• Nutritional Sciences
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• v.1 no.1
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• pp.34-41
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• 1998

This study examined the proper roles of dietitian and nurse-teacher in the weight control program (WCP) in schools and the effect of the WCP on subjects with respect to anthropometric measurements, nutrition knowledge, dietary attiude, and behavior changes. The program consisted of six sessions of nutrition education and frequent face-to-face nutrition counseling. Subjects were 22 obese children in the 4th and 5th grade who underwent counseling and 18 obese children in another school who served as a control group. After two months of WCP, obesity index such as .elative body weight (RBW, from 135.7 to 132.5), tricep skinfold thickness (TSFT, from 34.9 to 32.8 mm), and body fat content (from 32.0 to 29.8%) had decreased significantly in the experimental group, while the control group showed no significant differences in these indices. The reductions in obesity indices were maintained in the experimental group except for fat content (32.6%), which returned to its original value within six months. The control group significantly increased fat content in the same period (from 31.2% to 36.2%). Both groups decreased RBW, TSFT, and fat content while midarm circumference and waist/hip ratio remained the same after one year. Subjects' nutrition knowledge was improved with average test scores from 15.1 to 16.7 while nutrition attitude and behavior test scores remained unchanged suggesting that behavior modification may require more time than knowledge acquirement. These results suggest that proper nutrition counseling can initiate weight reduction. However, the maintenance of controlled weight requires changes in attitude and behavior which have not been achieved by the present WCP. The role of school dietitian for WCP in this study was limited to assisting the nurse-teacher in nutrition education. Expansion of dietitian's role in nutrition education and counseling is needed.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.27-35
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• 2010

Asphalt Plug Joint(APJ) is an buried expansion joint that enabling the smooth connection of expansion gap and road pavement by filling the gap with bituminous mixture of 20% bitumen and 80% aggregate by weight, so it secures evenness and expansion or contraction using the material's properties. Although APJ is designed to have a 6-7 year lifecycle, there are some cases where it is damaged within the first six months. This early damage cause traffic congestion due to frequent repair works, and social cost exceeding the installation cost of the joint. So, in this research, we have developed a new system of Buried Folding Lattice Joint(BFLJ) which can overcome the disadvantages of APJ, and have analyzed and compared it's performance with the conventional APJ through experiment with specimens. As a result of the experiment, APJ had crack formation on both ends of the gap plate, spreading to the surface of the expansion joint. With this result, we can conclude that the reason for early damage is the tension failure due to the concentration of strain in the asphalt mixture along the end of gap plate and the debonding along the joint section. In contrast, the newly developed BFLJ induced even transformation in the joint by applying moving stud and high performance material, and resolved APJ's disadvantage of strain concentration. Therefore, it could be seen that the newly developed BFLJ could overcome the disadvantages of APJ and prevent early damage.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.11
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• pp.3538-3548
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• 1996

In this study, as a part of basic study for developing the simulation program for the assemssment of reliability of electronic EMC packaging which covers from EMC mixing step to thermal analysis, comparison between a measured and predicted values of material properties of EMC and finitde element analysis of thermal stress are performed. For the experimental testing specimens of fifty, sixty hive and eighty percent filler($13\mu m$, spherical silica) weight fraction are fabricated using tranfer molding. Coefficient of thermal expansion, elastic modulus and thermla conductivity are measured using these specimens and then these measured values are compared with the predicted values by various equations ( such as dilute suspension method. self consistent method, generalized self consistent method, Hashin-Shtrikman's bounds. Shapery's bounds, Nielsen's method and others). Measured values are distributed within the upper and lower bounds of equations. Measured elastic modulus and coefficient of thermal expansion approaches closely the perdicted values with self consisten mehtod and upper bound of Shaperys equation respectively. However small differences of thermal conductivity between the different filler volume fraction are obserbed. FEM analysis indicates that firstly stress is concentrated at the corner section of EMC and secondly EMC with eighty percent filler weight fraction shows less thermal stress when package is cooling down and relatively high thermal stress when package is heating up.

• Journal of Korean Institute of Industrial Engineers
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• v.9 no.2
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• pp.9-25
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• 1983

The purpose of this study was to film up computerized analyses for both kinematic posture(film analysis) and muscle dynamics (EMG) during a weight-lifting motion. (Snatch, Clean and Jerk) Using a motor drive camera (3.5 frames/sec) and a Location Analyzer, motion tracks of 13 landmarks, which were attached to the major joints, during the motion were converted into digital values. At the same time, EMG amplitudes from 11 major muscle groups were recorded. Recorded data were processed via analog/hybrid computer (ADAC 480) and digital computer (PDP 11/44). Landmark locations and EMG amplitude were integrated by a computerized routine. Computer output included graphic reproductions on sepuential dislocations of body segments, center of gravity of body segments and the associated changes on EMG amplitude such as % EMG's of major muscle group during a weight lifting motion. The results strongly suggest that the computerized motion-EMG integration can provide a further working knowledge in selection and in training of workers and athletes. Suggestions for a further study include additional device for velocity measurement, expansion of the link model for biomechanical analysis and other implementations necessary for athletic application.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.139-149
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• 2011

