• Title/Summary/Keyword: Multi-body

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Development of a vestibulo-ocular reflex measurement system for the study of cybersickness (사이버멀미 경감 연구를 위한 전정안구반사 측정 시스템 개발)

  • Jeon, Hyeonjin;Chang, EunHee;Wendimagegn, Tariku Weldtsadik;Park, Chan Hyun;Jeong, Ji Woon;Kim, Hyun Taek
    • Science of Emotion and Sensibility
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    • v.18 no.1
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    • pp.27-38
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    • 2015
  • Vestibulo-ocular reflex (VOR) is a compensatory response of the extraocular muscles generated by vestibular signals to stabilize images on the retina during head/body movements. It has been reported that mismatches between retinal and vestibular information, which cause motion sickness or cybersickness, modify VOR. To investigate the characteristic changes of VOR in subjects experiencing cybersickness, we developed a low-cost, multi-purpose VOR measurement system using LabVIEW and Arduino. To test the applicability of the system, we performed two experiments. In Experiment 1, horizontal and vertical VORs of four participants were measured using a vestibular autorotation task. In Experiment 2, eight participants were exposed to a virtual navigation to measure changes of VORs as an index of cybersickness. We observed significantly greater head rotations and eye movements while the participants were exposed to the virtual navigation than to a static image. The results suggest that the present system can help understand the psychophysiological mechanisms of cybersickness symptoms.

Design and simulation of hydraulic system for launch vehicle holding device (우주발사체 지상고정장치 유압시스템 설계 및 해석)

  • Kim, Dae Rae;Yang, Seong Pil;Lee, Jaejun;Kim, Bum Suk;Lee, Young-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.12
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    • pp.1087-1094
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    • 2016
  • The responsibility of the vehicle holding device (VHD) is to hold the launch vehicle while it is stayed on launch pad and release the holding mechanism to allow a lift-off of launch vehicle at a moment of lift-off. During a release of the holding mechanism, in order to prevent the Ka doing a doing a doing mode which is vertical oscillation of entire liquid propellant and very severe for vehicle structure, gradual release of holding force is required. Also, a release operation of all 4 VHD should be synchronized very precisely. In this study, to comply the "gradual release and synchronized operation requirement", concept of VHD hydraulic system using an accumulator, pyro valve and orifice to control speed of hydraulic cylinder is proposed instead of using complicated hydraulic components. Then through multi-body dynamic analysis and computational hydraulic analysis, a size of orifice to meet a target speed of hydraulic cylinder is calculated. Through this study, simple and reliable VHD hydraulic system complying requirements is designed.

Relations between Multidimensional Perfectionism and Eating Disorder in High School and College Students Majoring in Dance (무용전공 고등학생과 대학생들의 다차원적 완벽주의와 섭식장애의 관계)

  • Hong, Go-Eun;Kim, Dong-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.6
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    • pp.379-388
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    • 2016
  • High school and college students majoring in dance have different types of stress because of their different circumstances and goals. The purpose of this study was to investigate the relation between multidimensional perfectionism and eating disorder in high school and college students who are majoring in dance. Questionnaires for eating disorder (Eating Disorder Inventory-2(EDI-2) made by Garner (1990) and adapted by Lee (1998)) and multidimensional perfectionism (Multidimensional Perfectionism Scale(F-MPS) made by Frost (1990) and translated by Hyun (1992) were utilized after the sentences in the questionnaires were partially revised and (rendered more appropriate for?) the purpose of this study. The questionnaires were completed by all of the subjects (n=250), but 32 of them were excluded due to insincere answers. Thus, a total of 218 questionnaires were analyzed using SPSS version 21.0. The results showed that the students with a higher education level and who were more career oriented were more likely to suffer from multidimensional perfectionism and eating disorder. In addition, multidimensional perfectionism (concern about mistakes, constant personal and parental expectation) resulted in the development and maintenance of eating disorder for the students majoring in dance. In conclusion, higher education level and greater career orientation induce greater stress in dance major students and cause them to have an incorrect physical image. Thus, these factors may cause higher psychological pressure leading to multidimensional perfectionism and eating disorder. Therefore, these students need to know how to correctly manage their body weight and how to prevent eating disorder.

