• Title/Summary/Keyword: Control of separation

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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%.

An intelligent eddy current signal evaluation system to automate the non-destructive testing of steam generator tubes in nuclear power plant

  • Kang, Soon-Ju;Ryu, Chan-Ho;Choi, In-Seon;Kim, Young-Ill;Kim, kill-Yoo;Hur, Young-Hwan;Choi, Seong-Soo;Choi, Baeng-Jae;Woo, Hee-Gon
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10b
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    • pp.74-78
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    • 1992
  • This paper describes an intelligent system to automatic evaluation of eddy current(EC) signal for Inspection of steam generator(SG) tubes in nuclear power plant. Some features of the intelligent system design in the proposed system are : (1) separation of representation scheme ,or event capturing knowledge in EC signal and for structural inspection knowledge in SG tubes inspection; (2) each representation scheme is implemented in different methods, one is syntactic pattern grammar and the other is rule based production. This intelligent system also includes an data base system and an user interface system to support integration of the hybrid knowledge processing methods. The intelligent system based on the proposed concept is useful in simplifying the knowledge elicitation process of the rule based production system, and in increasing the performance in real time signal inspection application.

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Anodic bonding Characteristics of MLCA to Si-wafer Using Evaporated Pyrex #7740 Glass Thin-Films for MEMS Applications (파이렉스 #7740 유리박막을 이용한 MEMS용 MLCA와 Si기판의 양극접합 특성)

  • Chung, Gwiy-Sang;Kim, Jae-Min;Yoon, Suk-Jin
    • Journal of Sensor Science and Technology
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    • v.12 no.6
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    • pp.265-272
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    • 2003
  • This paper describes anodic bonding characteristics of MLCA (Multi Layer Ceramic Actuator) to Si-wafer using evaporated Pyrex #7740 glass thin-films for MEMS applications. Pyrex #7740 glass thin-films with same properties were deposited on MLCA under optimum RF magneto conditions(Ar 100%, input power $1\;W/cm^2$). After annealing in $450^{\circ}C$ for 1 hr, the anodic bonding of MLCA and Si-wafer was successfully performed at 600 V, $400^{\circ}C$ in - 760 mmHg. Then, the MLCA/Si bonded interface and fabricated Si diaphragm deflection characteristics were analyzed through the actuation test. It is possible to control with accurate deflection of Si diaphragm according to its geometries and its maximum non-linearity is 0.05-0.08 %FS. Moreover, any damages or separation of MLCA/Si bonded interfaces do not occur during actuation test. Therefore, it is expected that anodic bonding technology of MLCA/Si wafers could be usefully applied for the fabrication process of high-performance piezoelectric MEMS devices.

Prediction of Fatigue Life in 2 Ply Rubber/Cord Laminate (2층 고무/코드 적층판의 피로 수명 예측)

  • 임동진;이윤기;윤희석;김민호
    • Composites Research
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    • v.16 no.3
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    • pp.9-17
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    • 2003
  • In order to simulate the crack connection between cords and the interply crack growth in the belt-layer of real tire, 2 ply rubber/cord laminate specimens with exposed edges were tested in 4~11mm displacement control. Measurement of the crack connection is evaluated when crack reaches the half of the length between 45$^{\circ}$ aligned cords, and the amount of the crack growth is measured by the steel probe method. 2 dimensional analytic modeling was performed to simulate the crack connection between cords at the exposed edges. Also, the theoretical life of the specimens was calculated from the crack connection life between cords(critical value) and from the critical value to the final failure by the use of Tearing energy(T); the strain energy release per unit area of one fracture surface of a crack. Then, theoretical life was compared with those of experiments. The life prediction up to the critical value has about 20% error compared to experimental life, and up to the final failure about 65% error. Therefore, total theoretical life has about 45% error compared to the experimental life, which is conceivable in the case of rubber.

