• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.427-434
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• 2000

In tradition, there have been two kinds of drying methods, which are sun drying and artificial drying. The sun drying method which has been adopted traditionally has been replaced by the hot-air drying method which is one of the most general methods of artificial drying, with its simple drying system, low initial cost of drying plant, and easy operating method. But the hot-air drying method has some defects; (1) much energy loss happens due to the discharge of hot air during the drying process, (2) control of drying rate is not easy on account of changing relative humidity of inlet air for uniform hot air temperature, (3) high temperature of foods in drying process brings about the production of low-grade drying products. Vacuum drying takes advantage of energy saving and mass production because it reduces the drying time by increasing the drying rate under low temperature condition. The aim of this paper is to develop the low temperature vacum dryer, with low initial investments and operating costs, easy operating method and trouble-free operation.

• 한방재활의학과학회지
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• 제15권1호
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• pp.109-126
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• 2005

Objectives : This study is to examine the influence of exorcise program to body shape and body composition of women. Exercise program is composed muscular resistance exercise and aerobic exorcise with 70min/time, 5day/week for 4weeks and designed for the reinforcement of muscular strength and the decease the decrease of obesity. Methods : The subjects of this study are 26 females who are from twenty until thirty-nine years old and are divided into two groups according to Obese Rate. normal weight group is 18 females under a BMI of 23 and overweight group is 8 females over a BMI of 23. we measured body compositon and body shape with body composition analyzer(inbody 3.0) measured body compositions are body weight, Lean body mass, base metabolic rate, body fat, %body fat, waist hip ratio, body mass index. measured 6body shade are upper arm circumference, chest circumference, waist circumference, hip circumference, thigh circumference. the measurements had been taken before exercise of each group, after 4 weeks, after 8 weeks, after 12 weeks. Body compositon and body shape of the measured data were analyzed by two-way repeated ANOVA followed by Dunnett's Post hoc test using SPSS. Differences were considered significant at p<0.05. Results and Conclusions : The weight was reduced at a significant level in overweight group after 4 weeks. Body fat percent was reduced at a significant level in normal group alter 4 weeks and overweight group after 8 weeks. Waist-hip ratio was reduced at a significant level in normal and overweight group after 4 weeks. Lean body mass and body metabolic rate were reduced but did not satisfy statistical significance. Circumference of all body parts showed an decrease after 12 weeks exercise program. Upper Arm, Chest, Waist, Hip Circumference were reduced at a significant level in overweight group after 4 weeks, but In normal group only Waist Circumference was reduced at a significant level after 4 weeks. Aerobic and Circuit weight training for 12 weeks reduced body weight and body fat percent, waist circumstance statistically significant without loss of lean body mass and body metabolic rate. Also these change was more effective in overweight group than in normal group.

• 한국화재소방학회논문지
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• 제33권4호
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• pp.35-40
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• 2019

본 연구에서는 콘 칼로리미터의 발열량 산출 값에 대한 신뢰성 평가를 위한 기초 연구로 산소소모지수법의 주요 인자인 질량유량에 관한 측정 불확도 관계식을 분석하였다. 본 연구에서 사용한 콘 칼로리미터의 덕트는 길이가 5 m이고 직경이 0.2 m로 내부가 완전히 빈 공간인 경우와 기공의 직경이 3 mm인 격자망 그리고 기공의 직경 10 mm와 기공률 0.76인 허니컴 형상의 덕트를 각각 제작하였다. 덕트 내부로 유입되는 질량유량을 산출하기 위해서 양방향 차압계와 온도센서를 유동의 수직방향으로 균일한 위치에 4개씩 설치하였으며, 레이놀즈 수 증가에 따른 속도구배와 유동의 섭동을 측정하였다. 그 결과 흡입용량이 증가할수록 난류강도에 비례하여 세 가지 형상 모두 속도구배가 증가하였으며, 95% 신뢰수준에서 질량유량에 대한 확장 불확도의 편차는 완전히 빈 공간, 격자망(d_p = 3 mm) 그리고 허니컴(d_p = 10 mm, 𝜖 = 0.76) 순으로 낮게 나타났다. 주목할 만한 점으로는 송풍기의 흡입용량이 가장 높은 조건일 때 격자망(d_p = 3 mm)이 허니컴(d_p = 10 mm, 𝜖 = 0.76) 형상에 비해서 흡입용량의 저항성은 높은데 비해서 질량유량의 확장불확도는 오히려 증가하였으며, 본 연구의 결과는 콘 칼로리미터의 덕트 내부 유동 안정성 향상을 위한 설계 자료의 활용이 가능할 것으로 판단된다.

