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

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SIMULATIONS OF THE INTERACTING MAGELLANIC SYSTEM

  • GARDINER LANCE T.;NOGUCHI MASAFUMI
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.93-94
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    • 1996
  • The Galaxy and the Large and Small Magellanic Clouds (LMC and SMC respectively) form a triple system of mutually interacting galaxies. We have carried out a set of N-body simulations on the gravitational interaction of the SMC with the Galaxy and the LMC in order to model prominent features such as the Magellanic Stream, the inter-Cloud Bridge, and the large depth of the SMC which are thought to be products of the tidal interactions among the members of this system.

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TRIBOLOGY:STATE OF THE ART AND ADVANCES IN CIS

  • Myshkin, N.K.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1993.12a
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    • pp.1-31
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    • 1993
  • General state of research in fundamentals and applied areas of tribology is analysed with taldng account of changes in structure of funding and other aspects of transfer from centmllzed state economy to market one under simultaneous effect of USSR disintegration to independent states. Belarus Tribology Society as a coordinating body is presented. Activities of the major centers of research in friction, wear and lubrication are shown. Recent advances in development of analytical and calculation methods, surface characterization, wear testing and standardization, condition monitoring and tribomaterials are considered.

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The Effect of Repetitive Insertion and Pullout of Spinal Screws on Pullout Resistance : A Biomechanical Study (척추 수술에 사용되는 나사못의 반복 삽입과 인출이 인장항력에 미치는 영향 : 생체 역학적 연구)

  • Bak, Koang Hum;Ferrara, Lisa;Kim, Kwang Jin;Kim, Jae Min;Kim, Choong Hyun;Benzel, Edward C.
    • Journal of Korean Neurosurgical Society
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    • v.30 no.2
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    • pp.131-136
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    • 2001
  • Object : The clinical uses of screws are increasing with broader applications in spinal disorders. When screws are inserted repeatedly to achieve optimal position, tips of screw pitch may become damaged during insertion even though there are significant differences in the moduli of elasticity between bone and titanium. The effect of repeated screw insertion on pullout resistance was investigated. Methods : Three different titanium screws(cortical lateral mass screw, cancellous lateral mass screw and cervical vertebral body screw) were inserted into the synthetic cancellous material and then extracted axially at a rate of 2.4mm/min using Instron(Model TT-D, Canton, MA). Each set of screws was inserted and pulled out three times. There were six screws in each group. The insertional torque was measured with a torque wrench during insertion. Pullout strength was recorded with a digital oscilloscope. Results : The mean pullout force measurements for the cortical lateral mass screws($185.66N{\pm}42.60$, $167.10N{\pm}27.01$ and $162.52 N{\pm}23.83$ for first, second and third pullout respectively : p=0.03) and the cervical vertebral body screws($386.0N{\pm}24.1$, $360.2N{\pm}17.5$ and $330.9N{\pm}16.7$ : p=0.0024) showed consecutive decrease in pullout resistance after each pullout, whereas the cancellous lateral mass screws did not($194.00N{\pm}36.47$, $219.24N{\pm}26.58$ and 199.49N(36.63 : p=0.24). The SEM after insertion and pullout three times showed a blunting in the tip of the screw pitch and a smearing of the screw surface. Conclusions : Repetitive screw insertion and pullout resulted in the decrease of pullout resistance in certain screws possibly caused by blunting the screw tip. This means screw tips suffer deformations during either repeated insertion or pullout. Thus, the screws that have been inserted should not be used for the final construct.

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Indications and findings of flexible bronchoscopy in trauma field in Korea: a case series

  • Dongsub Noh
    • Journal of Trauma and Injury
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    • v.36 no.3
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    • pp.206-209
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    • 2023
  • Purpose: Since its implementation, flexible fiberoptic bronchoscopy (FBS) has played an important role in the diagnosis and treatment of tracheobronchial tree and pulmonary disease. Although FBS is often performed by endoscopists, it has also been performed by surgeons, albeit rarely. This study investigated FBS from the surgeon's perspective. Methods: This retrospective study included patients who underwent FBS performed by a single thoracic surgeon between March 2017 and December 2021. Accordingly, the epidemiology, purpose, results, and complications of FBS were analyzed. Results: A total of 47 patients received FBS, whereas 13 patients underwent repeat FBS. Their mean age was 60.7 years. The main organs injured involved the chest (n=22), brain (n=9), abdominal organ (n=7), cervical spine (n=4), extremities (n=4), and face (n=1). The average Injury Severity Score was 22.5. Indications for FBS included atelectasis or haziness on chest x-ray (n=34), pneumonia (n=17), difficult ventilator management (n=7), percutaneous dilatory tracheostomy (n=3), blood aspiration (n=2), foreign body removal (n=2), and intubation due to a difficult airway (n=1). The findings of FBS were mucous plugs (n=36), blood and blood clots (n=16), percutaneous dilatory tracheostomy (n=3), foreign bodies (n=2), granulation tissue at the tracheostomy site (n=2), tracheostomy tube malposition (n=1), bronchus spasm (n=1), difficult airway intubation (n=1), and negative findings (n=5). None of the patients developed complications. Conclusions: FBS is an important modality in the trauma field that allows for the possibility of diagnosis and therapy. With sufficient practice, surgeons may safely perform FBS at the bedside with relative ease.

