• Title/Summary/Keyword: mass irregularity

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A Study on Magnetoresistance Uniformity of NiFE/CoFe/AlO/CoFe/Ta TMR Devices Prepared by ICP Sputtering (ICP 스퍼터를 이용한 NiFe/CoFe/AlO/CoFe/Ta TMR 소자 제작에 있어서의 자기저항 균일성 연구)

  • 이영민;송오성
    • Journal of the Korean Magnetics Society
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    • v.11 no.5
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    • pp.189-195
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    • 2001
  • We prepared TMR junctions of NiFe(170 )/CoFe(48 )/Al(13 )-O/CoFe(500 )/Ta(50 ) structure on 2.5$\times$2.5 $\textrm{cm}^2$ area Si/SiO$_2$ substrates in order to investigate the uniformity of magnetoresistance(MR) value using a ICP magnetron sputter. Each layer was deposited by the ICP magnetron sputter and tunnel barrier was formed by the plasma oxidation method. We measured MR ratio and resistance of TMR devices with four-terminal probe system by applying external magnetic field. Although we used ICP sputter which is known as superior to make uniform films, the standard variation of MR ratio was 2.72. The variation was not dependent on the TMR devices location of a substrate. We found that MR ratio and spin-flip field (H's) increased as the resistance increased, which may be caused by local interface irregularity of the insulating layer. The variation of resistance value was 64.19 and MR ratio was 2.72, respectively. Our results imply that to improve the insulating layer fabrication process including annealing process to lessen interface modulation in order to mass produce the TMR devices.

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Study of Bone Mineral Density, Body Composition and Dietary Habits of $20{\sim}30$ Years Women ($20{\sim}30$대 젊은 여성의 골밀도, 신체조성과 식행동 연구)

  • Koo, Jae-Ok;Ahn, Hong-Seok;Yoo, Sook-Young
    • Korean Journal of Community Nutrition
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    • v.13 no.4
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    • pp.489-498
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    • 2008
  • This study was carried out to identify bone mineral density(BMD), body composition, lifestyle and dietary habits of young women by physical measurement and questionnaires. The study subjects, 190 young women living in Seoul, were divided into three age groups: $20{\sim}24$ years(93), $25{\sim}29$ years(44) and $30{\sim}39$ years(53). There was no significant difference in mean body muscle mass, protein, mineral, body fat and BMI among the three age groups. The rate of low weight(18%) in 20 years group was higher that of the 30 years(11.3%). The mean BMD and T-score were $0.44g/cm^2$ and -0.66. BMD and T-score of the forearm bone were significantly higher in the $30{\sim}39$ years group. But BMD and T-score of calcanues were not significantly different among the three age groups. The rate of normal, osteopenia and osteoporosis subjects by BMD were 60.5%, 38.4%, 1.1%, respectively. The rate of osteopenia in $20{\sim}24$ years group was significantly higher than the other age groups. The rate of meal irregularity was significantly higher in $20{\sim}24$ years group. The rate of women who walk and are exposed to sunlight more than 1hr per day were significantly higher in $20{\sim}24$ years group than the others. However, the score of food behaviors is significantly higher(bad) in $20{\sim}24$ years group than the others. The relationship between BMD and frequency of food intake showed significant differences in beans, broom, seaweed and rice wine. In conclusion, the risk rate of BMD was very high, 40% of the subjects, and the risk rate of BMD was higher in 20 years group than 30 years group, and the rate of low weight in 20 years group was higher than in 30 years group. The food habits and behaviors were not healthy enough. Therefore, nutrition education is needed for bone health.

RADARSAT SAR Investigations of Lineament and Spring Water in Cheju Island (RADARSAT SAR 자료를 이용한 제주도 선구조 연구 및 용천 특성 연구)

  • 원중선;류주형;지광훈
    • Korean Journal of Remote Sensing
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    • v.14 no.4
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    • pp.325-342
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    • 1998
  • Two RADARSAT SAR images with different modes acquired by Canadian Space Agency to test the effectiveness of geological lineament extraction and spring water detection over the Cheju Island. Geological lineaments are poorly developed this basalt dominant volcanic island, but more linear features can be extracted when SAR and TM images are simultaneously analyzed than when TM image alone is used. This results mainly owe to the facts that RADARSAT SAR systems are able to provide data with different frequencies, azimuth, and incidence angles. Distribution of spring water along coast is poorly correlated with geological lineaments or drainage pattern, but those in middle range of mountain region are developed along geological lineaments. Detection of spring water using remotely sensed images are turned out to be very difficult to achieve. Radial shaped sea surface temperature anomaly derived from TM thermal band should be the best candidate for spring water, but the resolution is not high enough. We also investigate the normalized radar cross section (or sigma naught) converted from RADARSAT and ERS-1 SAR data but to discriminate the spring water effectively except where relatively large water mass is observed on land side. Speckle noise and irregularity in physical sea surface condition are the serious obstacles for this application. ERS-1 SAR image acquired in low incidence angle was more useful for geological lineament estimation and water body study than RADARSAT SAR images with high incidence angles. Therefore the selection of incidence angle is critical in geological and spring water applications of SAR images, and low incidence angles less than about 30$^{\circ}$ are recommended to monitor the Cheju volcanic island.

