• 한국전문물리치료학회지
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• 제28권1호
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• pp.59-64
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• 2021

Background: Hip flexor muscles are very important in the hip joint structure as a mover and stabilizer. In addition, isometric hip flexor strength in the supine position needs to be considered with isometric core strength (WICS) to measure a precise strength in a clinical way. Objects: We compared isometric hip flexor strength in the supine position in subjects with and without WICS (between factors) and conditions with and without an external support (within factors). Methods: A total of 34 subjects (16 with WICS, 18 without WICS) participated in this study. We used the double-bent leg-lowering test to divide the subjects in two groups according to the presence of WICS. Isometric hip flexor strength was evaluated in the supine position both with and without an external support condition. The two-way mixed analysis of variance was applied to identify significant differences between groups (with vs. without WICS: between factors) and conditions (with vs. without an external support: within factors). Statistical significance was set at α = 0.05. Results: In subjects with WICS, isometric hip flexor strength was greater with an external support than without it (p = 0.0064). In subjects without WICS, there were no significant differences in isometric hip flexor strength in the presence or absence of an external support (p = 0.075). The isometric hip flexor strength was significantly greater with an external support condition in particular in subjects with WICS. Conclusion: The findings of this study reported that an external support condition in individuals with WICS may contribute to the improvement of isometric hip flexion strength in the supine position. Therefore, isometric core strength should be evaluated to distinguish the weakness between core region and hip flexors.

• 한국전문물리치료학회지
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• 제29권4호
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• pp.282-288
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• 2022

Background: Pilates exercises are used for body shape correction because they can achieve correct posture alignment through spinal stabilization. Objects: This study aimed to determine whether the use of reformers increases the effectiveness of Pilates core exercises on body alignment in standing. Methods: The study included 30 women without known diagnoses of musculoskeletal and neurological disorders or cancer. Those who had taken more than 10 Pilates lessons were excluded. The participants were randomly assigned to either the reformer exercise group or the mat exercise group, and interventional Pilates exercises were performed for 60 minutes a day, three times a week, for a total of 8 weeks. Ten movements of the reformer and mat Pilates core exercise programs were included. Exbody^® 9100 MOMI musculoskeletal analysis equipment (Exbody Inc.) was used to assess the alignment of the standing posture in the frontal plane. Results: As a result of comparing the differences within and between the groups before and after the intervention using the two-way mixed analysis of variance test, height differences in the head, pelvis, left and right, shoulders, scapulas, knees, and ankles in the frontal plane after the intervention were found in both groups. For example, the left-right symmetry of the body alignment in the standing posture was significantly improved within each group (p < 0.05). However, no significant difference was found between the groups (p > 0.05). Conclusion: Both the reformer and mat Pilates core exercises were effective for standing posture alignment, which has clinical significance. If an exercise program is developed based on the analysis of movements necessary for posture improvement and the target muscles to be strengthened, the same effect can be achieved only with mat exercise without using the reformer equipment at the beginner stage.

• International Journal of Fluid Machinery and Systems
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• 제6권4호
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• pp.200-205
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• 2013

In order to investigate the characteristics of unsteady flow in a mixed flow pump guide vane under the small flow conditions, several indicator points in a mixed flow pump guide vane was set, the three-dimensional unsteady turbulence numerical value of the mixed flow pump which is in the whole flow field will be calculated by means of the large eddy simulation (LES), sub-grid scale model and sliding mesh technology. The experimental results suggest that the large eddy simulation can estimate the positive slope characteristic of head & capacity curve. And the calculation results show that the pressure fluctuation coefficients of the middle section in guide vane inlet will decrease firstly and then increase. In guide vane outlet, the pressure fluctuation coefficients of section will be approximately axially symmetrical distribution. The pressure fluctuation minimum of section in guide vane inlet is above the middle location of the guide vane suction surface, and the pressure fluctuation minimum of section in which located the middle and outlet of guide vane. When it is under the small flow operating condition, the eddy scale of guide vane is larger, and the pressure fluctuation of the channel in guide vane being cyclical fluctuations obviously which leads to the area of eddy expanding to the whole channel from the suction side. The middle of the guide vane suction surface of the minimum amplitude pressure fluctuation to which the vortex core of eddy scale whose direction of fluid's rotation is the same to impeller in the guide vane adhere.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.161-164
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• 2002

This study was performed to find out the regression function to calculate the modulus of elasticity of concrete mixed by river coarse aggregate. The distribution of the group of core strength made a normal curve and the effect factor in the modulus of elasticity was 0.97 at the concrete compounded by river coarse aggregate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.357-364
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• 1997

In this experiment high-strength concrete of good workability is made by means of either replacing unit cement quantity to fly-ash by 20% or using low heat cement to reduce the internal hydration heat suggested as the fault of concrete. Concrete is poured through ready mixed concrete to test the ability of applying to the substantial works and is carried out the test of flowing and core strength and record of temperature of imitating specimens. It is capable to apply high-strength concrete replaced to fly-adh 20% to the substantial works through the experiment

• 한국주거학회논문집
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• 제21권5호
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• pp.13-22
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• 2010

This study has the purpose to reveal the differences of residents' using behaviors of living facilities at 3 complexes. The physical characteristics of the complexes have been investigated by a literature study and field survey. In addition, questionnaires were answered by residents on living facilities using behavior on community environment. The tools of analysis are frequency, percentage, and cross tabulation using SPSS WIN 12.0 program. Followings are the results of the study. 1) The developmental concept of 3 complexes maintained its initial identity. (1) The residence-oriented complex, having wider residential space, had better downtown access and more convenient facilities for daily life. (2) The residence-government mixed complex, constructed with an eco-friendly concept, had wider green and public service space and good downtown access but on the other hand, had less convenience facilities because of a short period from construction. (3) The residence-industry mixed complex, located in sub-urbanity and conceding more land for industries, had poor access to downtown but had more convenient facilities for workers' use. 2) The most frequently visited convenience facilities were shopping facilities, large or small, and banks, and activities were commonly done in the complex or adjacent area. This means it is recommended that the developer of the new complex locate convenience facilities in multi-core concentration types or street types rather than one-core concentration types.

