• 제목/요약/키워드: Reference stress

검색결과 648건 처리시간 0.029초

장애아동의 비만실태와 관련요인에 관한 연구 (A Study on the Prevalence and Predisposing Factors for Obesity Among Mentally Disabled Children in Korea)

  • 하영미;윤순녕
    • 한국학교보건학회지
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    • 제18권2호
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    • pp.27-43
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    • 2005
  • Purpose: The purpose of this study was to estimate obesity rate among mentally disabled children in six public schools in Korea. Furthermore, this study identified several factors that correlated with these children's obesity. The results of this study can help identify mentally disabled children who are at an increased risk for obesity and can be used to promote good health in this population. Methods: 1,102 subjectsfrom six public special schools were classified 4 groups who assessed for BMI for age-gender specific reference chart(1998) based on our previous data. Moreover, 207 parents were surveyed to identify predisposing factors for children's obesity, including characteristics of the children and parents, socioeconomic factors, children's eating habits, and children's exercise habits. Results: The prevalence of obesity among the 1,102 mentally disabled children was 17.3%. There was a statistically significant correlation between obesity and factors, such as age, maternal education, parents' perceptions about their child's obesity, frequency of breakfast, and exercise habits. Each of these factors was determined to have a statistically significant influence on obesity when all other factors were controlled in a multivariate analysis with multiple logistic regression analysis. Conclusions: Parental perceptions had an especially strong impact on the weight of their mentally disabled child. This is presumably due to the great influence that parents have on the lifestyles of their children, including dietary habits and frequency of exercise. Furthermore, the rate of obesity was directly proportional to the age of the child. The results of this study strongly indicate the need for preemptive health education programs that stress weight management for mentally disabled elementary school students.

원자로내 핵연료봉 제거 로봇 구조물의 휨변형구조해석 (Structural Deflection Analysis of Robot Manipulator for Removing Nuclear Fuel Rod in Nuclear Reactor Vessel)

  • 권영주;김재희
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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    • pp.203-209
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    • 1999
  • In this study, the structural deflection analysis of robot manipulator for removing nuclear fuel rod from nuclear reactor vessel is performed by using general purpose finite element code (ANSYS). The structural deflection analysis results reported in this study is very required for the accurate design of robot system. The structural deflection analysis for the manipulator's structural status at which the gripper grasps and draws up the nuclear fuel rod is done, For this beginning structural status of robot manipulator's removing motion, the reaction forces at each joint have static maximum values as reported in the reference(6), and so these forces may cause the maximum deflection of robot structure. The structural deflection analysis is performed for selected four working cases of the proposed structural model and results on deformation, stress for the manipulator's solid body and the deflection at the end of robot manipulator's gripper are calculated. And further, the same analysis is performed for the slenderer manipulator with cross section reduced by one-fifth of each side length of proposed model. The analysis is performed not only for the nuclear fuel rod with weight load of 300kg but also for nuclear fuel rods with weight loads of 100kg, 200kg, 400kg and 500kg. The static structural deflection analysis results show that the deflection value increases as the load increases and the largest value (corresponding to the weight load of 500kg in case 1) is much smaller than the gap distance between nuclear fuel rods. but the largest value for the slenderer manipulator is almost as large as the gap distance, Hence, conclusively, the proposed manipulator's structural model is acceptably safe for mechanical design of robot system.

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고차전단변형이론에 기초한 4절점 가변형률 판 요소를 이용한 대칭 및 비대칭 적층 판의 유한요소해석 (FE Analysis of Symmetric and Unsymmetric Laminated Plates by using 4-node Assumed Strain Plate Element based on Higher Order Shear Deformation Theory)

