• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.66-71
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• 2011

This study focused on the application of the Passive Solar Chamber System (PSCS) as proposed by a previous study. The seasonal performance and sizing method for the system were investigated for a feasibility of the PSCS in Korean climate. For seasonal performance, heat and ventilation performances of the PSCS were analyzed for the months of January and August. This study proposed a simple configuration method in which the designer can decide on the system size at the preliminary design stage by using system efficiency, overall heat transfer coefficient transmission, monthly solar radiation, highest and lowest temperatures. During weeks that require heating, the system showed to acquire a daily average heat amount of $860.28Wh/m^2$ day. For cooling periods, the system was computed to supply a daily average natural ventilation of $1,360.2m^3/day$ to the room. Moreover, proposed sizing method and the overall computation results showed a 6.04~7.24% error of assessment.

• 방사성폐기물학회지
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• 제3권3호
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• pp.183-192
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• 2005

자연환기는 처분장의 작업 환경 및 위생, 부유 방사성 핵종의 노출 등과 같은 안전문제에 있어 자연환기 자체만으로는 기계적 강제 환기에 비해서 덜 효과적이지만 처분장 내의 수분제거, 작업 환경 조성과 관련하여 라돈 (Rn) 가스의 희석과 같은 향후 처분장의 장기적 환경을 위해서는 중요한 역할을 할 수 있고, 환풍기와 같은 환기 설비를 이용해야하는 기계환기에 비해 경제적으로 매우 효과적 일수 있다. 본 논문에서는 지하 처분장의 건설 및 운영 기간동안 자연환경 조건에 따라 처분장에 스스로 생기는 자연 환기의 타당성에 대하여 기술하였다. 자연 동굴을 통한 자연환기 유사에 의해 밝혀진 증거들과, 수직갱을 갖는 산악 도로터널에서의 자연 환기 측정, 그리고 주어진 자연환기 압력에 의한 공기 발생량 계산 등을 통해서 자연 환기는 한국형 지하 방사성 폐기물 처분장에 잠재적으로 매우 유익함을 알 수 있다. 효과적으로 유도된 자연 환기는 방사성 폐기물 처분장 내에 발생하는 열과 습도, 그리고 라돈 가스를 제어하기에 경제적으로 좋은 방법이 될 수 있다. 자연환기를 통해 처분장의 전반적 열적 특성은 개선될 수 있고, 수분으로 포화된 공기는 효과적으로 건조되고 그 건조상태 유지 기간은 확장 될 수 있을 것이다.

• Journal of Chest Surgery
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• 제25권12호
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• pp.1542-1549
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• 1992

From March 1986 to August 1992, 18 patients underwent diaphragmatic plication for the diaphragmatic paralyses complicating various pediatric cardiac procedures. Age at operation ranged from 16 day to 84 months with mean age of 11.8 months. In order of decreasing incidence, the primary cardiac procedures included modified Blalock-Taussig shunt [ 5 ], Arterial switch operation [ 4 ], modified Fontan operation [ 2 ], and others [ 7 ]. The suspicious causes of phrenic nerve injury included overzealous pericardial resection [ 7 ], direct trauma during the procedure [ 6 ], dissection of fibrous adhesion around the phrenic nerve [ 3 ] and unknown etiology [ 2 ]. The involved sides of diaphragm were right in 10, left in 7 and bilateral in one. The diagnosis was suspected by the elevation of hem-idiaphragm on chest x-ray and confirmed by fluoroscopy. The interval between primary operation and plication ranged from the day of operation to 38 postoperative days [mean : 14 days]. The method of plication were "Central pleating technique" described by Schwartz in 16 and other techniques in 2. Five patients expired after plication and the cause of death were not thought to be correlated directly with the plication itself. In the remaining 13 survivors, extubation or cessation of positive ventilation could be done between the periods of the day of plication and 14th postoperative days [mean; 3.8day]. We have made the following conclusions : 1] Phrenic nerve paralyses are relatively common complication after pediatric cardiac procedures and the causes of phrenic nerve injury are mostly preventable; 2] Phrenic nerve palsy is associated with corisiderable morbidity; 3] diaphragmatic plication is safe, reliable and can be applicable in patients who are younger age and require prolonged positive pressure ventilation.ntilation.

