• 물과 미래
• /
• 제12권1호
• /
• pp.56-59
• /
• 1979

직접유출 수문곡선의 감수부를 유발하는 지표하류출 과정이 사대종확산모형기법에 의하여 모의되었다. 유출과정은 필시곡선도에 의한 소유역을 대표하는 개급적 선형 수로를 통하여 상류선형수로의 유출과 핵심 소유역의 유효강우량을 추적하여 수행된다. 유출 속도, 확산인자, 침투와 지표하흐름 영역에 관한 매개변수의 산출과정이 기록된다.

• 한국정밀공학회지
• /
• 제19권8호
• /
• pp.84-91
• /
• 2002

This paper analyzes the subsurface stress at the spherical contact using Hamilton equation, and with that data, calculates the fatigue limit under the variations of friction coefficient using fatigue theory. After rough surface being made, this paper figures out the random load generated by contacting to the rough surface, analyzes the stress of its subsurface, and calculates the fatigue limit of the rough surface using fatigue theory. The three parts of the fatigue theory are applied, which are critical plane theory, stress invariant theory and mesoscopic theory.

• International Journal of Safety
• /
• 제6권2호
• /
• pp.43-48
• /
• 2007

We introduced the Excavation One Call System (EOCS) as a pilot system, in Seoul, Korea. The system utilizes the phone and internet to transfer information about digging underground and buried gas pipelines, although currently written forms are used in accordance with the City Gas Business Law. After one year, we evaluated the business model by surveying the excavators and the operators of the gas companies. This paper shows that the EOCS was more effective in preventing the buried gas pipelines from being damaged than the existing method that has to use due form. It also shows that the EOCS was more convenient and cost efficient than the present policies in place. We come to the conclusion that the EOCS should be extended nationwide and gradually include other subsurface facilities.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
• /
• pp.57-59
• /
• 2004

This paper reports the observation of the interferometric synthetic aperture radar (InSAR) phase anomaly on a newly reclaimed mudflat, Hwaong, in west coast of Korea, detected by a series of Radarsat-l SAR data obtained mostly during 2003. The observed phase anomaly could be from subsidence of mud land caused by volumetric contraction of mud in dry season. This process must have been initiated from March 2002 when tidal water supply to this region was permanently blocked by the newly constructed embankment. The maximum subsidence rate measured from InSAR signal is about 3 cm per month. The local heterogeneity of the subsidence rate over the reclaimed mudflat may indicate various mud composition, surface-subsurface hydrological processes, or subsurface information of the mud and basement rock structure. In-situ measurement must follow to support this observation from space.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제18권2호
• /
• pp.45-53
• /
• 2013

Many cases of strategically designed groundwater remediation have lack of information of hydraulic conductivity or permeability, which can render remediation methods inefficient. Many studies have been carried out to minimize this shortcoming by determining detailed hydraulic information either through direct or indirect measurements. One popular method for hydraulic characterization is the pilot point method (PPM), where the hydraulic property is estimated at a small number of strategically selected points using secondary measurements such as hydraulic head or tracer concentration. This paper adopted a D-optimality based pilot point method (DBM) developed previously for hydraulic head measurements and extended it to include both hydraulic head and tracer measurements. Based on different combinations of trials, our analysis showed that DBM performs well when hydraulic head is used for pilot point selection and both hydraulic head and tracer measurements are used for determining the conductivity values.

• Tribology and Lubricants
• /
• 제25권6호
• /
• pp.399-403
• /
• 2009

The objective of this paper is to predict pitting initiation by using a contact analysis and subsurface stress. Contact stresses are obtained by contact analysis of a semi-infinite solid based on the use of influence functions. Subsurface stress field is obtained using rectangular patch solutions. It is used Mesoscopic multiaxial fatigue criterion to predict contact fatigue life. It is important to predict pitting initiation to enhance reliability of the mechanical elements. Pitting life prediction in the spur gears which are fundamental mechanical element is presented in this paper.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권3호
• /
• pp.3-9
• /
• 2011

Partitioning tracers have been used with non-partitioning, inert tracer such Br, for detection, estimation, and monitoring of remediation performance of the subsurface contaminated with nonaqueous phase liquids (NAPLs). Various partitioning tracers with different partition coefficients between aqueous and nonaqueous phase liquids can be used to determine the hydraulic conductivity, dispersivity, and residual mass of NAPLs in the subsurface soil matrices. Temporal moment-generating equations were used to analyze the field pilot-scale test results. The pilot-scale tests included conservative tracer tests and partitioning tracer tests. Analyses of nonaqueous phase liquid distribution and characteristics of groundwater bearing soil media were performed.

• 한국환경과학회지
• /
• 제16권12호
• /
• pp.1325-1335
• /
• 2007

The utility of soil-gas surveys is directly proportional to their accuracy in reflecting and representing changes in the subsurface concentrations of source compounds. Passive soil-gas vapor-phase is merely a fractional trace of the source, so, as a matter of convenience, the units used in reporting detection values from EMFLUX surveys are smaller than those employed for source-compound concentrations. According to the Leaking Underground Storage Tank(LUST) Program Annual Report, approximately 16 U.S. million dollars were spent for environmental site investigations at over 1,600 Underground Storage Tank(UST) sites and approximately over 1,000 acres of land was characterized and remediated in the State of Illinois in the year of 2003 alone. The main purpose of this study is to propose an idea to significantly reduce the site investigation cost by utilizing a passive soil-gas survey and conventional intrusive drilling method and to fully define the three dimensional characteristics of subsurface contamination from two industrial drycleaning facilities.

• 한국정보통신학회논문지
• /
• 제6권8호
• /
• pp.1305-1309
• /
• 2002

표면하 레이더는 건물의 크랙과 같은 정보를 수집하기 위해 좁은 펄스를 사용하므로 넓은 대역의 주파수 특성을 가진다. 본 논문에서는 광대역 특성을 가지는 안테나를 마이크로트립을 이용하여 보우타이 형태로 설계하였다. 설계 기판으로는 ${\varepsilon}_r=4.0$, t=1.6mm의 FR-4 유전체 기판을 사용하였다. 설계된 안테나는 s11<-10 dB에서 9.31%의 대역폭을 가지고, 5.78 GHz에서 -27.45 dB의 s11과 1.089의 VSWR 값을 나타내었다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2000년도 가을 학술발표회 논문집
• /
• pp.585-592
• /
• 2000

Primary purpose of the system developed in this study is 3-D seismic data processing system for subsurface structure imaging and this system is developed in PC based on Linux for lower-cost computer. Basic data processing modules are originated from SU (Seismic Unix) which is widely used in 2-D seismic data processing and auxilious modules are developed for 3-D data processing. The system which is constructed by using these data processing modules is designed to GUI (Graphic User Interface) in order that one can easily control and for this purpose, GTK (Gimp Tool KiT) conventionally adapted in producing Linux application.