• 한국화재소방학회논문지
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• 제31권3호
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• pp.63-72
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• 2017

본 논문에서는 저압용 10회로 분전반을 전기공업협동조합(KEMC) 2102-610 규정에 근거하여 제작하였다. 또한, 개발된 10회로 분전반의 특성 평가를 실시하여 안전성을 확보하고자 한다. 개발된 10회로 분전반은 내식성, 절연 재료의 특성, 자외선 복사의 내성, 기계적 충격 등에 적합하도록 설계되었다. 개발된 분전반은 외함의 보호 등급, 감전방지와 보호회로, 개폐 장치와 구성품, 내부 전기 회로와 연결부, 외부 도체의 단자, 절연 특성, 온도 상승 시험, 열저항 등이 적합하도록 제작하였다. 개발된 10회로 분전반은 단상 회로와 3상 회로 등으로 구분되어 있다. 분기된 각각의 차단기 부하측에 센서 모듈을 설치하여 부하의 전선로에서 발생되는 누설전류의 크기를 실시간 측정할 수 있다. 그리고 부하의 용도 및 목적 등에 따라 회로를 증설할 수 있고, 각각의 부하 상태 역시 실시간 부하 관리 및 점검이 가능하다. 개발된 10회로 분전반의 온도 상승 시험을 실시한 곳은 인입 접속부, 주회로 및 분기회로 모선, 모선지지물 등 18 개소이다. 온도가 가장 높게 측정된 곳은 분기회로 모선용 MCCB 전원측 접속부의 R-phase으로 $65.3^{\circ}C$, 부하측은 T-phase으로 $61.6^{\circ}C$로 기록되었다. 그리고 내열 실험 장치를 이용하여 MCCB를 $180^{\circ}C$에서 6시간 동안 열적 스트레스를 인가하였을 때 작동 손잡이의 변형이 확인되었고, 트립 상태로 이동한 것이 확인되었다.

• 환경영향평가
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• 제27권6호
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• pp.647-657
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• 2018

본 연구는 국가의 하천환경관리차원에서 정립되고 있는 한국형 하천환경 평가체계의 하천환경 자연도와 하천 친수도에 대해 하천정비 및 관리계획의 지구지정 기준으로서의 적용가능성을 검토하고자 수행하였다. 관련 법제도적 기준과 지침을 검토한 결과 보전지구 지정기준인 역사문화적 가치는 친수지구와의 연계성의 검토할 필요가 있는 것으로 판단되었다. 또한 본 연구에서는 자연환경적 특성을 반영한 하천 환경 자연도의 기준의 1단계 보전과 복원지구의 구분에 이어 인문사회적 특성을 반영한 하천 친수도를 적용하여 친수지구를 구분하는 순차적인 평가방식을 제안하였다. 시험하천인 갑천과 유등천에 적용한 결과 현재 상태의 하천환경특성을 적절하게 반영하고 있는 것으로 판단되었다. 특히 기존의 지구구분 자료가 좌안과 우안의 차이를 반영하지 못한 점이나 과도한 친수지구의 지정 등의 문제에 대해 본 연구결과는 보다 분명한 기준을 제공한 것으로 판단되었다. 한편 본 연구에서 제시한 지구지정의 기준은 하천의 물리적 특성을 기준으로 한 평가단위의 설정과 함께 다양한 하천환경의 특성을 반영한 것으로서 또 다른 법적 규제나 지역의 여건 등은 행정적 절차에서 조정, 보완되어야 할 것으로 판단되었다.

• Journal of Welding and Joining
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• 제30권1호
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• pp.64-71
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• 2012

The characteristics of high heat input (342kJ/cm) EG (Electro Gas Arc) welded joint of EH36-TM steel has been investigated. The weld metal microstructure consisted of fine acicular ferrite (AF), a little volume of polygonal ferrite (PF) and grain boundary ferrite (GBF). Charpy impact test results of the weld metal and heat affected zone (HAZ) met the requirement of classification rule (Min. 34J at $-20^{\circ}C$). In order to evaluate the relationship between the impact toughness property and the grain size of HAZ, the austenite grain size of HAZ was measured. The prior austenite grain size in Fusion line (F.L+0.1 mm) was about $350{\mu}m$. The grain size in F.L+1.5 mm was measured to be less than $30{\mu}m$ and this region was identified as being included in FGHAZ(Fine Grain HAZ). It is seen that as the austenite grain size decreases, the size of GBF, FSP (Ferrite Side Plate) become smaller and the impact toughness of HAZ increases. Therefore, the CGHAZ was considered to be area up to 1.3mm away from the fusion line. Results of TEM replica analysis for a welded joint implied that very small size ($0.8\sim1.2{\mu}m$) oxygen inclusions played a role of forming fine acicular ferrite in the weld metal. A large amount of (Ti, Mn, Al)xOy oxygen inclusions dispersed, and oxides density was measured to be 4,600-5,300 (ea/mm2). During the welding thermal cycle, the area near a fusion line was reheated to temperature exceeding $1400^{\circ}C$. However, the nitrides and carbides were not completely dissolved near the fusion line because of rapid heating and cooling rate. Instead, they might grow during the cooling process. TiC precipitates of about 50 ~ 100nm size dispersed near the fusion line.

