• Title/Summary/Keyword: bucket

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Experimental Study on the Combustion Chracteristics in the Moxa Bucket Moxibustion (온통구(溫筒灸)의 연소특성(燃燒特性)에 관한 실험적(實驗的) 연구(硏究))

  • Choi, Jung-Sun;Yoon, Ju-Yeong;Lee, Geon-Mok;Lee, Geon-Hui
    • Journal of Acupuncture Research
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    • v.24 no.1
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    • pp.49-77
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    • 2007
  • Objectives: The purpose of this study is to investigate the mechanism and effect of moxa bucket moxibustion. Objectively, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxa bucket moxibustion. Methods: We have selected of the moxa bucket moxibustion. We make a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results: 1. We can design the moxa bucket moxibustion that it has 57.6$^{\circ}C$ maximum temperature with 7g weight and 10mm height, if we use more weight of moxa or lower the height of moxa, we can observe relatively elavated maximum temperature. We observe the maximum temperature following the measuring position of moxa bucket and we can see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket. 2. We can design the moxa bucket moxibustion with 5g moxa and 10mm height that it has 0.121 $^{\circ}C$/sec of maximum temperature gradient, and it has relatively high temperature gradient at lower weight and height condition. 3. We can design the moxa bucket moxibustion with 7g moxa and 15mm height that it has 4,135sec of the longest effective temperature combustion time, if we use more weight of moxa or higher height of moxa, we can observe relatively extended effective temperature combustion time. We observe the longest effective combustion time following the measuring position of moxa bucket. We can see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket.

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Surface Flatness Test using 2-Bucket Algorithm Phase-shifting Interferometry (2-Bucket 알고리즘 위성 전이 간섭계를 이용한 평면 편평도 측정)

  • 정근욱;김동욱;길상근;박한규
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.11
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    • pp.62-69
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    • 1992
  • In this paper, a measurement system of surface flatness test using 2-Bucket algorithm phase-shifting interferometry is designed and constructed. In the conventional surface flatness test system using phase shifting interferometry, it is needed more than 3 fringe datas but we propose 2-Bucket algorithm phase-shifting interferometry which only uses two fringe datas. 2-Bucket algorithm uses the relative phase differences of the neighbour pixels. If we watch the result of phase-shift error test simulation, 2-Bucket algorithm has the same calculating values that 3-Bucket, 4-Bucket and 5-Bucket algorithm have them. Experiments have been carried out on the silicon wafer. The measurement of silicon wafer's surface flatness shows that the flatness topography using 2-Bucket algorithm is similar to that of other algorithms.

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Experimental Study on the Characteristics of Combustion in Middle Size-direct Moxibustion (중주(中炷) 직접구(直接灸)의 연소특성에 관한 실험적 연구)

  • Choi, Youn-Sung;Kim, Do-Ho;Lee, Geon-Hui;Lee, Geon-Mok
    • Journal of Acupuncture Research
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    • v.26 no.1
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    • pp.111-119
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    • 2009
  • Objectives : The purpose of this study is to investigate the mechanism and effect of moxa bucket moxibustion, to be used as the quantitative data through the measurement of temperature, and to grasp the thermodynamic characteristics of moxa bucket moxibustion. Methods : We have selected the moxa bucket moxibustion. We have made a comparative study of the thermodynamic characteristics of moxa bucket moxibustion. We have examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa bucket moxibustion made by oak wood. Results : 1. We could design the moxa bucket moxibustion so that it has $57.6^{\circ}C$ maximum temperature with 7g weight and 10mm height, if we use more weight of moxa or lower height of moxa, we can observe relatively elevated maximum temperature. We observed the maximum temperature following the measuring position of moxa bucket and we could see higher temperature at the center of the moxa bucket and lower temperature at the side of the moxa bucket. 2. We could design the moxa bucket moxibustion with 5g moxa and 10mm height so that it has 0.12 $1^{\circ}C/sec$ of maximum temperature gradient, and it has relatively high temperature gradient at lower weight and height condition. 3. We could design the moxa bucket moxibustion with 7g moxa and 15mm height so that it has 4,135sec of the longest effective temperature combustion time. If we use more weight of moxa or higher height of moxa, we can observe relatively extended effective temperature combustion time. Conclusions : We observed the longest effective combustion time following the measuring position of moxa bucket. We can see a higher temperature at the center of the moxa bucket and a lower temperature at the side of the moxa bucket.

