• 아태비즈니스연구
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• 제15권1호
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• pp.209-223
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• 2024

Purpose - This article analyzes the impact of macroeconomic variables of the United States, China, and Korea on KOSPI and VKOSPI, in that United States and China have a great influence on Korea, having an export-driven economy. Design/methodology/approach - The influence of US, China, and Korea interest rates, industrial production index, consumer price index, US employment index, Chinese real estate index, and Korea's foreign exchange reserves on KOSPI and VKOSPI is analyzed on monthly basis from Jan 2012 to Aug 2023, using multifactor model. Findings - The KOSPI showed a positive relationship with the U.S. industrial production index and Korea's foreign exchange reserves, and a negative relationship with the U.S. employment index and Chinese real estate index. The VKOSPI showed a positive relationship with the Chinese consumer price index, and a negative relationship with the U.S. interest rates, and Korean foreign exchange reserves. Next, dividing the analysis into two periods with the Covid crisis and the analysis by country, the impact of US macroeconomic variables on KOSPI was greater than Chinese ones and the impact of Chinese macroeconomic variables on VKOSPI was greater than US ones. The result of the forward predictive failure test confirmed that it was appropriate to divide the period into two periods with economic event, the Covid Crisis. After the Covid crisis, the impact of macroeconomic variables on KOSPI and VKOSPI increased. This reflects the financial market co-movements due to governments' policy coordination and central bank liquidity supply to overcome the crisis in the pandemic situation. Research implications or Originality - This study is meaningful in that it analyzed the effects of macroeconomic variables on KOSPI and VKOSPI simultaneously. In addition, the leverage effect can also be confirmed through the relationship between macroeconomic variables and KOSPI and VKOSPI. This article examined the fundamental changes in the Korean and global financial markets following the shock of Corona by applying this research model before and after Covid crisis.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1400-1407
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• 2015

This paper deals with methodology to control an automatic substation system. The control system can predict the power system condition by a voltage stability index (VSI). The strategies in this paper is called as Voltage-Reactive Power Control (VRPC), which regulates an abnormal voltage of a target substation by using coordination between tap changers and shunt capacitor/reactor. This method is efficient for better voltage profile. The monitoring substation includes whole of substations around the contingency event. The control quantities of the monitoring substations are decided by the calculation of the VSI, called as a Z-index. Case studies with BC Hydro-Quebec system are presented to illustrate this approach using real-time simulator.

• 대한통합의학회지
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• 제8권1호
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• pp.87-99
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• 2020

Purpose : This study aims to investigate the effect of somatosensory stimulation on the upper limb sensory and function and self-esteem of stroke patients. Methods : This study period was march 4 to april 4 (5 weeks). The subject were 20 stroke patients with somatosensory impairment in B hospital, seongnam, gyeonggi province. They were devided into two group-experimental and control-with 10 members each. The members of the experimental group underwent somatosensory stimulation, whereas the members of the control group underwent an occupation-based intervention for 5 weeks. Thirty-minute therapy was provided 3 times per week for 5 weeks. Before and after the intervention, both groups were evaluated via light touch, static two-point discrimination, stereognosis, Fugl-Meyer assessment (FMA), and self-esteem scale Results : In this study, light touch was not significant in both groups. Static two-point discrimination was significant among the experimental group member's index fingers. Among the control group members, it was significant in the ring finger. The comparison between the two groups was significant in the index finger. The stereognosis results were significant in the experimental group but not in the control group. The comparison between the groups after the intervention was not significant. FMA was significant in the shoulder/ elbow/ forearm (SEF), hand and coordination among the experimental group. Among the control group, it was significant in the SEF and hand. The comparison between the groups was significant in the SEF, hand and coordination. The self-esteem scale results were significant among both groups, and the comparison between the group's score was likewise significant. Conclusion : In conclusion, somatosensory stimulation therapy increases the static two-point discrimination, stereognosis, upper extremity function, and self-esteem of patients with stroke. Therefore, while somatosensory stimulation therapy is not the best therapy, it is one of the best occupational therapies for stroke patients.