A Case of Giant Cell Interstitial Pneumonia (거대세포 간절성 폐렴(Giant Cell Interstitial Pneumonia) 1예)

  • Kang, Kyeong-Woo;Park, Sang-Joon;Suh, Gee-Young;Han, Joung-Ho;Chung, Man-Pyo;Kim, Ho-Joong;Kwon, O-Jung;Rhee, Chong-H.;Choi, Jae-Wook
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.260-267
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    • 2000
  • Giant cell interstitial pneumonia. a synonym for hard metal pneumoconiosis, is a unique form of pulmonary fibrosis resulting from an exposure to hard metal dust. A case of biopsy-proved giant cell interstitial pneumonia in the absence of appropriate history of exposure to hard metal dust is reported. The patient presented with clinical features of chronic interstitial lung disease or idiopathic pulmonary fibrosis. He worked in a chemical laboratory at a fertilizer plant, where he had been exposed to various chemicals such as benzene and toluene. He denied having any other hobby in his house or job at work, which may have exposed him hard metal dust. High-resolution CT scan revealed multi-lobar distribution of ground glass opacity with peripheral and basal lung predominance. The retrieved fluid of bronchoalveolar lavage contained asbestos fiber and showed neutrotphil predominance. Surgical lung biopsy was performed for a definite diagnosis. Lung specimen showed alveolar infiltration of numerous multinucleated giant cells with mild interstitial fibrosis. Upon detailed examination of the lung tissue, one asbestos body was found. An analysis for mineral contents in lung tissue was performed. Compared with the control specimen, the amount of cobalt and several hard metal components in the lung tissue of this patient was ten times higher. We speculated that the inconsistency between occupational history and the findings of pathologic and mineralogical analyses could be explained by the difference in individual immunologic reactivity to hard metal dust despite the relatively small amount of unrecognized environmental exposure(ED: It's hard to understand what this phrase is trying to say).

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Effect of Earthing Mat on the Quality of Sleep (어싱매트가 수면의 질에 미치는 영향)

  • Yum, Byeong Soo;Park, Jae Beum;Kim, Ki-Youn
    • Journal of Environmental Health Sciences
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    • v.46 no.1
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    • pp.103-109
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    • 2020
  • Objectives: Using as a sleep evaluation tool the Pittsburgh Sleep Quality Index (PSQI), this paper studied the effects of earthing on the amount and quality of sleep by examining a patient population of people who used and did not use earthing mats and a group of general healthy people. Methods: From September to November 2019, 30 patients who voluntarily used an earthing mat, 40 patients who did not use an earthing mat, and 40 healthy people who did not use an earthing mat were selected. A questionnaire applying the PSQI (Pittsburgh Sleep Quality Index) after being translated into Korean was distributed starting November 29, 2019 to 110 subjects. Out of them, 101 subjects who completed the questionnaire were examined. All statistics used SPSS 25.0. Results: The first overall score showed that all three groups had problems sleeping, with five points or more, but the general population had better sleep quality than the patient group. It also showed that the using matgroup had better quality of sleep than the ones that did not use the earthing mat In addition, the analysis of the third group through the variance analysis showed significance at >0.05 for the general population and the patient group. Based on this, a multi-comparison analysis of the third group showed significantly less than 0.05 in patients who do not use an earthing mat compared to the public. First of all, there are no statistically significant differences between the three groups in subjective sleep quality, sleep latency, and sleep time, but an analysis of multiple comparison analysis with the general population group showed that the quality of sleep was worse compared to those that used the mat. In addition, sleep efficiency, sleep disorder, sleeping pills, and daytime dysfunction were found to be less than >0.05 in the three groups. Conclusions: These results suggest that if you ground your body to Earth during sleep, the secretion of cortisol will decrease night levels, sync more with the natural 24-hour circulation rhythm profile, and that when you sleep, sleep is better and pain and stress are associated with the study. While the preceding study cannot confirm that contact with the ground affects the quality of sleep, it suggests that it is relevant as shown in this paper.