• Korean Chemical Engineering Research
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• 제50권6호
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• pp.1086-1092
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• 2012

본 촉매가스화 실험에서 촉매로서 가치가 있는 천연광물과 순수촉매를 사용하여 저급석탄의 $CO_2$분위기하 활성화 에너지 및 생성된 합성가스의 성분을 분석하였다. 먼저 공업 분석과 원소 분석을 통해 6가지 저급석탄의 회분과 황 함유량을 측정하였다. 그 후 Thermogravimetric Analyzer (TGA)를 통해 저급석탄 열분해반응 특성을 고려하여 실험에 가장 적합한 저급석탄을 선정하였다. 선정된 삼화 저급석탄은 촉매와 섞어 $CO_2$분위기하 TGA실험을 진행하였으며, 결과를 토대로 Kissinger 방법을 이용한 활성화 에너지를 구하였다. 또한 shrinking core model을 이용해 활성화 에너지를 구하여 Kissinger 방법과 비교하였다. 그리고 반응기에서 이산화탄소 분위기하 생성된 합성가스는 Gas Chromatography (GC)를 이용하여 분석하였다. 가스를 분석한 결과 수소의 생성량은 $K_2CO_3$를 촉매로 사용하였을 경우 가장 크게 나타났으며, 앞서 구한 활성화 에너지 결과와 일치하는 경향을 나타내었다.

• Korean Chemical Engineering Research
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• 제55권1호
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• pp.99-106
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• 2017

본 연구에서는 인도네시아 저등급 석탄인 Kideco탄을 이용하여 질소 분위기 하에 등온상태에서 촤(char)를 생성한 후 반응가스(스팀,이산화탄소)를 주입하여 합성가스를 생성하는 가스화를 진행하였다. 온도가 반응속도에 미치는 영향을 알아보기 위해 $850^{\circ}C$ 이하의 운전온도(700, 750, 800, $850^{\circ}C$)에서 반응을 진행하였다. 촉매가 미치는 영향을 알아보기 위해 알카리계 촉매인 탄산칼륨과 금속촉매인 니켈을 이용하였으며 두가지 촉매의 혼합비율(1:9, 3:7, 5:5, 7:3, 9:1)을 다르게 하여 연구를 수행하였다. 탄산칼륨은 물리적 혼합을 통해 니켈은 이온교환법을 통해 준비하였다. 기-고체 반응 특성을 알아보기 위해 열중량분석기와 가스크로마토그래피를 통해 얻은 실험결과를 shrinking core model (SCM), volumetric reaction model (VRM), random pore model (RPM) and modified volumetric reaction model (MVRM)에 적용하여 비교하였다.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.589-600
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• 2022

Investigations on the molten-pool sloshing behavior are of essential value for improving nuclear safety evaluation of Core Disruptive Accidents (CDA) that would be possibly encountered for Sodium-cooled Fast Reactors (SFR). This paper is aimed at synthesizing the knowledge from our recent studies on molten-pool sloshing behavior with solid particles conducted at the Sun Yat-sen University. To better visualize and clarify the mechanism and characteristics of sloshing induced by local Fuel-Coolant Interaction (FCI), experiments were performed with various parameters by injecting nitrogen gas into a 2-dimensional liquid pool with accumulated solid particles. It was confirmed that under different particle-bed conditions, three representative flow regimes (i.e. the bubble-impulsion dominant, transitional and bed-inertia dominant regimes) are identifiable. Aimed at predicting the regime transitions during sloshing process, a predictive empirical model along with a regime map was proposed on the basis of experiments using single-sized spherical solid particles, and then was extended for covering more complex particle conditions (e.g. non-spherical, mixed-sized and mixed-density spherical particle conditions). To obtain more comprehensive understandings and verify the applicability and reliability of the predictive model under more realistic conditions (e.g. large-scale 3-dimensional condition), further experimental and modeling studies are also being prepared under other more complicated actual conditions.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.364-369
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• 2002

Hepatitis C virus (HCV) is remarkably efficient at establishing chronic infection. One of the reasons for this appears to be the suppression of the accessory cell function of professional antigen presenting cells. In the present study, the immunosuppressive activity of HCV protein was examined on dendritic cells (DCs) generated from mouse bone marrow progenitor cells in vitro. We found that the DCs forced to express HCV protein have defective allostimulatory ability. DCs expressing HCV protein were phenotypically indistinguishable from normal DCs. However, they were unable to produce IL-12 effectively when stimulated with lipopolysaccharide. The functional domain of the HCV protein essential for immunosuppression was determined using a series of ${NH_2}-and$ C-terminal deletion mutants of HCV core protein. We found that amino acid residues residing between the 21 st and the 40th residues from the ${NH_2}-terminus$ of HCV core protein are required for immunosuppression. These findings suggest that HCV core protein suppresses the elicitation of protective Th1 responses by the inhibition of IL-12 production by DCs.