• 한국보건간호학회지
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• 제27권1호
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• pp.102-112
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• 2013

Purpose: The purpose of this study was to determine the effects of a weight loss program administered through a smart phone application on body composition and obesity in adolescents. Methods: This study applied a 6-week weight loss program with dietary education, exercise therapy, and behavior modification therapy from 4 June 2012 to 20 July 2012. The collected data were analyzed by descriptive statistics and the Wilcoxon signed rank test using the SPSS WIN 18.0 program. Results: After the 6-week program, the average weight of the subjects was reduced from 75.96kg to 74.41kg (Z=$-3.994^p$, p<.001), while the body mass index (BMI) decreased from 29.23 to 28.60 (Z=$-3.980^p$, p<.001), and the obesity index decreased from 38.45% to 35.59% (Z=$-3.977^p$, p<.001). The percentage of body fat decreased from 32.45 to 31.92 (Z=$-3.947^p$, p<.001), and the rate of skeletal muscle growth increased from 26.06% to 26.58% (Z=$-3.822^p$, p<.001). Conclusion: A weight loss program using a SNS (social network service) application, with dietary education, exercise therapy, and behavior modification therapy can reduce obesity and impact body composition in a short-term. Therefore, the utilization of the SNS application can be used to effectively enhance the management of adolescent obesity.

• 한국유체기계학회 논문집
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• 제8권4호
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• pp.39-47
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• 2005

The present study has been performed to investigate the influences of rectangular fins on heat transfer in an impingement/effusion cooling system with crossflow. To simulate the impingement/effusion cooling system with initial crossflow, two perforated plates are placed in parallel and staggered arrangements with a gap distance of 2 times of the hole diameter. The crossflow passes between the plates, and various rectangular fins are installed on the plates. Reynolds number based on the hole diameter is fixed to 10,000 and the flow rate of crossflow is changed from 0.5 to 1.5 times of that of the impinging jet. A naphthalene sublimation method is used to obtain the heat/mass transfer coefficients on the effusion plate. Also to analyze the flow characteristics, a numerical calculation is performed. When rectangular fins are installed, the flow and heat transfer pattern is changed greatly from the case without fins. In the injection hole region, the jet impinges on effusion plate without deflection and wall jet spreads symmetrically. In the effusion region, the crossflow accelerates due to the decrease of cross-sectional area in the channel. Local heat/mass transfer coefficients are enhanced significantly compared to the case without fins. As the blowing ratio increases, the effect of rectangular fins against the crossflow becomes more significant and then the higher average heat/mass transfer coefficients are obtained than the case without fins. However, the increase of blockage effect gives more pressure loss in the channel.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.1955-1962
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• 2020

In a sudden shutdown of primary pump or coolant loss accident in a marine nuclear power plant, the primary flow decreases rapidly in a transition process from forced circulation (FC) to natural circulation (NC), and the lower flow enters the steam generator (SG) causing reverse flow in the U-tube. This can significantly compromise the safety of nuclear power plants. Based on the marine natural circulation steam generator (NCSG), an experimental loop is constructed to study the characteristics of reverse flow under middle-temperature and middle-pressure conditions. The transition from FC to NC is simulated experimentally, and the characteristics of SG reverse flow are studied. On this basis, the experimental loop is numerically modeled using RELAP5/MOD3.3 code for system analysis, and the accuracy of the model is verified according to the experimental data. The influence of the flow variation rate on the reverse flow phenomenon and flow distribution is investigated. The experimental and numerical results show that in comparison with the case of adjusting the mass flow discontinuously, the number of reverse flow tubes increases significantly during the transition from FC to NC, and the reverse flow has a more severe impact on the operating characteristics of the SG. With the increase of flow variation rate, the reverse flow is less likely to occur. The mass flow in the reverse flow U-tubes increases at first and then decreases. When the system is approximately stable, the reverse flow is slightly lower than obverse flow in the same U-tube, while the flow in the obverse flow U-tube increases.