Development of Structure Analysis Program for Jointed Concrete Pavement Applying Load Discretization Algorithm (하중변환 알고리듬을 적용한 줄눈 콘크리트 포장해석 프로그램 개발)

  • Yun, Tae-Young;Kim, Ji-Won;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.5 no.4 s.18
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    • pp.1-11
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    • 2003
  • Recently, the new pavement design method considering Korean environment and the specification for improving performance of pavement are being developed in Korea. The Jointed Concrete Pavement Program Applying Load Discretization Algorithm (called HEART-JCP) is one of the results of Korea Pavement Research Project in Korea. HEART-JCP program is developed to analyze various loading condition using the load discretization algorithm without mesh refinement. In addition, it can be modified easily into multi-purpose concrete pavement nidyses program because of the modularized structure characteristic of HEART-JCP. The program consists of basic program part and load discretization part. In basic program part, the displacement and stress are computed in the concrete slab, sub-layer, and dowel bar, which are modeled with plate/shell element, spring element and beam element. In load discretization program part, load discretization algorithm that was used for the continuum solid element is modified to analyze the model with plate and shell element. The program can analyze the distributed load, concentrated load, thermal load and body load using load discretization algorithm. From the result of verification and sensitivity study, it was known that the loading position, the magnitude of load, and the thickness of slab were the major factors of concrete pavement behavior as expected. Since the result of the model developed is similar to the results of Westergaard solution and ILLISLAB, the program can be used to estimate the behavior of jointed concrete pavement reasonably.

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A Study on the Development of Multifuntional Real-Time Inclination and Azimuth Measurement System (다용도 실시간 경사각과 방위각 연속 측정 시스템 개발연구)

  • Kim, Gyuhyun;Cho, Sung-Ho;Jung, Hyun-Key;Lee, Hyosun;Son, Jeong-Sul
    • Journal of the Korean earth science society
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    • v.34 no.6
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    • pp.588-601
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    • 2013
  • In geophysics and geophysical exploration fields, we can use information about inclination and azimuth in various ways. These include borehole deviation logging for inversion process, real-time data acquisition system, geophysical monitoring system, and so on. This type of information is also necessarily used in the directional drilling of shale gas fields. We thus need to develop a subminiature, low-powered, multi-functional inclination and azimuth measurement system for geophysical exploration fields. In this paper, to develop real-time measurement system, we adopt the high performance low power Micro Control Unit (made with state-of-the-art Complementary Metal Oxide Semiconductor technology) and newly released Micro Electro Mechanical Systems Attitude Heading Reference System sensors. We present test results on the development of a multifunctional real-time inclination and azimuth measurement system. The developed system has an ultra-slim body so as to be installed in 42mm sonde. Also, this system allows us to acquire data in real-time and to easily expand its application by synchronizing with a depth encoder or Differential Global Positioning System.

A Longitudinal Study of the Relationship Between Health Behavior Risk Factors and Dependence in Activities of Daily Living (건강위험행태인자와 일상생활 의존성과의 관련성에 대한 추적자료 분석)

  • Jung, Sang-Hyuk;Ostbye, Truls;Park, Kyoung-Ok
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.3
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    • pp.221-228
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    • 2006
  • Objectives: The purpose of this study was to shed further light on the effect of modifiable health behavior risk factors on dependence in activities of daily living, defined in a multidimensional fashion. Methods: The study participants were 10,278 middle aged Americans in a longitudinal health study, the Health and Retirement Survey (HRS). A multi-stage probability sampling design incorporating the effect of population sizes (Metropolitan and non-metropolitan), ethnicity (the non- Hispanic White, the Hispanic, and the Black), and age (age 51-61) was utilized. Basic Activities of Daily Living (ADL) were measured using five activities necessary for survival (impairment in dressing, eating, bathing, sleeping, and moving across indoor spaces). Explanatory variables were four health behavior risk factors included smoking, exercise, Body Mass Index (BMI), and alcohol consumption. Results: Most participants at baseline were ADL independent (1992). 97.8% of participants were independent in all ADL's at baseline and 78.2% were married. Approximately 27.5% were current smokers at baseline, and the subjects reported moderate or heavy exercise were 74.8%. All demographic characteristics and behavioral risk factors were significantly associated with the ADL status at Wave 4 except alcohol consumption. Risk behaviors such as current smoking, sedentary life style and high BMI at Wave 1 were associated with ADL status deterioration; however, moderate alcohol consumption tended to be more related to better ADL status than abstaining at Wave 4. ADL status at Wave 1 was the strongest factor and the next was exercise and smoking affecting ADL status at Wave 4. People who were in ADL dependent at Wave 1 were 15.17 times more likely to be ADL dependent at Wave 4 than people who were in ADL independent at Wave 1. Concerning smoking cigarettes, people who kept only light exercise or sedentary life style at Wave 1 were 1.70 times more likely to be died at Wave 4 than the people who did not smoke at Wave 1. Conclusions: All demographics and health behaviors at wave 1 had consistently similar OR trends for ADL status to each other except alcohol consumption. Smoking and exercise in health behaviors, and age and gender in demographics at Wave 1 were significant factors associated with ADL group separation at Wave 4.