Synthesis of Nano Sized Cobalt Powder from Cobalt Sulfate Heptahydrate by Liquid Phase Reduction (액상환원공정을 이용한 황산코발트로부터의 코발트 나노분말 합성)

  • An, Se-Hwan;Kim, Se-Hoon;Lee, Jin-Ho;Hong, Hyun-Seon;Kim, Young-Do
    • Korean Journal of Materials Research
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    • v.21 no.6
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    • pp.327-333
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    • 2011
  • Nanostructured cobalt materials have recently attracted considerable attention due to their potential applications in high-density data storage, magnetic separation and heterogeneous catalysts. The size as well as the morphology at the nano scale strongly influences the physical and chemical properties of cobalt nano materials. In this study, cobalt nano particles synthesized by a a polyol process, which is a liquid-phase reduction method, were investigated. Cobalt hydroxide ($Co(OH)_2$), as an intermediate reaction product, was synthesized by the reaction between cobalt sulphate heptahydrate ($CoSO_4{\cdot}7H_2O$) used as a precursor and sodium hydroxide (NaOH) dissolved in DI water. As-synthesized $Co(OH)_2$ was washed and filtered several times with DI water, because intermediate reaction products had not only $Co(OH)_2$ but also sodium sulphate ($Na_2SO_4$), as an impurity. Then the cobalt powder was synthesized by diethylene glycol (DEG), as a reduction agent, with various temperatures and times. Polyvinylpyrrolidone (PVP), as a capping agent, was also added to control agglomeration and dispersion of the cobalt nano particles. The optimized synthesis condition was achieved at $220^{\circ}C$ for 4 hours with 0.6 of the PVP/$Co(OH)_2$ molar ratio. Consequently, it was confirmed that the synthesized nano sized cobalt particles had a face centered cubic (fcc) structure and with a size range of 100-200 nm.

Identifying Ambient PM2.5 Sources and Estimating their Contributions by Using PMF : Separation of Gasoline and Diesel Automobile Sources by Analyzing ECs and OCs (PMF 모델을 이용한 미세분진의 오염원 확인과 기여도 추정 : 탄소성분을 이용한 휘발유 및 경유차량 오염원의 분리)

  • Lee, Hyung-Woo;Lee, Tae-Jung;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.1
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    • pp.75-89
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    • 2009
  • The purpose of this study was to identify $PM_{2.5}$ sources and to estimate their contributions to the border of Yongin-Suwon area, based on the analysis of the $PM_{2.5}$ mass concentration and the associated inorganic elements, ions and carbon components. The contribution of $PM_{2.5}$ sources were estimated by using a positive matrix factorization (PMF) model to identify air emission sources. For this study, $PM_{2.5}$ samples were collected from May, 2007 to April, 2008. The inorganic elements were analyzed by an ICP-AES. The ionic components in $PM_{2.5}$ were analyzed by an Ie. The carbon components were also analyzed by DRI/OGC analyzer. After performing PMF modeling, a total of 12 sources were identified and their contributions were quantitatively estimated. The contributions from each emission source were as follows: 11.3% from oil combustion source, 3.4% from bus/highway source, 5.8% from diesel vehicle source, 4.7% from gasoline vehicle source, 8.8% from biomass burning source, 15.1 % from secondary sulfate, 5.2% from secondary nitrate source, 13.4% from industrial related source, 4.1% from Cl-rich source, 19.6% from soil related source, 1.0% from aged sea salt, and 7.4% from coal combustion source, respectively. This study provides basic information on the major sources affecting air quality, and then it will help to effectively control $PM_{2.5}$ in this study area.

Development of Coolant/Waste-oil Separating and Cooling System with Chip Treatment (칩 처리가 포함된 절삭유/폐유 분리 및 냉각 시스템 개발)

  • Kim, Joong-Seon;Lee, Dong-Seop;Wang, Duck-Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.3
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    • pp.16-23
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    • 2017
  • For most machine tools, it is necessary to remove chips and coolant oil because it they will continue to be created during the manufacture of workpieces. Existing products that are in use are installed and used as they reflect depending on the characteristics of each device separately. This study proposes a method to remove the security chip as well as developing an integrated system capable of reducing coolant damage. The Leverage AutoCAD and CATIA program was used for 2D and 3D design, shapes were identified by utilizing the KeyShot program, and the load and displacement analysis of the development apparatus was performed utilizing the ANSYS program. After the prototype underwent sufficient design review, the mixed oil separation device had a complete sensor control program using the LabVIEW program. The chip design process for transferring experiments and experiments on the mixed oil cooling device were developed for performance tests of the product. The final product resulted in an increase in space utilization during commercialization, reduced installation costs, and caused social effects such as pulmonary flow reduction, which, through the economic costs, reduces pollution, resulting in various benefits to the industry, such as deceased errors in the workplace decreases.

