• 제목/요약/키워드: methods: n-body

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가시화 기반 N-body GPU 충돌 체크 방법 (Visibility based N-Body GPU Collision Detection)

  • 성만규
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2022년도 추계학술대회
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    • pp.400-403
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    • 2022
  • 본 논문은 가시화 기반 LBVH(Linear Bounding Volume Hierarchy))을 이용한 빠른 GPU기반 N-body 충돌 체크 알고리즘을 제안한다. 본 알고리즘은 움직이는 n-body 개체에 대한 수정된 모튼코드(Morton code)를 이용하며, 이 모튼코드는, 일반적으로 사용되는 개체의 위치 정보뿐 아니라 이 개체가 스크린상에 차지하는 가시화 영역 정보를 이용하기 때문에, 카메라의 위치 및 방향에 따라 화면상에 차지하는 영역이 작은 개체에 대한 빠른 GPU기반 정렬(sorting)이 가능하게 된다. 실험을 통해, 본 논문에서 제안하는 방법이 기존 방법보다 15%이상 성능 향상이 있음을 알게 되었다

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NUMERICAL METHODS FOR COMPUTATIONS OF NONEQUILIBRIUM HYPERSONIC FLOW AROUND BODIES

  • Park, Tae-Hoon;Kim, Pok-Son
    • Journal of applied mathematics & informatics
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    • 제9권1호
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    • pp.1-13
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    • 2002
  • In this paper we present numerical methods fur computations of nonequilibrium hypersonic flow of air around bodies including chemical reaction effects and present numerical result of the flow over concave corners. We developed implicit finite difference method to overcome numerical difficulties with the lack of resolution behind the shock and near the body. Using our method we were able to find details of the flow properties near the shock and body and were able to continue the computation of the flow for a long distance from the corner of the body.

전신마취 복부 수술 후 적극적인 가온요법이 통증, 체온 및 체온불편감에 미치는 효과 (The Effects of Active Warming on Pain, Temperature, and Thermal Discomfort in Postoperative Patients after General Anesthesia for Abdominal Surgery)

  • 김언진;이윤미
    • 중환자간호학회지
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    • 제10권3호
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    • pp.53-64
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    • 2017
  • Purpose : This study investigated the effects of active warming using a Warm Touch warming system or a cotton blanket in postoperative patients after general anesthesia for abdominal surgery. Methods : This quasi-experimental study utilized two experimental groups and one control group: a cotton-blanket group (n = 25) were warmed with a cotton blanket and a sheet; a forced-air warming group (n = 24) were warmed with a Warm Touch warming system, a cotton blanket, and a sheet; and a control group (n = 25) were warmed with a sheet. Measurement variables were postoperative pain, body temperature, and thermal discomfort. Data were analyzed using a one-way ANOVA, ${\chi}^2-tests$, Fisher's exact test, and a repeated measures ANOVA. Results : The effects of active warming using a Warm Touch warming system and a cotton blanket on postoperative patients was significant in reducing pain (F = 13.91, p < .001) and increasing body temperature (F = 12.49, p < .001). Conclusion : Active warming made a significant difference in pain and body temperature changes. Active warming methods may help patients' postoperative recovery and prevent complications. Further research is needed to explore the effects and side effects of active warming on recovering normothermia.

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고주파요법이 부분비만치료에 미치는 영향 (Effects of High Frequency Therapy on Localized Obesity)

  • 신승우;최영민;심우진;이형철;김길수
    • 한방비만학회지
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    • 제6권2호
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    • pp.75-83
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    • 2006
  • Objectives : This study was performed to identify the effects of high frequency therapy on localized obesity. Methods : This trial was carried out in 12 volunteers. Volunteers were divided into 3 groups; upper arm group (n=4), thigh group (n=4) and abdomen group (n=4) according to local obesity type. Body weight and body fat were measured by Inbody 720 and CT (Computed Tomography) immediately before and following high frequency therapy. Diathermy was performed twice a week for 4 weeks for a total of 8 treatments. Results : In the upper arm group, body weight, body fat mass, fat area by CT scan and circumference were increased after treatment but not significantly (p>0.05). In the thigh group, body weight, body fat mass and circumference were decreased and fat area by CT scan was increased but both not significantly (p>0.05). In the abdomen group, significant differences were not found despite decreases in body weight, body fat mass, visceral fat and subcutaneous fat after diathermy (p>0.05). Conclusions : There was no significant effects of high frequency therapy on localized obesity.

