• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.33-40
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• 2020

Chiller systems which have better temperature stability than Direction expansion coils are often used as condensing units in HVAC systems for offshore plants. Large capacity compressors and electronic expansion valves in chiller systems are mostly imported, and the size of a chiller system depends on heat exchangers such as evaporators and condensers which are locally produced. Due to limited space in the offshore plants, shipyards are demanding manufacturers to make equipment compact. In this paper, a shell & tube heat exchanger, which is used as an evaporator in the conventional flooded chiller system, is replaced by a newly developed compact plate & shell heat exchanger. The main development process of the plate & shell heat exchanger is introduced, and its performances were experimentally evaluated with a real flooded chiller system, and the results are presented.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.887-895
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• 2019

Recently, the number of underground road development projects has been increasing to solve traffic problems in the national capital region and metropolitan areas with intensified overcrowding, and there has been a tendency to plan underground roads by applying a double-deck tunnel technology that has advantages in constructability and economical efficiency. The double-deck tunnel has a structure where one excavation section is divided into two parts and used as up and down lines, and is mainly used as a road for small vehicles only due to its low floor height. In addition, due to the small cross-sectional area, it has characteristics different from those of general road tunnels in terms of ventilation and disaster prevention. In this regard, this study proposed an operational plan that applies an oversized exhaust system, which is one of semi-transverse ventilation systems, to small cross-sectional tunnels like double-deck tunnel with low floor height, and a comparative analysis between smoke exhaust characteristics according to the fire occurrence locations and oversized exhaust systems was conducted using the Fire Dynamics Simulator (FDS). The results showed that unlike uniform exhaust, intensive smoke exhaust using the oversized exhaust port maximized the delay effect of smoke diffusion and limited the smoke within 50 m above and below the fire point.

• Journal of Life Science
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• v.13 no.4
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• pp.448-456
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• 2003

The purpose of this study was to determine changes in their cardiorespiratory function and body composition in female workers after aerobic exercise and circuit weight training. The subjects of this study were 16 female workers in B city and was divided into exercise and control groups which were composed of 8 people respectively. The members of exercise group had aerobic exercise and circuit weight training an hour a day, 5 days per week, for 8 weeks while controled group did not. Both groups were pretested and posttested, and the results of this study on cardiorespriatory function and body composition are as follows. Exercise group showed significant decrease in heart rate at rest(p<.001). Exercise group showed significant increase in the oxygen uptake at rest, in the maximum oxygen uptake and in the vital capacity(p<.001). Exercise group showed significant decrease in the %fat and fat(p<.001). Exercise group showed significant increase in the %LBM and LBM(p<.001).

• Journal of Life Science
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• v.20 no.3
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• pp.437-443
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• 2010

This study was designed to examine the aerobic capacity and ventilatory response during an incremental exercise in elite high school cyclists. Twelve boys ($17{\pm}1\;yr$, $175{\pm}5\;cm$, $70{\pm}9\;kg$) participated in anthropometric measurements, incremental exercise testing, and pulmonary function tests. During incremental exercise testing using a cycle ergometer, their maximal oxygen uptake ($VO_2max$), maximal power output, ventilation, ventilatory equivalents for oxygen ($V_E/VO_2$) and carbon dioxide ($V_E/VCO_2$), respiratory rate, and tidal volume were measured. Time variables such as inspiratory time (Ti), expiratory time (Te), breathing time (Tb), and inspiratory duty cycle (Ti/Tb), as well as inspiratory flow rate ($V_T$/Ti) were assessed. Pulmonary function of vital capacity (FVC), forced expiratory volume in one second ($FEV_1$), $FEV_1$/FVC, and peak expiratory flow were evaluated. Their $VO_2max$, maximal heart rate, and Wmax were $57.5{\pm}3.9\;ml{\cdot}kg^{-1}{\cdot}min^{-1}$, $194.1{\pm}8.6\;beat{\cdot}min^{-1}$, and 452 W, respectively. $VO_2max$ was not related to any anthropometric parameters. Most ventilatory variables progressively increased with exercise intensity. As intensity increased, Ti, Tb, Tb decreased while Ti/Tb was maintained. Below an intensity of 250 W, height, weight, body mass index, and body surface were highly correlated with $V_T$/Ti and Ti/Tb (p<0.05). Collectively, $VO_2max$ appeared to be lower than adult cyclists, suggesting a different pattern of ventilatory control as age advances. Morphological characteristics were not related to $VO_2max$ in the population. Time variables of ventilatory response seemed to be related only at an exercise intensity level of less than 250 W. $V_T$/Ti may be related to exercise endurance capacity, but Ti/Tb was similar to adult cyclists.

• Clinical and Experimental Pediatrics
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• v.52 no.12
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• pp.1392-1395
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• 2009

Pulmonary vascular air embolism is a rare and, universally, almost a fatal complication of positive pressure ventilation in newborn infants. Here, we report a case of this unusual complication in a very-low-birth-weight infant who showed the clinical and radiological features of this complication along with pulmonary hypoplasia and massive hydrops. The possible pathogenesis has been discussed and a brief review of related literature has been presented.