Effects of ᴅ-allulose on body fat accumulation in rats fed severely carbohydrate-restricted diets containing beef tallow or soybean oil

  • Tatsuhiro Matsuo;Shunsuke Higaki;Reiko Inai;Susumu Mochizuki;Akihide Yoshihara;Kazuya Akimitsu
    • Journal of Nutrition and Health
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    • v.57 no.2
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    • pp.185-195
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    • 2024
  • Purpose: The carbohydrate-restricted diet has been recognized to be effective into preventing and alleviating lifestyle-related diseases, such as obesity and type 2 diabetes. The rare sugar ᴅ-allulose is a functional monosaccharide with anti-obesity effects. In the present study, we examined the effects of dietary ᴅ-allulose on body fat accumulation in rats fed severely carbohydrate-restricted diets containing high concentrations of different fats, beef tallow, or soybean oil. Methods: Male Wistar rats (n = 35, 3-week-old) were divided into 5 groups: One chow-fed control (C) group, and four carbohydrate-restricted groups, namely, beef tallow (B), beef tallow + ᴅ-allulose (BA), soybean oil (S), and soybean oil + ᴅ-allulose (SA), with free access to the diet and water for 8 weeks. The B and BA diets contained 23% beef tallow and 2% soybean oil, whereas the S and SA diets contained 25% soybean oil. Furthermore, the BA and SA diets contained 5% ᴅ-allulose. Results: The final body weight, weight gain, and food intake were significantly higher, and food efficiency was significantly lower in the control group compared to the other carbohydrate-restricted groups. Intra-abdominal adipose tissue, carcass fat, and total body fat weights were not influenced by dietary fat type or ᴅ-allulose supplementation, except for the epididymal adipose tissue weight. In contrast, carbohydrate restriction suppressed body weight gain in rats, but remarkably increased body fat accumulation. Conclusion: Under carbohydrate-restricted conditions, no anti-obesity effects of dietary ᴅ-allulose were observed, regardless of the dietary fat type. The causes of these effects are unknown. However, they may be influenced by a very low carbohydrate and high protein diet. Further research is required to elucidate the effects of ᴅ-allulose under various nutrient compositions with different fat, carbohydrate, and protein energy ratios.

Effects of the Whole-body Vibration Exercise Combined with Ankle Joint Mobilization on the Gait Function and Balancing Ability in Stroke Patients: A Preliminary Randomized, Controlled Study (발목관절 가동술과 결합한 전신진동운동이 뇌졸중 환자의 보행 기능과 균형 능력에 미치는 영향: 무작위 대조 예비연구)

  • Su-Bong, Son;Kyoung-Wook, Choi;Tae-Wu, Kim;Sang-Young, Park;Yong-Jun, Cha
    • Journal of the Korean Society of Physical Medicine
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    • v.17 no.4
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    • pp.103-111
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    • 2022
  • PURPOSE: This study was performed to investigate the effects of the whole-body vibration exercise combined with ankle joint mobilization on the gait and balancing ability in patients with hemiplegic stroke. METHODS: A total of 19 patients at a rehabilitation hospital who had suffered a hemiplegic stroke were randomly assigned to the experimental group (whole-body vibration exercise combined with ankle joint mobilization, n=10) or control group (whole-body vibration exercise, n=9). All participants underwent 30 min of comprehensive rehabilitation therapy (5 × /week for 6 weeks). Additionally, the experimental group performed the whole body vibration exercise and ankle joint mobilization (15 minutes each, 30 minutes total, 3 × / week for 6 weeks). In the control group, only the whole- body vibration exercise was performed in the same manner and not the ankle joint mobilization. The gait and balancing abilities were measured before and after the 6-week training. RESULTS: Significant improvements were observed in the 10-m walk test, timed up-and-go (TUG) test, center of pressure (COP) path length, and COP path velocity in the experimental group (p < .05). The experimental group showed a larger decrease in the COP path length and velocity than the control group (COP path length, -10.27 mm vs. -3.67 mm, p < .05; COP path velocity, -.33 cm/sec vs. -.13 cm/sec, p < .05, respectively). CONCLUSION: The whole-body vibration exercise combined with ankle joint mobilization could be effective in improving the gait and balancing ability of stroke patients and could also be more effective for improving the static balance ability than the general whole-body vibration exercise alone.