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남자 대학생들의 흡연여부에 따른 유산소운동이 체열과 혈액 검사치에 미치는 영향 (The Effects of Aerobic Exercise on Body Temperature and Blood Components on Smoking Male University Students)

  • 이진;방현수
    • 대한물리치료과학회지
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    • 제24권2호
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    • pp.1-8
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    • 2017
  • Background: To determine the effect of Aerobic exercise(AE) on body temperature and blood components in smoking male subjects. Methods: 15 subjects were randomly assigned to Smoking group(smoking, n=8) and Non-smoking group(Non-smoking, n=7). To measure body temperature and blood components. For evaluation of body temperature, the Infrared Thermography, IT was used, and blood components was measured using the Complete Blood cell Count(CBC). Results: The results shows that White blood cell (WBC) was significantly (p<0.05) increased in Smoking group. and no significantly difference between groups(p<0.05). Regarding body temperature, was significantly (p<0.05) increased in Smoking group and Non-somking group. and no significantly difference between groups(p<0.05). Conclusion: Aerobic exercise can increase White blood cell and body temperature in smokers.

Comparison of association between physical activity and resting metabolic rate in young and middle-aged Korean adults

  • Hwang, Hyejung;Jung, Won-Sang;Kim, Jisu;Park, Hun-Young;Lim, Kiwon
    • 운동영양학회지
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    • 제23권2호
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    • pp.16-21
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    • 2019
  • [Purpose] The purpose of this study was to comparatively investigate the correlation among body composition, resting metabolic rate (RMR), and physical activity (PA) between young and middle-aged Korean adults. [Methods] A total of 53 [male n=23, female n=30] subjects were included in this study, among whom 34 subjects were healthy young adults [male n=18, female n=16] and 19 were middle-aged adults [male n=5, female n=14]. The body composition and RMR of all the participants were measured after overnight fasting (≥8 h). The Korean version of the WHO Global Physical Activity Questionnaire (GPAQ) was used to assess physical activity. [Results] Body composition was not significantly different between young adults and middle-aged adults. Whole-body bone mineral density and bone mineral contents (BMC) were significantly lower in middle-aged adults than in young adults. Total blood cholesterol (TC) and blood glucose levels were significantly higher in middle-aged adults (TC; 195.21 ± 43.34, glucose; 103.57 ± 12.61 mg/dL) than in young adults. RMR was significantly lower in middle-aged adults (1619.57 ± 290.28 kcal/day) than in young adults (1894.37 ± 405.00 kcal/day). In middle-aged adults physical activity (PA). PA (METs, min, EE) was inversely correlated with fat mass (FM, kg, and %) and blood triglyceride (TG) level in young adults. In middle-aged adults, PA showed a significant positive correlation with lean body mass (LBM), FM (%), and RMR. Furthermore, PA EE showed significant interrelatedness with BMC among middle-aged adults. [Conclusion] These results demonstrated that high PA levels enable LBM and RMR maintenance in middle-aged adults. Furthermore, in young adults, more PA is required to induce change in body composition.

3차원 비선형 조파문제 해석을 위한 수치해법 연구 (A Study of Numerical Method for Analysis of the 3-Dimensional Nonlinear Wave-Making Problems)

  • 하영록;안남현
    • 동력기계공학회지
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    • 제16권5호
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    • pp.40-46
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    • 2012
  • 본 연구에서는 자유표면 유동문제를 효율적으로 계산하기 위한 방법으로서, 수치 파수조를 구현하여 잠수체에 의한 조파현상을 시간영역에서 다룰 수 있는 수치해법에 대하여 소개하였다. 그리고 이를 이용하여 수행된 연구내용들을 검토하고 양력물체의 경우를 포함하기 위하여 개선된 수학적 정식화 및 수치해법의 개요를 다루었다. 임의의 운동을 하는 양력물체에 의한 조파현상을 전산기로 구현하는 수치 파수조는 과중한 계산시간이 문제가 되는데, 이는 수치 Kutta 조건의 구현과 양력표면 후방의 wake 영역을 계산에서 고려해야 하기 때문이다. 따라서 한층 더 수치계산의 효율성이 중요하다고 판단되므로, 본 연구에서 소개된 3차원 고차 스펙트럴/경계요소법(High-Order Spectral/Boundary Element Method)은 자유표면 요소수를 N이라 할 때 그 계산량이 NlogN에 비례(N이 클 때는 거의 선형적으로 비례)하여 증가하므로 기존의 방법들 보다 매우 효율적인 수치해법이라 할 수 있다. 향후, 본 연구의 타당성 검증을 위한 수치코드의 개선과 여러 가지 수치계산결과 비교 등의 노력이 더 필요하다고 생각된다.

