• Title/Summary/Keyword: Roll-to-Roll process

Search Result 812, Processing Time 0.029 seconds

Development of Hot Rolling Process Analysis Simulator and Its Application(II) (열간압연 공정 해석용 시뮬레이터의 개발과 응용(II))

  • 이원호;이상룡
    • Transactions of Materials Processing
    • /
    • v.8 no.1
    • /
    • pp.78-91
    • /
    • 1999
  • The endless hot rolling has been focused as an innovative process technology for increasing the productivity drastically and reducing the imperfection of quality in hot rolled steel strip. To realize it in actual mill, a lots of new facilities such as bar coiler, movable LASER welder and high speed strip shear should be equipped. And also it is necessary to develop the control technique for changing the roll gap and rolling speed during rolling, which is named as Flying Gap and Speed Change control technology. To prevent a strip rupture caused by excessive tension, it is very important to minimize fluctuations in strip thickness and intension during FGSC control. In this paper, the mathematical model for FGSC control algorithm was suggested and dynamic simulation is performed to accertain the effect of suggested control method on fluctuations in strip thickness and tension. For endless hot rolling simulation, a lots of FGSC control situations, for instance - strip thickness change from strip to strip - strip width change from strip to strip - carbon content change from strip to strip are considered.

  • PDF

Rolling Force Prediction in Cold rolling Mill using Neural Networks (신경망을 이용한 냉연 압하력 예측)

  • Cho, Yong-Jung;Cho, Sung-Zoon
    • IE interfaces
    • /
    • v.9 no.3
    • /
    • pp.298-305
    • /
    • 1996
  • Cold rolling mill process in steel works uses stands of rolls to flatten a strip to a desired thickness. Most of rolling processes use mathematical models to predict rolling force which is very important to decide the resultant thickness of a coil. In general, these mathematical models are not flexible for variant coil types and cannot handle various elements which is practically important to decide accurate rolling force. A corrective neural network is proposed to improve the accuracy of rolling force prediction. Additional variables-composition of the coil, coiling temperature and working roll parameters-are fed to the network. The model uses an MLP with BP to predict a corrective coefficient. The test results using 1,586 process data collected at POSCO in early 1995 show that the proposed model reduced the prediction error by 30% on average.

  • PDF

A Case Study on ERP System Implementation in Samsung Display Devices Co. (삼성전관(주)의 ERP시스템 구축사례)

  • Kim, Sang-Hun
    • Korean Management Science Review
    • /
    • v.15 no.2
    • /
    • pp.91-108
    • /
    • 1998
  • Recently ERP(Enterprise Resource Planning) package has been on of important issues in developing information systems in many Korean companies. The main objectives of this study are to analyse the case of implementing ERP system in Samsung Display Devices Co. which is rated to be successful, and to derive significant implications for effective ERP implementation. First, this study focused on showing the detailed roadmap of performing ERP implementation project which largely consists of 5 stages(planning and organizing, visioning. process redesign and mapping, testing and arrangement, and installation and roll-out to overseas subsidiaries), and explaining key activities in each stage. Second, the performance of this project was evaluated on the basis of both process-centered critieria and result-centered ones. Finally, this study intended to discuss and explicate the bottlenecks and the critical success factors in implementing this project. The findings of this case study are thought not only to be useful as a practical guideline in carrying out ERP implementation project but also to provide significant basis for constructing the theoretical framework of effective ERP implementation.

  • PDF

GCP(GROUND CONTROL POINT) FOR AUTOMATION OF THE HIGH RESOLUTION SATELLITE IMAGE REVISION

  • Jo, Myung-Hee;Jung, Yun-Jae
    • Proceedings of the KSRS Conference
    • /
    • 2007.10a
    • /
    • pp.219-222
    • /
    • 2007
  • Today, use of high resolution satellite image with at least 1m resolution is expanding into many more areas including forest, river way, city, seashore and so forth for disaster prevention. Interest in this medium is increasing among the general public due to the roll-out to the private sector as Google earth, Virtual Earth and so forth. However, pre-processing process that revises the geometrical distortion that result at the time of photographing is required in order to use high resolution satellite image. The purpose of this research is to search the most accurate GCP(Ground Control Point) information acquisition method that is used for the revision of high resolution satellite image's geometrical distortion through automated processing. Through this, it is possible to contribute to increasing the level of accuracy at the time of high resolution satellite image revision and to secure promptness.