Numerical Analysis for Dynamic Characteristics of Next-Generation High-Speed Railway Bridge (차세대 고속철 통과 교량의 동적특성에 대한 수치해석)

  • Oh, Soon-Taek;Lee, Dong-Jun;Yi, Seong-Tae;Jeong, Byeong-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.2
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    • pp.9-17
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    • 2022
  • To take into account of the increasing speed of next generation high-speed trains, a new design code for the traffic safety of railway bridges is required. To solve dynamic responses of the bridge, this research offers a numerical analyses of PSC (Pre-stressed Concrete) box girder bridge, which is most representative of all the bridges on Gyungbu high-speed train line. This model takes into account of the inertial mass forces by the 38-degree-of-freedom and interaction forces as well as track irregularities. Our numerical analyses analyze the maximum vertical deflection and DAF (Dynamic Amplification Factor) between simple span and two-span continuous bridges to show the dynamic stability of the bridge. The third-order polynomial regression equations we use predict the maximum vertical deflections depending on varying running speeds of the train. We also compare the vertical deflections at several cross-sectional positions to check the influence of running speeds and the maximum irregularity at a longitudinal level. Moreover, our model analyzes the influence lines of vertical deflection accelerations of the bridge to evaluate traffic safety.

Study on Dietary Habit and Effect of Onion Powder Supplementation on Serum Lipid Levels in Early Diagnosed Hyperlipidemic Patients (초기진단 고지혈증 환자의 식습관 조사와 양파가루 섭취가 혈중지질에 미치는 영향 연구)

  • Lee, Kyung-Hea;Kim, Yang-Ha;Park, Eun-Ju;Cho, Sung-Rae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.5
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    • pp.561-570
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    • 2008
  • This study aimed to determine the effects of freeze-dried onion powder (OP) which contains rich in quercetin (22 mg/10 g) on hyperlipidemic participants. Fourteen participants (total cholesterol level in plasma $270.8{\pm}21.4mg/dL$) $40{\sim}59$ years of age who were diagnosed as hyperlipidemia by a physician at Fatima Hospital in Changwon took part in this study for 12 weeks. We investigated the anthropometric data and dietary habit by using questionnaires. Also, blood samples were collected from the patients in fasting before and after this 12 weeks intervention study. 78.6% of the patients showed interest in health diet management and weight control; however, they also showed some problems in their dietary habit (meal irregularity, food choice, calorie nutrient balance, high fat and cholesterol etc.) and life style (smoking, eating out, alcohol intake) that could have adverse effect on hyperlipidemic therapy. Most participants (85.7%) thought that OP was good for their health. The total cholesterol and LDL-cholesterol significantly decreased with OP intake. The HDL-cholesterol increased and the Atherogenic index (AI) significantly decreased. Regarding the correlations of dietary habit and life style with anthropometric and biochemical factors, the alcohol intake level was significantly correlated with the frequency of eating out and body mass index (BMI). Exercise level showed positive correlation with HDL-cholesterol and negative correlation with atherogenic index (AI). These results suggest that the intake of polyphenol rich onion may decrease the risk of hyperlipidemia by reducing cholesterol level. We consider these hypolipidemic effects of OP as a possible functional food. However, further research such as a well designed longterm clinical study with experimental and placebo groups is needed.

A Study on BMI, Diet Perception and Dietary Behavior of Female University Students (여대생의 체질량지수, 다이어트 인식과 다이어트 행동에 관한 연구)

  • Lee, JinHee
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.3
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    • pp.463-472
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    • 2020
  • The purpose of this study is to identify the BMI, diet perception and diet behavior of female university students. A descriptive survey design was used 165 students from October 29 to November 9, 2018. Data were analyzed using mean, t-test, ANOVA, cross analysis with SPSS 21.0. Total diet perception was 3.44 points, highest sub category was 'practice' with 4.00 points, followed by 'information and education' with 3.58 points, 'necessity' with 3.32 points and lowest category was 'self-recognition' with 2.84. 65 students(43.0%) were 'less than three times' in 'Number of diets' and diet methods was 65(43.0%) for 'food control' and 62(41.1%) for 'exercise'. During in a week, 98 students(84.9%) exercised within three hours, followed by 33(21.9%) who did not exercised at all. 22 students(14.6%) said they experienced damage from dieting, while the types included gastrointestinal disease, menstrual irregularity and hair loss. The total score of diet perception according to BMI was lower in the underweight group than in the normal and overweight groups(p<.001). In diet 'practice' category, low weight group scored lower than normal weight and overweight groups(p<.05). In 'information and education' category, overweight group scored the highest, followed by normal and underweight groups(p<.001). In diet 'necessity' and 'self-recognition' categories, low weight group scored lower than normal weight and overweight groups(p<.001). Diet behavior by diet perception was different in number and method of diet(p<.001). Based on the results, it is thought that attention and education are needed to form a proper diet perception and maintain healthy living for female university students.