• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.76-80
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• 2015

The purpose of this study is to understand the cavitation phenomena in centrifugal pumps through computational fluid dynamics method. NPSH characteristic curve is measured from different flow operating conditions. Steady state, liquid-vapor homogeneous method with two equations transport turbulence model is employed to estimate the NPSH curve in centrifugal pumps. The Rayleigh-Plesset cavitation model is adapted as source term for inter-phase mass transfer in order to understand cavitation phenomena in centrifugal pumps. The cavitation incipient curve is clearly estimated at different flows operating conditions. A relationship is made between cavitation incipient and NPSH curve. Also the effects on water vapor volume fraction and pressure load distributions on the impeller blade are also described.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.654-658
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• 2010

과부하 맨홀의 손실계수에 대한 연구는 국내외에서 지속적으로 수행되어 왔다. 그러나 실제 하수관거 설계 및 평가에 이러한 손실계수의 적용여부에 따른 맨홀의 흐름변화에 대한 연구는 이루어진바 없다. 따라서 본 연구에서는 실무에서 하수관거 설계 및 평가 시 가장 많이 사용되는 상용프로그램 SWMM 모형을 활용하여 손실계수 적용 여부에 따른 맨홀의 수두변화를 비교 하였다. 손실계수의 영향을 확인하기 위해 가상유역을 설정하였으며, 이때 가상유역 내에는 4개의 합류맨홀을 포함하고 있고, 그 외 맨홀은 중간 맨홀 및 $90^{\circ}$ 접합맨홀로 이루어져 있다. 손실계수는 윤세의 등(2008, 2009, 2010)이 제시한 값을 적용하였다. 과부하 맨홀에 손실계수를 적용한 결과 맨홀 내 수심은 증가하였고 동수경사선이 높아짐으로써 손실계수 적용 후 침수가 발생하는 맨홀도 나타났다. 따라서 도시유역의 하수관거 평가 시 맨홀에 과부하가 발생하는 경우에는 손실계수를 적용 후 평가가 이루어져야 할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.625-629
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• 2010

암거 수리설계는 상류부의 수위를 과다하게 상승시키지 않는 상태에서 안전하게 계획홍수량을 하류로 소통시킬 수 있도록 최적의 단면을 결정하는 것이다. 현재 국내 암거 설계는 한국도로공사(1991)에서 발표한 "도로배수계획"을 이용하고 있는데, 이는 주로 미국도로성(FHWA)에서 발표한 설계기법을 따른 것이며, 이 기법은 설계항목과 관련되는 설계유량과 지배단면을 결정하여 시행오차적인 방법으로 계획 상류부 수심을 산정하는 순서로 진행된다. 상류부 수심을 결정하기 위해서 미국도로성의 기법은 계산도표를 이용하여 손실 수두와 한계수심을 산정한다. 그러나 계산도표를 이용하여 설계할 경우 주관적인 오차가 생길 수 있으며 전산해석에 있어서도 큰 장애요인이 될 수 있다. 본 연구에서는 기존 연구에서 기술된 암거 설계법을 전반적으로 재검토하여 일부 수식 전개 과정에서 발생한 오류를 수정하고, 암거의 규격 산정 시 암거의 형상을 미리 결정하여 암거 프로그램 개발 시 효율적일 것으로 판단되는 새로운 방법을 개발하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06b
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• pp.67-81
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• 2003

터널 설계 조사단계 및 시공중 RMR 및 Q분류를 시행하고자 하는 경우, 여러 가지 제약조건으로 말미암아 지하수 조건에 해당하는 항목인 Jw의 선정은 조사자의 경험에 의존하고 있다. Jw 선정시에는 되도록 정량적인 선정이 가능한 지하수 유입량 자료에 기초하는 것이 바람직하기 때문에, 본 고에서는 여러 가지 예측방법을 검증함으로서 보다 합리적인 방법을 제안하고자 한다. 절리수두, 지하수 유입량, 수리전도도 특성 등의 다양한 자료를 구한 대전 LNG Pilot Cavern의 결과를 바탕으로 수치해석 결과, 이론식에 의한 결과를 측정결과와 상호 비교하였다. 그 결과 합리적인 수리전도도 모델을 선정할 수 있다면 이론식으로도 Jw값을 비교적 근사하게 선정할 수 있다는 사실을 제안하였다.

