• Title/Summary/Keyword: Production Line

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A Study on the Effect of Accelerated Curing on 28-Days Compressive Strength of Concrete (촉진양생이 콘크리트의 28일 압축강도에 미치는 영향에 관한 연구)

  • 최세규;유승룡;김생빈
    • Magazine of the Korea Concrete Institute
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    • v.8 no.4
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    • pp.141-148
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    • 1996
  • The pulished works on Accelerated Curing Effect were generally performed around from 1960 to 1970th century for 18 to 24 hours - total curing periods. It is not possible to define the effect of temperature rise because those results were obtaine mainly by using the manually operated steam-curing tank. Thus, it may not be available to apply those data immediately on the domestic PC wall production line. The testing specimens were made from the standard mix proportion according to those of domestic PC factories to establish a basic data for the Accelerated Curing Effect. The experimental tests were conducted according to the conditions of each sub-curing periods. By comparing the results of compression tests on de-molded and 28-day water-curing specimens, we find that the most effective curing condition to obtain more than the required design strength after 28 day of water curing may be as follows: the presteaming period does not affect seriously and less than$30^{circ}C/hr$- the rate of temperature rise andless than $82^{circ}C$ - maximum temperature are necessary. It seems that post-curing procedure is very important factor to increase the effect of accelerated curing.

Sensitivity Analysis of Design Parameters for Quadruple Offset Butterfly Valve by Operating Torque (작동 토크를 평가 함수로 하는 사중편심 버터플라이밸브 설계 파라미터 민감도 분석)

  • Lee, Dong-Myung;Kim, Soo-Young
    • Journal of Ocean Engineering and Technology
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    • v.28 no.2
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    • pp.160-166
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    • 2014
  • Because of industrial development, industrial facilities are becoming more complex and diversified. Plant industries are focused on productivity improvement, cost reduction, and product uniformity by simplifying production processes using automated control. Furthermore, plant industries require higher pressures and temperatures to improve energy efficiency. For this reason, the valves used in plants are operated under harsh conditions. Globe valves and gate valves are mainly used for high pressure these days. However, these valves have various problems, including low maintainability and high cost, due to structural problems. Therefore, butterfly and ball valve applications are increasing in industrial plants. This paper suggests a quadruple-offset butterfly valve that is applicable to bi-direction use, and the principle design parameters are suggested. The selected design parameters are an eccentric flange center line and shaft centerline(Offset 1), an eccentric seat centerline and disc shaft centerline(Offset 2), the angle between the flange centerline and seat wedge angle(Offset 3), the angle between the vertical direction of the disc shaft centerline and seat centerline(Offset 4), and the seat engagement angle. To analyze the interaction effect of the design parameters, ANOM and ANOVA were performed with an orthogonal array. The parameters were found to have effects in the following order: Offset 2, Offset 1, engagement angle, Offset 3, and Offset 4. The interaction between the parameters was insignificant.

Identification of Functionally Different Rat IgE in RBL-2H3 Exocytosis

  • Kim, Jin-Sub;Cho, Sungae;Joo, Kyoung-Hwan;Lee, Joon-Sang;Conrad, Daniel H.;Cho, Sung-Weon
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.195-201
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    • 2002
  • Background: IgE is closely related to the development of allergies. However, the poor relationship between the specific IgE level and the severity of allergic diseases suggests the possibility of functionally different IgE isoforms. With this in mind, rat basophilic leukemia (RBL)-2H3 activation was analyzed with each type of rat IgE for two parameters, exocytosis and IL-4 mRNA production. RBL-2H3 has been well documented in the rat mucosal mast cell line. Methods: RBL-2H3 cells sensitized with each kind of rat IgE was activated by cross-linking FcRI with B5 (monoclonal anti-rat IgE mouse IgG antibodies). The RBL-2H3 exocytosis was measured by analyzing the ${\beta}$-hexosaminidase level, and the level of IL-4 mRNA synthesis was analyzed using semiquantitative RT-PCR. Rat IgE, which was produced by a parasite infection (REP), was prepared using either Paragonimus westermani metacercariae (REP-PW) or Anisakis simplex third stage larvae (REP-AS). A rat IgE prototype of IR162 was prepared by a peritoneal injection of immunocytoma. Results: The level of exocytosis showed a linear relationship with the rat IgE concentration when REP-PW or REP-AS was applied. However, it exhibited a biphasic response with IR162. In addition, the time course of heating at $56^{\circ}C$ illustrated the similarity between REP-PW and REP-AS, which differed from that of IR162. In contrast, the level of IL-4 mRNA synthesis in the RBL-2H3 cells with IR162 was comparable to that of either REP-PW or REP-AS. Conclusion: These results suggest that functionally different rat IgE isoforms exists in RBL-2H3 exocytosis.