A case of lethal kwashiorkor caused by feeding only with cereal grain (미음 수유만으로 발생한 치명적인 Kwashiorkor 1례)

  • Lee, Hyun Ju;Km, Kyung Hye;Park, Hye Jin;Lee, Kye Hyang;Lee, Gyeong Hoon;Choi, Eun Jin;Kim, Jin Kyung;Chung, Hai Lee;Kim, Woo Taek
    • Clinical and Experimental Pediatrics
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    • v.51 no.3
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    • pp.329-334
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    • 2008
  • Kwashiorkor is a syndrome of severe protein malnutrition, which manifests itself in hypoalbuminemia, diarrhea, dermatitis, and edema. It can be life-threatening due to associated immune deficiency and an increased susceptibility to infections. Kwashiorkor should be treated early with nutritional support and the control of infection. Dilated cardiomyopathy may develop during the treatment and in such cases a poor prognosis is expected. Kwashiorkor has been known as a common disease of poor countries. To date, in fact, there has been no report of kwashiorkor leading to death in technically advanced countries. We here report a fatal case of a baby girl admitted with kwashiorkor. She had been fed only with cereal grain mixed with juice, without any protein supplement, for 2 months. This diet was deficient not because of poverty, but due to the illiteracy of her parents. The patient suffered from diarrhea, whole body edema, hypothermia, and dermatitis. Laboratory findings revealed an immune-deficient state featuring leukopenia and decreased immunoglobulin. Blood and urine cultures revealed Alcaligenes Xylosoxidans growth. The patient was fed frequent small amounts of protein-containing formula and intravenous albumin and micronutrients were administered for nutritional support. She was also treated with intravenous immunoglobulin and antibiotics in order to control infection. Nevertheless, she developed dilated cardiomyopathy and multi-organ failure and died. We review this case in light of the literature.

Genetic Relationship of Productive Life, Production and Type Traits of Korean Holsteins at Early Lactations

  • Wasana, Nidarshani;Cho, GwangHyun;Park, SuBong;Kim, SiDong;Choi, JaeGwan;Park, ByungHo;Park, ChanHyuk;Do, ChangHee
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.9
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    • pp.1259-1265
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    • 2015
  • The present study was performed to study the genetic relationship of productive life with production and type traits of Korean Holsteins at first three lactations. The data for the analysis from 56,054, 28,997, and 11,816 animals of first, second and third parity cows which were born from 2006 to 2011 were collected by Dairy Cattle Improvement Center, National Agricultural Co-operative Federation. Milk, protein and fat yields adjusted for 305 days and average somatic cell score considered as production traits and analyzed type traits were stature, strength, body depth, dairy form, rump angle, rump width, rear leg side view, foot angle, front attachment placement, rear attachment height, rear attachment width, udder cleft, udder depth, front teat placement and front teat length. A multi trait genetic analysis was performed using Wombat program with restricted maximum likelihood animal model composed of fixed effect of birth year, farm and the random effect of animal and random residual effect according to the traits. Heritability estimates of productive life were between 0.06 and 0.13. Genetic and phenotypic correlations between production and productive life traits ranged from 0.35 to 0.04 for milk, 0.16 to 0.05 for protein and 0.18 to 0.02 f 15-0034 (2nd) 150520 or fat. Somatic cells score showed a negative genetic and phenotypic correlation with productive life and also udder type traits, indicating that the selection for higher udder traits will likely to improve resistance to mastitis and persistence in the herd. Among all dairy form type traits, udder characters such as udder cleft showed a significant relationship with productive life. However, a specific change of heritabilities or correlations were not observed with the change of parity. Moreover, further studies are needed to further confirm the significance of the above traits and the effect of parity on above relationships in order to minimize both voluntary and involuntary culling rates while improving herd health and maintaining high yielding dairy cows.