• 상하수도학회지
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• 제19권3호
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• pp.279-287
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• 2005

In this study, I suggest an effective operation of waterwork facilities in large cities and a scientific method for utilizing water in water distribution systems. To achieve this goal, my simulation were carried out on data from Kwangju City using Pipenet '98, a pipe-network program. From this simulation, I examine the possibilities of application the system in large cities, comparing data measured at 33 hydraulic pressure monitoring places from waterwork enterprises. The result is coincident with that of waterwork enterprises, with about a 12.5% average error rate and $0.32kg/cm^2$ average deviation. The method and program I use here can be helpful in cities where there is a need to extend the waterwork facilities, or where there is a need to suspend the water supply, and/or there is an accident. The simulation shows how to expand waterwork facilities effectively, how to prevent accidents, and how to estimate the hydraulic pressure even in the areas without monitoring places.

• 한국습지학회지
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• 제22권2호
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• pp.145-152
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• 2020

고속도로는 많은 자동차 운행대수와 함께 높은 주행속도 및 급격한 주행속도 변화구간(휴게소, 영업소 등)으로 인하여 비점오염물질의 배출이 높은 지역에 해당한다. 국내 고속도로는 절토층 및 성토층에 조성됨으로써 적정 토양침투량 확보가 어려워 다양한 종류의 비점오염저감시설이 설치되지 못하고 있다. 본 연구는 토양치환 기법에 대한 연구를 통해 고속도로에 설치 가능한 시설의 종류를 확대하고 비용효율적 침투시설의 설계를 유도하기 위하여 수행되었다. 침투율이 낮은 원지반에 토양치환을 수행할 경우 시설 내 체류시간이 약 30% 지연되고, 시설 내 침투 및 저류율은 약 20% 증대하며, 비점오염물질 Total Suspend Soiled (TSS), Chemical Oxygen Demand (COD), Biological Oxygen Demand(BOD), Total Nitrogen(TN) 및 Total Phosphorus(TP) 제거효율이 약 20% 증가하는 것으로 나타났다. 원지반 내 침투율이 낮은 곳에 토양치환을 수행할 경우 저류량, 체류시간 및 침투면적이 증가하여 침투율이 향상되는 것으로 나타났다. 원지반 토양의 침투능이 낮은 토양에 침투시설을 적용하기 위해서는 물환경보전법 시행규칙 별표17(비점오염저감시설의 설치기준)의 개선이 필요하며, 이 경우 토양 침투율이 시간당 13 mm 이하일 때 토양치환을 통해 법적 처리용량을 확보하도록 요구할 수 있다.

• Steel and Composite Structures
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• 제18권1호
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• pp.165-185
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• 2015

The suspended zipper bracing system is suggested to reduce the flaws of ordinary zipper braced and concentric inverted V braced frames. In the design procedure of suspended zipper bracing systems, columns and top story truss elements are strengthened. This bracing system show different performances and characteristics compared with inverted V braced and ordinary zipper frames. As a result, a different response modification factor for suspend zipper frames is needed. In this research paper, the response modification factor of suspended zipper frames was obtained using the incremental dynamic analysis. Suspended zipper braced frames with different stories and bay lengths were selected to be representations of the design space. To analyze the frames, a number of models were constructed and calibrated using experimental data. These archetype models were subjected to 44 earthquake records of the FEMA-P695 project data set. The incremental dynamic analysis and elastic dynamic analysis were carried out to determine the yield base shear value and elastic base shear value of archetype models using the OpenSEES software. The seismic response modification factor for each frame was calculated separately and the values of 9.5 and 13.6 were recommended for ultimate limit state and allowable stress design methods, respectively.

• Archives of Reconstructive Microsurgery
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• 제10권1호
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• pp.60-63
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• 2001

The reconstruction of the suborbital area followed by resection of skin cancer has been used many methods including skin graft, local flaps, free flaps, and skin expansion. The radial forearm free flap has become a workhorse flap in this area because of its lack of bulk, ease of dissection, malleability, and hairlessness. When the suborbital defect especially including full-thickness defect of lower lid was reconstructed with many free flaps, the ectropion and the deformity of medial and lateral canthal area were common problems encountered as late complication due to gravitational descent. To improve the final aesthetic result in patients with suborbital defect, the radial forearm free flap was elevated as a composite radial forearm - palmaris longus free flap, in which the vascularized palmaris longus london was included and anchored to the periorbital bone with $mitek^{(R)}$ as sling, to suspend the flap against gravity and inferior descent, and thereby creating a more natural cheek contour. Two clinical cases were presented as an example of this procedure. Postoperative results emphasize the importance of suspension sling with palmaris longus tendon using $mitek^{(R)}$ in reconstruction of the suborbital defect with radial forearm free flap.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1159-1163
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• 2005

The Sonication method is widely used with surfactants to suspend individual single walled nanotubes in solution, and it is well known that sonication-induced tube cutting occurs. Recently, it is found out that ultrasonicated nanotubes yield simultaneous separation by tube length and diameter. Nanotubes that have been cut shortest possess the greatest enrichments of large-diameter species. In this study, we cut single walled carbon nanotubes using a ball milling method and find out similar behavior compared to the sonication process Cutting mechanisms are also investigated using continuum approaches.

