• Title/Summary/Keyword: Capacity balance

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Uncertainty Analysis of Dynamic Thermal Rating of Overhead Transmission Line

  • Zhou, Xing;Wang, Yanling;Zhou, Xiaofeng;Tao, Weihua;Niu, Zhiqiang;Qu, Ailing
    • Journal of Information Processing Systems
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    • v.15 no.2
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    • pp.331-343
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    • 2019
  • Dynamic thermal rating of the overhead transmission lines is affected by many uncertain factors. The ambient temperature, wind speed and wind direction are the main sources of uncertainty. Measurement uncertainty is an important parameter to evaluate the reliability of measurement results. This paper presents the uncertainty analysis based on Monte Carlo. On the basis of establishing the mathematical model and setting the probability density function of the input parameter value, the probability density function of the output value is determined by probability distribution random sampling. Through the calculation and analysis of the transient thermal balance equation and the steady- state thermal balance equation, the steady-state current carrying capacity, the transient current carrying capacity, the standard uncertainty and the probability distribution of the minimum and maximum values of the conductor under 95% confidence interval are obtained. The simulation results indicate that Monte Carlo method can decrease the computational complexity, speed up the calculation, and increase the validity and reliability of the uncertainty evaluation.

A Case of Operational Efficiency Improvement in EPS Motor Manufacturing Process Using IE Technique (IE 기법을 활용한 EPS 모터 제조공정의 운영효율성 향상 사례)

  • Kim, Jung Suop;Lee, Ji Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.7
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    • pp.63-72
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    • 2017
  • This paper proposes a procedure to improve the operational efficiency of the automotive parts manufacturing process by applying classical IE techniques composed of process analysis, work method analysis, and motion analysis, and a specific application case is outlined. The proposed procedure was developed originally by the Task Force organized in L company's automotive parts manufacturing business unit. The balance efficiency and production capacity were used as measures of operational efficiency. The developed procedure follows the general procedure of analyzing the phenomenon at the manufacturing shop, deriving an improvement solution to solve the problem, evaluating each derived alternative, and implementing it to the field to achieve productivity improvement. Among the methods used in each phase of the procedure, function analysis used in the waste discovery phase and R&R evaluation method used in the alternative assessment phase are unique techniques developed by L company's TF. The R&R Evaluation method techniques are described in detail because this method is highly applicable and extensible. A case of applying developed procedures to improve the EPS motor manufacturing process is discussed. As a result, the line balance efficiency and production capacity were increased to a satisfactory level.

Effect of convergence body stabilization exercise on the visual response speed and functional movement, balance, and vital capacity of High School Football Players. (융복합적 신체안정화운동이 고등학교 축구선수의 시각반응속도와 기능적 움직임, 균형 및 폐활량에 미치는 영향)

  • Seo, Yeon-Soon;Song, In-Young;Yoon, Jong-Hyuk
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.191-202
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    • 2022
  • The purpose of this study is to examine the effect of a 10-week body stability exercise program, which was conducted on 24 male football players. The result of the Visual Response Speed Test using BlazePod, showed a significant increase of the upper arms, left foot and right foot for 15 second in number of reactions and reaction time (p<0.001). As a result of evaluating whether or not 7 functional movements were improved in order to evaluate the functional movement screen, Hurdle Step (p=0.001) and Active Straight Leg Rise (p=0.022) movements were significantly improved. significantly improved. As a result of measuring the y-balance Test in order to evaluate the balance ability, composite score(p<0.001) of both sides was significantly improved. The result of evaluating vital capacity, which was conducted to evaluate mobility and muscle endurance, showed a significant improvement in Forced vital capacity(p<0.001) and Forced expiratory volume in 1.0(p=0.003). In conclusion, a 10-week BSE program intervention in high school period, which can most improve the technical fitness necessary for the game in power, agility, leg strength, leg stability, mobility, and muscle endurance, will improve overall technical fitness, prevent football players from being injured and enhance their performance.

The Effects of One Year Exercise Program on Exercise Capacity & Cognitive Function in Male Patients with Dementia (1년간의 복합 운동프로그램이 남성 치매환자의 운동능력과 인지기능에 미치는 영향)

