• Title/Summary/Keyword: dynamic weight

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The Effect of Shoe Lift of the Paretic Limb on Dynamic Weight Bearing in Hemiplegics (편마비 환자의 신발 높이 조절이 동적체중부하율에 미치는 영향)

  • Yoon, Jung-Gyu;Kim, Byung-Wook
    • Journal of Korean Physical Therapy Science
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    • v.8 no.2
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    • pp.1073-1080
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    • 2001
  • The purpose of this study was to determine the effect of lift to the shoe of the affected limb on gait patterns in subjects with hemiplegia. The subjects of this study were 18 post-stroke hemiplegics. For the study, insole of the paretic side was lifted 10 mm higher, and duration of dynamic weight bearing was measured. before and after the lift application. For the measurement of carry-over effect of lift, we got data of there three items prior to and 3 weeks after lift application and 3 days after removal of the lift. Dynamic weight bearing was significantly decreased in heel contact and footflat phases only when just after application of the lift, without any change after 3 weeks application. In heel-off phase, dynamic weight bearing did not show any significant difference between before and just after application of lift whereas significantly decreased after 3 weeks application. According to this study, lift applied to the shoe of the paretic limb was not significantly effect in inducing dynamic weight bearing, but changed a dynamic weight bearing.

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Multi-step design optimization of a high speed machine tool structure using a genetic algorithm with dynamic penalty (동적 벌점함수 유전 알고리즘과 다단계 설계방법을 이용한 공작기계 구조물의 설계 최적화)

  • 최영휴;배병태;김태형;박보선
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.108-113
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    • 2002
  • This paper presents a multi-step structural design optimization method fur machine tool structures using a genetic algorithm with dynamic penalty. The first step is a sectional topology optimization, which is to determine the best sectional construction that minimize the structural weight and the compliance responses subjected to some constraints. The second step is a static design optimization, in which the weight and the static compliance response are minimized under some dimensional and safety constraints. The third step is a dynamic design optimization, where the weight static compliance, and dynamic compliance of the structure are minimized under the same constraints. The proposed design method was examined on the 10-bar truss problem of topology and sizing optimization. And the results showed that our solution is better than or just about the same as the best one of the previous researches. Furthermore, we applied this method to the topology and sizing optimization of a crossbeam slider for a high-speed machining center. The topology optimization result gives the best desirable cross-section shape whose weight was reduced by 38.8% than the original configuration. The subsequent static and dynamic design optimization reduced the weight, static and dynamic compliances by 5.7 %, 2.1% and 19.1% respectively from the topology-optimized model. The examples demonstrated the feasibility of the suggested design optimization method.

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Structural Design Optimization of a High Speed Machining Center by Using a Simple Genetic Algorithm (유전 알고리즘을 이용한 고속 금형센터의 구조설계 최적화)

  • 최영휴;박선균;배병태;이재윤;김태형;박보선
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.1006-1009
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    • 2000
  • In this study, a multi-step optimization technique combined with a simple genetic algorithm is introduced in order to minimize the static compliance, the dynamic compliance, and the weight of a high speed machining center simultaneously. Dimensional thicknesses of the eight structural members on the static force loop are adopted as design variables. The first optimization step is a static design optimization, in which the static compliance and the weight are minimized under some dimensional and safety constraints. The second step is a dynamic design optimization, where the dynamic compliance and the weight are minimized under the same constraints. After optimization, the weight of the moving body only was reduced to 57.75% and the weight of the whole machining center was reduced to 46.2% of the initial design respectively. Both static and dynamic compliances of the optimum design are also in the feasible range even though they were slightly increased than before.

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Structural Design Optimization of a Micro Milling Machine for Minimum Weight and Vibrations (마이크로 밀링 머신의 저진동.경량화를 위한 구조 최적설계)

  • Jang, Sung-Hyun;Kwon, Bong-Chul;Choi, Young-Hyu;Park, Jong-Kweon
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.18 no.1
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    • pp.103-109
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    • 2009
  • This paper presents structural design optimization of a micro milling machine for minimum weight and compliance using a genetic algorithm with dynamic penalty function. The optimization procedure consists of two design stages, which are the static and dynamic design optimization stages. The design problem, in this study, is to find out thickness of structural members which minimize the weight, the static compliance and the dynamic compliance of the micro milling machine under several constraints such as dimensional constraints, maximum compliance limit, and safety factor criterion. Optimization results showed a great reduction in the static and dynamic compliances at the spindle nose of the micro milling machine in spite of a little decrease in the machine weight.

Nonlinear vibration of Mindlin plate subjected to moving forces including the effect of weight of the plate

  • Wang, Rong-Tyai;Kuo, Nai-Yi
    • Structural Engineering and Mechanics
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    • v.8 no.2
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    • pp.151-164
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    • 1999
  • The large deflection theory of the Mindlin plate and Galerkin's method are employed to examine the static responses of a plate produced by the weight of the plate, and the dynamic responses of the plate caused by the coupling effect of these static responses with a set of moving forces. Results obtained by the large deflection theory are compared with those by the small deflection theory. The results indicate that the effect of weight of the plate increases the modal frequencies of the structure. The deviations of dynamic transverse deflection and of dynamic bending moment produced by a moving concentrated force between the two theories are significant for a thin plate with a large area. Both dynamic transverse deflection and dynamic bending moment obtained by the Mindlin plate theory are greater than those by the classical plate.