• 한국지반공학회논문집
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• 제17권6호
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• pp.111-121
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• 2001

낙석방지울타리는 도로절개면 상부에서 발생한 낙석의 도로 유입을 차단하기 위하여 설치되는 구조물로 국내 국도 절개면 중 70%이상 시공되어 있다. 이와 같이 도로 절개면의 재해예방을 위하여 범용적으로 사용되는 시설물로서 그 중요성이 매우 강조될 수 있으나 국내의 경우 아직까지 설계 및 시공에 대한 기준이 미흡하고 절개면의 높이, 경사도 등 특성을 고려하지 않은 단일 표준단면도에 의해 설계, 시공되어 이의 효율성에 한계가 있는 것이 사실이다. 따라서, 본 연구에서는 현장실험을 통해 낙석방지울타리의 흡수가능에너지를 파악하였다. 실험을 위하여 높이 20m, 경사 65도의 절개면을 선정하여 4개 규모의 콘크리트 볼(0.7, 1.3, 2.3, 4.3 톤)을 절개면 상부로부터 낙하시켜 낙석방지 울타리의 성능을 평가하였다. 본 논문은 시공완료된 절개면을 대상으로 현장실물실험을 통해 낙석운동에너지, 암반의 반발계수, 낙석방지울타리의 흡수에너지 등을 산정하여 절개면 특성별 낙석방지울타리의 설계에 필요한 기초 자료를 제공하고자 하였다. 현장실험을 통해 획득한 낙석방지울타리의 흡수가능에너지는 약 50kJ로 이는 약 0.4톤의 낙석이 10m의 높이에서 낙하할 때 발생하는 에너지와 동일하다.

• 대한조선학회논문집
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• 제49권1호
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• pp.79-86
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• 2012

It is very important to investigate and understand the motion of a FPSO on waves because green water phenomenon occurs owing to the relative motions between incident waves and a ship on them. In this research, both experimental and some numerical approaches have been performed in head sea conditions with regular waves. As an object model of this research, a FPSO model is set free to heave and pitch during the experiments. Also, the motions of the FPSO model which are the results of the experiments are used for the corresponding numerical computations. The purpose of this study is to clarify the effect of bow flare on green water load. In this research, it is found that the amount of green water entered from the side of bow is decreased by the increase of bow flare angle. Moreover, the relation between the green water on the bow upper deck and the impact load on the vertical wall located at turrethead is investigated. The results of this research could be used as one of the fundamental data to design bow flares. Also, an optimized bow flare angle is proposed in this study.

• Journal of Korean Dental Science
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• 제11권1호
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• pp.14-20
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• 2018

Purpose: The purpose of this study is to measure and compare the removal torques of different cements applied in attachments of zirconia restorations on titanium (Ti) abutments fitted with retrievable cement-type slot (RCS) on the lingual side for the better retrievablity by use of a slot driver. Materials and Methods: Three types of cements were used in the experiment: two permanent cements in $RelyX^{TM}$ U200 (RU) (3M ESPE) which is a resin cement and $FujiCem^{TM}$ (FC) (GC) which is a resin-modified glass ionomer cement, and a temporary cement in $Freegenol^{TM}$ temporary cement (TC) (GC). Measurements of removal torques were conducted as follows; an attached sample was fixed on the equipment customized for the experiment; a slot driver was connected to a MGT12 (Mark-10 Corp.), a torque measurement instrument; the sample had the driver fitted to its RCS and then was rotated until the it was removed; and finally, the maximum torque value was recorded. Result: As for the removal torque measurement results, the average values were $47.9{\pm}2.6Ncm$ for RU, $43.4{\pm}1.5Ncm$ for FC, and $20.9{\pm}1.0Ncm$ for TC. The statistical analysis using Kruskal-Wallis test yielded the significance probability of P<0.05 (P=0.002), which confirmed the presence of significant differences between the three groups. Conclusion: All three cements exhibit clinically acceptable levels of removal torque when applied to an upper zirconia implant restoration fitted with a lingual slot, with RU and FC, the two permanent cements, having the significantly higher values than that of TC, the temporary cement.

• 대한통합의학회지
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• 제1권1호
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• pp.61-68
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• 2013

Purpose : The purpose of this study is to evaluate the stability and balance of the body, mobility complex exercise group and a student group for FMS tests to compare the differences between the two groups to identify its purpose. Method : The subjects of this study FMS measuring D University Physical Therapy, a student enrolled patients (7:7), and 7 patients total of 14 patients was conducted, compound exercise group weekly stretching 10 minutes, the 24 members who have run a complex exercise, 10 minutes of cool down stretching, 20-minute aerobic exercise were included in the study. Result : The results of this study, according to 1) Deep squat, Inline lunge, Trunk Stability Push-up there was significant difference(p<0.05), compound exercise group came out significantly higher. 2) Hurdle Step, Shoulder Mobility Reaching, Active Straight-leg Raise, Rotary stability in measured target these women flexibility because the test items that did not show a significant difference(p>0.05), the two groups averaged compared to the other items were higher. Complex exercise group, a statistically significant difference was overall average. Conclusion : FMS can not be resolved because of a compensatory mechanism to identify disparities and unbalanced movement patterns can help. Therefore, if the FMS and other tests conducted by splicing, will be utilized more profitably, and you will be able to suggest ways that can have a positive impact injury prevention is added to the side to expand the scope of the physical therapist.

