• Journal of Advanced Marine Engineering and Technology
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• 제28권6호
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• pp.938-945
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• 2004

Intrinsic safety is generally considered the safest method of operating electrical instrumention in potentially explosive atmospheres. The method of intrinsic safety limits the energy passing into the hazardus area. The energy limitation is provided by the use of safety barriers which are mounted in the safe area. Because of the energy limitation, regardless of the fault in the hazardous area, sufficient energy cannot be released to ignite the explosive atmosphere. The following industries are known to have hazardous locations: chemical. munitions, petrochemical, auto(paint spray booths), grain, waste water, printing, distillers, pharmaceutical. breweries, cosmetics, and utilities. In this paper, a isolator type barrier for ship(LNG, LPG, etc,) and test equipment confidence are proposed. The test equipments are designed for mechanical electrical life time test and vibration. All of test results satisfy the goal and the studied barrier shows the improved confidence.

• 전기학회논문지
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• 제60권10호
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• pp.1935-1940
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• 2011

The control logic of steam temperature was redesigned, tested and applied to the power plant after its steam temperature equipments had been revised. This power plant use the ancillary gas gotten in the process of making iron in the steel mill. The boiler of power plant has the superheater and reheater to make the superheated steam. The superheater and reheater have the spray valve to control their temperature. The reheater has the gas bypass damper additionally in this plant. The control logics were redesigned in cascade forms and the initial parameters of control logics were calculated from the several step tests. The final parameters could be obtained through the several repeated tests and the feedforward functions were added by temperature deviation and air flow. The power plant is being commercially-operated normally by improved control logics and It is expected that this improved controls help the efficiency improvement and safe operation of plant.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.591-595
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• 1997

In analysis of piping vibration of petrochemical plant, the forcing functions mainly depend upon the equipment working mechanism and vibration resources in the piping systems. In general, harmonic function is used for the system with rotary equipments. Mechanical driving frequencies, wave functions, and response spectrum are used for reciprocating compressors, surge vibration of long transfer piping, and seismic/wind vibration, respectively. In this study, for the spray injection case inside the pipe, forcing function was modeled, in which two different fluids are distributed uniformly. To confirm the results, the scheme used for the forcing function was applied for real piping system. The vibration mode of the real system was consistent with the 4th mode obtained by simulation using the forcing function formulated in this study.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.838-843
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• 1998

Risk importance measures are widely wed to rank risk contributors in risk-based applications. Typically, Fussell-Vesely (F-V) importance and risk achievement worth (RAW) are used in the component importance raking for the reliability centered maintenance (RCM) analysis of safety system in nuclear power plants (NPPs). This study was performed as part of feasibility study on RCM for domestic NPPs, which is focused on the component importance ranking approach the maintenance recommendation. The approach of modulizing faulting tree basic events was applied in the simplification process of the PSA model and the validity of the approach was evaluated As a result of the case study, this paper included the importance and the maintenance recommendations for the safety-related equipments associated with safety injection and containment spray in large loss of coolant accident sequences.

• Journal of Biosystems Engineering
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• 제31권3호
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• pp.182-187
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• 2006

Aerial application using an unmanned agricultural helicopter can reduce labor and pollution. The development of an agricultural helicopter became urgent for both precise and timely spraying. In this study, a rotor system for unmanned helicopter capable of 20 $kg_f$ payload, was developed and lift capability was evaluated. A lift force over the dead weight of the helicopter was obtained at the pitch angle of $6^{\circ}$. As the pitch angle increased to $8^{\circ}\;and\;10^{\circ}$, the total lift increased to $74{\sim}81\;kg_f\;and\;86{\sim}93\;kg_f$, respectively. A range of engine speed at the rated flight condition, lifting mean payload of 23 $kg_f$ was determined. The data acquired from this study will be used for designing tail system and RF console in the next stage of the research. The rated lift capability was enough for loading 20 liters of spray material including spraying equipments.