• The Journal of Korean Physical Therapy
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• 제24권2호
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• pp.151-156
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• 2012

Purpose: The purpose of this study was to investigate the adverse effects of sensorimotor function at the shoulder joint according to long-term cane usage in stroke patients without apraxic behavior, in terms of the presence of shoulder joint pain, accuracy of tracking task, proprioceptive joint position sense, and nine-hole pegboard. Methods: Nineteen stroke patients with long-term cane usage (cane usage group) and nineteen stroke patients without cane usage (non-cane usage group) were recruited. All subjects were tested in pain presence, a tracking task for visuomotor function, joint reposition, and nine-hole pegboard in the shoulder joint regarding the non-affected side. Results: In the accuracy index for tracking task and the nine-hole pegboard test, significant differences were observed between the cane usage group and the non-cane usage group. However, although a higher emergence of shoulder pain and a lower accuracy for joint reposition sense were detected in the cane usage group in comparison to the non-cane usage group, there were no significant differences between the two groups. Conclusion: Our findings suggest that long-term cane usage could induce to decrease in delicate movement and coordination in the non-affected upper arm in stroke patients. In addition, they could experience high frequency of shoulder pain and poor joint reposition sense. Therefore, careful evaluation and observation will be required concerning stroke patients with long-term cane usage.

• 전자공학회논문지
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• 제51권6호
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• pp.9-17
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• 2014

이종 네트워크(HetNet)란 매크로셀 내에 소형셀이 혼재한 네트워크이다. 이종 네트워크에서는 대형셀로부터 소형셀 사용자에게 미치는 간섭이 소형셀 사용자의 성능을 열화시키는 주 원인 중 하나이며, 이 간섭을 줄이기 위해 향상된 셀간 간섭 조정기법(eICIC)이 필요하다. 기존의 eICIC 관련 연구에서는 프레임별 채널 변화를 거의 고려하지 않고 네트워크의 장기 처리율을 최대화하는 데 치중되어 성능 향상이 제한적이었다. 이 논문에서는 네트워크 전체 효용을 최대화하기 위해 매 프레임마다 동적으로 셀간 간섭을 제어하고 사용자를 스케줄링하며, 전수검색보다 계산 복잡도가 낮은 새로운 알고리즘을 제안한다. 제안된 알고리즘이 기존 알고리즘보다 네트워크 전체 처리율을 향상시키며, 사용자의 수가 많을 때 사용자간 공평성을 향상시킴을 컴퓨터 모의실험을 통해 보인다.

• Physical Therapy Rehabilitation Science
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• 제6권2호
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• pp.53-58
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• 2017

Objective: The purpose of this study was to determine the effect of upper extremity coordination exercise (UECE) during standing on the paretic side on balance, gait ability and activities of daily living (ADL) in persons with stroke. Design: A randomized controlled trial. Methods: A total of 27 patients with hemiplegic diagnosis after stroke were divided into two groups. Fourteen patients were in the study group and 13 patients were in the control group. The study group received conventional physical therapy and UECE during standing on the paretic side. The control group received conventional physical therapy and simple upper extremity exercise (SUEE). Subjects in both groups were given upper extremity training for 30 minutes per day, five times a week for 4 weeks. Initial evaluation was performed before treatment and reevaluated 4 weeks later to compare the changes of balance, gait ability and ADL (Korean version of modified Barthel index, K-MBI). Results: Both groups showed a significant effect for balance, gait ability and ADL (p<0.05). In the Independent t-test, between both groups showed a significant effect for balance and gait ability except ADL (p<0.05). Conclusions: In this paper, we investigated the changes in balance, walking, and ADL through UECE. We found significant changes in the study group and the control group. Results of the present study indicated that UECE during standing on the paretic side for 4 weeks had an effect on balance, gait ability and ADL (K-MBI) in persons with hemiplegia after stroke.

• International journal of advanced smart convergence
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• 제4권2호
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• pp.38-45
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• 2015

Peer-to-Peer(P2P) systems are generally classified into two categories; hybrid and pure P2P. Hybrid systems have a single central index server keeping the details of shared information, so that undesirable effects such as heavy load on that server and lack of fault-tolerance can be caused. Pure P2P causes the other problems such as message flooding and scalability although it shows high degree of fault-tolerance. Recently, mobile agent-based distributed computing has been receiving wide attention for its potential to support disconnected operations, high asynchrony, and thus saving network bandwidth. In this paper, a new scheme of peer coordination is proposed for a decentralized P2P network with self-organizing structure. We deployed mobile agents for incorporating the advantages of usage of mobile agents into our P2P network. Proposed P2P network has both advantages of hybrid and pure P2P. The problems of heavy load on the server and lack of fault-tolerance are improved by using multiple special peers called super-peers. And the problems of pure P2P can be reduced by using mobile agents.

