• 한국전문물리치료학회지
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• 제15권4호
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• pp.18-26
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• 2008

The present study was aimed at investigating the postural control ability of volleyball players with functional ankle instability. The subjects were 26 male volleyball players were divided into 2 groups (13 subjects with functional ankle instability and 13 subjects with ankle stability) who could evaluate Questionnaire. All the male participants were tested by a Balance Master System. This study were to measure of static balance ability, dynamic balance ability, motor function the difference between functional ankle instability group and control group. Ankle instability group and stable group in postural sway ($^{\circ}/sec$) on film surface with eye closed in modified clinical test sensory interaction on balance, and left unilateral stance with eye opened and closed were significantly different (p<.05). The ankle instability group and stable group in limit of stability were significantly different (p<.05). The ankle instability group and stable group in left/right rhythmic weight shirt were significantly different (p<.05). The ankle instability group and stable group in turn time (sec) & turn sway ($^{\circ}$) during step/quick turn and end sway ($^{\circ}/sec$) in tandem walk were significantly different (p<.05). This study showed that volleyball players with functional ankle in stability were effected postural control ability by static balance & dynamic balance ability. Further study is needed to measure various athletic with functional ankle instability for clinical application.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1192-1205
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• 2016

Field programmable gate array (FPGA)-based systems are thought to be a practical option to replace certain obsolete instrumentation and control systems in nuclear power plants. An FPGA is a type of integrated circuit, which is programmed after being manufactured. FPGAs have some advantages over other electronic technologies, such as analog circuits, microprocessors, and Programmable Logic Controllers (PLCs), for nuclear instrumentation and control, and safety system applications. However, safety-related issues for FPGA-based systems remain to be verified. Owing to this, modeling FPGA-based systems for safety assessment has now become an important point of research. One potential methodology is the dynamic flowgraph methodology (DFM). It has been used for modeling software/hardware interactions in modern control systems. In this paper, FPGA logic was analyzed using DFM. Four aspects of FPGAs are investigated: the "IEEE 1164 standard," registers (D flip-flops), configurable logic blocks, and an FPGA-based signal compensator. The ModelSim simulations confirmed that DFM was able to accurately model those four FPGA properties, proving that DFM has the potential to be used in the modeling of FPGA-based systems. Furthermore, advantages of DFM over traditional reliability analysis methods and FPGA simulators are presented, along with a discussion of potential issues with using DFM for FPGA-based system modeling.

• PNF and Movement
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• 제4권1호
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• pp.27-36
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• 2006

Purpose : The main purpose of this study was to investigate the effect on Balance Ability of Knee Osteoarthritis(OA) by Lower Extremity Patterns with dynamic reverse in Proprioceptive Neuromuscular Facilitation(PNF). Methods : The subjects were consisted of 30 women patients with knee OA. All subjects were randomly assigned to PNF group. Each group had a treatment for 30 minutes per day and three times a week during 8 weeks period. Was used to measure recovery or worse of patient's condition, muscle assessment questionnaire(MAQ) was used to measure patient' s muscular strength, Endurance, coordination/balance, KWOMAC was used to pain, stiffness, and physical function, and BPM was used to measure path, anterior-posterior. Results : This study results in following conclusons. 1. MAQ score was significantly decreased in PNF group(p<.05). 2. KWOMAC score was significantly decreased in PNF group(p<.05). 3. BPM were score was significantly decreased in PNF group(p>.05). Conclusion : From this result the PNF treatment retrogression characteristic will be effective in treatment of patient, with the arthritis and widely may be applied at a therapist.

