• Title/Summary/Keyword: High set-up

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A Dynamic Set-up Technique for High Accuracy set-up of Continuous Hot Strip Finishing Mill (열간 마무리압연 설정의 정도향상을 위한 동적 설정법)

  • 문영훈;이준정
    • Transactions of Materials Processing
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    • v.5 no.3
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    • pp.232-238
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    • 1996
  • A dynamic mill set-up technique was developed to achieva a more precise roll gap set-up of the finishing mill stands for steel strip rolling. In the conventional mill set-up model the set-up values such as roll gap and roll speed are determined before the sheet bar reached the entry side of the finishing mill train and maintained constant until the strip top end passes through the last stand. In the way however a dynamic set-up logic that gives a way to adjust the roll gap value of the final mill stand for the strip ingoing from the ahead of the front stand was developed and attached to the existing set-up model. The roll gap modification is based on the analysis of the observation in the third stand of the finishing mill train. The dynamic set-up model was proved very effective for the more precise mill set-up and for operational stability in the hot strip finishing mill train.

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A Scheduling Strategy for Reducing Set-up Time and Work-In-Process in PCB Assembly Line (PCB조립 라인의 준비 시간 단축 및 재공품 감소를 위한 스케줄링 전략)

  • 이영해;김덕한;전성진
    • Journal of the Korean Operations Research and Management Science Society
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    • v.22 no.1
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    • pp.25-49
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    • 1997
  • Printed circuit board (PCB) assembly line configuration is characterized by very long set-up times and high work in process (WIP) inventory level. The scheduling method can significantly reduce the set-up times and WIP inventory level. Greedy sequence dependent scheduling (GSDS) method is proposed based on the current methods. The proposed method is compared with the current method in terms of three performance measures: line throughput, average WIP inventory level, and implementation complexity.

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The Characteristics of the Set-up Effect of Driven Piles (타입 말뚝의 지지력 증가효과 특성)

  • 조천환
    • Journal of the Korean Geotechnical Society
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    • v.19 no.4
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    • pp.235-246
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    • 2003
  • Since the study of Lee et al.(1994) there have been some case studies on the set-up effect of driven piles in Korea country. However, comprehensive examination on the analyses of the set-up effect with various testing data has not been carried out. In particular, the analysis of the influence of soil type and pile shape on the set-up effect has not been reported. It is necessary to analyse the test results of production piles in order to apply the set-up effect of driven piles for the field engineering. In this study some test piling and analyses were performed to give basic information to the piling design as well as the research on the set-up effect in sandy soils. The analyses on the set-up effect were performed with the monitoring data obtained from the high-strain dynamic loading tests. It was shown that the set-up effect of driven piles was not only affected by soil type but also by soil formation history It turned out that the set-up effect in sandy soils was considerable one that should not be ignored in the field, and that the bearing capacity increase of pile is mainly caused by the increase of shaft resistance. It was shown that the set-up effect of closed pile was larger than that of opened pile in clayey soils, while the set-up effect of opened pile was larger than that of closed pile in sandy soils.

A Study on the Classification of Brassiere Cups by Breast Volume Measurement Values on Women in their Twenties (20대 여성의 유방 부피 계측치에 따른 브래지어 컵의 분류)

  • Park, Yu-Sin;Kim, Seon-Mi;Kim, Eun-Ran
    • Journal of the Ergonomics Society of Korea
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    • v.23 no.2
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    • pp.93-104
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    • 2004
  • The research subjects of this study were 30 unmarried Korean women from 20 to 29 who had never had an operation on their breast. Measurement method using plaster breast mold was used for measuring their volume of breast. The correlation between their breast volume and the methods to set up brassiere cups with the existing method and with their circumference of breast was analyzed using KendalI's Coefficient. which was to figure out a method which had a bigger correlation with the volume of breast between the method to set up brassiere cups using the existing method and the method using the circumference of breast. The results analyzed showed that the coefficient of correlation between the existing method and the volume of breast was .12 and the significance level was .45. They didn't have any correlation. On the other hand. the coefficient of correlation between the circumference of breast and the volume of breast was .82. which was very high values and the significance level was very high .0001. Therefore. it turned out that it was difficult to set up brassiere cups by using the existing method and it was easier and more reliable to set up the cups by using the circumference of breast.

Development of Set-up Model for Elongation Control in Steel Skin Pass Mill (조질압연에서의 연신율제어를 위한 set-up 모델 개발)

  • 이원호
    • Transactions of Materials Processing
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    • v.10 no.2
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    • pp.130-136
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    • 2001
  • The mathematical set-up model was developed to reduce the mechanical property deviation in annealed and slightly rolled steel strip. The mechanical peculiarities of skin pass rolling process, such as high friction value and non-circular contact arc, low reduction and non-negligible entry and exit elastic zones as well as central restricted deformation zone are all taken into account. The deformation of work rolls is calculated with the influence function method and arbitrary contact arc shape is permitted. The strip deformation is modeled by slab method and the entry and exit elastic deformation zones are included. The strip restricted deformation zone near the neutral point is also considered. It was revealed that the new model has better accuracy than present regression model by statistical analysis with actual mill rolling data.