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THE DISCRETE-TIME ANALYSIS OF THE LEAKY BUCKET SCHEME WITH DYNAMIC LEAKY RATE CONTROL

  • Choi, Bong-Dae;Choi, Doo-Il
    • Communications of the Korean Mathematical Society
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    • v.13 no.3
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    • pp.603-627
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    • 1998
  • The leaky bucket scheme is a promising method that regulates input traffics for preventive congestion control. In the ATM network, the input traffics are bursty and transmitted at high-speed. In order to get the low loss probability for bursty input traffics, it is known that the leaky bucket scheme with static leaky rate requires larger data buffer and token pool size. This causes the increase of the mean waiting time for an input traffic to pass the policing function, which would be inappropriate for real time traffics such as voice and video. We present the leaky bucket scheme with dynamic leaky rate in which the token generation period changes according to buffer occupancy. In the leaky bucket scheme with dynamic leaky rate, the cell loss probability and the mean waiting time are reduced in comparison with the leaky bucket scheme with static leaky rate. We analyze the performance of the proposed leaky bucket scheme in discrete-time case by assuming arrival process to be Markov-modulated Bernoulli process (MMBP).

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Analysis of Damage Trend for Gas Turbine 1st Bucket Related to the Change of Models (모델 변천에 따른 가스터빈 1단 버켓의 손상경향 분석)

  • Kim, Moon-Young;Park, Sang-Yeol;Yang, Sung-Ho;Choi, Hee-Sook;Ko, Won;Song, Kuk-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.6 s.261
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    • pp.718-724
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    • 2007
  • Some of gas turbine model of 7F-Class has constructed and is operating with units domestically. Non-destructive testing (NDT) is one of the methods being used to inspect damage $1^{st}$ stage bucket and review damage trends. We also analyze damage configuration and microstructure according to material and compare with pape of electric power research institute (EPRI). The damaged mode could be determined by leveraging failure analysis. Especially, configuration uprate of bucket is not only to prevent damage during operation but also avoid domestic manufacturing by the competitors. Modifications were mainly concentrated on surfaces such as cooling hole and bucket tips. Analyzing of bucket damage, the earlier model of 7F-Class used with one cycle with equivalent operation hour (EOH), has various cracking of the bucket surface. Bucket damage of new model is centered on tip area (54%) as analyzed by EPRI research. We conclude that improving bucket configuration would increase repair rate on the bucket tip.

A study on improvement of leaky bucket UPC algorithm in ATM networks (ATM 망에서의 Leaky Bucket UPC 알고리즘의 성능 개선에 관한 연구)

  • 심영진;박성곤;조용환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.5
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    • pp.1116-1125
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    • 1997
  • In this paper, the modified UPC(Usage Parameter Control) algorithm is proposed. The proposed UPC algorithm is based on Leakey Bucket algorithm and adds the characteristics of the jumping window algorithm for monitoring the average bit rate. The proposed algorithm let a cell, which is tagged by Leaky Bucket algorithm, pass through the network, if the network does not violate the average bit rate. The measuring method of window mechanism like jumping window. This paper supposes On/Off traffic source model of rthe performance evaluation and analysis of the proposed algorithm. Therefore, as simulation results, the proposed algorithm acquires more reduced results of the cell loss rate and bucket size than the Leaky Bucket algorithm.