• Structural Engineering and Mechanics
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• 제31권5호
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• pp.507-526
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• 2009

Based on numerical and experimental methods, a systematic structural evaluation of a steel natatorium in service was carried out in detail in this paper. Planning of inspection tasks was proposed firstly according to some national codes in China in order to obtain the economic and reliable results. The field visual inspections and static computation were conducted in turn under in-service environmental conditions. Further a three-dimensional finite element model was developed according to its factual geometry properties obtained from the field inspection. An analytical modal analysis was performed to provide the analytical modal properties. The field vibration tests on the natatorium were conducted and then two different system identification methods were used to obtain the dynamic characteristics of the natatorium. A good correlation was achieved in results obtained from the two system identification methods and the finite element method (FEM). The numerical and experimental results demonstrated that the main structure of the natatorium in its present status is safe and it still satisfies the demand of the national codes in China. But the roof system such as purlines and skeletons must be removed and rebuilt completely. Moreover the system identification results showed that field vibration test is sufficient to identify the reliable dynamic properties of the natatorium. The constructive suggestion on structural evaluation of the natatorium is that periodic assessment work must be maintained to ensure the natatorium's safety in the future.

• 한국항해항만학회지
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• 제36권9호
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• pp.741-751
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• 2012

This article analyzes the interdependency between nonrenewable marine sand resources and renewable fishery resources by the developed dynamic bioeconomic model. The developed bioeconomic model is applied to a case study of efficient sustainable management for marine sand mining, which adversely affects a valuable blue crab fishery and its habitat in Korea. The socially-efficient extraction plan for marine sand and the time-variant environmental external costs to society in terms of diminished harvest rate of blue crab are determined. To take into account long-term effects from destroyed fishery habitat, a Beverton-Holt age structure model is integrated into the bioeconomic model. The illustrative results reveal that the efficient sand extraction plan is dynamically constrained by the stock size of the blue crab fishery over time. Thus, the dynamic environmental external cost is more realistic resource policy option than the classical fixed external cost for determining socially optimal extraction plans. Additionally, the economic value of bottom habitat, which supports the on- and off-site commercial blue crab fishery is estimated. The empirical results are interpreted with emphasis on guidelines for management policy for marine sand mining.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권1호
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• pp.37-47
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• 2018

Dynamic simulation is critical for electrical ship studies as it obtains the necessary information to capture and characterize system performance over the range of system operations and dynamic events such as disturbances or contingencies. However, modeling and simulation of the interactive electrical and mechanical dynamics involves setting up and solving system equations in time-domain that is typically time consuming and computationally expensive. Accurate assessment of system dynamic behaviors of interest without excessive computational overhead has become a serious concern and challenge for practical application of electrical ship design, analysis, optimization and control. This paper aims to develop a systematic approach to classify the sophisticated dynamic phenomenon encountered in electrical ship modeling and simulation practices based on the design intention and the time scale of interest. Then a novel, comprehensive, coherent, and end-to-end mathematical modeling and simulation approach has been developed for the latest Medium Voltage Direct Current (MVDC) Shipboard Power System (SPS) with the objective to effectively and efficiently capture the system behavior for ship-wide system-level studies. The accuracy and computation efficiency of the proposed approach has been evaluated and validated within the time frame of interest in the cast studies. The significance and the potential application of the proposed modeling and simulation approach are also discussed.

• 환경영향평가
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• 제21권5호
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• pp.757-765
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• 2012

The purpose of this study was to estimate the spatial-temporal NPP(Net Primary Productivity) and SCS(Soil Carbon Storage) of forest ecosystem under climate change in the capital area of South Korea using Mapss-Century1 (MC1), one of Dynamic Global Vegetation Models (DGVMs). The characteristics of the NPP and SCS changes were simulated based on a biogeochemical module in this model. As results of the simulation, the NPP varies from 2.02 to 7.43 tC $ha^{-1}\;yr^{-1}$ and the SCS varies from 34.55 to 84.81 tC $ha^{-1}$ during 1971~2000 respectively. Spatial mean NPP showed a little decreasing tendency in near future (2021~2050) and then increased in far future (2071~2100) under the condition of increasing air temperature and precipitation which were simulated by the A1B climate change scenario of Intergovernmental Panel on Climate Change (IPCC). But it was estimated that the temporal change of spatial mean NPP indicates 4.62% increasing tendency in which elevation is over 150m in this area. However, spatial mean SCS was decreased in the two future periods under same climate condition.