  • Kwak Yi-Sub;Um Sang-Yong
    • Journal of Life Science
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    • v.15 no.2 s.69
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    • pp.220-224
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    • 2005
  • The purpose of the present study is to investigate the effects of long-term exercise program on exercise capacity and cognitive function (MMSE) in male patients with dementia. 24 male patients were divided into two experimental groups : the exercise group (n=12) and the control group (n=12). The exercise group participated in regular exercise program for 12 months, and their exercise capacity (cardiopulmonary function, muscle strength, muscular endurance, flexibility, balance, agility) and MMSE (Mini-mental state examination) levels were evaluated at baseline (pre), after 6 months (mid) and after 12 months (post). The subjects carried on group-exercise of $VO_{2}max\;30\~60\%$, $30\~60$ minute a day, $2\~3$ times per week. Statistical techniques for data analysis was paired samples t-test. The level of statistical significance was ${\le}.05.$ The results of this study were summarized as follows: In the exercise group, there were significant differences in cardiopulmonary function, muscle strength, muscular endurance and MMSE at the times of pre & mid and pre & post, there were significant differences in balance and agility at the time of pre & post only, whereas there was no significant difference in flexibility following the long-term exercise. In the control group, there were no significant differences in all the times. Based on the results of this particular study, one year exercise program increases on the cognitive function & exercise capacity in male patients with dementia.

Effects of Underwater Treadmill Gait Training on Gait, Balance, and Pulmonary Function in Stroke Patients

  • Yang, Ho-june;Choi, Jong-duk
    • Physical Therapy Korea
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    • v.22 no.4
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    • pp.34-43
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    • 2015
  • The purpose of this study was to compare the effects of underwater treadmill gait training (UTGT) and overground treadmill gait training (OTGT) on the gait, balance ability and pulmonary function of stroke patients. Twenty subjects were recruited for this study. The subjects were randomly assigned to two groups: UTGT ($n_1$=10) and OTGT ($n_2$=10). The 10 m walk test (10 MWT), Berg Balance Scale, Timed Up and Go (TUG) test, center of pressure, pulmonary function of forced vital capacity (FVC), forced expiratory volume after 1 sec (FEV1) and FEV1/FVC were measured before and after 4 weeks of training. Both groups undertook the gait training for 30 min a day, 3 times a week, for 4 weeks, and rating of perceived exertion of the groups were measured and compared. All the studied variables were significantly improved in both groups (p<.05) at the end of the study, except in the FEV1 of OTGT (p>.05). There was significant between-group difference in all of the variables, except in the 10 MWT (p>.05). These findings suggest that UTGT is more effective than OTGT in improving the balance and pulmonary functions of stroke patients.

A Case Study on the Capacity Design for Manufacturing Process of Bearing-Race (베어링궤도 제조공정의 용량설계에 관한 사례연구)

  • Moon, Dug-Hee;Song, Cheng
    • IE interfaces
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    • v.15 no.4
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    • pp.349-355
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    • 2002
  • In order to build a new factory, we must have answers regarding the following questions; 1. what is to be produced? 2. how are the products to be produced? 3. how much of each product will be produced? The answers are related to product-design, process-design and capacity-design respectively and they are used for layout-design as the input data. Especially capacity design decision provides the information regarding the number of equipments required and the balance of the line. This paper introduces a case study on the capacity design for a new factory where the retainers of ball bearing are manufactured. A simulation model is developed with ARENA for analyzing the system considered. The major objectives of the study are evaluating the performance of the line which is originally suggested by the company, and finding out alternatives for improving the system. Number of WIP between the processes are also investigated because it affects the space planning of the layout.

A study on long-term capacity procurement mechanism in electricity markets (전력시장에서 장기적 용량확보 메커니즘에 관한 연구)

  • Lee, Seung-Hyun;Chung, Koo-Hyung;Han, Seok-Man;Kim, Bal-Ho
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.398-399
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    • 2006
  • The procurement of generation and transmission/Distribution capacity in vertically-integrated electric industry is sufficient by facility construction in suitable time. However, the introduction of competitive electricity market increase the efficiency of availability for facilities and fuels. As a result, long-term capacity procurement is required for stable demand-supply balance since it is expected to maintain their generation capacity at a minimum for profit maximization. In this paper, a new long-term capacity procurement mechanism is proposed, which is able to assure supplemental contribution in competitive electricity market.

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Effects of Proprioceptive Neuromuscular Facilitation Program Combined with Dynamic Neuromuscular Stabilization Approach on Balance in Patient with Cerebellum Atrophy -Case Report- (동적 신경근 안정화 접근법과 결합한 PNF 중재 프로그램이 소뇌 위축 환자의 균형에 미치는 영향 -사례보고-)