• 한국임상약학회지
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• 제10권3호
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• pp.107-110
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• 2000

Theophylline and $\beta$-adrenergic agonists are frequently used together in patients with respiratory diseases. However the clinical impact of $\beta_2$-adrenergic agonists on the blood concentration of theophylline is not fully evaluated. Formoterol, a newly available oral ${\beta}_2$-adrenergic agonist is frequently used in pediatric respiratory patients. The objective of this study was to investigate the effect of oral formoterol on theophylline's blood concentration. Randomized prospective study was conducted. Twenty-four children were enrolled on the study. Their age ranged 2 to 73 months (mean 35.8 months). Theophylline group (12 patients) received 10 mg/kg/day of for theophylline orally. Theophylline/formoterol group (12 patients) received 10 mg/kg/day of theophylline and $4\;{\mu}g/kg/day$ of formoterol orally. All medications were administered at least for 5 days starting on admission day. Theophylline's trough concentrations were obtained on days 3 and day 5. Pulse rates were recorded before the study medications were given on admission, and days 3 and day 5. Statistical significance was calculated by two-tailed Student's t-test. Theophylline's levels in children given theophylline and formoterol together were lower an those given theophylline alone ($6.38\pm0.90\;{\mu}g/ml\;vs\;7.43\pm0.77\;{\mu}g/ml$ on day 3(p<0.05), $5.62\pm0.56\;{\mu}g/ml\;vs.\;6.78\pm0.61\;{\mu}g/ml$ on day 5 (p<0.05)). In both groups, theophylline's trough concentration on day 5 were lower than day 3. There was no significant side effects in both groups. In conclusion, the new ${\beta}_2$ selective adrenergic agonist formoterol reduced serum theophylline levels in children with respiratory diseases. Further investigation is needed to clarify the long term effect of this drug interaction.

• 한국세라믹학회지
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• 제35권2호
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• pp.172-179
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• 1998

Valve lifter namely tappet is supported by lifter hole which is located upper side of camshaft in cylinder block transforms rotatic mvement of camshaft into linear movement and helps to open and shut the en-gine valve as an engine parts. The face of valve lifter which is continuously contacting with camshaft brings about abnormal wears such as unfair wear and early wear because it is severely loaded in the valve train system. These wears act as a defect like over-clearance and cause imperfect combustion of fuel during the valve lifting in the combustion chamber. Consequently this imperfect combustion makes the engine out-put decrease and has cause on air pollution. To prevent these wears therefore The valve lifter cast in me-tal developed into SiC ceramics valve lifter which has an excellence in wear and impact resistance As a results the optimum process conditions like injection condition mixture ratio and debonding process could be established. After sintering fine-sinered dual microstructure in which prior ${\alpha}$-SiC matches well with new SiC(${\beta}$-SiC) produced by reaction among the ${\alpha}$-SiC carbon and silicon was obtained. Based on the study it is verified that mechanical properties of SiC valve lifter are excellent in Vickers hardness 1100-1200 bending strength (300-350 Pa) fracture toughness(1.5-1.7 Mpa$.$m1/2) Through engine dynamo test-ing SiC valve lifter and metal valve lifter are examined and compared into abnormal phenomena such as early fracture unfair and early wear. It is hoped that this research will serve as an important springboard for the future study of heavy duty diesel engine parts developed by ceramics which has a good wear resis-tance relaibility and lightability.

• 성인간호학회지
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• 제12권4호
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• pp.497-506
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• 2000

The purpose of this phenomenological study was to explore and describe the experience of people with HIV/AIDS. Three men and three women with HIV/AIDS participated in the study. They were asked open-ended and descriptive questions in order for them to talk about their experience in their own terms. Interviews were audiotaped and transcribed to maintain data integrity and to reduce perceptual bias. The transcripts were analyzed by the Colaizzi method. Member checks from the participants were used to validate the emergent themes. Seven themes emerged from the analysis. 1. People with HIV/AIDS have a strong impact and emotional reaction when receiving positive HIV test results. 2. All people with HIV/AIDS attempt to conceal HIV infection because of fear of stigma or rejection. 3. After the initial brief traumatic reaction to HIV/AIDS diagnosis, all participants feel lonely because they had no one to express or share their own experiences. 4. People with HIV/AIDS reflect on their life, think about the death and dying process and they become depressed. 5. Most participants feel that the family members who know his/her diagnosis are a big source of support. 6. According to the normativeness of infection route of HIV, the degree of guilty feeling differs among participants. 7. Although all participants think medication is a lifeline, the adherence to medication is not maintained because of side effects, denial and concealment of HIV/AIDS. The results of this study may help nurses and other health care workers to implement more efficient nursing strategies for people with HIV/AIDS by more deeply understanding their experience.