• 한국산학기술학회논문지
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• 제17권2호
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• pp.601-609
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• 2016

본 논문은 관절염을 앓고 있는 노인여성(환자군; $65.25{\pm}5.9$세, 11명)과 일반 노인여성(통제군; $64.50{\pm}7$세, 11명)을 대상으로 12주간의 수중운동(주 3회)을 실시 한 후 동적평형성과 통증(통증자각도)의 변화를 알아보고자 실시되었다. 동적평형성은 시각정보의 유무에 따라 개안 시와 폐안 시로 나누어 측정하였다. 12주간의 수중운동에 따른 개안 시 동적평형성은 관절염 환자군(p<.001)과 통제군(p<.05)에서 유의하게 향상되었고, 폐안 시 관절염 환자군에서도 유의하게 향상된 결과를 보였다(p<.05). 또한, 통증자각도(VAS) 평가에 의한 통증 변화는 관절염 환자군의 10요인(푹신한 의자에 똑바로 앉아있기 힘든가, p<.01), 11요인(누워있을 때 통증이 덜해지는가, p<.05), 12요인(통증때문에 일상생활에 지장이 있는가, p<.05), 13요인(통증 때문에 직장일 또는 집안일에 지장이 있는가, p<.01)에서 유의한 통증 감소가 나타났다. 본 연구 결과를 통해 12주간의 수중 운동은 골관절염 노인 환자에게 개안 시와 폐안 시 모두 동적평형 능력을 향상 시키고, 일부 통증요인 감소에 효과적인 운동임을 알 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.927-932
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• 2001

It is intended to develope an algorithm for dynamic simulation of fast-acting solenoid valves. The coupled equations of the electric, magnetic, and mechanical systems should be solved simultaneously in a transient nonlinear manner. The transient nonlinear electromagnetic field is analyzed by the Finite Element Method (FEM), which is coupled with nonlinear electronic circuitry. The dynamic movement of the solenoid valve is analyzed at every time step from the force balances acting on the plunger, which include the electromagnetic force calculated from the Finite Element analysis as well as the elastic force by a spring and the hydrodynamic pressure force along the flow passage. Dynamic responses of the solenoid valves predicted by this algorithm agree well with the experimental results including bouncing effects.

• 펄프종이기술
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• 제39권1호
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• pp.8-15
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• 2007

In an effort to develop control strategies for the wet-end of paper machines, dynamic models for retention and formation processes have been developed. The retention process, including headbox total and filler consistencies, white water total and filler consistencies, the basis weight and the ash content of paper, can be modeled from first-principles (mass balances). To include the effect of wet-end chemistry variables, first-pass retention was included as a parameter dependent on operating conditions. In addition, dynamics of formation was simulated by developing an empirical model of formation and coupling with the dynamic models for the retention process. A series of experiments were performed using a pilot paper machine. The experimental results and the model predictions showed relatively good agreement.

• 한국통신학회논문지
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• 제27권11C호
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• pp.1040-1045
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• 2002

This paper focuses on a hash-based, distributed Wet caching network that eliminates inter-cache communication. An agent program on cache servers, a mapping program on the DNS server, and other components comprised in a distributed Web caching network were modified and developed to implement a so-called "consistent" hashing. Also, a dynamic load balancing algorithm is proposed to address the load-balancing problem that is a key performance issue on distributed architectures. This algorithm effectively balances the load among cache servers by distributing the calculated amount of mapping items that have higher popularity than others. Therefore, this developed network can resolve the imbalanced load that is caused by a variable page popularity, a non-uniform distribution of a hash-based mapping, and a variation of cache servers.

• 대한물리치료과학회지
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• 제30권3호
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• pp.59-71
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• 2023

Background: This study was to investigate the effects of coordinative locomotor training(CLT) using elastic bands on pain, dynamic balance, muscle strength, and muscle activity of female college students with patellofemoral pain syndrome(PFPS). Design: Randomized Controlled Trial Methods: Twenty-six female college students with PFPS were assigned randomly to an experimental(n=13) or control(n=13) group. The experimental group performed CLT using an elastic band. The control group performed squat exercises to strengthen muscle strength. The 30-minute inter- vention was applied a total of twelve times, three times a week for four weeks. All subjects measured the pain, the muscle strength, the dynamic balance, and the muscle activity(VL/VM ratio) before and after intervention. A paired t-test was used for the determination of differences before and after treatment, and an independent t-test was used for the determination of differences between treatment groups. Results: As a result of comparison within groups, the experimental group showed significant differences in pain, muscle strength, dynamic balance, and VL/VM ratio after the experiment(p<0.05), and the control group showed significant differences in pain, muscle strength, and dynamic balance after the experiment(p<0.05). In comparison between the two groups, the experimental group showed more significant differences in pain, dynamic balance, and VL/VM ratio than the control group(p<0.05), and the control group showed more significant differences in muscle strength than the experimental group(p<0.05). Conclusion: Based on these results, CLT using elastic bands effectively improved the pain, muscle strength, dynamic balance, and VL/VM ratio of female college students with PFPS.