  • 이상진;김하룡
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2008년도 춘계 학술발표회 논문집
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    • pp.95-100
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    • 2008
  • 대칭 및 비대칭 적층판의 거동을 연구하기 위하여 가변형률과 고차전단변형이론을 바탕으로 4절점 판 유한요소(HSA4)를 개발하였다. 개발된 판 요소는 적층 판의 두께 방향으로 나타나는 전단변형의 포물선 분포를 고려하기 위하여 Reddy의 고차전단변형이론을 도입하였다. 특히 전단변형을 고려한 판 요소에서 발생하는 전단과대현상을 해결하기 위하여 가변형률을 채용하였다, 본 연구를 통하여 개발한 판요소는 고차전단변형이론을 도입하여 각 절점당 7개의 자유도를 가지므로 요소전체에 28개의 자유도로 판의 변형을 표현하게 된다. 개발된 유한요소의 성능을 검증하고 우수성을 보여주기 위해 다양한 두께를 가지는 대칭 및 비대칭 적층 판에 대한 수치해석을 수행하였으며 그 결과를 다른 고차전단변형이론에 의해 도출된 참고해들과 비교하였다.

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DSC를 이용한 토목섬유가 포함된 경계면의 변형율 연화 모델 개발 (Development of Strain-softening Model for Geosynthetic-involved Interface Using Disturbed State Concept)

  • Woo, Seo-Min;Park, Jun-Boum;Park, Inn-Joon
    • 한국지반공학회논문집
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    • 제19권5호
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    • pp.223-232
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    • 2003
  • 본 연구에서는 DSC를 이용한 구성방정식을 이용하여 토목섬유 사이의 접촉전단 응력과 변위와의 관계를 모델링하였다. DSC 모델은 두 개의 기준 상태, 즉 상대적으로 손상되지 않은 RI 상태와 완전히 파괴된 FA 상태와 한가지의 교란 함수로 구성된다. 본 모델은 통합된 모델로서, RI 상태를 탄성-완전 소성 모델, 계층적 단일 항복곡면 (HiSS) 모델 등 다양한 모델을 이용하여 모사할 수 있다. 한편 본 모델은 탄성과 소성 변위를 동시에 고려할 수 있다는 장점을 가지고 있다. 4가지의 대형 직접전단 시험으로부터 측정된 자료와 측정자료로부터 도출된 모델 변수를 이용하여 재해석한 결과를 서로 비교하여, 둘 사이의 비교 결과가 상당히 일치함을 발견하였으며, 특히 표면이 매끄러운 지오멤브레인의 접촉면에서는 매우 상관관계를 보였다. 비록 표면이 거친 지오멤브레인이 포함된 접촉면에서는 예측 최대 전단강도가 실험결과와 약간의 차이를 보이기는 하였지만, 전체적으로 본 모델이 최대 전단응력이 나타나는 변위점과 대변형에서의 전단강도를 상당히 정확히 예측하였으며, 이를 통해 본 모델이 변형율 연화 현상을 보이는 접촉면 전단거동의 모델링에 유용함을 확인하였다.

쏙의 생물학 - 최근 서해안 바지락 양식장에 이상 증식한 쏙의 제거 대책을 중심으로 - (Biology of the Mud Shrimp Upogebia major (de Haan, 1841), with Particular Reference to Pest Management for Shrimp Control in Manila Clam Bed in the West Coast of Korea)

  • 홍재상
    • Ocean and Polar Research
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    • 제35권4호
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    • pp.323-349
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    • 2013
  • The mud shrimp Upogebia major (Upogebiidae: Decapoda: Crustacea) is a common species on muddy and sandy mud tidal flats in the west coast of Korea. They reside in Y-shaped burrows that can extend up to more than 2 meters below the sediment surface. They feed on suspended detritus carried into their burrow by the beating of their pleopods and captured by their hairy first two pairs of thoracic legs. Mud shrimp burrows provide a habitat for a variety of small organisms such as crabs, shrimps, polychaetes, and mollusks. Ovigerous females are observed from December to May. Females deposit eggs only once per breeding season. They start hatching in March and the pelagic larvae of first zoea appear in March and April, followed by benthic settlement in May. Growth over the first year is rapid, and females deposit their first eggs in the third breeding season, 31 months after their settlement. Adult shrimps live for 4~5 years. Depth of the burrow increases with body length. The deep burrows provide refuge from predators and physical stress, allowing the shrimps to survive for a long time. The mud shrimps supply oxygen-rich water to their deep burrows, and exert a great influence on the structure and metabolism of the tidal flat benthic community. However, recently this type of mud shrimp has posed a serious threat to the Korean clam industry along the west coast of Korea. The extensive burrowing shrimp populations suddenly invaded the tidal flats from 2010 where the clams (Ruditapes philippinarum) are raised. As a consequence, clam production has decreased by about 10% over the past three years in some Korean clam beds. Therefore, the objective of this study is to review the biology of this mud shrimp in order to seek solutions to control the burrowing of these shrimps.

