• 한국농공학회지
• /
• 제16권3호
• /
• pp.3539-3542
• /
• 1974

Maximum density and optimum moisture content of a soil may be one of the very important properties to be specified in the design of earth structures and their works. However, the determination of these soil properties may not be done without the necessary equipment and time-consuming field tests. This study was conducted to develop an easier method by determing the relations between the natural moisture content and optimum moisture content and between maximum density and optimum moisture content so determined. These velations are remarkably defferent according to the areas where the samples were taken, and thus analysis of the experimental results are shown by regions as follows: Eastern Districs:{{{{Tdmax= { 1} over {0.0090Wopt+0.417 } ( delta = +- 0.042, gamma =0.92) Wopt=0.251WN+8.5( delta = +- 2.41%, gamma =0.87) }}}} Southern Districts: {{{{Tdmax= { 1} over {0.0088Wopt+0.412 } (delta = +- 0.083, gamma =0.89) Wopt=0.332WN+8.42(delta = +- 3.41%, gamma =0.84)}}}}Central Districtsl1): {{{{Tdmax= { 1} over {0.0112Wopt+0.383} ( delta = +- 0.052, gamma =0.97) Wopt=0.758WN+2.606( delta = +- 4.72%, gamma =0.79)}}}}($\delta$:Standard Deviation, ${\gamma}$:Correlation Coefficient)

• KIEAE Journal
• /
• 제8권3호
• /
• pp.13-18
• /
• 2008

Recently it is urgent issue in every department that problem from environmental disruption such as global warming. As the case of streetscape works essentially at city scenery, it is inevitable that changing from present view, which centers facilities and buildings, to environmental harmonic scenery. This study plans climate adjusting ability and improvement of thermal efficiency by putting ecological elements to buildings on a street which are essential factors of streetscape. Ultimately, this not only makes a pleasant environment but also revives being withered earth. Street-environment on eco-scape will take a part in designing sustainable city. This study acquires the way how buildings on a street get applied ecological elements as following. Roof level part : the greening surface of the rooftop(included plant box type), the greening roof as a type of pergola, the greening surface of the middle floor rooftop(included plant box type). Elevation part : climbing type, downfall type, espalier, flower bed in balcony type, wall-installing type, water wall type, other design types. Ground level part : paving the whole surface with permeability, paving the gap with permeability, plant box type, ground plant type, waterside zone, wetland, fence greening type, terrace greening type, retaining wall greening type.

• 산업기술연구
• /
• 제24권B호
• /
• pp.107-116
• /
• 2004

This thesis is results of experimental works on the behavior of the cut-and-cover tunnel. Centrifuge model tests were performed to simulate the behavior of the cut-and-cover tunnels having cross sections of national road and subway tunnels. Model experiments were carried out with changing the cut slope and the slope of filling ground surface. Displacements of tunnel lining resulted from artificially accelerated gravitational force up to 40g of covered material used in model tests, were measured during centrifuge model tests. In model tests, Jumunjin Standard Sand with the relative density of 80 % and the zinc plates were used for the covered material and the flexible tunnel lining, respectively. Basic soil property tests were performed to obtain it's the property of Jumumjin Standard Sand. Shear strength parameters of Jumunjin Standard Sand were obtained by performing the triaxial compression tests. Direct shear tests were also carried out to find the mechanical properties of the interface between the lining and the covered material. Compared results model tests estimation with respect to displacements of the lining.

• Journal of information and communication convergence engineering
• /
• 제5권4호
• /
• pp.295-299
• /
• 2007

This paper presents the ASF(Additional Secondary Factor) modeling of DGPS beacon signal. In addition to DGPS's original purpose, the feasibility to utilize DGPS system for timing and navigation has been studied. For timing and navigation, the positioning system must know the accurate time delay of signal traveling from the transmitter to receiver. Then the delay can be used to compute the user position. The DGPS beacon signal transmits the data using medium frequency, which travels through the surface and cause the additional delay rather than the speed of light according to conductivities and elevations of the irregular terrain. We introduce the modeling of additional delay(ASF) and present the results of implementation. The similar approach is Locan-C. Loran-C has been widely used as the maritime location system and was enhanced to E-Loran(Enhanced Loran). E-Loran system uses the ASF estimation method and is able to provide the more precise location service. However there was rarely research on this area in Korea. Hence, we introduce the ASF and its estimation model. With the comparison of the same condition and data from the original Monteath model and ASF estimation data of Loran system respectively, we guarantee that the implementation is absolutely perfect. For further works, we're going to apply the ASF estimation model to Korean DGPS beacon system with the Korean terrain data.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2006년도 공동학술대회 논문집
• /
• pp.221-224
• /
• 2006

소규모 공동 탐지를 위한 시험지역에서 시추공 편차를 고려한 탄성파 토모그래피를 수행하였다. 시추공 편차보정방법은 일정 거리를 더하는 보정과 일정 각을 시추공간 거리에 고려하는 보정을 적용하였다. 시추공 편차를 고려한 토모그래피는 영상의 왜곡을 줄일 수 있어 공동을 명확히 영상화할 수 있었으며, 일정 각을 거리에 고려하는 보정방법이 공동탐지에 가장 효과적이지만 일정 거리 보정도 만족할 만한 결과를 얻을 수 있음을 알 수 있었다.