• Tuberculosis and Respiratory Diseases
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• v.66 no.1
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• pp.27-32
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• 2009

Background: The management of patients with lung cancer has improved recently, and many of them will require admission to the medical intensive care unit (MICU). The aim of this study was to examine the clinical characteristics and to identify risk factors for mortality in patients with lung cancer admitted to the MICU. Methods: We conducted retrospective analysis on 88 patients with lung cancer admitted to the MICU between April 2004 and March 2008. Results: Of the 88 patients (mean age, 66 years), 71 patients (80.7%) had non-small cell lung cancer and 17 patients (19.3%) had small cell lung cancer. Distant metastasis were present in 79 patients (89.8%). The main reasons for MICU admission were acute respiratory failure (77.3%), sepsis (11.4%), and central nervous system dysfunction (4.5%). Mechanical ventilation was used in 54 patients (61.4%). Acute Physiology and Chronic Health Evaluation (APACHE) II score, length of MICU stay, need for mechanical ventilation, source of MICU admission were correlated with MICU mortality. The type of lung cancer and metastasis were not predictive factors of death in MICU. Conclusion: Most common reason for ICU admission was acute respiratory failure. Mortality rate of lung cancer patients admitted to the MICU was 65.9%. APACHE II score, length of ICU stay, need for mechanical ventilation, source of MICU admission were predicted factors of death in the MICU.

• Food Science and Preservation
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• v.8 no.3
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• pp.286-290
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• 2001

Ginger was stored in the 0.05mm and 0.08mm of PE film bags and the styrofoam box. During the ginger storage, weight losses in the PE film bags were effectively supressed than in the control bag, and storage was better in the 0.08mm PE film bag while the spoilage of ginger was higher than in 0.05mm bag. The effective storage temperature was 10$^{\circ}C$ at which was no scouting during the storage. And the perforation in the PE film bag helped the healthy ginger ratio. Single perforation of 6an diameter was good for 0.05mm film and three for 0.08mm film. When CO$_2$absorbent was added into the film bag, the spoilage and mold occurence was lowered. In the styrofoam box, the healthy ginger ratio also increased by incorporating the absorbents, but there were no great differences between activated charcoal and calcium hydroxide.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.2
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• pp.21-30
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• 1990

근리주구개념은 도시사회구조를 이해하는 기본적 틀로서 인식되어왔을 뿐 아니라 도시공원의 계획에 따르는 공원체계의 개발 및 도시민의 여가행동 규명에 중요한 하부체계로 사용되어왔다. 80년대를 전후하여 발표된 다수의 논문에서 보고되고 있는 도시공원의 낮은 이용사례는 공원의 소극적 관리 상황 뿐 아니라 계획 그 자체에 문제가 있음을 환기시키고 있다. 본 연구는 미국의 소 도시를 대상으로 지역주민에 의한 근린주구 개념을 파악하고 주민의 근린공원 이용실태를 분석하여 전통적인 근린 공원계획의 설정목표 및 기준상의 문제를 제조명하고자 한다. 연구결과 주민의 근린주구개념의 '동질성'의 사회경제적 기능주의 입장보다는 물리지형적 특성으로 기울어 사회학자 및 공원계획가의 근린주구에 대한 기본전제에서 벗어나고 있으며, 계획가에 의해 임으로 설정된 근린공원의 서비스 영역(0.8km 둘레) 내부에 위치한 주민들의 공원비용은 주민자신에 의해 도출된 근린 주구 영역이 공원의 포함여부에 커다랗게 영향받고 있음이 밝혀졌다. 본 연구는 근린주구의 사회학적 개념과 현상학적 접근방식의 일환으로 Cognitive Mapping 기법에 대한 정리도 제시한다.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.329-331
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• 2010

전력회사로부터 공급되는 전력을 분배하고 제어하는 기능을 갖는 배전반은 아파트를 비롯한 대단위 인구밀집 주택 지역과 고압 변전소 등에 설치된다. 배전반에 수용되는 전력설비의 사고는 전력 기기의 열화에 의한 사고, 접점 및 각 연결 부위의 접촉 불량에 의한 과열 현상 등에 의한 사고 등으로 구분할 수 있으며 과열 현상에 의한 사고의 원인 중의 하나는 배전반 천정면의 결로에 의한 것으로, 물방울이 각종 기기에 직접 접촉하여 폭발하는 사고로 연결된다. 배전반의 결로는 일중 온도가 급격한 변화를 보이는 계절이나 지역에서 배전반 내부와 외부의 온도 차이와 내부 습도에 의해 발생한다. 본 논문에서는 온도와 습도의 단순 비교를 통하여 환풍기, 열풍기, 환기 등을 제어하여 결로를 해결하는 기존의 방식을 개선하여, 노점온도 계산에 의한 히터 구동 방안을 제시한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.267-274
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• 2019

To investigate the effect of high-intensity interval training (HIIT) on the outcomes of cardiac rehabilitation(CR) in elderly and younger patients with myocardial infarction(MI). Of the MI patients who received hospital-based CR from 2015 to 2017, we retrospectively reviewed the medical records of the patients who continued follow-up through the outpatient clinic. A total of 39 patients (20 elderly patients (${\geq}60year$($64.1{\pm}3.6$)) and 19 younger patients (< 60 year($55.6{\pm}2.3$)) was included in this study. The HIIT program was composed of 10 minutes of warm-up, 30 minutes of interval aerobic exercise, and 10 minutes of cool down. The aerobic exercise based on their initial exercise tolerance test outcome consisted of 3-minute usual intensity phase (60-70% of heart rate/VO2 reserve) and 4-minute of high-intensity phase (70-90% of heart rate/VO2 reserve). Exercise capacity was measured by exercise tests before and after hospital- based CR. Before CR, elderly group had a significantly lower exercise capacity in Exercise time, peak VO2, METs, Anaerobic threshold, VEmax, 02pulse than younger group. Both group showed similar improvement of cardiopulmonary exercise capacity after CR. And HIIT is safe and effective in elderly patients. It is considered necessary to further expansion for the participation of high intensity interval training in elderly patients.