  • Na, Eun-Jin;Moon, Sang-Hyun;Kim, Eun-Kyung;Park, Du-Jin
    • PNF and Movement
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    • v.14 no.3
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    • pp.237-244
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    • 2016
  • Purpose: This case report examines the influence of proprioceptive neuromuscular facilitation (PNF) combined with a dynamic neuromuscular stabilization approach on balance in patients with cerebellar atrophy. Methods: The target subject of this case report was a 34-year-old woman who was informed of the purpose of this research and voluntarily agreed to participate in it. The case report conformed to research ethics based on the Helsinki Declaration. The target subject was confirmed to have cerebellar atrophy from an unknown cause in 2009 and was diagnosed with slight ataxia. At that time, she could carry out daily activities without physical therapy. On May 19, 2015, she suffered both a subdural hemorrhage (SDH) and subarachnoid hemorrhage (SAH) in a traffic accident. She was urgently moved to the emergency room and managed by nonsurgical treatment, and then, the cerebellar atrophy and ataxia gradually deteriorated. To evaluate the patient's balance capacity before and after intervention, the trunk impairment scale (TIS), trunk impairment scale (OLST) during eye-closing/opening, timed up and go test (TUG), and visual analogue scale (VAS) were conducted. The PNF intervention program was executed for 30 min, four times a week, for three weeks. Results: The TIS and OLST during eye-closing/opening were improved by as much as a point, by 8.15 s and 6.21 s, respectively, after applying the PNF program. TUG and VAS decreased by 1.33 s and 3 points, respectively, after intervention. According to the result, the OLST during eye-closing/opening and VAS improved remarkably in comparison with those before intervention. Conclusion: As the final result of the case report, PNF intervention combined with DNSA more effectively improved the static balance capacity, such as the OLST during eye-closing/opening and VAS, compared to the dynamic balance capacity. In addition, the intervention duration and period of the exercise program are recommended to be more than 1 h a day for four weeks considering the learning ability of a patient with cerebellar atrophy.

On response of Surface Equilibrium Temperature for Change of Surface Characteristics : An EBM Study (지표 특성 변화에 대한 평형온도의 반응 연구 : EBM 연구)

  • Seo, Ye-Won;Chu, Jung-Eun;Ha, Kyung-Ja
    • The Korean Journal of Quaternary Research
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    • v.24 no.2
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    • pp.1-11
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    • 2010
  • Energy Balance Model (EBM) was used to experiment the distribution of surface equilibrium temperature which responds to external forcing associated with the surface characteristics. Surface equilibrium temperature is calculated as sum of incoming solar radiation and latitudinal transport is balanced with outgoing infrared radiation. To treat incoming solar radiation, the source of the earth energy, significantly for energy balance, the experiment for surface equilibrium temperature distribution was performed considering the energy balance with the latitudinal albedo change as well as land and sea distribution. In addition, linear albedo change experiment, arctic albedo 5%, 10%, 15% change experiments and the opposite albedo change experiments between arctic and mid-latitudes were performed using incoming solar radiation as an external forcing. Moreover, with and without ice-albedo feedback experiments were performed. Increasing of arctic albedo is blocked out the incoming solar radiation so that it induces decreasing of latitudinal heat transport. It is strengthened energy transport from low latitudes by keeping arctic low energy states. Therefore the temperature change in the mid-latitudes exhibits larger response than that of arctic due to the difference of transport. The land which has lower heat capacity than sea can be reach to equilibrium temperature shortly. Also land is more sensitive to temperature change with respects to albedo. Thus it induces the thermal difference between land and sea. As a result, the equilibrium temperature exhibits differently as the difference of albedo and heat capacity which are the one of surface characteristics. Surface equilibrium temperature decreases as albedo increase and the ratio of temperature change is large as heat capacity is small. The decreasing of surface equilibrium temperature with respects to increasing of linear albedo is accelerated by ice-albedo feedback. However local change of surface equilibrium temperature decreases non-linearly.

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A Study on Computation Methods of Monthly Runoff by Water Balance Method (물수지 개념을 이용한 월유출량 산정방법에 관한 연구)

  • Im, Dae-Sik;Kim, Hyeong-Su;Seo, Byeong-Ha
    • Journal of Korea Water Resources Association
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    • v.34 no.6
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    • pp.713-724
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    • 2001
  • Hydrologists have tried to develop monthly runoff simulation models which are important factor in wafer resources planning. One of the models called Kajiyama formu]a is widely used for monthly runoff simulation in Korea. In recent work by Xiong and Guo (1999), they suggested Two-parameter monthly water balance model to simulate the runoff and showed that the model can be used for the water resources planning program and the climate impact studies. However, they estimated two parameters of transformation of time scale, c and of the field capacity, SC by the trial and error method. Therefore, the purpose of this study is to suggest the estimation methodologies of c and SC, and compare Kajiyama formula with a Two-parameter monthly water balance model to simulate the runoff in Han river and IHP representative basins in Korea. The c is estimated by using the relationship of actual and potential evaporations, and SC is estimated from association with CN. We show that the estimated c and SC can be used as the initial or optimal values in the model.

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