• 한국가스학회지
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• 제22권5호
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• pp.100-106
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• 2018

국내산업단지 내 고압 매설배관은 장기사용배관이 많고 독성 가연성 불활성 등 고압가스는 물론 다양한 유해화학물질이 한도로 내에 복잡하게 매설되어있어 다양한 타공사 등 사고 발생 시 인접하여 매설된 다른 배관에 손상을 미칠 수 있어 높은 수준의 안전관리가 요구되고 있다. 이에 본 연구에서는 고압가스매설배관과 도시가스매설배관 안전관리실태를 심층비교분석을 통하여 고압가스 매설배관의 효율적인 안전관리방식 도출에 활용하고자한다.

• Structural Engineering and Mechanics
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• 제47권2호
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• pp.167-183
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• 2013

Methods for estimating structural reliability using probability ideas are well established. When the residual ultimate strength of a buried pipeline is exceeded the limit, breakage becomes imminent and the overall reliability of the pipe distribution network is reduced. This paper is concerned with estimating structural failure of underground flexible pipes due to corrosion induced excessive deflection, buckling, wall thrust and bending stress subject to externally applied loading. With changes of pipe wall thickness due to corrosion, the moment of inertia and the cross-sectional area of pipe wall are directly changed with time. Consequently, the chance of survival or the reliability of the pipe material is decreased over time. One numerical example has been presented for a buried steel pipe to predict the probability of failure using Hasofer-Lind and Rackwitz-Fiessler algorithm and Monte Carlo simulation. Then the parametric study and sensitivity analysis have been conducted on the reliability of pipeline with different influencing factors, e.g. pipe thickness, diameter, backfill height etc.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.415-419
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• 1999

Many bipolar logic circuit of conventional occurred problem of speed delay according to deep saturation state of vertical NPN Transistor. In order to remove minority carries of the base region at changing signal in conventional bipolar logic circuit, we made transistor which is composed of NPN transistor shortened buried layer under the Base region, PNP transistor which is merged in base, epi layer and substrate. Also the Ring-Oscillator for measuring transmission time-delay per gate was designed as well. The structure of Gate consists of the vertical NPN Transistor, substrate and Merged PNP Transistor. In the result, we fount that tarriers which are coming into intrinsic Base from Emitter and the portion of edge are relatively a lot, so those make Base currents a lot and Gain is low with a few of collector currents because of cutting the buried layer of collector of conventional junction area. Merged PNP Transistor's currents are low because Base width is wide and the difference of Emitter's density and Base's density is small. we get amplitude of logic voltage of 200mv, the minimum of transmission delay-time of 211nS, and the minimum of transmission delay-time per gate of 7.26nS in AC characteristic output of Ring-Oscillator connected Gate.

• 전자통신동향분석
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• 제5권1호
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• pp.55-70
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• 1990

SIMOX SOI is known to be one of the most useful technologies for fabrications of new generation ULSI devices. This paper describes the current status of SIMOX SOI technology for ULSI applications. The SIMOX wafer is vertically composed of buried oxide layer and silicon epitaxial layer on top of the silicon substrate. The buried oxide layer is used for the vertical isolation of devices The oxide layer is formed by high energy ion implantation of high dose oxygen into the silicon wafer, followed by high temperature annealing. SIMOX-based CMOS fabrication is transparent to the conventional IC processing steps without well formation. Furthermore, thin film CMOX/SIMOX can overcome the technological limitations which encountered in submicron bulk-based CMOS devices, i.e., soft-error rate, subthreshold slope, threshold voltage roll-off, and hot electron degradation can be improved. SIMOX-based bipolar devices are expected to have high density which comparable to the CMOX circuits. Radiation hardness properties of SIMOX SOI extend its application fields to space and military devices, since military ICs should be operational in radiation-hardened and harsh environments. The cost of SIMOX wafer preparation is high at present, but it is expected to reduce as volume increases. Recent studies about SIMOX SOI technology have demonstrated that the performance of the SIMOX-based submicron devices is superior to the circuits using the bulk silicon.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.553-562
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• 2008

A remediation technique for buried pipeline system subject to permanent ground deformation is proposed. Specifically, EPS (expanded polystyrene) geofoam blocks are used as low density backfill, thereby reducing soil restraint and pipeline strains. In order to evaluate this remediation technique, a series of 12 centrifuge model tests with HDPE pipe were performed. The amount or spatial extent of the low density backfill was varied, as well as the orientation of the pipe with respect to the fault offset. Specifically, in the $-63.5^{\circ}$ test, the orientation was such that the pipe was placed in flexure and axial tension. The $-85^{\circ}$ orientation placed the pipe mainly in flexure. In all cases, the behavior of the remediated pipe was compared to that for the unremediated pipe. The geofoam backfill was successful in improving pipe behavior for two of the three pipe/fault orientations. However, for the $60^{\circ}$ orientation, the pipe buckled in compression irrespective of the geofoam backfill.

