• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.76.3-77
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• 2021

GMT secondary mirror system consists of 7 segmented adaptive mirrors. Each segment consists of a thin shell mirror, actuators and a reference body. The thin shell has a few millimeters of thickness so that it can be easily bent by push and pull force of actuators to compensate the wavefront disturbance of light due to air turbulence. The one end of actuator is supported by the reference body and the other end is adapted to this thin shell. One of critical role of the reference body is to provide the reference surface for the thin shell actuators. Therefore, the reference body is one of key components to succeed in development of GMT ASM. Recently, Korea Research Institute of Standards and Science (KRISS) and University of Arizona (UA) has signed a contract that they will cooperate to develop the first set of off-axis reference body for GMT ASM. This project started August 2021 and will be finished in Dec. 2022. The reference body has total 675 holes to accommodate actuators and 144 pockets for lightweighting. The rear surface has a curved rib shape with radius of curvature of 4387 mm with offset of 128.32mm. Since this reference body is placed just above the thin shell so that the front surface shape needs to be close to that of thin shell. The front surface has a concave off-axis asphere, of which radius of curvature is 4165.99 mm and off-axis distance is about 1088 mm. The material is Zerodur CTE class 1 (CTE=0.05 ppm/oC) from SCHOTT. All the actuator holes and pockets are machined normal to the front surface. It is a very complex challenging optical elements that involves sophisticated machining process as well as accurate metrology. After finishing the fabrication of reference body in KRISS, it will be shipped to UA for final touches and finally sent to Adoptica in Italy, in early 2023. This paper presets the development plan for the GMT ASM Reference Body and relevant fabrication and metrology plans.

• Journal of the Korean Society of Food Culture
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• v.37 no.2
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• pp.109-118
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• 2022

This study was undertaken to compare meal skipping, snacking, and weight perceptions between students on-campus living alone and off-campus living with parents, in an urban college in the United States. The self-report survey was completed by 219 college students (on-campus=100, off-campus=119) between April and May 2012. Two-thirds (67%) of the respondents skipped at least one meal in the past week, and most participants showed strong desires to lose weight despite their normal/under-weight status. Significant differences between the two groups were obtained for the reason to skip a meal and the type of snack consumed. Compared to on-campus students, significantly higher values were obtained for off-campus students for choosing 'no time to prepare' as a meal skipping reason for lunch and dinner, and 'sweets' as a preferred snack. In addition to the group comparison, multiple regression results indicate that the body mass index (BMI) positively correlates with meal skipping and snacking frequencies. Younger students and female students were determined to have a higher frequency of meal skipping and morning snacking. Future research is required to study the dietary factors associated with living arrangements, to help college students develop healthy eating habits.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.894-902
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• 2022

This study investigated the effects of photoperiod (NL 12L:12D and LL 24L:0D) and body sizes (30 g and 50 g) on parr-smolt transformation, post-smolt growth and blood properties in the off-season parr-smolt stage of Atlantic salmon reared in a recirculating aquaculture system (RAS). Potential off-season salmon smolt were reared in a freshwater RAS for 80 days and then all experimental fish were transferred to seawater. In both LL groups (LL-30 and LL-50), we recorded and increase in specific growth rate and reduction in feed conversion, although there were no significant difference in body size. The values of osmolality, and serum Na⁺, Cl^- and cortisol concentrations in the LL groups were maintained at lower levels than in NL group fish, and LL group fish were observed to recover to the pre-seawater adaptation state more rapidly than those in the NL group. ID chips were inserted in all smolts reared in freshwater. These fish were subsequently transferred to full-strength seawater and thereafter individual growth rates were monitored for 120 days. The results indicated that compared with smolt reared under natural photoperiodic condition, 24 h lighting in freshwater contributed to enhancing post-smolt specific growth rate in seawater.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.80-84
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• 2015

In this paper, the valves for a LPG gas cylinder have been investigated on the body height and weight by comparing design data between typical automatic shut-off vertical and newly developed horizontal valves. The height of an automatic shut-off horizontal valve is radically reduced by 41~42% compared with that of a typical automatic shut-off vertical valve. And, the body weight of a horizontal valve is also reduced by 29~40% compared with that of a vertical shut-off valve. This result is just achieved by a structural design modification from typical vertical valve to horizontal arrangement of various valve components.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.129-138
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• 2005

The purpose of this study was to investigate the techniques used by long jumpers who recorded over 8meters in 2002 Busan Asian Game and 2003 Daegu Universiade. The kinematic characteristics from the last three stride to takeoff at the takeoff board were analyzed such as velocities, heights and angles. The real-life three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation procedure. The conclusion were as follows; 1. The height variation who recorded over 8 meters of center of gravity of the jumpers at the last stride was under 8cm. In order to record over 8meters the national long jumpers should have under 10cm height variation. 2. In the approach phase the horizontal velocity of the jumpers should reach to 10.5m/s in last three strides and 9.79m/s in touch down at take off board. 3. The horizontal velocity at take off board must have over 8.51m/s and the vertical velocity must have 3.75m/s simultaneously in order to record 8meters. 4. The forward body lean angle should have over 20degrees with pushing the take off board in forwarding movement. The appropriate body variation range ratio between take off and touch down should be 1.2 vs 1 and the trunk angle at touch down on the board should be close to the erect posture for higher body flight.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.1
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• pp.53-64
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• 2009