• 한국농공학회논문집
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• 제62권5호
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• pp.27-37
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• 2020

As domestic meat consumption increases, the broiler production industry has been larger and denser. The concentration of particulate matter (PM) and harmful gases generated is also increasing inside livestock house. However, the current research status of PM exposed to farm workers and the health effects are in the early stage. To understand PM concentration affecting workers in the broiler house, field monitoring was conducted according to its size distributions. Concentrations of PM₁₀, PM_2.5, and TD (Total Dust) were monitored using personal air samplers with teflon filter during working and moving periods considering the ventilation systems of 6 broiler houses. The purpose of this study is to monitor the PM concentration in the experimental broiler houses operated by forced ventilation system generally used in Korea and to evaluate the regional concentrations through airflow pattern. The PM concentrations were increased from inlet to outlet vents resulting in 1,872 of TD, 1,385 of PM₁₀, and 209 ㎍/㎥ of PM_2.5, respectively. The TD and PM₁₀ concentrations were increased when the workers and broilers were moving. Among them, the particle size that occupied the largest amount of PM was 13.75 ㎛. These results suggest that personal protection equipments are important to reduce the health effect from PM inhalation.

• 한국작물학회지
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• 제32권2호
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• pp.130-136
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• 1987

공시품종인 Burley 21을 수확한 후 건조하고 무더운 시기에 처리하여 건조하우스의 환기시기, 환기량 및 달줄간격 등의 건조실관리에 따른 급건조방지 방법을 밝히고자 시험한 결과 요약하면 다음과 같다. 1. 건기에는 건조시 시종환기구에서 온도가 낮았고 급건엽발생도 제일 적었다. 2. 급건엽발생시기는 황변말부터 갈변말까지로 이 시기에 탈수를 지연시키는 것이 가장 중요하다. 3. 급건엽발생이 적을수록 품질 및 물리성이 양호하였다. 4. 측면을 1.5m로 충분히 환기시킨 구에서 급건엽발생이 가장 적었다. 5. 달줄간격을 좁힐수록 온도에는 크게 영향을 미치지 않았으나 온도는 높게 유지하여 급건엽발생을 크게 감소시켰다. 6. 급건엽의 내용성분은 충분히 분해가 일어나지 않았다.

• Tuberculosis and Respiratory Diseases
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• 제83권4호
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• pp.303-311
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• 2020

Background: If the duration of mechanical ventilation (MV) is related with the intensive care unit (ICU) readmission must be clarified. The purpose of this study was to elucidate if prolonged MV duration increases ICU readmission rate. Methods: The present observational cohort study analyzed national healthcare claims data from 2006 to 2015. Critically ill patients who received MV in the ICU were classified into five groups according to the MV duration: MV for <7 days, 7-13 days, 14-20 days, 21-27 days, and ≥28 days. The rate and risk of the ICU readmission were estimated according to the MV duration using the unadjusted and adjusted analyses. Results: We found that 12,929 patients had at least one episode of MV in the ICU. There was a significant linear relationship between the MV duration and the ICU readmission (R²=0.85, p=0.025). The total readmission rate was significantly higher as the MV duration is prolonged (MV for <7 days, 13.9%; for 7-13 days, 16.7%; for 14-20 days, 19.4%; for 21-27 days, 20.4%; for ≥28 days, 35.7%; p<0.001). The analyses adjusted by covariables and weighted with the multinomial propensity scores showed similar results. In the adjusted regression analysis with a Cox proportional hazards model, the MV duration was significantly related to the ICU readmission (hazard ratio, 1.058 [95% confidence interval, 1.047-1.069], p<0.001). Conclusion: The rate of readmission to the ICU was significantly higher in patients who received longer durations of the MV in the ICU. In the clinical setting, closer observation of patients discharged from the ICU after prolonged periods of MV is required.

• 한국식품영양학회지
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• 제27권1호
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• pp.128-135
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• 2014

The purpose of this study is to analyze the gap in perceived importance-satisfaction rates of foreign Chinese students regarding the university foodservice selection attributes. All statistical analyses are conducted by the SPSS package program (ver 20.0). The results of the statistical analyses are as follows: The validity of the 22 food service selection attributes is being evaluated via the exploratory factor analysis and then five factors are extracted. The five factors are: 'Factor 1. Cleanness and service quality', 'Factor 2. Food quality and price', 'Factor 3. Physical environment', 'Factor 4. Convenience', and 'Factor 5. Service environment'. According to the results of one-way ANOVA, physical environment showed that significant differences across the periods of residence in Korea and the eating frequency at on campus foodservices. On the other hand, the food quality and price, convenience, and service environment showed that significant differences across the periods of residence in Korea. In addition, according to the Importance-Satisfaction Analysis results, 'ventilation of dining room' is the key aspect that university food service managers should reinforce. In conclusion, in order to increase the customer satisfaction rates, the food service managers should not only improve the quality of food and service but also the physical environments of the food service facility.