• 한국전자파학회논문지
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• 제14권8호
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• pp.803-808
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• 2003

손실 반공간에 두 개의 원통형 파이프가 묻혀 있는 경우 파이프와 주변 매질의 특성을 반복 기법 최적화 역산란을 적용하여 구했다. 산란 전계는 경계요소법을 이용하여 계산하였으며 파이프의 크기, 위치, 내부매질의 비유전을, 도전을, 주변 매질의 비유전을, 도전을 등의 파라미터는 측정 산란 전계로부터 유전 알고리즘과 Levenberg-Marquardt 알고리즘의 혼합 알고리즘을 이용하여 역으로 계산하였다. 두 파이프가 거의 근접해 있는 경우도 역산란이 가능함을 보였다. 산란 전계의 측정오차에 의한 illposednes 는 파수 영역에서 지수 함수적으로 감쇄하는 감쇄모드를 제거하여 안정화시켰다.

• Corrosion Science and Technology
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• 제11권2호
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• pp.56-64
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• 2012

Factors affecting corrosion of stainless steels such as pH, oxidation and redox potential (ORP), soil resistivity, water content of soil, chloride ion concentration, bacteria activity, and corrosion potential have been investigated using soil analysis, bacterial analysis, surfacial analysis, and analysis of corrosion potentials of several stainless steels buried in 8 sites of Seoul metropolitan for one year. Corrosion potential was affected by occurrance of corrosion as well as bacteria activity but the behavior of corrosion potential with time is different depending on occurrance of corrosion and bacteria activity. The main factor affecting corrosion of stainless steels in soil is level of chloride ion concentration which is also a main factor affecting corrosion of stainless steels in chloride containing drinkable water. Furthermore, guideline of stainless steels in drinkable water is concluded to be applicable to that in soil by the results from surfacial analysis.

• Computers and Concrete
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• 제24권5호
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• pp.445-452
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• 2019

In this paper, dynamic stress, strain and deflection analysis of concrete pipes conveying nanoparticles-water under the seismic load are studied. The pipe is buried in the soil which is modeled by spring and damper elements. The Navier-Stokes equation is used for obtaining the force induced by the fluid and the mixture rule is utilized for considering the effect of nanoparticles. Based on refined two variables shear deformation theory of shells, the pipe is simulated and the equations of motion are derived based on energy method. The Galerkin and Newmark methods are utilized for calculating the dynamic stress, strain and deflection of the concrete pipe. The influences of internal fluid, nanoparticles volume percent, soil medium and damping of it as well as length to diameter ratio of the pipe are shown on the dynamic stress, strain and displacement of the pipe. The results show that with enhancing the nanoparticles volume percent, the dynamic stress, strain and deflection decrease.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.86-90
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• 1992

We have studied the characteristics of n-and p-channel FETs with submicron channel length fabricated by twin-well process. Threshold voltage variation and potential distribution with channel ion implantation conditions and impurity profile of n-and p-channel region wee simulated using SUPREM-II and MINIMOS 4.0 simulater, P-channel FET had buried-channel in the depth of 0.15 $\mu\textrm{m}$ from surface by counter-doped boron ion implantation for threshold voltage adjustment. As a result of device measurement, we have obtained good drain saturation characteristics for 3.3 [V] opreation, minimized short channel effect with threshold voltage shift below 0.2[V], high punchthrough and breakdown voltage above 10[V] and low subthreshold value.

• 한국지반공학회논문집
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• 제15권6호
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• pp.99-109
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• 1999

국내 일반폐기물 매립지의 경우 함수비가 높은 쓰레기의 특성으로 인하여 매립지 내부에 누적수위가 발생하는 경우가 많고 따라서 매립된 복토재와 쓰레기의 수리특성의 파악은 매우 중요하다. 폐기물 매립지의 설계시공 과정에서 매립지 하부차수재와 주변지반의 수리특성에 대해서는 많은 지반조사와 연구가 되어있으나 매립지내부 쓰레기와 복토재의 수리적특성 및 흐름거동에 대한 조사 및 해석은 국내외적으로 되어있지 않다. 본 논문에서는 국내 대표적 폐기물 매립지에 대한 현장 지반조사로부터 쓰레기와 복토재의 지반공학적 특성을 파악하고 양수시험(pumping test)과 순간충격시험(slug test)을 이용하여 매립된 쓰레기와 복토재의 수리특성을 파악하였다. 현장지반조사 결과 매립된 쓰레기의 다짐정도는 실내시험의 최대 단위중량 값을 상회하는 것으로 나타났으며 쓰레기에 의하여 덮여진 중간 저투수성 복토재는 침출수와 가스의 수직 흐름을 방해하고 있는 것으로 보여진다. 현장 양수시험과 순간충격시험의 투수계수는 상호간에 잘 일치하고 문헌에서 나타난 잘 다져진 쓰레기의 투수계수 범위에 있는 것으로 나타났다.