• 한방재활의학과학회지
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• 제20권4호
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• pp.73-81
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• 2010

Objectives : The purpose of this study is to establish literatural evidence about thermotherapy and cryotherapy for Korean medicine through literatural review. Methods : Applicable paragraphs which were related to the thermotherapy and cryotherapy of cutaneous and muscle meridian were phrased from in "Yibujicheng(醫部集成) and "Dongyibaojian(東醫寶鑑)" where were archiving of Oriental or Korean medicine literatures. Searched paragraphs were analysed for establishing historical and theoretical bases of thermotherapy and cryotherapy in Korean medicine. Results : Thermotherapy of cutaneous and muscle meridian(經皮經筋溫熱療法) such as hot pack, warm water therapy, paraffin bath, ultrasound is originated from yu(慰) warm water(溫水) hot water(熱水). Matching indications are various pain conditions(caused by coldness(寒), hard-work(僗若), extravasated blood(瘀血), inflammatory skin disease, frostbite and several internal diseases. It also treats gynecological diseases and facial palsy. Diathermic therapy on acupuncture points(穴位照射溫熱療法) such as infra-red, microwave, shortwave is originated from huolu(火爐), wenlu(溫爐), xianglu(香爐), lamp light(燈火). Its objective is to improve the effects of herb medicine by aiding sweating or to treat the residual symptoms of fever disease or to care skin disease and pain from bone fracture, contusion. Cryotherapy of cutaneous and muscle meridian(經皮經筋溫寒冷療法) such as ice pack, ice spray, iced whirpool, cool water bath is originated from lengfu(冷敷), lengtie(冷貼), lengshiyu(冷石熨). Matching indications are contusions, animal bite injury, corn(肉刺) and (淋病), eye disease, nasal bleeding, hemorrhoid, inflammatory skin disease and chicken pox. Conclusions : Thermotherapy and cryotherapy of cutaneous and muscle meridian(經皮經筋溫冷療法) are the treatments which were used in Korean medicine from the ancient Korean medicine. As scientific equipments were originated from yu(慰), huolu(火爐), wenlu(溫爐), xianglu(香爐), lamp light(燈火). lengfu(冷敷), lengtie(冷貼), lengshiyu(冷石熨). It can be said that these are elements of Korean medicine. More rigorous studies are needed to establish clinical evidence about not only thermotherapy and cryotherapy but also the other physiotherapy of Korean medicine.

• 청정기술
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• 제3권2호
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• pp.36-46
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• 1997

CFC 및 유기염소계 용제는 정밀기기 및 전자산업에서 세정제로 여러 가지 우수한 성질이 있어 오랫동안 사용하여 왔지만 오존층을 파괴하는 물질로 규명되어 대체 세정제로의 사용이 불가피한 실정이다. 대체 세정제로서는 여러 종류가 있지만 수계/준수계 세정제가 환경친화적이라 장기적으로 가장 바람직하여 이의 사용과 개발이 선진국을 중심으로 점차 증가일로에 있다. 그러나 이에 대한 국내의 이용 및 연구는 빈약하다. 본 연구에서는 수계세정제중 알칼리성, 중성, 산성, 비휑금형과 이의 주요구성성분, 그리고 준수계세정제중 테르펜계 및 glycol ether계를 분석하였다. 또한 수계/준수계세정제를 사용함으로써 이용가능한 여러 세정장치를 비교평가하였고 산업체에서 세정시스템의 선정시 중요 고려사항을 분석제안하였다.

• Journal of Pharmaceutical Investigation
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• 제22권3호
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• pp.205-210
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• 1992

In order to develop a controlled-release oral drug delivery system (DDS) of theophylline (TP), microporous membrane-coated tablets were prepared and evaluated in vitro and in vivo. Rapidly water-soluble core tablets of TP (300 mg) were prepared by wet granulation and compression technique, Then the core tablets were spray-coated with polyvinylchloride (PVC) in which micronized sucrose particles were dispersed. Effect of formula compositions of coating suspensions on the pharmaceutical characteristics such as membrane strength and dissolution was investigated in vitro. The membranes remained unbroken in pH 1.2 buffer at $37^{\circ}C$ at least for 2 hours after the disintergration test. TP was released from the coated-released tablets at a zero-order rate over 8 hours. The release at pH 1.2 and 4.0 was similar in rate but a little more rapid than that at pH 6.8. The coated tablets were administered to three healthy male volunteers and their saliva profiles of TP were compared with those from the commercial sustained release TP tablets such as Slobid and Asconthin. Saliva TP concentrations from the coated tablets were successfully sustained over 48 hours after the dosing and were comparable to those of the commercial sustained-release tablets. The membrane-coating technique is very simple and does not need any sophisticated equipments. In this respect, the membrane-coated tablets may be superior to the commercial sustained-release tablets and this technique is worth adopting by the pharmaceutical industries.