Smart Warehouse Management System Utilizing IoT-based Autonomous Mobile Robot for SME Manufacturing Factory (중소제조기업을 위한 IoT기반의 자율이동모듈을 활용한 스마트 창고관리 시스템 개발)

  • Kim, Jeong-A;Jeong, Jongpil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.5
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    • pp.237-244
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    • 2018
  • The Smart Factory level of manufacturing factories of SMEs now lacks a system for grasping the accurate inventory amount associated with inventory movements in managing warehouses at the basic level. Also, it is difficult to manage accurate materials for loss of data due to worker manual work and production method due to experience. In order to solve this problem, in this paper, automatic acquisition of inventory to minimize manual work to grasp workers' Inventory and improve automation is done. In the smart warehouse management system using the IoT-based autonomous mobile module, the autonomous mobile module acquires the data of the inventory storage while moving through the line. In order to grasp the material of the Inventory storage, The Camera module recognizes the name of the inventory storage. And Then, If output matches, the data measured by the sensor is transferred to the server. This data can be processed, saved in a database, and real-time inventory quantity and location can be grasped in a web-based monitoring environment for administrators. The Real-time Automatic Inventory (RAIC) systems is reduce manual tasks and expect the effects of automated inventory management systems.

Business Strategies of Japanese Newspaper Companies: Top-level Managers' Perception and Reacting toward the Newspaper Crisis (일본 신문기업의 경영전략 연구: 경영진의 위기인식과 대응책을 중심으로)

  • Kim, Young-Ju;Jung, Jae-Min
    • Korean journal of communication and information
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    • v.51
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    • pp.65-86
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    • 2010
  • This paper reviews the problems and opportunities of Japanese newspaper industry. In the focus are particularly issues related to causes of the crisis and reacting strategies overcoming the crisis. To answer the questions, we conducted in-depth interviews with top-level managers of major newspaper companies in Japan. Secondary data were gathered to complement the interview. Top managers mainly perceived the causes of the crisis as young readers' alienation from newspaper due to the change of media environment and structural factors such as increasing production/distribution costs and diminishing appeals for advertisers. They are implementing several strategies to overcome this crisis - developing newspaper content for young readers; packaging customized on-off line advertisement; extending news distribution via online and mobile platforms; diversifying business into diverse sectors such as real-estate; enhancing brand equity of newspaper; and collaborating with rival newspaper companies in operating news site and joint printing/distribution. Lessons from the case of Japanese newspaper industry may be useful starting points for the Korean newspaper companies agonizing for diminishing circulation and advertising revenues.

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Fabrication and Performance Evaluation of Zinc Oxide Varistors for the Arresters used for Station System (발변전소 피뢰기용 산화아연소자의 제작 및 성능평가)

  • Cho, Han-Goo;Han, Se-Won;Kim, Suk-Soo;Yoon, Han-Soo;Lee, Un-Yong;O, Cheol-Gyu;Yu, Kun-Yang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.636-639
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    • 2004
  • This paper presents the fabrication and performance evaluation of zinc oxide varistors for the arresters used for station system. ZnO varistors were fabricated with typical ceramic production methods and the structural and electrical characteristics were investigated. All varistors exhibited high density, which were in the range of $5.41{\sim}5.49g/cm^3$. In the electrical properties the reference voltage increased in the range of $4.410{\sim}5.250kV$ with increasing their thickness and the residual voltage exhibited the same trends as the reference voltage. In the long duration current impulse withstand test, E-2 and F-1 samples failed in the two and four shots, respectively, but E-1 and F-2 samples survived 18 shots during the test. Before and after this test, the variation ratio of residual voltage of E-1 and F-2 samples were -0.34% and 0.05%, respectively, which were in the acceptance range of 5%. According to the results of tests, it is thought that if the fabrication process such as insulating coating, sintering condition, and soldering method is improved, these ZnO varistors would be possible to apply to the station class arresters in the new future.

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A Study on Minimal Expression Techniques Depicted in Modern Fashion Design (현대패션에 나타난 최소표현기법에 관한 연구)

  • 김은덕;김민자
    • Journal of the Korean Society of Costume
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    • v.24
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    • pp.157-176
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    • 1995
  • The purpose of this treatise is to study external form and internal meaning of minimal expression fashion which appeared as a major stream in modern fashion trends to understand one aspect of modernism in fashion and also to gain insight into internal value of human beings through fashion. The results can be summarized as follows : Firstly , minimalism is a trend in art attempting to seek essence of the object by presenting simple and disciplined expressions by minimal formative means and minimal production process. Secondly, minimal expression in fashion means seeking simplicity an dpurity by using minimum design elements and minimal productive process. Thirdly, external from of minimal expression fashion can be created through application of following minimal expression techniques. 1. Minimal expression techniques in terms of line mean smooth curve flowing along body contours, straight lines of diagonal lines into desciplined silhouette or rendering internal contour lines. 2. Minimum expression techniques in terms of forms mean forms of smooth curves flowing along boyd or forms with simple geometric forms from qualitative aspects, In terms of volume it means quest for essence of pure body itself by revealing body as it is by minimizing the size of dress or its area and herein is contained using simple geometric pattern or utilizing textiles without any patterns.3. Minimal expression techniques by colors mean simple colors such as primary colors, colors without clear distinctions or natural colors and in terms of quantity it means quest for one color within one item of dress or combination of each items when getting dressed. 4. Minimal expression techniques in terms of fabrics mean fabrics with simple surfaced. In terms of quantity it means quest for essence of tight fitting thin textiles to human body or using transparent materials to human body thus exposing body contours as it is. 5. Minimal expression techniques in terms of productive process mean minimizing process of tailoring , sewing or ornamenting and seeking for simplicity and purity. 6. Minimal expression techniques in terms of manufacturing process mean selection of technique conveying simple image with disciplined simple image. Fourthly, minimal expression fashion with external expression as mentioned in the above lay body-priority style and its internal meaning can be asummed as quest for essence and purity of human body.