For a realization of the ubiquitous society, applying IT to vehicle industry has recently been an attractive issue to make wireless communication in body area network possible to everywhere. In this paper, we propose the physical layer symbol structure based on PPM scheme of the IEEE 802.15.4a for the off-body high data rate WBAN system. We propose four symbol structures which is classified according to the number of the chip and whether the channel coding is used or not. We calculate the required SNR through the link budget calculation and the recently proposed off-body WBAN channel environment was applied in the simulation. The results of four systems show that small number of burst's chip enhances the performance and the system is capable to achieve the data rate of 10 Mbps.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.203-212
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• 2007

Means measuring carcass cut traits in live pigs is needed to genetically improve the production of favorite cuts in swine. The data of body measurements as well as carcass traits were collected from 432 heads of 4 crossbred lines. Weights of most parts and percentages of belly and boston in carcass were significantly influenced by days to slaughter. Most of off test body measurements show higher correlations with carcass cut traits than body measurements of on test and market do. The multiple regression equations for estimation of carcass cut traits by off test body measurements have higher accuracy than by body measurements of on test and market. The coefficients of determination in estimation of polynomial regression with off test body measurements after adjustments of carcass cut traits for days to market were ranged 0.59 to 0.68 and 0.33 to 0.43 in weights and percentages of carcass cuts, respectively. Develop- ment of an excellent Korean type seed stock for favorite cuts can be expected, if the estimation of carcass cut traits for live animals is implemented in swine genetic improvement program.

• Journal of Multimedia Information System
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• v.7 no.4
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• pp.269-276
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• 2020

The small craft including jet-board for leisure are commonly smaller than the general commercial vessels. For the floating vessel, the motion analysis is significantly important component to design the shape. It is, however, hardly predicting its behavior by using conventional boundary element method due to violating small amplitude assumption for potential theory. The computational fluid dynamics method can afford to simulate such small craft, but its grid system was not able to calculate motion, because movable body disturbs the grid system by confliction. The dynamics fluid body interaction model with over-set mesh system can be dealt with movable floating body under irregular ocean wave. In this study, several cases were considered to reveal that DFBI is essential method to predict floating body motion. The single phase simulate was conducted to establish the shape perfection, and then the validated vessel was simulated with ocean waves weather DFBI option on or off. Through the comparison, the results between the cases of DFBI on and off shows significantly difference. It was claimed that the DFBI was necessary not only to calculation body motion, but also to predict accurate drag and lift force on the floating body for small size craft.

• Nutritional Sciences
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• v.8 no.1
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• pp.50-55
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• 2005

This study was conducted to determine the relationship between the body fat percent (BF%) and body mass index (BMI) of Koreans and the differences with Caucasians. Complete data were collected from 3297 subjects (2441females and 856 males) between the ages of 18 and 79. Data were collected between September 2001 and November 2001 in Seoul and Pusan. For the statistical analysis, only the data on subjects between the ages of 18 and 65(3200) were used Body weight and height were measured BMI (kg/$m^2$) was computed From BMI, BF (%) was calculated using age- and sex-specific prediction formulas. BF% was assessed using an INBODY 2.0 body fat analyser. Data analysis showed that the females were significantly younger than the males, were smaller, lighter and had a lower body mass index. Body fat percent of the females was higher than that of the males. 1he differences between actual measured BF% and BF% as predicted from prediction equations from the literature, based on BMI, age and sex, were correlated with level of body fat and age. There is a significant age-related decrease in body fat in Koreans for any given BMI and sex, which is remarkably different compared to age-related increases in body fat in the European reference group. For the same age and BF%, Korean females have a slightly lower BMI than their European counterparts. Korean males have, for the same age and BF%, a higher BMI than their European counterparts. The differences between females and males were not significant. It was concluded that, assuming that the data on body fat percent was correct, that the relationship between BF% and BMI is quite different in Koreans than in European Caucasians. Thus, for younger Koreans cut-off values for obesity should be slightly lower than those for Caucasians whereas for older Koreans the cut-off points for obesity should be higher than those for Caucasians.

• The Korean Journal of Community Living Science
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• v.13 no.3
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• pp.69-80
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• 2002

This study was conducted to investigate the relationship among body image Perception, eating behavior and health status in young females. The survey was carried out by self-questionnaires for 293 female high school students(HS) and 164 female college students(CS) living in Daegu and suburbs of Daegu. For the perception of body image, 9-grade body figure drawings were used based on average Korean body size. EAT-26 and Rosenberg Self-Esteem Scale were used to measure the tendency of eating disorder and self-esteem. It appeared that 40.5% of the subjects were off the normal range of body weight; especially 34.2% of the subject were underweight. The subjects' perception about current body image was within normal range. Almost of all the subjects believed that the ideal body image was thinner than their own current body image, and they wanted to be thinner than their current body image. The change of eating behaviors related to weight control of CS was significantly higher than that of HS students. EAT-26 score, self-esteem score, and subjective health status score were no difference between groups. The cut-off point of the eating disorder in this study was equal to or greater than 20 in EAT-26 score. The rates of the eating disorder were very high as 9.6% of HS and 8.5% of CS. Eating disorder was positively correlated with BMI, current body image, dissatisfaction of body image and the change score of eating behavior. But eating disorder was negatively correlated with health status. From the results of this study, we suggested that one of causes related to the eating disorder behaviors in adolescent females was resulted from misperception about ideal body image. There is a great need to provide nutrition educations concerning appropriate perception of body image and weight control among adolescent females.