interaction of large floating structures has been rigorously analyzed and the shear effect on the structural deformation has been investigated in oblique waves. A constant panel method(CPM) based on the Green function method is implemented for computing the hydrodynamic pressure, while a finite element method(FEM) is applied for the structural response based on the Mindlin plate theory with including shear deformation. In order to validate the method, we compared numerical results with experimental ones of Mega Float carried out by Yago & Endo in head waves. General behavior shows good agreement but the local displacement at the ends is slightly different. The numerical results show that the radiation pressure due to the fluid-structure interaction is locally larger than that of wave excitation and mooring devices greatly reduce the response. It is observed that the shear effects among the total deformation constitutes about 4% in the case of Mega Float in oblique waves.

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Effects of Earth's Atmosphere on Terrestrial Reference Frame : A Review (지구 대기가 지구 기준계에 미치는 영향 : 기존 모델 분석)

  • Na, Sung-Ho;Cho, Jungho
    • Geophysics and Geophysical Exploration
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    • v.18 no.3
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    • pp.133-142
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    • 2015
  • Displacement of the Earth's surface due to atmospheric loading has been recognized since a century years ago, and its accurate estimation is required in present day geodesy and surveying, particularly in space geodesy. Atmospheric load deformation in continental region can readily be calculated with the given atmospheric pressure field and the load Green's function, and, in near coastal area, approximate model is used for the calculation. The changes in the Earth's atmospheric circulation and the seasonal variation of atmospheric pressure on two hemispheres of the Earth are the each main causes of variation of the Earth's spin angular velocity and polar motion respectively. Wind and atmospheric pressure do the major role in other periodic and non-periodic perturbations of the positions in the Earth's reference frame and variations in the Earth's spin rotational state. In this reviewing study, the developments of related theories and models are summarized along with brief description of phenomena, and the geodetic perturbing effects of a hypothetical typhoon passing Korea are shown as an example. Finally related existing problems and further necessary studies are discussed in general.