• Title/Summary/Keyword: Line balance

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A Stochastic Linear Scheduling Method using Monte Carlo Simulation

  • Soderlund, Chase;Park, Borinara
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.169-173
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    • 2015
  • The linear scheduling method or line-of-balance (LOB) is a popular choice for projects that involve repetitive tasks during project execution. The method, however, produces deterministic schedule that does not convey a range of potential project outcomes under uncertainty. This results from the fact the basic scheduling parameters such as crew production rates are estimated to be deterministic based on single-point value inputs. The current linear scheduling technique, therefore, lacks the capability of reflecting the fluctuating nature of the project operation. In this paper the authors address the issue of how the variability of operation and production rates affects schedule outcomes and show a more realistic description of what might be a realistic picture of typical projects. The authors provide a solution by providing a more effective and comprehensive way of incorporating the crew performance variability using a Monte Carlo simulation technique. The simulation outcomes are discussed in terms of how this stochastic approach can overcome the shortcomings of the conventional linear scheduling technique and provide optimum schedule solutions.

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A Study on the Relationship between Cycle Time and Balance Delay (조립생산에 있어서 주기시간과 라인평형 지연관계에 관한 연구)

  • 박명규
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.5 no.7
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    • pp.17-24
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    • 1982
  • Most line balancing technique widely used in manufacturing industry is done by balancing to a cycle or operator, time determined to provide the exact number of required units per day. No thought is given to benefit foregone by making slight changes to cycle time to achieve better distribution of the work among operators. This study provides a method to minimize balance delay by the choice of cycle time.

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The Effects of Coordinative Locomotor Training Program for Life-Care Promotion on Balance of Obese Elderly Women (라이프케어 증진을 위한 협응적 이동훈련 프로그램이 비만 여성노인의 균형에 미치는 영향)

  • Lee, Dong-Ryul
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.1
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    • pp.17-25
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    • 2020
  • The purpose of this study was to examine the effects of coordinative locomotor training (CLT) program on the balance for the promotion of life care of elderly obese women. Ten participants of elderly obese women who were able to walk independently without surgery experience of lumbar, hip or knee joint within the past year were recruited and under went the pretest, CLT (20 sessions), followed by the post-test. The test included BMI test using In-body, joint kinematics using myoVIDEO, muscle activation using surface EMG test (erector spinae (ER), external oblique abdominalis (EO), quadriceps femoris (Quad), hamstring muscle (Ham)) and balance tests including dynamic balance test using forced treadmill, Berg balance scale (BBS) and timed up go (TUG). The CLT program was conducted 60 minutes a day, 5 days a week, over 4 weeks period. As a result of this study, The the trunk and hip joints kinematics during the stance and swing phases of gait were a statistical significance levels were set at p <0.05. The ER and EO muscle activation were significantly improved after intervention (p <0.05). The length of gait line and single support line of change of center of pressure (COP) were significantly increased after intervention (p <0.05). The BBS and TUG were also significantly enhanced after intervention (p <0.05). The results of this study showed that CLT program for the improvement of life care had significant effects on improving postural instability, muscle weakness, reduced balance ability and falling risk of obese elderly women. Therefore, it is recommended to apply CLT program to improve life-care through improving balance ability and preventing fall of obese elderly women.

Effect of Proprioceptive Neuromuscular Facilitation Chopping Pattern on Neglect, Balance, and Activity of Daily Living of Stroke Patients with Hemi-Spatial Neglect: A randomized clinical trial (고유수용성신경근촉진법 내려치기 패턴 훈련이 편측무시가 있는 뇌졸중 환자의 편측무시, 균형능력 및 일상생활수행능력에 미치는 영향: 무작위 임상 시험)

  • Kang, Tae-Woo;Kim, Beom-Ryong
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.2
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    • pp.107-115
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    • 2019
  • PURPOSE: This study examined the effects of the chopping pattern of proprioceptive neuromuscular facilitation (PNF) on the neglect, balance ability, and activities of daily living in stroke patients with hemi-spatial neglect. METHODS: Twenty stroke patients with neglect volunteered for this study. The subjects were assigned randomly to either the experimental group (EG, n=10) or control group (CG, n=10). The chopping pattern of PNF and exercise therapy were applied in the EG and CG, respectively, for four weeks. Neglect, balance, and activities of daily living were evaluated at the pre-and post-intervention. The assessment tools included a line-bisection test, balance test using Space balance 3D, and modified Barthel index. The pre-and post-intervention values were compared in each group using a paired t-test and the between-group differences were assessed using an independent t-test. Statistical significance was set to ${\alpha}=.05$ for all variables. RESULTS: Significant differences were observed between the EG and CG in terms of neglect, balance, and activities of daily living (p<.05). Both groups showed significant improvement in neglect, balance, and activities of daily living (p<.05). CONCLUSION: These results suggest that the chopping pattern of PNF is effective in improving the hemi-spatial neglect, balance, and activities of daily living in stroke patients with neglect.