• 농촌의학ㆍ지역보건
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• 제25권2호
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• pp.245-263
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• 2000

본 연구는 자기기입식 설문조사를 통해 농약살포를 대부분 담당하는 남성 농민들에 대하여, 농부증을 포함한 만성증상과 농약살포시의 이상증상경험, 이상증상 경험시 살포한 농약, 농약살포시의 안전수칙 준수, 보호구의 착용실태, 가족 중 농약으로 인한 사고경험을 조사하고, 농약노출과 연관된 변수들간의 연관성, 급성중독경험 및 만성증상과 관련된 요인을 고찰하였다. 만성증상으로는 '몸이 나른하고 힘이 없다', '허리가 아프다'. '밤중에 소변을 보기 위해 깬다' 등의 증상이 많았으며, 농약살포 시의 임상증상 경험율은 '피부발진/가려움증', '어지러움/두통'의 경우가 가장 높은 것으로 조사되었다. 또한, 조사 대상자의 7.1%가 가족중 농약으로 인한 사고경험이 있는 것으로 조사되었으며, 이중 농약살포시 중독, 안전사고 및 자살사례를 확인할 수 있었다. 농약살포 시의 준수사항 중, '뿌린 후 목욕을 한다'와 '뿌린 후 바로 옷을 갈아입는다' 등의 경우가 준수율이 높았으나, '보호구를 잘 세탁해서 보관한다', '뿌린 후 용변을 볼 경우 손을 씻는다', '한낮에는 뿌리지 않는다' 등의 경우는 낮은 준수율을 보였다. 농약살포시 보호구는 '물에 타서 살포할 경우', '입제를 살포할 경우'에 비해 보호구를 더 잘 착용하였으며, 착용율은 모자, 장화, 마스크, 장갑, 방제복 하의의 순이었다. 농약살포시 이상증상경험과 관련된 요인은 농약살포시 준수사항 준수, 살포시간, 과수재배, 경작면적, 연간 농약살포일 등이었으며, 농민의 만성증상과 관련된 관련된 요인은 농약살포시 이상증상 경험, 경작면적, 농사경력, 농약살포시 준수사항 준수, 전업여부, 농약에 대한 노출 등이었다. 본 연구결과를 통해 농약살포시 준수사항의 준수율과 보호구 착용율을 높이며 농약으로 인한 안전사고를 방지하기 위한 체제적인 교육 및 홍보가 필요함을 알 수 있다. 또한, 농약에 대한 노출이 농민의 만성증상의 한 원인이라는 결론을 내리기는 어려우나, 원인적 연관성일 가능성을 배재할 수는 없을 것으로 생각되며, 따라서, 농약노출을 정확히 산출하고, 좀더 명확한 건강영향의 생물학적 지표(biological marker)를 측정하여 이들의 연관성을 고찰하는 연구가 이루어져야 할 것으로 생각된다.

• 한국화재소방학회논문지
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• 제28권4호
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• pp.1-7
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• 2014

자동차의 엔진룸의 내부를 살펴보면 여러 가지의 장치 및 장비가 복잡하게 설치되어 있고 각종 오일 등의 인화물질을 포함하고 있어 재발화 가능성이 매우 높다. 또한, 폭발가능성도 높기 때문에 운전자나 탑승자가 보닛을 열고 엔진룸에 직접 분말 소화기를 분사하는 방식으로는 한계가 있다. 따라서 엔진룸 내부에서 화재를 감지하여 소화약제를 분사한 뒤, 화재를 진화하는 소화시스템과 엔진룸 내부의 고열에 견딜 수 있고, HFC-227ea를 포함하는 충분한 점성을 가진 폼 형태의 소화약제를 개발 및 시험하였다. 그리고 포소화약제가 가지고 있는 소화원리인 질식 및 냉각효과와 HFC-227ea가 가진 부촉매효과를 동시에 이끌어 내고, 소화 후에도 분말 소화기처럼 잔존물에 의한 2차 피해가 없는 맞춤형 소화약제를 개발하였으며, 차량을 이용한 충돌실험을 통하여 방출이 완료된 후에도 이물질 없이 소화약제를 제거할 수 있는 장점이 존재하는 실험결과를 획득하였다.