• The Journal of Korean Physical Therapy
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• v.2 no.1
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• pp.123-125
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• 1990

문헌에 의하면 대상포진의 원인은 바이러스에 대한 세포성 면역이 저하될 때, 또는 악성종양 등으로 면역억제제 치료를 받아서 2차적으로 면역이 저하될 때 체내에 잠재해 있던 바이러스가 재활되어 발병하는 것으로 추정하고 있다. 본 저자도 이에 대하여 의견을 같이하고 있는데 노령층의 $60\~70$대 여자환자수가 압도적으로 많았다는 점과, $20\~39$세 사이의 청${\cdot}$장년층에서는 단1명의 대상자가 없다는 점뿐 아니라, 본 대상자중 11세의 소녀는 7세때 뇌종양 수술을 2차례에 걸쳐 실시한 후 면역제제를 계속적으로 사용하는 있는 점 등은 문헌의 발병원인과 상당히 일치하였다. <전파 양식> 비말 감염 (droplet infection)으로 전파되며, 수두와 달리 전염성이 높지 않다. <잠복기> 잠복해 있던 바이러스가 언제 재활할지 알 수 없으므로 불명이다. 그러나 본조사에서는 대상포진에 대한 병력을 가진 사람이 없었고, 발생 원인을 본인 자신도 모르고 있었다. <합병증> Ramsay Hunt의 증후에 의하면 합병증은 외이도의 수포, 안면신경마비, 혀의 2/3부분의 미각상실, 간혹 청각 및 평행장애를 일으킨다고 한다. <치료> 대상포진의 대증요법으로 calamine lotion Burrow solution의 wet dressing 진통제 및 cytosine arabinoside나 adenosine arabinoside와 같은 항히스타인제, 최근에는 Acyclovir가 많이 사용되고 있는 것으로 알려졌다.

• Journal of Korean Neurosurgical Society
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• v.30 no.7
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• pp.939-942
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• 2001

Thirty nine-year-old man who required urgent shunt operation due to rapidly deteriorating visual acuity suffered from ventriculitis after aneurysmal operation. Daily dose of 20mg of vancomycin and amikyn were given intraventricularly via external ventricular catheter after failure of various kinds of systemic antibiotics. The exit of the catheter was made on the upper chest wall to prevent superinfection. External ventricular drainage could finally be switched to ventriculo-peritoneal shunt and he was discharged with clinical improvement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.56-63
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• 2018

The management of Combined Sewer Overflows(CSOs) and Separated Sewer Overflows(SSOs) discharge directly to the effluent system in an untreated state, which occurs when the facility capacity is exceeded due to heavy rain, has become an important issue in recent years as the heavy rain becomes a regular phenomenon. Despite the continuous development of filtration technology, targeting densely populated urban areas, CSOs are rarely applied. Therefore, this study was carried out to optimize the process to apply CSOs in a pilot-scale horizontal flow filtration system with a rope-type synthetic fiber. The research was carried out in two steps: a preliminary study using artificial samples and a field study using sewage. In the preliminary study using an artificial sample, head loss of the filter media itself was analyzed to be approximately 1.1cm, and the head loss was increased by approximately 0.1cm as the linear velocity was increased by 10m/hr. In addition, the SS removal efficiency was stable at 81.4%, the filtration duration was maintained for more than 6 hours, and the average recovery rate of 98% was obtained by air backwashing only. In the on-site evaluation using sewage, the filtration duration was approximately 2 hours and the average removal efficiency of 83.9% was obtained when belt screen (over 450 mesh) was applied as a pre-treatment process to prevent the premature clogging of filter media. To apply the filtration process to CSOs and SSOs, it was concluded that the combination with the pre-treatment process was important to reinforce the hydraulic dimension for the stable maintain of operation period, rather than efficiency. Compared to the dry season, the quality of incoming sewage was lower in the rainy season, which was attributed to the characteristics of the drainage area with higher sanitary sewerage. In addition, the difference in removal efficiency according to the influent quality of the wet season and dry season was small.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.234-242
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• 1987