스마트폰 유형에 따른 문자 입력 시 뇌파 및 아래팔 근활성도 비교 (A Comparison of EEG and Forearms EMG Activity depend on the Type of Smartphone when Inputting Text Messages)

  • 이형수;고경진;김진원;박송이;박지선;박진리;석혜리;양구름;양시은;윤광오
    • 대한통합의학회지
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    • 제2권2호
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    • pp.79-88
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    • 2014
  • Purpose: This study investigated the relationship between smartphone addiction propensities and compare muscle activity of the forearms and brain wave depend on the type of smartphone when inputting text messages. Method: We used an EMG to measure the change in muscle activity by attaching pads to the four muscles in both forearms of all 16 participants. We simultaneously conducted EEG measurements by observing the changes in alpha and beta waves recorded from electrode attached to both ears and the forehead of the participants. The participants had to input a given text using three different types of smartphones for ten minutes each. Result: The comparison of the EMG when inputting text involved a one way analysis of variance and the results showed that the iPad3 was highest for muscle activity followed by GALAXY Note2 and iPhone4. For EEG measurement, a one way analysis of variance was also used and the results showed iPhone4 was higest followed by GALAXY Note2 and finally iPad3 for EEG stress score. Conclusion: The results are thought to be used as reference data for smart phone users.

유니버설조인트 시험방식을 이용한 치과용 임플란트의 피로시험 및 가속수명시험에 관한 연구 (Study on the Fatigue Test and the Accelerated Life Test for Dental Implant using Universal-Joint Test Type)

  • 도경훈;이석진;김종미;김성민
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제17권1호
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    • pp.50-57
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    • 2017
  • Purpose : This paper is a comparative analysis results of the fatigue test for dental implants and accelerated life test by using a static type loading device commonly used in Korea and a dynamic type loading device (universal-joint) recommended by FDA. Methods : Fatigue tests of dental implant is based on ISO 14801 and classified into static load test and dynamic load test. The tests were carried out on three test specimens by four load stress steps under each loading device. For analysis on failure mode such as crack, fracture and permanent deformation of test specimens, we used X-ray three-dimensional computed tomography on test specimens before and after the fatigue tests. The design of the accelerated life test was based on the analysis results of the fatigue life data obtained from the dynamic load test and the statistical analysis software (Minitab ver.15) was used to analyze the appropriate life distribution. Results : As a result of the fatigue tests and the accelerated life tests at same acceleration condition under each test method, the fatigue life under the dynamic type loading device (universal-joint) was shorter than when static type loading device was applied. Conclusion : This paper can be used as a reference when the universal-joint type loading device for implants fatigue test is applied as ISO 14801.

조기 영어교육의 실태와 바람직한 방향 -우리나라 초등학교 영어교육을 중심으로- (The current state of early English education and its more desirable direction)