Feasibility Study on Thermal Power Plant Condenser Heat Recovery for District Heating and Fuel Line Preheating (발전소 복수기 배열회수의 지역난방 및 연료라인 예열용 활용타당성 검토)

  • Jung, Hoon;Hwang, Gwang-Won
    • New & Renewable Energy
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    • v.5 no.3
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    • pp.40-48
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    • 2009
  • Recovered heat has been considered as a renewable energy in Europe since 2008 because its great effect on energy saving and carbon decreasing in plant process. Energy saving and decreasing green gas are critical issue today, so various technologies to save energy and decrease carbon dioxide in plant process have been applied to many industrial area. In this paper, the feasibility of condenser heat recovery by heat pump in power plant for district heating and fuel line preheating were reviewed by verifying energy (heat) balance and mass balance of power plant model. Some ways to compose proper system to recover heat of condenser are suggested and their possibilities are also reviewed. Limitations on heat recovery in power plant are also reviewed. The results are verified by calculating input/output energy based on actual performance test data of Taean Thermal Power Plant in Korea. There is noticeable improvement of plant performance in some cases which demand low temperature (<100 C) heat like distrcit heating, fuel line heating, and so forth.

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Effects of hippotherapy on children with cerebral palsy: systematic review and meta-analysis

  • Kim, Kwon-Hoi;Lee, Suk-Min
    • Physical Therapy Rehabilitation Science
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    • v.9 no.1
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    • pp.55-65
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    • 2020
  • Objective: The most important goal of hippotherapy is to improve function, gait, and balance. The purpose of this study was to investigate the effects of hippotherapy on function, gait, and balance of children with cerebral palsy (CP). Design: A systematic review and meta-analysis. Methods: We've searched the PubMed, EMBASE, and Cochrane Library CENTRAL databases for English experimental studies published up until September 2018. To analyze the effects of hippotherapy on the function, gait, and balance of children with cerebral palsy, the systematic review and meta-analysis were performed on Patient/Participants/Population Problem, Intervention, Comparison, Outcome with Timing, Setting Study Design. Papers retrieved from the database were removed from the literature management database. Methodological quality evaluation was evaluated using Cochrane's risk of bias. Data was analyzed using the Revman 5.3 program of the Cochrane library. Results: In this study, we found that the effect size of hippotherapy, denoted as d, was -3.82, and that hippotherapy had the most effect on gait, but no statistical significant difference was observed. We also found no significant difference in function and balance after hippotherapy. It was found from the funnel plot that there was no publication bias as the plot was symmetrically distributed around the dotted line. Conclusions: There are many unclear studies and a lack of randomized controlled trials (RCTs) in this research area. More RCTs on the effects of hippotherapy on children with CP should be conducted in the future.

Comparison of Postural Control Ability according to the Various Video Contents during Action Observations

  • Goo, Bon Wook;Lee, Mi Young
    • The Journal of Korean Physical Therapy
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    • v.33 no.1
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    • pp.16-20
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    • 2021
  • Purpose: This study examined the effects of the type of video contents used for action observations on the ability to control posture. Methods: The participants were 48 healthy adults. The two hands of the participants were crossed on both shoulders, and the other foot was placed in a straight line in front of the target to allow them to watch a video of the monitor. The videos were presented in random order with three video contents (natural, stable balance posture, and unstable balance posture) consisting of 30 seconds each. A 15-second resting time was given between each video. During action observation using various video content forms, the posture control ability was measured using a TekScan MetScan® system. Results: The results revealed statistically significant differences in the area of movement and the distance by COP and distance by the type of action-observation videos, and the distance by the anteroposterior and mediolateral sides (p<0.05). The stable balance posture and unstable balance posture video showed significant differences in the distance by the COP, anteroposterior, and mediolateral distance. (p<0.05) Conclusion: This study suggests that choosing the contents of the videos is important during action-observation training, and action-observation training can help improve postural control.