Rough rice samples of four rice varieties were collected from twenty five locations through the country just after 1986 rice growing season. Various characteristics related to rice grain quality were observed to clarify the degree of locational variation of physico-chemical properties, and cooking and eating quality of rice grains. Grain weight, grain shape, degree of translucency and chalkiness of rice grain, amylogram properties of rice flour, water uptake during cooking, and cooked rice appearance were different between varieties tested. High degree of locational variation were found in following characteristics, degree of translucency and chalkiness of rice grain, water uptake during cooking, cooked rice appearance and amylogram properties. Eating quality of cooked rice indicated by sensory score showed different tendency of locational variation between rice varie-ties tested, and locations produced rice grains showing better eating quality were not coinside with among varieties tested. Grain weight, degree of translucency and chalkiness of rice grain, and cooked rice appearance of rice samples showing better eating quality were quite different to rice grains showing poor eating quality. Rice having better eating quality of a japonica variety, Chucheong, showed higher value of peak and final viscosity, viscosity after cooling, consistency and set back on amylograph compared with those of poor eating quality rices, and break down value of better rice was lower than that of poor rice. However, a Tongil type variety, Taebaek, did not show any consistent difference between better and poor rices. Rice samples from six locations in Chucheong and four locations in Taebaek showed special properties on amylogram compared with other rices collected in this study.

• Clinical and Experimental Pediatrics
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• v.45 no.10
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• pp.1234-1240
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• 2002

Purpose : This study was carried out to obtain the vaccination rate and age appropriateness of vaccination in children under five years of age in Jeonbuk province. Methods : Eight hundred and fifty infants and children were enrolled in this study. Vaccination rate(Number of vaccinees/Number of subjects), places of vaccination, age appropriateness of vacination were examined by either vaccine record review or interview with parents or guardians. Results : The salient features of the findings were as follows : All subjects were aged under five and mostly under two years of age(68.8%). Places of vaccination were health centers or subcenters( 50.4%), private clinics(44.3%), and general hospitals(5.3%). Routine vaccinations such as BCG, hepatitis B vaccine(HBV), diphtheria, tetanus, acellular pertussis(DTaP) and Trivalent Oral Polio Vaccine(TOPV), measles, mumps, rubella(MMR), and Japaneses B encephalitis(JBE) were vaccinated mostly in health centers or subcenters, while chickenpox(CHP) and haemophilus influenzae vaccines(Hib), which are not routine in Korea, were vaccinated in private clinics. The vaccination rates of BCG(99.2%), HBV(93.5%) and DTaP(96.1%) were very high. But those of MMR(83.7%), CHP(72.5%), JBE(50.2%), and Hib(15.8%) were lower than expected. Considering the age appropriateness of vaccination, some infants and children were not appropriately vaccinated(vaccination rate/age appropriateness of vaccine; HBV, 93.5%/88.4% : DTaP, 94.6%/73.1% : JBE, 50.2%/ 18.5%). Conclusion : The vaccination rate of BCG, HBV, DTaP and TOPV was very high, but MMR, CHP, JBE, and Hib vaccination rate was not high enough to be able to protect against epidemic. We should pay more attention to vaccinating children, and there is a need for a program that will enhance coverage for vaccines.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.637-645
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• 2013

Masan bay with a semi-enclosed waters has serious water quality problems due to the low flow and river pollution load from land, and shows the vulnerable locational characteristics to storm surge. We are seeking the way of both operating disaster prevention facilities and water quality improvement measures in the bay. That is, the water was exchanged using the head difference occurred by operating disaster prevention facilities. The location of disaster prevention facilities was assumed to be in the inlet of the bay, in the vicinity of Machang bridge, and in the vicinity of Dot island and the operation time was assumed to be early morning hours(01~05) considering the number of shipping passage and annual tide, and spring tide of the largest head difference. In addition, the experiment case of water exchange including the in-outflow feeder pipe was tested. According to the simulation results, water exchange rate in all experiments has shown a steady increase. Water exchange rate of the whole of Masan bay in the case of present is 38.62%. The water exchange rate of the inside of Masan bay compared with the inlet of bay, appeared to be very low. Thus, we judged that the characteristics of semi-enclosed waters were well reproduced. On the results of the experiment of disaster prevention facilities and in-outflow feeder pipe, the case of the operation of disaster prevention facilities, water exchage rate is high compared with the case of present. And, the higer the operating frequency, the more water exchange is appeared. The cases of water exchange prevention facilities through the in-outflow feeder pipe caused by the head difference, also showed the higest improvement of the water quality. Compared with the south of Machang bridge, the effect of water exchange was better in the inlet of Masan bay and Dot island. On the other hand, the inlet of Masan bay is higer than Dot island as for water exchange of the whole of Masan bay, but opposite, water change rate including Masan inside was higher in the case of Dot island.