PMDSPH: A Hybrid N-Body and SPH Code and Its Application to the Milky Way

  • FUX ROGER
    • 천문학회지
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    • 제34권4호
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    • pp.255-259
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    • 2001
  • PMDSPH is a combined 3D particle-mesh and SPH code aimed to simulate the self-consistent dynamical evolution of spiral galaxies including live stellar and collisionless dark matter components, as well as an isothermal gas component. This paper describes some aspects of this code and shows how its application to the Milky Way helps to recover the gas flow within the Galactic bar region from the observed HI and CO longitude-velocity distributions.

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한국성인의 제2형 당뇨병 유무에 따른 체액 조성 차이 및 영양소 섭취량 분석 (Analysis of difference in body fluid composition and dietary intake between Korean adults with and without type 2 diabetes mellitus)

  • 김유경 ;최하늘 ;임정은
    • Journal of Nutrition and Health
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    • 제56권4호
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    • pp.377-390
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    • 2023
  • 본 연구는 한국인을 대상으로 제2형 당뇨병 환자와 질병이 없는 정상대조군을 비교하여 성별에 따른 체액 불균형 정도와 영양소 섭취량을 평가하고자 하였다. 조사대상자는 총 57명으로, T2DM이 있는 T2DM군 (n = 36)과 T2DM이 없는 정상대조군 (n = 21)으로 나누어 분석하고, 성별에 따른 체액량의 차이를 고려하여 남성 T2DM군 (n = 24), 남성 정상대조군 (n = 9), 여성 T2DM군 (n = 12), 여성 정상대조군 (n = 12)으로 세분화하여 지표들의 특징을 분석하였다. BIA를 통하여 연구대상자의 체액 조성을 분석한 결과, ECW/ICW는 T2DM군이 정상대조군보다 유의적으로 높았고, 부종지수를 나타내는 ECW/TBW는 T2DM군이 정상대조군보다 유의적으로 높게 나타났다. 성별에 따른 체액 조성을 분석한 결과, 남성과 여성 모두 T2DM군은 정상대조군보다 높은 ECW/ICW, ECW/TBW를 보이며 동일한 체수분율 양상이 나타났다. 식사일기를 통해 연구대상자의 영양소 섭취량을 분석한 결과, 1,000 kcal 당 탄수화물, 식이섬유, 비타민 A, 비타민 C, 나트륨, 칼륨 섭취량은 T2DM군이 정상대조군보다 많았고, 1,000 kcal 당 지방, 콜레스테롤 섭취량은 T2DM군이 정상대조군보다 적었다. 본 연구를 통해 T2DM 환자에게서 체액 불균형이 나타날 가능성이 높음을 알 수 있었으며 추후 당뇨 합병증의 평가, 진단의 기초 자료로 널리 활용될 것으로 사료된다.

Effect of Using Electrical Stimulation and Ultrasound with Aerobic Exercise on Local Lipolysis

  • Choi, Sug-Ju;Jeong, Jin-Gu;Seo, Sam-Ki
    • The Journal of Korean Physical Therapy
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    • 제22권6호
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    • pp.13-19
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    • 2010
  • Purpose: This study was designed to measure the effects of weight, abdominal girth, body fat, abdominal fat and cholesterol levels in combination with electrical stimulation, ultrasound and aerobic exercise on obesity and local lipolysis. Methods: Subjects were 30 obese adults who volunteered to take part in the experiment and had no physical diseases. They were randomly divided into three groups: (1) an aerobic exercise group (n=10), (2) an electrical stimulation group with aerobic exercise (n=10), and (3) an ultrasound stimulation group with aerobic exercise (n=10). Each experimental group went through 8 weeks of training. Results: All measured items including weight, girth of the abdomen, body fat, and cholesterol levels showed significant differences among groups. All three groups showed decreases for all items. The electrical stimulation + aerobic exercise group (group II) showed greater effects than the aerobic exercise group (group I) and the ultrasound stimulation group with aerobic exercise (group III). Conclusion: Electrical stimulation + aerobic exercise and ultrasound stimulation + aerobic exercise cause decreases in weight, girth of the abdomen, body fat and cholesterol level compared to aerobic exercise alone. These methods can be considered to be effective adjuvants to aerobic exercise in obese adults.