• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.314-319
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• 2006

Main focus on balance shaft module is to reduce the vibration triggered from engine block and compensate it from unbalance mass in balance shaft. Since the performance of balance shaft module is controlled by rotor shape including unbalance mass, a design strategy on rotor is key issue on determine the quality of balance shaft system. Even the design result on balance shaft mostly affect the lay-out of housing and other related components, its issue on balance shaft should be considered in advance throughout the total design procedure. In this paper, optimal design strategy focused on balance shaft is presented to make a design process efficiently with ensuring its high performance. And its method is verified with field design process of balance shaft in commonly adapted vehicle with 3-cylinder and 4-cylinder engine.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.181-188
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• 2019

In this study, the Heat & Mass balance design optimization tool has developed by linking the design input/output variables with the Heat & Mass balance calculation solver and optimization algorithm and also automating the iterative calculation process. As a result of testing this optimization tool for 10 kinds of power plant, it was expected to improve the NPV and IRR compared with general design methods.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.1-7
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• 2010

Large quantity of bending deformation as well as irregular rotating torque fluctuation are the main struggles of the balance shaft module during a high speed rotation. Since two issues are much sensitive to the location of both supporting bearing and unbalance mass at a balance shaft, it is recommended to construct a design strategy on balance shaft at the early stage so as to save developing time and effort before approaches to the detailed design process. In this paper, an optimal design formulation is proposed to minimize the elastic strain energy due to bending as well as the kinematic energy of polar moment of inertia in rotation. Case studies of optimal design are conducted for different mass ratio as well as linear combination of objective function and its consequence reveals that global optimum of balance shaft model is existed over possible design conditions. Simulation shows that best locations of both supporting bearing and unbalance are globally 20% and 80%, respectively, over total length of a balance shaft.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.143-150
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• 2004

In this paper we study the estimation problem of individual weights of objects using an A-optimal chemical balance weighing design. We assume that in this model errors are correlated and they have the same variances. The lower bound of tr$(X'G^{-1}X)^{-1}$ is obtained and a necessary and sufficient condition for this lower bound to be attained is given. There is given new construction method of A-optimal chemical balance weighing design.

• CDE review
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• v.2 no.2
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• pp.52-54
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• 1996

드럼세탁기에 있어서 weight는 세탁기의 진동 및 소음에 중요한 역할을 한다. 기존 pulsator 세탁기는 액체밸런스를 사용하여 세탁물의 편심을 상쇄시켜 세탁기의 진동을 억제시키지만, 드럼세탁기는 주물이나 시멘트 등을 weight balance로 사용하고, 세탁기 구동부의 무게, damping system 등과의 상호작용으로 세탁기의 진동을 억제시킨다. 본 연구에서는 Ideas-Design의 Master Molder와 Assembly을 사용하여 드럼세탁기의 weight balance을 설계한다. 이와 같이 weight balance는 드럼진동 및 소음 뿐만 아니라 세탁기의 전체 무게에도 매우 큰 영향을 미친다.

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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• pp.192-200
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• 2023

Objective: This study aimed to assess the effectiveness of a balance training program in improving balance and functional independence to reduce fall risks among community-dwelling elders. Design: A multi-center randomized controlled trial Methods: A total of 66participants were randomly assigned to a balance training group or a control group. The balance training program, conducted three times a week for 32 weeks, included warm-up exercises, main balance training exercises, and cooldown stretch exercises. Outcome measures included the Berg Balance Scale (BBS), Timed Up and Go Test (TUGT), and Modified Barthel Index (MBI). Results: The balance training group demonstrated significant improvements in all outcome measures, indicating enhanced balance, improved functional mobility, and increased independence in activities of daily living. In contrast, the control group showed only slight improvements in BBS, TUGT and MBI scores. Conclusions: These findings provide evidence supporting the effectiveness of balance training programs in reducing fall risk and promoting health and wellbeing among community-dwelling elders. Future research should aim to refine the design of these programs and assess the sustainability of the observed improvements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.101-106
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• 2006

Balance shaft has a key role in reducing a engine vibration in a vehicle and widely applied for current models. Since balance shaft module consists many sub-component and each part has its own operational characteristics, some different analysis backgrounds should be integrated into one sub-part in balance shaft module and this is the main obstacles in making a design process. Moreover, the balancing shaft is rotating in high speed and such condition requires large safety factors in a design process owing to a lot of unexpected problems with the overwhelming rotation. Balance shaft is the core-component generating the intended unbalance as well as cancelling the unbalance force or moment by the engine module. So, the balance shaft should meet the high fatigue resistance not to mention of NVH performance. In this paper, a design strategy focused on balance shaft is developed to build a optimal model considering a engine vibration. Putting the unbalance mass distribution as main design parameter, some candidate model is verifed with structural and fatigue analysis and most appropriate model is proposed here.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.393-398
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• 2007

Balance shaft has a key role in reducing a engine vibration in a vehicle and widely applied for current models. Since balance shaft module consists many sub-component and each part had its own operational characteristics, some different analysis background should be integrated into one sub-part in balance shaft module and this is the main obstacles in making a design process. Moreover, the balancing shaft rotating in high speed and such condition requires large safety factors in a design process owing to a lot of unexpected problems with the overwhelming rotation. Balance shaft is the core-component generating the intended unbalance as well as canceling the unbalance force or moment by the engine module. So, the balance shaft should meet the high fatigue resistance not to mention of NVH performance. In this paper, a design strategy focused on balance shaft is developed to build a optimal model considering a engine vibration. Putting the unbalance mass distribution as main design parameter, some candidate model is verified with structural and fatigue analysis most appropriate model is proposed here.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.801-806
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• 2008

Large quantity of bending deformation as well as rotating torque fluctuation at the balance shaft are main struggles during the operation in a high speed rotation and thereby, two issues should be cleared at the design process of balance shaft module. Since two issues are highly related with balance shaft itself and particularly much sensitive to the location of both supporting bearing and unbalance mass, the design strategy on balance shaft should be investigated at the aspect of controlling two critical issues at the early stage of balance shaft design. To tackle two main problems, the formulation of objective function that minimizes critical issues, both bending deformation as well as torque fluctuation, is suggested to derive the optimal information on balance shaft. Then, optimal informations are reviewed at the practical logics and the guideline at the selection of locations, both supporting bearing and unbalance mass, is addressed at the final chapter.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.470-478
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• 2021

Objective: This study aimed to determine the effect of proprioceptive neuromuscular facilitation (PNF) balance exercise on the ability to balance and walk in patients with hemiplegia caused by stroke. Design: A randomized controlled trial Methods: Following baseline measurements, patients (n=24) with hemiplegia caused by stroke were randomized into two groups: the PNF balance group (n=12) that received PNF balance exercise and the balance group (n=12) that received general balance exercise. Each group joined the intervention for 30 minutes, 5 times per week for 6 weeks. Both groups performed the Timed Up and Go test (TUG) and Berg Balance Scale (BBS) for balance, as well as the 10-meter walking test (10MWT) and 6-minute walk test (6MWT) for walking. The data were collected both before and after the intervention. The paired t-test was used to compare the post-intervention changes compared with pre-intervention data. An independent t-test was used to analyze the differences in the dependent variables between the two groups. Results: After the 6-week intervention, both groups showed significant improvements in balance (TUG, BBS) and walking (10MWT, 6MWT) parameters (p<0.05). The patients in the PNF balance group showed greater improvements in balance (TUG, BBS) and walking (10MWT, 6MWT) than those in the balance group (p<0.05). Conclusions: PNF balance exercise shows improvements in balance and walking parameters in patients with hemiplegia caused by stroke.