A Study on Smoke Control Characteristic by the Effect off Jet Fan Installation Distance (제트팬 이격거리에 따른 연기제어특성에 관한 연구)

  • Kim, Jong-Yoon;Jeon, Yong-Han;Seo, Tae-Beom;Yoo, Ji-Oh;Rie, Dong-Ho
    • Fire Science and Engineering
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    • v.22 no.1
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    • pp.16-23
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    • 2008
  • In this research, the visualization experiment for a scaling tunnel was conducted to establish the optimum fire protection system in tunnel fires. In order to find the optimal operating condition of jet fan with the fire, the characteristics of smoke propagation was considered to find the optimal operating condition of jet fan at the time of tunnel fire, the concentration of smoke was measured experimentally for various jet fan position and it's operating condition. As a result, when jet fan in the vicinity of fire operates at the upstream, the back-layering of the smoke should be considered with separation distance from the fire source. The distance between the jet fan and the fire should be longer than 50 m. On the other hand, when the vicinity jet fan operates at the downstream, the back-layering of smoke does not occur, but stratification is not maintained because the smoke dispersion occurs at the downstream due to the operation of the jet fan.

Pollutant Load Characteristics by Direct Runoff and Baseflow from Small Scale Agricultural Watershed (농업소유역에서 직접유출과 기저유출에 의한 오염부하특성)

  • Shin, Yong-Cheol;Lyou, Chang-Won;Choi, Ye-Hwan;Lim, Kyoung-Jae;Choi, Joong-Dae
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2005.10a
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    • pp.580-585
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    • 2005
  • Natural environment of Weolgok-ri watershed has been well preserved as a traditional agricultural watershed. A year record of streamflow, $NO_3-N$, T-N and T-P concentrations data(Apr, 2004-Mar. 2005) was examined to estimate annual and seasonal patterns of pollutnat loads in streamflow and baseflow from the agriculture watershed. To estimate pollutant loads from baseflow, baseflow component from total stream flow was seperated using digital filter method in the Web-based Hydrograph Analysis Tool system. Loads of $NO_3-N$, T-N and T-P from streamflow and baseflow were evaluated to investigate pollutant loads contribution by baseflow. The $NO_3-N$, T-N, and T-P loads from streamflow were 13.85 kg/ha, 45.92 kg/ha and 1.887 kg/ha, respectively. $NO_3-N$, T-N and T-P loads from baseflow were 7.43 kg/ha, 24.70 kg/ha, 0.582 kg/ha, respectively. It was found that $NO_3-N$ and T-N loads were contributed by the baseflow(53% and 53% of Total-loads) than the direct runoff(47% and 47% of Total loads). However, only 30% of total T-P was contributed by the baseflow. It is recommended that one needs to assess pollutant load contribution by the baseflow to identify appropriate control strategies for effective watershed management.

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The Effect of Sandplay Therapy with Parent-Children on Mother-Child's Attachment Security and Communication (부모-자녀모래놀이치료가 모-자의 애착안정성과 의사소통에 미치는 효과)

  • Oh, Aenia;You, Seung-Eun;Park, Boo-Jin
    • Korean Journal of Child Studies
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    • v.34 no.6
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    • pp.31-55
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    • 2013
  • This study aimed to look into the effect of sandplay therapy with parent-children on mother-child's attachment security and communication. This study first conducted a scale of attachment security targeting child and mother who is bringing children in the age of 5 to 6 years in two kindergartens located in Seodaemun-gu, Seoul, and composed experimental group and control group of four couples respectively by selecting randomly from eight mother-child couples that received low grades. Sandplay therapy with parent-children was conducted for 12weeks on a weekly basis for 50minutes each. To study the attachment security, we used the Klabsbrun-Bowlby(1976)' Separation Anxiety Test and Mother's attachment scale. In this study, it is Seperated in based on Lee Na Gueng(2001) by functional communication and dysfuctional communication in order to measure changes in communication for situation that may occur during Sand play theraphy and record of observation about changes in each session. Data logging makes watching videos that recorded parent-children sand play therapy every situations. When observes the functional communication or dysfunctional communication between mother and the child, checking the corresponding to each entries, the frequency is recorded and qualitatively analyzed by each sessions. To study mother and child have been enhanced stability of the attachment and the relationship had improved results. Also, in each session the observation of increased functional communication, and dysfunctional communication results appear to reduce in parent-children sand play therapy. As a result, a couple sand play therapy has positive impact to improved the relationship between the mother and the child.