• 생물환경조절학회지
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• 제6권3호
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• pp.133-142
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• 1997

본 연구는 권취식 창개폐기의 설계 및 개발에 필요한 자료를 제시하고자 수행되었다. 기존의 단순 이론모델식으로는 정확한 권취토크를 예측할 수 없기 전문에 모형시험과 현장시험을 통하여 새로운 권취식 창개폐장치의 소요토크 모델식을 개발하였다. 본 연구에서의 결과를 요약하면 다음과 같다. 1. 권취식 창개폐장치에 있어서 권취토크는 곡부 권취면의 경사각을 따라 증가하는 경향을 나타내고 있으며, 경사각이 90$^{\circ}$인 수직면에서 최대를 나타냈고 수편면에서 최소값을 나타냈다. 2. 온실의 길이에 따른 소요토크는 권취하중의 증가와 축파이프의 변형의 영향으로 지수함수적으로 늘어나는 경향을 나타냈다. 3. 권취식 창개폐장치의 소요토크 계산의 이론식은 T ＝ W.(r＋a).sin$\theta$＋W.Cr.cos$\theta$로 나타낼 수 있으며, 여기서 축파이프의 권취반경 r과 축변형보정계수 $\alpha$를 더한 (r＋$\alpha$)는 축파이프의 최대변형값인 $\delta$에 지수함수적으로 비례하는 경향이 나타났다. 4. 권취반경 r과 축변형보정계수 $\alpha$의 합인 (r＋$\alpha$)은 22.2mm 파이프에 0.1mm 비닐로 피복을 했을 때 (r＋$\alpha$)＝2.10338$\times$$10^{0.00779{\delta}}$ 로 구할 수 있으며, 25.4mm 파이프에서는 (r＋a)＝2.58063$\times$$10^{(0.00452{\delta})}$로 구할 수 있다. 5. 권취식 창개폐장치의 소요토크에서 천창 등 곡부의 개폐시 고려되어야 할 굴름저항 보정계수는 피복재의 상태에 따라 다소 다를 수 있으나 0.7~0.8 정도의 값을 적용시키면 될 것으로 판단되었다. 6. 실제 권취식 창개폐를 사용하는 온실에서 권취축 파이프의 허용 변형정도를 최대 40cm 이하로 하는 것이 타당할 것으로 판단되며, 이때의 예상소요토크는 110m 온실인 경우 25.4mm 파이프를 축파이프로 사용한 경우 344kg.cm이며, 22.2mm 파이프의 경우 287kg.cm 정도이므로 새롭게 개발된 차동링기어 유성치 차감속기도 적당할 것으로 판단된다.

• Journal of Chest Surgery
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• 제18권2호
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• pp.345-351
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• 1985

Tracheal stenosis is due to tracheostomy or prolonged intubation. Development of tracheal stenosis following tracheostomy is very serious complication. In recent practice, tracheostomy has became more popular because of increased occasions of major and minor traumas. At the Dept. of thoracic surgery, Chonbuk national university hospital, we have experienced one case of tracheal stenosis following tracheostomy for assisted ventilation. Chest X-ray revealed the narrowing of trachea at cervicothoracic junction due to previous tracheostomy. We resected the narrow segment & tracheal reconstruction was performed with an excellent result in postoperative periods. Postoperative air tracheogram did not reveal demonstrable narrowing of air filled trachea.

• Journal of Chest Surgery
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• 제15권1호
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• pp.73-76
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• 1982

For the treatment of acute respiratory failure and emergency care of an urgent patient, tracheostomy in itself may have been a life saving procedure. But, among the variable complications following tracheostomy, the tracheal stenosis gives serious clinical manifestation which can only be corrected by surgical intervention in many occasions. At the Dept. of thoracic surgery, CAFGH, we have experienced one case of tracheal stenosis following tracheostomy for assisted ventilation. Tracheogram showed a 2.5 cm segmental narrowing 5 cm below the tracheostoma. Before recon-struction, we tried to dilate the stenotic segment for about 2 months, but the result was not satisfactory to relieve dyspnea. So, we resected the narrowed segment and tracheal reconstruction was performed with an excellent result in postoperative periods till now.