Efficient Dynamic Weighted Frequent Pattern Mining by using a Prefix-Tree (Prefix-트리를 이용한 동적 가중치 빈발 패턴 탐색 기법)

  • Jeong, Byeong-Soo;Farhan, Ahmed
    • The KIPS Transactions:PartD
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    • v.17D no.4
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    • pp.253-258
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    • 2010
  • Traditional frequent pattern mining considers equal profit/weight value of every item. Weighted Frequent Pattern (WFP) mining becomes an important research issue in data mining and knowledge discovery by considering different weights for different items. Existing algorithms in this area are based on fixed weight. But in our real world scenarios the price/weight/importance of a pattern may vary frequently due to some unavoidable situations. Tracking these dynamic changes is very necessary in different application area such as retail market basket data analysis and web click stream management. In this paper, we propose a novel concept of dynamic weight and an algorithm DWFPM (dynamic weighted frequent pattern mining). Our algorithm can handle the situation where price/weight of a pattern may vary dynamically. It scans the database exactly once and also eligible for real time data processing. To our knowledge, this is the first research work to mine weighted frequent patterns using dynamic weights. Extensive performance analyses show that our algorithm is very efficient and scalable for WFP mining using dynamic weights.

Effects of increasing weight load on dynamic balance (무게부하 증가가 동적 균형에 미치는 영향)

  • Woong-Jae Choi;Byung-Hoon Woo
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.4
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    • pp.606-615
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    • 2023
  • The purpose of this study was to investigate the effect of increasing weight load on the dynamic balance on Y-balance Test(YBT). 18 male and female adults in their 20-30s (age: 23.17±1.72 years, height: 172.46±9.84 cm, weight: 73.39±11.44 kg, leg length: 88.89±5.69 cm) participated in the experiment. To measure the dynamic balance, the YBT was used to measure the reach distance, composite score, and COP variables to derive the results. As a result of the study, dynamic balance was improved in weight load in posteromedial and posterolateral reach and overall score during YBT. As a result of COP, anteroposterior amplitude, left and right COP velocity, and COP area during anterior reach improved dynamic balance in weight load in the right foot, but there was no difference during the posteromedial reach, ML amplitude in the left foot, AP COP velocity in left foot, ML COP velocity and COP velocity in both foot, and COP area in both foot improved dynamic balance when weight load during posterolateral reach.

Structural Analysis and Dynamic Design Optimization of a High Speed Multi-head Router Machine (다두 Router Machine 구조물의 경량 고강성화 최적설계)

  • 최영휴;장성현;하종식;조용주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.902-907
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    • 2004
  • In this paper, a multi-step optimization using a G.A. (Genetic Algorithm) with variable penalty function is introduced to the structural design optimization of a 5-head route machine. Our design procedure consist of two design optimization stage. The first stage of the design optimization is static design optimization. The following stage is dynamic design optimization stage. In the static optimization stage, the static compliance and weight of the structure are minimized simultaneously under some dimensional constraints and deflection limits. On the other hand, the dynamic compliance and the weight of the machine structure are minimized simultaneously in the dynamic design optimization stage. As the results, dynamic compliance of the 5-head router machine was decreased by about 37% and the weight of the structure was decreased by 4.48% respectively compared with the simplified structure model.

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A Sequential Pattern Mining based on Dynamic Weight in Data Stream (스트림 데이터에서 동적 가중치를 이용한 순차 패턴 탐사 기법)

  • Choi, Pilsun;Kim, Hwan;Kim, Daein;Hwang, Buhyun
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.2
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    • pp.137-144
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    • 2013
  • A sequential pattern mining is finding out frequent patterns from the data set in time order. In this field, a dynamic weighted sequential pattern mining is applied to a computing environment that changes depending on the time and it can be utilized in a variety of environments applying changes of dynamic weight. In this paper, we propose a new sequence data mining method to explore the stream data by applying the dynamic weight. This method reduces the candidate patterns that must be navigated by using the dynamic weight according to the relative time sequence, and it can find out frequent sequence patterns quickly as the data input and output using a hash structure. Using this method reduces the memory usage and processing time more than applying the existing methods. We show the importance of dynamic weighted mining through the comparison of different weighting sequential pattern mining techniques.

The Effect of Shoe Lift of the Paretic Limb on Gait Patterns in Hemiplegics (환측 신발 높이기가 편마비 환자의 보행 특성에 미치는 영향)

  • Yoon, Jung-Gyu;Park, Jeong-Mee;Kim, Jong-Man
    • Physical Therapy Korea
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    • v.9 no.2
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    • pp.83-96
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    • 2002
  • The purpose of this study was to determine the effect of lift to the shoe of the affected limb on gait patterns in subjects with hemiplegia. The subjects of this study were 18 post-stroke hemiplegics. For the study, insole of the paretic side was lifted 10mm higher, and duration of static weight bearing, dynamic weight bearing and stance phase were measured from one cycle of the gait, before and after the lift application. For the measurement of carry-over effect of lift, we got data of those three items prior to and 3 weeks after lift application and 3 days after removal of the lift. Static weight bearing was significantly increased both just after and continuous application of lift for 3 weeks than before. Dynamic weight bearing was significantly decreased in heel contact and footflat phases only when just after application of the lift, without any change after 3 weeks application. In heel-off phase, dynamic weight bearing did not show any significant difference between before and just after application of lift whereas significantly decreased after 3 weeks application. Duration of stance phase was not changed among anytime of application. According to this study, lift applied to the shoe of the peretic limb was effective in inducing static weight bearing in the paretic limb, but did not significantly effect dynamic weight bearing on gait patterns. This study suggests that symmetry, induced by shoe lift applied to the paretic limb, could help correct abnormal posture that would be caused in standing and prevent development of abnormal muscle tone in subjects with hemiplegia caused by unilateral stroke.

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