  • 김해겸;차호순
    • 영어어문교육
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    • 제3호
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    • pp.141-183
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    • 1997
  • This paper aims to find out the current state of early English education in the world(including Korea) and to suggest its more desirable direction, with special reference to TEFL in elementary schools of Korea. In fact English teaching in elementary schools of Korea has been put into practice as an extracurricular activity since 1982. But in 1995 the Ministry of Education proclaimed a policy to establish a TEFL program as the regular course in elementary schools of Korea since 1997. In this connection, the writer surveyed several kinds of theories about early English education to verify the necessity and validity of Korea's elementary school English education. The logical result from these theories is that younger children are better equipped to learn foreign languages with efficiency than older children or adults. However, as most studies are based on logical inferences rather than on direct observation or experimental evidence, we are not sure that those theories are right. In this view, the writer put stress on the preparation of educational environments to establish a more desirable direction of early English education in Korea, since Korea's elementary school English education will be practiced under EFL environment, not ESL environment. The writer also pointed out some problems of educational finances, the curriculum development process and its content, teaching materials(textbooks and tapes), English teachers, teaching methods, evaluation, educational facilities. This paper concludes that we have to try to solve these problems to succeed in a TEFL program in elementary schools of Korea and suggests several things for a more desirable direction of Korea's elementary school English education.

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Proteomic Approach of the Protein Profiles during Seed Maturation in Common Buckwheat (Fagopyrum esculentum Moench.)

  • Park, Min-Hwa;Shin, Dong-Hoon;Han, Myoung-Hae;Yun, Young-Ho;Bae, Jeong-Sook;Lee, Yun-Sang;Chung, Keun-Yook;Lee, Moon-Soon;Woo, Sun-Hee
    • 한국자원식물학회지
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    • 제22권3호
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    • pp.227-235
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    • 2009
  • Single seeds of common buckwheat cultivar Suwon No. 1 when subjected to SDS-PAGE revealed very high polymorphism. High variation existed for protein or protein subunits with molecular weight 54-47kDa, 45-25kDa and 16-11kDa. The electrophoregram showed variation for globulin as well as other protein fractions. About 300 proteins were separated by two-dimensional electrophoresis in common buckwheat (Fagopyrum esculentum Moench.) seed. Seed maturation is a dynamic and temporally regulated phase of seed development that determines the composition of storage proteins reserves in mature seeds. Buckwheat seeds from 5, 10, 15, 20, and 25 days after pollination and matured stage were used for the analysis. This led to the establishment of high-resolution proteome reference maps, expression profiles of 48 spots. It was identified 48 proteins from MALDI-TOF/MS analysis of wild buckwheat seed storage proteins. The 48 proteins were found identical or similar to those of proteins reported in buckwheat and other plants; it is belonging to 9 major functional categories including seed storage proteins, stress/defense response, protein synthesis, photosynthesis, allergy proteins, amino acid, enzyme, metabolism, and miscellaneous. It appears that the major allergenic storage protein separated played the important role in buckwheat breeding and biochemical characterization.

Comparative proteome analysis of seeds of proso millet (Panicum miliaceum) cultivars

  • Roy, Swapan Kumar;Kwon, Soo Jeong;Park, Hyeong-Jun;Yu, Je-Hyeok;Sarker, Kabita;Cho, Seong-Woo;Jung, Tae-Wook;Park, Cheol-Ho;Woo, Sun-Hee
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.120-120
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    • 2017
  • Since the composition of proteins from the Korean cultivars of Proso millet is unknown; thereby, the present study was conducted to obtain a reference map of millet seed proteins and identify the functional characteristics of the identified proteins. Proteins extracted from the millet seeds of various cultivars, were investigated using proteomic techniques as 2D electrophoresis coupled with mass fingerprinting. The 1152 (differentially expressed) proteins were detected on 2-D gel. Among them, 26 reproducible protein spots were analyzed by MALDI-TOF-TOF mass spectrometry. Out of 26 proteins, 2 proteins were up-regulated towards all cultivars of millet, while 7 proteins were up-regulated and 13 proteins were down-regulated against only one cultivar. However, abundance in most identified protein species, associated with metabolism, transcription and transcription was significantly enhanced, while that of another protein species involved in polysaccharide metabolism, stress response and pathogenesis were severely reduced. Taken together, the results observed from the study suggest that the differential expression of proteins from the four cultivars of millet may be cultivar-specific. Taken together, a proteomic investigation of millet seeds from different cultivars, we sought to better understand the genetic variation of millet cultivars representing the future millet research, and the functional categorization of individual proteins on the basis of their molecular function.

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