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Analysis of the Bearing Behavior of a Tripod Bucket Installed in Clay (점성토 지반에 설치된 Tripod 버켓기초의 지지거동 분석)

  • Kim, Sung-Ryul;eong, Jae-Uk;Oh, Myounghak;Kwon, Osoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.3C
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    • pp.105-111
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    • 2012
  • Bucket foundations, which are used in the foundations of offshore wind turbines, should be able to withstand large amounts of horizontal and moment loads. Tripod bucket foundation, which combines three single buckets, has been used to increase horizontal and moment capacities. This study performed numerical analysis using ABAQUS (2010), to analyze the group effect and the bearing capacity of a tripod bucket in clay. Parametric studies were performed varying the bucket spacing ratio S/D (S=spacing between the centers of the bucket and the tower; D=diameter of the bucket) and depth ratio L/D (L=embedded length of skirt). The applied constitutive models were a linear elastic perfectly plastic model with Tresca yield criteria for normally consolidated clay and an elastic model for buckets. Loading in the vertical, horizontal, and moment directions was simulated with an increase in each movement at a reference point. The bearing behavior and the capacities of a single and a tripod bucket were compared. Capacity evaluation method of the tripod bucket was suggested using the capacity of a single bucket.

A Decentralized Self-Control Strategy for Assembly Cell Using Bucket Brigade (Bucket Brigade를 기반으로 한 분산자율형 조립셀 운영전략)

  • Koo, Pyung Hoi
    • Journal of Korean Institute of Industrial Engineers
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    • v.41 no.4
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    • pp.330-337
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    • 2015
  • A bucket-brigade is a way of transporting items where items are passed from one person to the next. The operation of the bucket brigade imitates the cooperative behavior of ants when brood, food or other resources are moved. Koo (2009) presented a bucket brigade-based assembly cell where each worker follows a simple rule: perform assembly operations on a product until the next worker downstream takes it over; then go back to the previous worker upstream to take over a new assembly job. In this way, the flow line is self-balanced without any predetermined job assignment. However, there are some productivity losses related to hand-off and blocking. This paper examines the hand-off and blocking losses and presents a new bucket brigade-based assembly cell where working areas for each assembler is restricted with the help of buffer interfaces. Simulation experiments are used to validate the performance of the new assembly system.

Application of Bucket-brigades to Order Picking in Warehouses (물류창고에서 Bucket Brigade를 활용한 오더피킹에 대한 연구)

  • Koo, Pyung-Hoi
    • IE interfaces
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    • v.21 no.3
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    • pp.333-342
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    • 2008
  • Warehouses form an important link in a supply chain network. Among a variety of activities in warehouses, order picking is the process of retrieving a number of items out of storage to meet customer orders. Today, as the transactions through direct sales are wide spread, warehouses often receive a large amount of small orders to be handled within tight time windows, which makes fast and efficient order picking more important than ever. This paper examines a new order picking method where the concept of bucket brigade (BB) is applied. Bucket brigade is a way of dynamically coordinating workers who progressively perform a set of operations along a flow line. In bucket brigades, a worker is not assigned his jobs in a static way. Each worker takes a job from his predecessor when he is free. We identify some considerations when bucket brigades are applied to order picking activities. A new BB picking protocol is presented to improve existing BB picking protocols. Through simulation experiments, the performance of BB order picking is evaluated under various logistics environments.

Application of Bucket Brigades in Assembly Cells for Self Work Balancing (자율적인 밸런싱을 실현하는 Bucket Brigade 기반의 조립셀 운영방식)

  • Koo, Pyung-Hoi
    • IE interfaces
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    • v.22 no.2
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    • pp.144-152
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    • 2009
  • Assembly line has been recognized as an efficient production system in mass production. However, the recent production environment characterized as mass customization urges production managers to transform a long assembly line to a number of short assembly cells. To maximize the utilization of resources in an assembly cell, it is important to have the line balanced. This paper presents a bucket brigade-based assembly cell. Bucket brigade is a way of coordinating workers who progressively perform a set of assembly operations on a flow line. Each worker follows a simple rule: perform assembly operations on a product until the next worker downstream takes it over; then go back to the previous worker upstream to take over a new assembly job. In this way, the line balances itself. The bucket brigade assembly cell is analyzed and compared with traditional assembly lines and general assembly cells. The paper also discusses some prerequisite requirements and limitations when the bucket brigade assembly cells are employed.