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Development of set-up model for elongation control in steel skin pass mill (강판의 연신율제어를 위한 Set-Up 모델 개발)

  • 이원호;이규택;류율리
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.317-317
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    • 2000
  • The mathematical set-up model was developed to reduce the mechanical property deviation in annealed and slightly rolled steel strip. The mechanical peculiarities of temper rolling process, such as high friction value and non-circular contact arc, Low reduction and non-negligible entry and exit elastic zones as well as central restricted deformation zone are all taken into account. The deformation of work rolls is calculated with the influence function method and arbitrary contact arc shape is permitted. The strip deformation is modeled by slab method and the entry and exit elastic deformation zones are included. The restricted deformation Bone near the neutral point is also considered. It was revealed that the new model has better accuracy than present regression model by statistical analysis with actual mill rolling data.

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Characteristics of Oceanographic Environment in a Building with a Sea Area for the Artificial Upwelling Structure. (인공용승구조물 설치해역의 해양환경 특성)

  • Kim Dong-Sun;Hwang Suk-Bum
    • Proceedings of KOSOMES biannual meeting
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    • 2005.11a
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    • pp.133-137
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    • 2005
  • To investigated the variation of marine environments due to set up of artificial structure, we carried out field observations. High temperature and salinity waters were distributed clearly in the southeastern part of study area during summer season. The variation of current structure was also occurred around study area where artificial structure set up. In 2005 after set up of artificial structure, the nutrient concentration increased greater than that in 2002 before set up artificial structures. To illustrate the characteristics of marine environment due to set up of artificial structure, quantitative analyses on the effect of artificial structure are important.

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An Experimental Study of Tension Properties on New Developed Up-Set Coupler (Up-Set Coupler 이음철근의 인장특성에 대한 실험적 연구)

  • Sim, Jong-Sung;Park, Cheol-Woo;Kang, Tae-Sung;Kim, Tae-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.5
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    • pp.109-115
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    • 2008
  • As structures are getting super-rise and large-sized, introducing the construction methods such as prefabrication of bar-meshes and complex method are being actively discussed to pursue the high quality of reinforced concrete, the simplification of field works, and the reduction of duration, as well as the study on how to connect reinforcing rods, which occurs while applying the same methods, is in progress Also, the pressure welded joint is a kind of method that heats the ends of reinforced bars locally and joint them, and after the pressure welding, the vulnerable part in the reinforced bar occur. Thus, in the construction field, the throughout quality control is necessary because of the delayed duration and the lowered construct ability. In this study, of the traditional lap splice method and the mechanical splice one, the screw coupler, we tried to look into through experiments the prefabrication method of bar-meshes, a typical joint method usually used for the joint parts for PSC structures applying the reinforced bar with its big diameter, and a newly-developed up-set coupler method. And we also examined the characteristic of tensile.

Availability and Reproducibility Evaluation of High-dose-rate Intraluminal Brachytherapy for Unresectable Recurrent Cholangiocarcinoma (재발한 간담도암 환자에서 시행 한 high-dose-rate intraluminal brachytherapy의 유용성 및 재현성 평가)

  • Park, Ju-Kyeong;Lee, Seung-Hun;Cha, Seok-Yong;Kim, Yang-Su;Lee, Sun-Young
    • Journal of the Korean Society of Radiology
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    • v.6 no.2
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    • pp.151-157
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    • 2012
  • General treatment for cholangiocarcinoma is complete surgical resection. However recurrence is common in those patients. In most of cases the purpose of the treatment for patients with recurrent is palliative. Therefore we adopt intraluminal catheter to treat a recurrent patient with high-dose-rate intraluminal brachytherapy. This study aims to evaluate the treatment procedure and set-up reproducibility of intraluminal brachytherapy in the recurrent patient. Study patient was diagnosed at rcT1N0M0 and undergone intraluminal brachytherapy after Arrow Sheath insertion. 3 Gy was delivered in every fraction with a total dose of 30 Gy. We planned dose normalization at distal, proximal and central axis point of narrowed bile duct far from 1 cm. To evaluate set-up reproducibility, we measured distance between distal, proximal treatment target volume point and anterior surface of the thoracic vertebral body respectively for five times before every treatment with dummy seed insertion. Mean distance between distal, proximal treatment target volume point and anterior surface of 10th and 11th thoracic vertebral bodies is 0.5 cm, 6.1 cm and standard deviation is 0.06, 0.08 respectively. In addition, set-up reproducibility was maintained significantly. The patient has been alive with no evidence of disease recurrence for more than a year and has not yet reported severe complications. In conclusion, high-dose-rate intraluminal brachytherapy for unresectable recurrence of cholangiocarcinoma maintains high set-up reproducibility without severe side effects.

A Study on the Development of Limited Slip Differential on All Terrain Vehicle (사륜구동 오토바이(ATV)용 차동제한장치(LSD) 개발에 관한 연구)

  • Kim, Jun-An;Jun, Jae-Uhk
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.1
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    • pp.8-15
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    • 2011
  • ATV(All Terrain Vehicle) has been developed to be used for agricultural fields on unpaved roads but now it is mostly used to transport a short distance and play leisure sports at mountains. Recently, main concerns on the automobile industry is developing not only a car safe, high fuel efficient and friendly related with environment but also two-wheeled vehicles. In order to maintain high fuel efficiency and safety of two-wheeled vehicle, it is essential that ATV should be set up differential gear. But we worried for ATV which had been set up differential gear not to run on unpaved roads. Therefore, it is necessary to develop LSD(Limited Slip Differential) that maintains existing advantages of ATV and ensures ATV to travel safely on roads. Now LSD equipped cars have a complicated structure, so setting up on ATV is unsuitable. Therefore, in this study, we have developed simple, small and well operating LSD.