• Physical Therapy Rehabilitation Science
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• 제9권3호
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• pp.165-170
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• 2020

Objective: To investigate the association between one-leg standing ability and postural control for chronic hemiparetic stroke. Design: Cross-sectional study. Methods: Forty individuals who had a first diagnosis of stroke with hemiparesis before six months and over had participated in this study. To analyze the relationship between one-leg standing ability and postural control in the participants, six clinical measurement tools were used for assessment, including the Timed-Up-and-Go (TUG) test, Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Fugl-Meyer Assessment (FMA), 5 times sit-to-stand (5TSTS) and one-leg standing (OLS). Results: After analyzation, the OLS scores in the more-affected side showed significant positive correlations with BBS scores (r=0.469, p<0.01), DGI scores (r=0.459, p<0.01).and FMA scores (r=0.425, p<0.01). The OLS scores in the more-affected side showed significant negative correlations with TUG score (r=-0.351, p<0.05). The OLS score in the less-affected side showed significant positive correlations with BBS scores (r=0.485, p<0.01), DGI scores (r=0.488, p<0.01) and FMA score (r=0.352, p<0.05). The OLS scores in the less-affected side showed significant negative correlation with TUG scores (r=-0.392, p<0.05) and 5TSTS (r= -0.430, p<0.01). The OLS scores in the more-affected side showed significant positive correlations with the OLS scores in less-affected side (r=0.712, p<0.01). Conclusions: The results of the study suggest that the OLS time may be moderately correlated with static and dynamic postural stabilities and motor recovery following stroke. This study also suggests that the OLS test is as a simple clinical tool for predicting postural control performance for individuals with chronic hemiparetic stroke.

• 한국물환경학회지
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• 제30권6호
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• pp.612-621
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• 2014

Physicochemical factors and the phytoplankton communities in the downstream area of Namhan-River were investigated from June 2012 to November 2013. We also assessed water quality using biological water quality indices. Total nitrogen was 2.4 mg/L, total phosphorus was 0.04 mg/L, and biological oxygen demand was 1.1 mg/L. This resulted in a level 2 (Ib, good) water quality rating. A total of 259 phytoplankton taxa were classified, consisting of 26 families, two subfamilies, 64 genera, 222 species, 32 varieties, and five formas. Bacillariophyceae dominated during a1l seasons and at all sites. The dominant species were Aulacoseira granulata, Cyclotella meneghiniana, C. stelligera, Melosira varians, Cocconeis placentula var. lineata, Nitzschia palea, N. amphibia, Cymbella minuta, and Achnanthes convergens. The diatom assemblage index for organic pollution values was level A-D, and TDI was level B-D. P-IBI at most sites was at the M (moderate) level, but TSI was at the E (eutrophic) level. Most indices dropped from upstream to downstream.

• Physical Therapy Rehabilitation Science
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• 제6권3호
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• pp.140-145
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• 2017

Objective: The purpose of this study was to investigate the effect of visual block with ankle joint fatigue on gait and dynamic balance ability. Design: Cross-sectional study. Methods: Thirty healthy young adults (men=15, women=15) between 22 to 25 years of age voluntarily participated in this study. All subjects performed the gait and dynamic balance test successively in two conditions: the visual block and the open eyes condition. Before the gait and dynamic balance test, muscle fatigue on the ankle joint was induced to all subjects by doing ankle dorsiflexion and plantarflexion alternately, and then gait parameters (step length, stride length, cadence, velocity, single limb support, and double limb support) were assessed by walking on the GAITRite system (CIR Systems Inc., USA). Subjects also performed the functional reach test (FRT) for assessment of dynamic balance. This study examined gait parameters and FRT scores in each visual block and open eyes condition. Results: The results showed that FRT scores with the visual block condition significantly decreased compared to without visual blocking (p<0.01). Step length, stride length, cadence, and velocity of gait parameters decreased significantly in the visual block condition (p<0.01) while there was no significant difference for single limb support. However, double limb support increased significantly in the visual block system (p<0.01). Conclusions: Therefore, blocking of visual information with muscle fatigue of the ankle joint can affect gait and balance ability of young adults and increase the risk of falls.