The combustion chamber and nozzle of a liquid rocket engine need thermal protection against the high temperature combustion gas. The nozzle extension of a high-altitude engine also has to be compatible with high temperature environment and several kinds of cooling methods including gas film cooling, ablative cooling and radiative cooling are used. Especially for an upper-stage nozzle extension having a large expansion ratio, the weight impact on the launcher performance is crucial and it necessitated the development of light-weight refractory material. The present survey on the nozzle extension materials employed in the liquid rocket engines of USA, Russia and European Union has revealed a trend that the heavier metals like stainless steels and titanium alloys are being substituted with light weight carbon fiber or ceramic matrix composite materials.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.701-706
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• 1999

The effect of siloxane oligomer content on thermal stability and internal stress of DGEBA epoxy resin was investigated. Siloxane-epoxy polymers having terminal epoxy group were prepared by reaction of siloxane-DDM prepolymer with DGEBA epoxy resin. Thermal stability was studied in terms of the initial decomposition temperature(IDT), temperature of maximum rate of weight loss($T_{max}$), integral procedural decomposition temperature(IPDT), and decomposition activation energy($E_t$) using TGA data. The thermal stability increased with increasing the siloxane oligomer content and showed a maximum value in the case of 5 wt% siloxane oligomer content in the blend system. While, the coefficient of thermal expansion(${\alpha}_r$) and the flexural modulus($E_r$) allowed us to study internal stress of the blend system. As the content of siloxane oligomer increases, the internal stress systematically decreases as decreasing both ${\alpha}_r$ and $E_r$.

• Journal of Aerospace System Engineering
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• v.2 no.4
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• pp.25-30
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• 2008

In general, we utilize momentum wheel to control spacecraft. It needs vacuum test to analyze the effect of space environments. The conventional vacuum connector which is composed of steel has problems for test with built in momentum wheel because of weight, thermal expansion, etc. We suggest possibility to manufacture the vacuum connector using aluminum mount, epoxy and industrial D-Sub considering cost, weight. We verify the performance through vacuum test.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.25-33
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• 2012

A genetic algorithm (GA) has been employed to optimize the major design variables of the liquid rocket engine. Pressure of the main combustion chamber, nozzle expansion ratio and O/F ratio have been selected as design variables. The target engine has the open gas generator cycle using the LO2/RP-1 propellant. The gas properties of the combustion chamber have been obtained from CEA2 and the mass has been estimated using reference data. The objective function has been set as multi-objective function with the specific impulse and thrust to weight ratio using the weight method. The result shows about 4% improvement of the specific impulse and 23% increase of the thrust to weight ratio. The Pareto frontier line has been also obtained for various thrust requirements.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.127-134
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• 2011

A genetic algorithm (GA) has been employed to optimize the major design variables of the liquid rocket engine. Pressure of the main combustion chamber, nozzle expansion ratio and O/F ratio have been selected as design variables. The target engine has the open gas generator cycle using the LO2/RP-1 propellant. The gas properties of the combustion chamber have been obtained from CEA2 and the mass has been estimated using reference data. The objective function has been set as multi-objective function with the specific impulse and thrust to weight ratio using the weight method. The result shows about 4% improvement of the specific impulse and 23% increase of the thrust to weight ratio. The Pareto frontier line has been also obtained for various thrust requirements.

• Korean Journal of Community Nutrition
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• v.12 no.6
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• pp.724-741
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• 2007

This study was carried out to investigate the body weight controls and eating disorders of university students in Gunsan. The subject of the present study included 229 male students (53.8%) and 197 female students (46.2%), totalling 426 students from Kunsan University. The subjects consisted of 56 underweight (13.1%), 265 with normal weight (62.2%), and 105 overweight (24.6%). Especially, in females, 20.8% of them were underweight, which is 6.6% higher than males, showing a significant difference (p<0.001). Regarding body image, 21.8% of the males thought they were fat, while 40.6% of the females thought they were fat. Regarding the perceived body type, shown in the difference between their own size and the ideal size, males recorded 0.03, while females recorded 1.75, showing a major significant difference (p<0.001). Regarding body satisfaction, 33.2% of the males were unsatisfied, while 52.8% of the females were unsatisfied (p<0.001). The social expectations of the male subjects' sizes and weights recorded 2.04, while that of females recorded -2.51, showing that people's opinions expected the female subjects' bodies to be thinner (p<0.001). Additionally, the social expectation of the subjects' weight control recorded an average of 15.22 (13.92 for males, 16.73 for females), showing that the female subjects' felt that people's opinions wished them to lose their weight (p<0.001). Regarding the recognition on weight control, interested males were 49.4%, while interested females were 86.8%, showing the females superior rate (p<0.001). The beliefs in relation to weight control recorded an average of 62.01, with the score of females of 67.89 being significantly higher than that of males which was 56.96. The subjects showed a relatively positive response towards weight control (p<0.001). EAT-26 score was employed to determine the eating attitudes in relation to gender. Here, the final score of males was 15.46, which was significantly lower than that of females, which was 22.21 (p<0.001). Furthermore, regarding the score of eating attitudes in relation to obesity index, the eating disorder scale scores on the questions related to bulimia and diets to lose weight as weight increases were high. However, the eating disorder scale score on oral control, which actually controls food, was low. To control the expansion of excessive weight control attempts and their side effects, the recognition of the students' body types needs to be corrected, and nutrition education programs on eating habits and eating disorders to foster proper weight loss are deemed necessary.