• 한국환경교육학회지:환경교육
• /
• 제19권2호
• /
• pp.159-171
• /
• 2006

A benefit-oriented socio-economic system causes environmental problems that become obvious and more serious on the earth. Therefore, every country in the world is making various efforts to solve serious environmental issues for making the sustainable society. And it is thought that environmental education should play a key role to make the efforts fruitful. Especially, enterprises should be given an important role on environmental education in the future society. This study inquires present activities done by enterprises on environmental education analyze their achievement and aims to clarify the role and prospects on environmental education in the future that the enterprise should carry out. The major results of this research are as follows; First, The approach form of the enterprise concerning environmental education can be classified into four stages, namely 'beginning stage', 'evolution stage', 'development stage' and 'partnership stage'. Present activities on environmental education have not been reached there though 'partnership stage' will be necessary for the sustainable society. Second, In the execution of environmental education, it independently works on environmental education in the enterprise that strongly recognizes the importance of environmental communication with citizens. In other words, it can be said a leading enterprise concerning environmental education, Third, Recognition of the enterprise concerning the importance of environmental education again and the establishment of the positive posture are important.

• 대한원격탐사학회지
• /
• 제27권3호
• /
• pp.289-301
• /
• 2011

In this paper an attempt has been made to classify Asia land cover considering climatic and vegetative characteristics. The sub-class clustering based on the 13 MODIS land cover classes (except water) over Asia was performed with the climate map and the NOVI derived from SPOT 5 VGT D10 data. The unsupervised classification for the sub-class clustering was performed in each land cover class, and total 74 clusters were determined over the study area. Via these clusters, the annual variations (from 1999 to 2007) of precipitation rate and temperature were analyzed as an example by a simple linear regression model. The various annual variations (negative or positive pattern) were represented for each cluster because of the various climate zones and NOVI annual cycles. Therefore, the detailed land cover map as the classification result by the sub-class clustering in this study can be useful information in modelling works for requiring the detailed climatic and vegetative information as a boundary condition.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
• /
• pp.87-100
• /
• 2007

Marine controlled source electromagnetics (CSEM) or sea bed logging (SBL) is an emerging technology which can provide quantitative information on hydrocarbon reservoir embedded in marine sediment. Electromagnetic responses to the resistive formation saturated with a certain amount of hydrocarbon can be characterized by less attenuated profile otherwise exponentially attenuated fields in conductive sea water or through sediments, and thus can be regarded as a direct indicator of hydrocarbon. In this paper, we introduce the technology of marine CSEM in terms of its physical characteristics and in comparison of typical three-dimensional (3-D) seismic method. History and evolution of commercial marine CSEM are also briefly summarized. We then introduce a representative case history showing how marine CSEM works in reality. Outlook of future applications and technical advances to be made are discussed. Finally, we demonstrate a test example of 2.5-D inversion of synthetic data as the groundwork of 3-D inversion of field data that is to be the ultimate goal of technical development.

• 한국농공학회지
• /
• 제16권4호
• /
• pp.3611-3616
• /
• 1974

Alluvial plain of the coast of Kum river tail were found as being mostly consisted of weak foundation. The settlement of the ground, density and change of moisture content which were formed by the load due the construction of earth works were disclossed by the field investigations and laboratory tests. The results are as follow, 1) Banking materials are SM and soft soil stratum is CL. 2) Field moisture content; Wf=19-1.37c c; percentage of clay (less than 0.005mm) 3) optimum water content and maximum density of banking materials; rt=2.15$\mid$0.0165W(12%24%) 4) Density and moisture coutent of banking materials; rt=2.146-0.0095W (8%50%) 5) Density and moisture content of weak foundation; rt=2.06-0. 007W After construction (20%50%) Befor construction (40%60%) 6) Load and settlement of weak foundation; Everage settlement ratio; 12% of actual load p Maximum settlement ratio; 19% of actual load p Minimum settlement ratio: 5% of actual load p 7) Relation of cohesion and unconfined compression test value; c=1/2qu (qu<0.5kg/$\textrm{cm}^2$) c=1/3qu (qu<0.5kg/$\textrm{cm}^2$)

• 지구물리와물리탐사
• /
• 제5권1호
• /
• pp.6-17
• /
• 2002

지형기복에 적용할 수 있는 굴절법 토모그래피법을 개발 및 적용하여 자료해석에 용이성을 주고자하였다. 굴절법 토모그래피의 적용에 있어서 중요한 요소인 측선길이 및 배치, 수신점과 송신점 간격 및 배치, 지형기복 여부를 살펴 보기 위하여 모형자료에 대한 결과를 살펴보았다. 또한 하부의 저속도 층의 규명을 위하여 VSP자료와 동시역산을 수행한 결과 시추공 주변의 저속도 층을 구별할 수 있었다. 택지개발 지역의 탐사 자료에 토모그래피법의 적용한 결과 두 측선에서 얻어진 속도구조의 연속성이 좋았고 또한 속도분포에 대하여 정량적으로 굴삭난이도를 평가하여 공학적으로 이용하고자 하였다.