The Effect of the Active Release Technique on Balance and Functional Movement in Youth Basketball Players

  • Kwang-Nam Kim;Byoung-Hee Lee
    • Journal of Korean Physical Therapy Science
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    • v.31 no.1
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    • pp.1-15
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    • 2024
  • Background: This study was conducted to apply active release techniques to male youth basketball players to help improve physical development and damage prevention and improve performance through improved balance and functional movement. Design: Randomized control trial. Methods: The subjects included 33 youth basketball players who were randomly assigned to the experimental group (n=17) and the control group (n=16). For the experimental group, the active release technique was applied to the hip muscles, calf muscles, posterior thigh muscles based on the distribution of injuries surveyed in youth basketball players in the Korean Basksetball League. The Y-balance test and the functional reach test (FRT) were used to assess balance and the Functional Movement Screen (FMS) was used to assess functional movement. Interventions were conducted twice a week for 4 weeks at 40 minutes per session. The experimental group was the active release technique group, and static stretching, a common exercise therapy technique, and self-myofascial release using a foam roller were applied for 20 minutes. The control group received general exercise therapy and placebo active release technique. The placebo active release technique applies pressure only. results:The experimental group showed a greater improvement in balance, as evidenced by the FRT, compared to the control group, which received general exercise treatment. However, there was no statistically significant difference in improvement between the 2 groups. In the case of the experimental group, the difference in the Y balance test before and after the intervention was larger than that of the control group, but there was no statistically significant difference. Significant improvement was found in functional movement, as evidence by the FMS, for the trunk stability test (p < 0.05), in-line lunge test (p < 0.05), rotational stability test (p < 0.05), total score (p < 0.05). Conclusion: In this study, the active release technique improved the balance and functional movement of young basketball players more than general exercise therapy. The application of the active release technique is therefore expected to assist in physical development, prevent damage, and improve the performance of youth basketball players.

A Study on 'Line Balancing' of Women's Jacket Production (여성복 재킷 생산라인의 라인 밸런싱에 관한 연구 - 공정편성 효율을 중심으로 -)

  • Shim, Kue-Nam;Kim, Jin-Seon;Oh, Ji-Yeong;Suh, Eun-Joung
    • Fashion & Textile Research Journal
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    • v.16 no.6
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    • pp.979-986
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    • 2014
  • This study establishes basic data for operations management by organizing processes and measuring time in the mini line for female jackets to improve productivity, ensure competitiveness, and maintain operator competency and the line process flow balance between apparel manufacturing companies. The results of this study are as follows. Sewing operations are divided into preparation functions, arrangement, partial tasks, and assembly that consist of 84 processes. The results from time measurement indicate that 3238.41seconds (sec) were required to produce a single jacket and that the average time required for operators was 231.32 sec. A control limit was established to increase the reliability of the measured value for net time. After outside values were removed, the operation time was measured to be 3176.35 sec. This accounted for 98.08% of the total operation time, with net time decreasing by 62.06. Skill and effort level coefficients were applied to measure the operator performance, the total real time was calculated to be 3415. The requirement for preparation and arrangement operations were 1233.35 sec, and 2182.22 sec for partial tasks and assembly operations. Process separation and organization were performed after the bottleneck operation was selected to identify the maximum line balance. Consequently, process efficiency of preparation and arrangement operations increased from 79.19% to 93.00%, and the partial tasks and assembly operations increased from 62.36% to 90.93%.

Development of Experimental Mobile Robots for Robotics Engineering Education by Using LEGO MINDSTORM (이동로봇을 중심으로 LEGO MINDSTORM을 응용한 로봇공학 교육용 실습 로봇개발)

  • Park, June-Hyung;Jung, Seul
    • The Journal of Korea Robotics Society
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    • v.7 no.2
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    • pp.57-64
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    • 2012
  • This paper introduces several mobile robots developed by using LEGO MIDSTORM for experimental studies of robotics engineering education. The first mobile robot is the line tracer robot that tracks a line, which is a prototype of wheel-driven mobile robots. Ultra violet sensors are used to detect and follow the line. The second robot system is a two-wheel balancing robot that is somewhat nonlinear and complex. For the robot to balance, a gyro sensor is used to detect a balancing angle and PD control is used. The last robot system is a combined system of a line tracer and a two-wheel balancing robot. Sensor filtering and control algorithms are tested through experimental studies.