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Development of Contact-Type Thickness Measurement Machine using LVDT Sensors (LVDT센서를 이용한 접촉식 두께자동측정기 개발)

  • Shin, Ki-Yeol;Hwang, Seon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.4
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    • pp.151-159
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    • 2015
  • In this study, we developed an automated contact-type thickness measurement machine that continuously and precisely measures the thickness of a PCB module product using multi-LVDT sensors. The system contains a measurement part to automatically measure the thickness in real time according to the set conditions with an alignment supply unit and unloading unit to separate OK and NG products. The sensors were calibrated before assembly in the measuring machine, and precision and accuracy performance tests were also performed to reduce uncertainty errors in the measurement machine. In the calibration test, the precision errors of the LVDT sensor were determined to be $1-3{\mu}m$ as 0.1% at the measuring range. A measurement error of 0.8 mm and 1.0 mm thickness test standards were found to be $1{\mu}m$ and $4{\mu}m$, and the standard deviations of two 1.0 mm products were measured as $14{\mu}m$ and $8{\mu}m$, respectively. In the measurement system analysis, the accuracies of test PCB standards were found to be $2{\mu}m$ and $3{\mu}m$, respectively. From the results of gage repeatability and reproducibility (R & R) crossed, we found that the machine is suitable for the measurement and process control in the mass production line as 7.92% of total gage R & R and in seven distinct categories. The maximum operating speed was limited at 13 pcs/min, showing a value good enough to measure.

Process Management Systems for Integrated Real-Time Shop Operations in Heterogeneous Multi-Cell Based Flexible Manufacturing Environment (이기종 멀티 셀 유연생산환경에서의 실시간 통합운용을 위한 공정관리 체계)

  • Yoon, Joo-Sung;Nam, Sung-Ho;Baek, Jae-Yong;Kwon, Ki-Eok;Lee, Dong-Ho;Lee, Seok-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.281-286
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    • 2013
  • As the product lifecycle is getting shorter and various models should be released to respond to the needs of customers and markets, automation-based flexible production line has been recognized as the core competitiveness. According to these trends, system vendors supply cell-level systems such as FMC(Flexible Manufacturing Cell) that is integration of core functions of FMS(Flexible Manufacturing System) and RMC(Reconfigurable Manufacturing Cell) that can easily extend components of FMC. In the cell-based environment, flexible management for shop floor composed of existing job shop, FMCs and RMCs from various system vendors has emerged as an important issue. However, there could be some problems on integrated operation between heterogeneous cells to use vendor-specific cell controllers and on seamless information flow with high level systems such as ERP(Enterprise Resource Planning). In this context, this paper proposes process management systems supporting integrated shop operation of heterogeneous multi-cell based flexible manufacturing environment: First of all, (1) Integrated Shop Operation System to apply the process management system is introduced, and (2) Multi-Layer BOP(Bill-Of-Process) model, a backbone of the process management system, is derived with its data structure. Finally, application of the proposed model is illustrated through system implementation results.

Web 2.0 and Firms' Business Model Application (웹2.0과 기업의 비즈니스 모델 활용방안)

  • Cho, Dong-Hwan
    • The Journal of the Korea Contents Association
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    • v.8 no.4
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    • pp.108-116
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    • 2008
  • Recently the advent of web 2.0 era is an important trend in the business environmental change. Web 2.0 era means users' active participation, share, and openness, develop 'Internet penetration into everyday life,' and change many aspects of our society. web 2.0 has been making these following changes in the socioeconomic aspects: 1) acceleration of system shift to a small quantity of multi-species production system 2) growing influence of on-line channel/information to consumers 3) various minorities' power increase in the socioeconomic sector. web 2.0 has been making these following changes in the enterprise management: 1) the pursuit of open innovation from outside 2) active employment of viral marketing through Internet 3) the pursuit of present business transformation 4) strengthening of customer communication through open dialogue. Firms must squarely look at socioeconomic changes owing to web 2.0, and utilize them as business opportunities.