• Title/Summary/Keyword: methods: n-body

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

  • Sung, Mankyu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.10a
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    • pp.400-403
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    • 2022
  • This paper propose a GPU-based N-body collision detection algorithm using LBVH (Linear Bounding Volume Hierarchy) technique. This algorithm introduces a new modified Morton code scheme where the codes use an information about how much each body takes a space in the screen space. This scheme improves the GPU sorting performance of the N-Body because it culls out invisible objects in natural manner. Through the experiments, we verifies that the proposed algorithms can have at least 15% performance improvement over the existing methods

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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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    • v.9 no.1
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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.

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

  • Kim, Unjin;Lee, Yun Mi
    • Journal of Korean Critical Care Nursing
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    • v.10 no.3
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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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Effects of High Frequency Therapy on Localized Obesity (고주파요법이 부분비만치료에 미치는 영향)

  • Shin, Seung-Uoo;Choi, Young-Min;Shim, Woo-Jin
    • Journal of Korean Medicine for Obesity Research
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    • v.6 no.2
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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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The Effects of Aerobic Exercise on Body Temperature and Blood Components on Smoking Male University Students (남자 대학생들의 흡연여부에 따른 유산소운동이 체열과 혈액 검사치에 미치는 영향)

  • Lee, Jin;Bang, Hyun-Soo
    • Journal of Korean Physical Therapy Science
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    • v.24 no.2
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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
    • Korean Journal of Exercise Nutrition
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    • v.23 no.2
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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.

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

  • Ha, Y.R.;An, N.H.
    • Journal of Power System Engineering
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    • v.16 no.5
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    • pp.40-46
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    • 2012
  • For free surface flow problem, a high-order spectral/boundary element method is adapted as an efficient numerical tool. This method is one of the most efficient numerical methods by which the nonlinear gravity waves can be simulated and hydrodynamic forces also can be calculated in time domain. In this method, the velocity potential is expressed as the sum of surface potential and body potential. Then, surface potential is solved by using the high-order spectral method and body potential is solved by using the high-order boundary element method. Using the combination of these two methods, the free surface flow problems of a submerged moving body are solved in time domain. In the present study, lifting surface theory is added to the former work to include effects of lift force. Therefore, a new formulation for the basic mathematical theory is introduced to contain the lift body in calculation.

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

  • FUX ROGER
    • Journal of The Korean Astronomical Society
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    • v.34 no.4
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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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Analysis of difference in body fluid composition and dietary intake between Korean adults with and without type 2 diabetes mellitus (한국성인의 제2형 당뇨병 유무에 따른 체액 조성 차이 및 영양소 섭취량 분석)

  • Yu-Gyeong Kim;Ha-Neul Choi ;Jung-Eun Yim
    • Journal of Nutrition and Health
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    • v.56 no.4
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    • pp.377-390
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    • 2023
  • Purpose: Diabetes mellitus (DM) causes body fluid imbalance because of hyperglycemia, but there is a lack of research on the relationship between DM and body fluid imbalance in the Korean population. This study compared the differences in body fluid composition and dietary intake between individuals with type 2 DM (T2DM) and a normal control (NC) group without the disease. Methods: In this study, 36 subjects with T2DM and 21 without diabetes were divided into the T2DM and NC groups. The subjects were divided into four subgroups to assess differences in body fluid volume according to sex: men T2DM group (n = 24), men NC group (n = 9), women T2DM group (n = 12), and women NC group (n = 12). The body fluid composition was measured using bioelectrical impedance analysis, including intracellular water (ICW), extracellular water (ECW), total body water (TBW), ECW/ICW, and ECW/TBW. Nutrient intake was evaluated using their dietary records. Results: The results showed that the ECW/ICW and the ECW/TBW were significantly higher in the T2DM group compared to the NC group. Both men and women in the T2DM group showed significantly higher ECW/ICW and ECW/TBW than the respective NC group. The T2DM group had a higher carbohydrate, dietary fiber, vitamin A, vitamin C, sodium, and potassium intake per 1,000 kcal and lower total daily energy, fat, and cholesterol intake per 1,000 kcal than the NC group. Conclusion: These results suggest a positive association between T2DM and body fluid imbalance. This study can be used widely as basic data for the evaluation and diagnosis of diabetic complications in the future.

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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    • v.22 no.6
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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.