• 한국환경보건학회지
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• 제22권2호
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• pp.83-89
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• 1996

In order to evaluate the air quality, dry and wet deposition samples were collected by deposit containers during four months in Inchon area. The samples were analyzed for its solid composition and trace elements(Ca, Cd, Cu, Fe, Mn, Ni, Pb, Zn). The main results are summarized below 1. The amounts of dry and wet deposition in Inchon area were 1.06~3.14 ton/$km^2$/month, and affected by the rainfall and suspended yellow sand. 2. Through the analysis of solid balance, we found that 50% of total solids(TS) was fixed suspend ed solids(FSS), 25% was fixed dissolved solids(FDS), and each of volatile suspended solids(VSS) and volatile dissolved solids(VDS) accounted for 12.5%. 3. The amounts collected by sampler for trace elements were 938 ~ 2,765 $\mu g$ calcium/10days sampler, 0.2 ~ 90.4 $\mu g$ cadmium/10days/sampler, 26 ~ 298 $\mu g$ copper/10days/sampler, 928 ~ 3,939 $\mu g$ iron/10days/sampler, 50 ~ 202 $\mu g$ manganese/10days/sampler, 4 ~ 37 $\mu g$ nickel/10days/sampler, 52 ~ 406 $\mu g$ lead/10days/sampler, and 97 ~ 1,317 $\mu g$ zinc/10days/sampler, respectively. 4. Using the manganese analysis, it was found that 76.1% of TS was from soil.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.949-958
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• 2020

차량을 구성하는 엔진, 미션, 현가, 제동, 조향장치 등 다양한 장치 중에서 현가 장치는 타이어와 차체 사이에 설치되어 노면에 의한 차량의 진동을 억제하여 승차감을 향상시키고 차륜과 노면 사이에 적절한 접지력을 유지시켜 차량의 조정안정성을 향상시키는 등 차량역학적인 측면에서 많은 영향을 미치는 장치 중의 하나이다. 본 연구에서는 차량용 현가 장치의 충격 흡수기를 실제 특성과 유사한 상세 모델로 모델링하고, 충격 흡수기의 주요 설계변수의 불확실성을 통계적으로 고려하여 설계변수의 불확실성이 현가 장치의 동적 특성에 미치는 영향에 대하여 연구하였다.

• 한국농공학회지
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• 제38권1호
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• pp.90-97
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• 1996

In Korea, total sediment discharge of a river has been estimated simply by using certain sediment transport formulas including, among others, Einstein's formula. Those formular, however, are known not to be reliable enough for the result calculated by them to be used directly to river planning and management. Therefore, the study used the Modified Einstein Procedure to the estimation of total sediment discharge, because this method is reliable estimated by measurement. Here, measurement of sediment discharge used depth integrating method. The major results obtained from the study for estimation by depth integrating method of sediment discharge in Naeseong stream are as follow; 1 The sedeiment characteristics of Naeseong stream are; The distribution of sediment grain size shows that silt and clay are 55% and sand is 45%. and the bed load sediment grain size is constituted that sand contained with the grain size from O.062mm to 2.0mm is 80% 2. The sediment rating formulas derived from the regression analysis between the sediment discharge and flow discharge are; Seogpo-Gyo : Qs=$0.017 \times 10^{-4} Q^{2.352}$, where discharge is l0cms $0.074 \times 10^{-4} Q^{2.066}$, where discharge is l0cms

• Journal of Korean Neurosurgical Society
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• 제45권1호
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• pp.39-42
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• 2009

We report a supratentorial primitive neuroectodermal tumor (sPNET) in 17-year-old primipara in the second trimester her pregnancy. Magnetic resonance imaging revealed a left frontoparietal mass with solid and cystic component. Gross-total resection was achieved via a left frontoparietal craniotomy. It was decided to suspend the radiotherapy and chemotherapy until the 30 weeks of gestation. But, a sudden uncal herniation was developed due to the reccurrence of the tumor and bleeding into the tumor at the 25 weeks of gestation and the patient died after urgent decompressive surgery. sPNETs is an extremely rare brain tumor in pregnancy and only two cases were reported in the literature to date. There is no universally agreed treatment protocol for sPNETs during pregnancy and a multidisciplinary approach is required in treatment. In the present study, the clinical, histopathological features and therapeutical difficulties of sPNETs diagnosed during pregnancy was discussed with the literature review.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.54-58
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• 2006

우주 시스템에 사용되는 각종 추진제 탱크는 내 외부압력 및 온도, 무게 등의 조건을 고려하여 설계되어야 한다. 특히 탱크의 외부 조건에 의해 탱크에 발생 또는 전달되는 정적, 동적 하중조건을 충분히 지지할 수 있도록 설계 고려하는 것이 탱크 설계의 주요한 인자 중 하나라고 할 수 있다. 이와 같이 탱크를 지지하는 것을 탱크 마운팅(tank mounting)이라고 한다. 탱크 마운팅을 위해서는 견고한 구조와 함께 간단한 제작성, 가벼운 무게, 저렴한 제작비 등을 고려하여야 한다. 본 논문에서는 추진제 탱크 마운팅 방법의 종류 및 특징에 대해 언급하고, 해외 우주관련 프로그램에 적용된 마운팅 방법에 대해 소개하도록 한다.