• The Journal of Korean Physical Therapy
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• 제29권2호
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• pp.95-100
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• 2017

Purpose: This study aimed to evaluate the changes in dorsiflexion and balance following proximal and distal tibiofibular joint manipulation in individuals with a history of lateral ankle sprain (LAS). Methods: Fifteen participants with a history of unilateral LAS, exhibiting a restriction in ankle dorsiflexion were included in this study. LAS ankle received a manipulation to the proximal and distal tibiofibular joint, while the opposite control ankle received no manipulation intervention. The outcome measures included ankle dorsiflexion and balance. Ankle dorsiflexion was measured using weight-bearing lunge test. Static and dynamic balances were measured using the overall, anterioposterior, and mediolateral balance index via the biodex balance system. Measurements were obtained prior to and following manipulation. Results: This study showed that ankle dorsiflexion and dynamic balance were improved following the manipulation compared to those prior to the manipulation (p<0.05). There was no significant change in static balance (p>0.05). Conclusion: The joint manipulation technique applied to the ankle of those with a history of LAS appears to improve ankle dorsiflexion and dynamic balance. This suggest that a manipulation to the proximal and distal tibiofibular joint could be provided as preliminary data regarding the prophylactic effects of recurrent LAS.

• 대한의생명과학회지
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• 제25권2호
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• pp.149-158
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• 2019

The objective of this study was to evaluate the effects of thoracic mobilization (TM) on the angle of thoracic kyphosis, and static and dynamic balances by application period. The subjects of this study were 18 adult males and females (${\geq}20years\; old$) who had the angle of thoracic kyphosis equal to or higher than $40^{\circ}$. A pre-test was conducted for all subjects and TM was carried out. Data were collected before the intervention, 3 weeks after the intervention, and 6 weeks after the intervention. It was measured three times per measurement and mean values were used for the analysis. The results of this study showed that the angle of thoracic kyphosis significantly (P<.05) decreased after applying TM. However, the migration area ($mm^2$) of the center of pressure (COP) in the static balance did not vary significantly. In the case of the dynamic balance, when eyes were open, the migration area ($mm^2$) of the COP significantly (P<.05) decreased after 3 weeks. When eyes were open, the migration area ($mm^2$) of the COP significantly (P<.05) decreased after 3 weeks and 6 weeks. Therefore, an intervention for improving the human body alignment and balance should be applied for a long-term, rather than a short-term, in order to be effective.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.109-114
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• 2008

A dynamic model has been developed to simulate dynamic operation of a real double-effect absorption chiller. Dynamic behavior of working fluids in main components was modeled in first-order nonlinear differential equations based on heat and mass balances. Mass transport mechanisms among the main components were modeled by valve throttling, 'U' tube overflow and solution sub-cooling. The nonlinear dynamic equations coupled with the subroutines to calculate thermodynamic properties of working fluids were solved by a numerical method. The dynamic performance of the model was compared with the test data of a commercial medium chiller. The model showed a good agreement with the test data except for the first 5,000 seconds during which different flow rates of the weak solution caused some discrepancy. It was found that the chiller dynamics is governed by the inlet temperatures of the cooling water and the chilled water when the heat input to the chiller is relatively constant.

• 설비공학논문집
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• 제20권12호
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• pp.781-788
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• 2008

A dynamic model has been developed to simulate dynamic operation of a real double-effect absorption chiller. Dynamic behavior of working fluids in main components was modeled in first-order nonlinear differential equations based on heat and mass balances. Mass transport mechanisms among the main components were modeled by valve throttling, 'U' tube overflow and solution sub-cooling. The nonlinear dynamic equations coupled with the subroutines to calculate thermodynamic properties of working fluids were solved by a numerical method. The dynamic performance of the model was compared with the test data of a commercial medium chiller. The model showed a good agreement with the test data except for the first 5,000 seconds during which different flow rates of the weak solution caused some discrepancy. It was found that the chiller dynamics is governed by the inlet temperatures of the cooling water and the chilled water when the heat input to the chiller is relatively constant.

• 국제지역연구
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• 제15권2호
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• pp.331-350
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• 2011

본 연구는 1989-2009년 기간 동안의 MTI 2단위, 56개 품목의 대일 수출입 시계열 패널자료를 사용하여 대일 상품수지 함수를 추정하였다. 대일 상품수지 함수는 정태패널 모형과 거래비용을 고려한 동태패널모형을 사용하여 추정하였으며 실증분석결과 정태패널모형보다는 거래비용을 고려한 동태패널모형이 모형의 안정성이 우수한 것으로 나타났다. 안정적인 대일 상품수지 함수의 추정의 의미는 비록 대일 상품수지 적자가 지속되고 있더라도 양국교역은 양국후생에 도움이 된다는 것을 의미한다. 동태패널 분석결과 균형 상품수지로의 조정속도는 0.0389로 매우 느린 것으로 나타났으며 이는 대일상품수지 균형으로의 조정에 필요한 비용이 현재 상품수지 적자로 인한 비용보다 크기 때문이다. 상품수지에 대한 일본실질소득 탄력성과 한국실질소득 탄력성은 각각 4.38168과 -0.835225로 이론에 부한하는 부호를 나타내며 유의한 것으로 나타나, 대일 수출상품은 사치재의 성격을 갖는 반면 수입상품은 필수재의 성격을 갖는 것으로 나타났다. 대일 상품수지의 환율탄력성(${\partial}TB/{\partial}ER$)은 0.478435로 비탄력적인 것으로 밝혀졌다. 이는 환율변동이 대일 상품수지에 미치는 영향이 작은 반면 대일 상품수지변동은 큰 폭의 원/엔 실질환율을 변동시킬 수 있음을 의미한다.