• 한국기계가공학회지
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• 제21권2호
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• pp.94-100
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• 2022

A study was conducted to significantly increase the heat transfer area by simultaneously burying the excel pipe in the floor and wall of a container house, thereby greatly reducing the initial heating time. In addition, a small hot water boiler suitable for the heating load of a small container house with a maximum area of 6 m² was studied. A wall-mounted hot water boiler was developed as a result of the study. When a hot water boiler is installed outdoors for heating, heat radiation energy is lost in winter from the hot water boiler and hot water pipe due to the low temperature. We propose an approach through which the energy loss was greatly reduced and the temperature of hot water increased in proportion to the operating time. Moreover, as the mass flow rate of the hot water flowing inside the excel pipe increased, the temperature of the hot water decreased. The temperature of the wall and floor surfaces of the container house increased in proportion to the increase in the mass flow rate of hot water flowing inside the excel tube. Natural convection heat transfer was realized from the wall and floor surfaces of the container house, and the heat transfer area was increased by a factor of 3 with respect to heat transfer area limited to the floor by the existing hot water panel. As a result, the initial temperature increase rate was much higher because of the larger heat transfer area.

• 한국산림과학회지
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• 제89권1호
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• pp.41-48
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• 2000

1992년 10월부터 1995년 11월까지 38개월 동안 경기도 광릉 시험림에서 낙엽활엽수(졸참나무, 서어나무, 까치박달 혼합)와 3종의 침엽수 낙엽의 분해율과 분해과정에 따른 영양염류 함량의 변화를 조사하였다. 38개월이 지난 후 혼합 활엽수, 잣나무, 리기다소나무 그리고 전나무 낙엽의 잔존률은 각각 16.2%, 29.8%, 33.5%, 53.9%로 활엽수, 소나무속(屬) 그리고 전나무 순으로 분해율이 감소하였으며, k는 각각 0.61, 0.40, 0.37, $0.21yr^{-1}$이었다. 전나무 낙엽의 초기 질소함량은 6.5mg/g으로 다른 종류의 낙엽에 비해 1/2 수준이었으며, 전나무 낙엽의 분해율이 낮은 것은 그것의 질소함량이 낮기 때문인 것으로 판단된다. 38개월이 경과된 낙엽에서 질소의 잔존률은 활엽수 낙엽에서 29%인데 비해 전나무 낙엽은 107.8%이었다. 인의 잔존률은 활엽수 낙엽에서 53.4%이었는데 비해 침엽수 낙엽은 모두 초기 값 이상이었다. 양이온의 잔존률은 38개월 경과된 낙엽에서 모두 초기 값 이하이었다. 분해과정에 따른 영양염류 함량의 변화 및 잔존량은 낙엽과 영양염류의 종류에 따라 차이가 있었다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.219-222
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• 2005

Recently, the interest of the engine capacity and environment of the atmosphere is increasing, so the researches for the engine capacity have been conducted for a long time. But the internal environment of an automotive engine is very severe. A piston is exposed to combustion gas of over $2000^{\circ}C$ and strong friction is occurred by high speed motion in the cylinder. The fraction between piston and wall of the cylinder causes the increase of temperature in the engine. The temperature of the engine has an effect on the engine capacity. If the temperature is high, the capacity of the engine is low. So we have to maintain the optimum temperature. To maintain the optimum temperature, the enough flow rate of the engine oil is needed. The oil jet is used to control the flow rate of the engine oil and supply the engine oil to the piston and cylinder. The purpose of this study is to check the mass flow rate of the engine oil and the characteristics of internal flow of the oil jet. Flow pattern of the engine oil is very important because it concludes the loss in the oil jet. This study is the previous research about the oil jet and we will consider the movement of the ball check valve to get more accuracy result.

• 혜화의학회지
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• 제19권2호
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• pp.179-186
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• 2011

Obhectives : The purposes of this study are to evaluate the effect of zymolysis-dietotherapy with herbal medicine on the obesity in Sasang constitution Methods : Seventy five patients were classified into four obesity groups by Body Mass Index, and four Sasang constitution groups by QSCC. Weight, body fat, body fat rate, BMI were compared in each group. Results : Weight, body fat, body fat rate, BMI were decreased significantly in all groups. There was statistically significant difference in the loss of weight, BMI between Taeumin and others. Decrement of body fat rate is not statistically significant between Taeumin and others. Conclusions : In conclusion, it was proved that zymolysis-dietotherapy with herbal medication is effective on the obesity treatment of all Sasang constitution groups. And the group of Taeumin lose more weight.