• Earthquakes and Structures
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• 제23권1호
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• pp.101-113
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• 2022

A new type of fabricated subway station construction technology can effectively solve these problems. For a new type of metro structure form, it is necessary to clarify its mechanical properties, especially the seismic performance. A soil-structure elastoplastic finite element model is established to perform three-dimensional nonlinear dynamic time-history analysis based on the first fabricated station structure-Yuanjiadian station of Changchun Metro Line 2, China. Firstly, the nonlinear seismic response characteristics of the fabricated and cast-in-place subway stations under different seismic wave excitations are compared and analyzed. Then, a comprehensive analysis of several important parameters that may affect the seismic response of fabricated subway stations is given. The results show that the maximum plastic strain, the interlayer deformation, and the internal force of fabricated station structures are smaller than that of cast-in-place structure, which indicates that the fabricated station structure has good deformation coordination capability and mechanical properties. The seismic responses of fabricated stations were mainly affected by the soil-structure stiffness ratio, the soil inertia effect, and earthquake load conditions rarely mentioned in cast-in-place stations. The critical parameters have little effect on the interlayer deformation but significantly affect the joints' opening distance and contact stress, which can be used as the evaluation index of the seismic performance of fabricated station structures. The presented results can better understand the seismic responses and guide the seismic design of the fabricated station.

• The Journal of Korean Physical Therapy
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• 제26권3호
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• pp.163-168
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• 2014

Purpose: The purpose of this study was to investigate whether ipsilateral shoulder pain affects the sensorimotor function of the same side shoulder in patients with stroke. Methods: Thirty stroke patients, who were divided into the ipsilateral shoulder pain group (n=15) and the ipsilateral shoulder non-pain group (n=15). Subjects were evaluated on performance of a tracking task, joint reposition test and 9-Hole pegboard test for sensorimotor functions, and Fugl-Meyer test and Motricity Index for functional ability of the contralateral side. Results: In comparison of the two groups, significant differences in performance on functional ability, including the Fugl-Meyer test(both upper and lower limb) and Motricity Index(only lower limb) were observed (p<0.05). With regard to sensorimotor functions, the ipsilateral shoulder pain group were observed significantly poor scores on the Accuracy Index, joint reposition score and 9-Hole pegboard test, when compared with the ipsilateral shoulder non-pain group (p<0.05). Conclusion: We found that ipsilateral shoulder pain could impede accurate performance of a movement and result in deteriorated proprioception of the ipsilateral shoulder. Therefore, careful evaluation and appropriate therapeutic intervention are essential for stroke patients who suffer from ipsilateral shoulder pain.

• 한국환경보건학회지
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• 제47권2호
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• pp.155-165
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• 2021

Objectives: Acute exposure to high concentrations of chemicals can occur when a chemical accident takes place. As such exposure can cause ongoing environmental pollution, such as in the soil and groundwater, there is a need for a tool that can assess health effects in the long term. The purpose of this study was assessing the health risks of residents living near a chemical accident site due to long-term exposure while considering the temporal concentration changes of the toxic chemicals leaked during the accident until their extinction in the environment using a multimedia environmental dynamics model. Methods: A health risk assessment was conducted on three cases of formaldehyde chemical accidents. In this study, health risk assessment was performed using a multimedia environmental dynamics model that considers the behavior of the atmosphere, soil, and water. In addition, the extinction period of formaldehyde in the environment was regarded as extinction in the environment when the concentration in the air and soil fell below the background concentration prior to the accident. The subjects of health risk assessment were classified into four groups according to age: 0-9 years old, 10-18 years old, 19-64 years old, and over 65 years old. Carcinogenic risk assessment by respiratory exposure and non-carcinogenic risk assessment by soil intake were conducted as well. Results: In the assessment of carcinogenic risk due to respiratory exposure, the excess carcinogenic risk did not exceed 1.0×10-6 in all three chemical accidents, so there was no health effect due to the formaldehyde chemical accident. As a result of the evaluation of non-carcinogenic risk due to soil intake, none of the three chemical accidents had a risk index of 1, so there was no health effect. For all three chemical accidents, the excess cancer risk and hazard index were the highest in the age group 0-9. Next, 10-18 years old, 65 years old or older, and 19-64 years old showed the highest risk. Conclusion: This study considers environmental changes after a chemical accident occurs and until the substance disappears from the environment. It also conducts a health risk assessment by reflecting the characteristics of the long-term persistence and concentration change over time. It is thought that it is of significance as a health risk assessment study reflecting the exposure characteristics of the accident substance for an actual chemical accident.