NUMERICAL METHOD IN WAVE-BODY INTERACTIONS

  • MOUSAVIZADEGAN S. H.;RAHMAN M.
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.73-91
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    • 2005
  • The application of Green's function in calculation of flow characteristics around submerged and floating bodies due to a regular wave is presented. It is assumed that the fluid is homogeneous, inviscid and incompressible, the flow is irrotational and all body motions are small. Two methods based on the boundary integral equation method (BIEM) are applied to solve associated problems. The first is a low order panel method with triangular flat patches and uniform distribution of velocity potential on each panel. The second method is a high order panel method in which the kernels of the integral equations are modified to make it nonsingular and amenable to solution by the Gaussian quadrature formula. The calculations are performed on a submerged sphere and some floating spheroids of different aspect ratios. The excellent level of agreement with the analytical solutions shows that the second method is more accurate and reliable.

Nutrition Value of Chlorella (II) (Chlorella Protein의 영양가(營養價)에 관한 연구(硏究) (II))

  • Park, Chung-Ung;Hwang, Ho-Kwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.3 no.1
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    • pp.43-46
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    • 1974
  • It was reported that the digestion ratio of chlorella was low because it had a low metabolic rate in body. Generally, the thickness of a cell membrane of it is $200-250\;{\AA}$, the weight of it is approximatly 13% of the total weight of a dry cell. And it is composed of protein, lipid, hemicellulose and ash etc. So, in order to elevate the digestion ratio of chlorella in body, we experimented the crude treatment methods of chlorella. The results obtained in this experiment are summarized as follows : 1. The digestion ratios calculated from ordinary N- balance method were 83.05% for 10% chl. (b) plus diastase group ; 81.25% for 10% chl. (b) plus amylase group, and 79.23% for 10% chl. (b), 58.55% for 10% chl. (a). 2. Biological values from this method were 80.25% for 10% chl. (b) plus diastase group, and 60% for 10% for chlorella(a).

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Proteasome Inhibition Activity of Hericium erinaceum (노루궁뎅이 버섯의 Proteasome 저해 작용)

  • Lee, Han-Na;Kim, Yu-Jin;Shim, Sang-Hee
    • Korean Journal of Pharmacognosy
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    • v.39 no.4
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    • pp.365-368
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    • 2008
  • Recently proteasome inhibitors have been emerged as potential anticancer agents. In a continuous study on exploring proteasome inhibitors from natural products, fruiting body of Hericium erinaceum was investigated. The MeOH extracts of the fruiting body of Hericium erinaceum was fractionated with several solvents and the fractions were evaluated on the activity to screen the proteasome inhibitors. The n-Hexane and CHCl3 frs. showed potent activity, of which chemical investigations led to ergosterol peroxide (1), hericenones C (2) and D (3). Their structures were determined by spectroscopic methods such as $^1H$-NMR, $^{13}C$-NMR, and FABMS spectra.

Clinical effect of Gigong therapy by measuring ABR-2000 on Neck Stiffness Patients (항강(項强)환자에게 기공외기요법(氣功外氣療法)을 응용한 경우의 ABR-2000측정 결과로 분석한 임상적 유효성)

  • Jung Eun-Young;Na Sam-Sik;Lee Ki-Nam
    • Journal of Korean Medical Ki-Gong Academy
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    • v.7 no.1
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    • pp.61-76
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    • 2003
  • Objective : This study is performed to evaluate the clinical effect of Gigong therapy by measuring ABR-2000 on neck stiffness patients. Methods : Among the outpatients with neck stiffness who visited to Wolgot Oriental Medical Clinic from 16 to 26, June 2003, we selected 22 persons. They were divided into two groups. One group was treated with acupuncture, cupping therapy added to Gigong therapy and the other was treated with the two formers. Before and after therapy, we measured ABR-2000 from the head, two hands and two feet. We selected 11 persons without specific conditions as a control group. Results : Between the control and the Gigong therapy, there were significant difference of differences. Gigong therapy plays role in relaxing inner and outer of the body. Conclusion : This result indicated that Gigong therapy is to regulate autonomic nerve and to relax the inner and outer of the body.