  • PDF

The Effect of Thickness on Flexible, Electrical and Optical properties of Ti- ZnO films on Flexible Glass by Atomic Layer Deposition

  • Lee, U-Jae;Yun, Eun-Yeong;Gwon, Se-Hun
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.196.1-196.1
    • /
    • 2016
  • TCO(Transparent Conducting Oxide) on flat glass is used in thin-film photovoltaic cell, flat-panel display. Nowadays, Corning(R) Willow Glass(R), known as flexible substrate, has attracted much attention due to its many advantages such as reliable roll-to-roll glass processing, high-quality flexible electronic devices, high temperature process. Also, it can be an alternative to flexible polymer substrates which have their poor stability and degradation of electrical and optical qualities. For application on willow glass, the flexibility, electrical, optical properties can be greatly influenced by the TCO thin film thickness due to the inherent characterization of thin film in nanoscale. It can be expected that while thick TCO layer causes poor transparency, its sheet resistance become low. Also, rarely reports were focusing on the influence of flexible properties by varying TCO thickness on flexible glass. Therefore, it is very important to optimize TCO thickness on flexible Willow glass. In this study, Ti-ZnO thin films, with different thickness varied from 0 nm to 50 nm, were deposited on the flexible willow glass by atomic layer deposition (ALD). The flexible, electrical and optical properties were investigated, respectively. Also, these properties of Ti-doped ZnO thin films were compared with un-doped ZnO thin film. Based on the results, when Ti-ZnO thin films thickness increased, resistivity decreased and then saturated; transmittance decreased. The Figure of Merit (FoM) and flexibility was the highest when Ti-ZnO thickness was 40nm. The flexible, electrical and optical properties of Ti-ZnO thin films were better than ZnO thin film at the same thickness.

  • PDF

A Study on Classification Algorithm of Arbitrary Polygon Curved Hull Plates for the Curved Hull Plates Forming (곡가공을 위한 임의 다각형 곡판 분류 알고리즘 연구)

  • Kim, Chan Suk;Son, Seung Hyeok;Shin, Jong Gye;Noh, Jackyou
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.51 no.4
    • /
    • pp.342-348
    • /
    • 2014
  • In general, the forming process of the curved hull plates consists of sub tasks, such as roll bending, line heating, and triangle heating. In order to complement the automated curved hull forming system, it is necessary to develop an algorithm to classify the curved hull plates of a ship into standard shapes with respect to the techniques of forming task, such as the roll bending, the line heating, and the triangle heating. In the previous research, the classification algorithm of curved hull plates was studied only about rectangle shaped plates, and other limitations were notified. In this paper, the classification algorithm is extended to classify not only rectangle shaped plates but also arbitrary polygon hull plates. The discrete curvature can be computed by using arbitrary polygon mesh which is represented by half-edge data structure and discrete differential geometry. The algorithm tests to verify the developed algorithm with sample plates of a real ship data have been performed.

Numerical Study of Double Diffusive Convection of a Stratified Fluid in an Annulus Due to Lateral Heating (환형밀폐용기내 성층화된 유체의 옆면가열에 의한 이중확산대류에 관한 수치해석)

  • 강신형;전창덕;이진호
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.19 no.7
    • /
    • pp.1720-1730
    • /
    • 1995
  • Finite-difference analysis was conducted to study the natural convection of a stably stratified salt-water solution in an annulus due to lateral heating. The main purpose of this study is to examine in detail the multi-layered flow structure. Calculation was thus made for R $a_{\eta}$=2*10$^{5}$ and 6.5*10$^{5}$ . Formation of layered flow structure, merging process of layers, the corresponding temperature and concentration distributions, Nusselt number variations with time are examined. Numerical results show that in each layer, the temperature profile looks 'S`-shaped and the concentration profile is uniform due to the convective mixing. The formation of the roll and the layer is governed by natural convection due to the temperature gradient and the merging process of the layer by diffusion of the concentration.ation.

Development of a precision machining process for the outer cylinder of vacuum roll for film transfer (실험계획법을 통한 3.5인치 도광판의 두께 편차 최적화에 대한 연구)

  • Hyo-Eun Lee;Jong-Sun Kim
    • Design & Manufacturing
    • /
    • v.18 no.2
    • /
    • pp.41-50
    • /
    • 2024
  • In this study, experimental design methods were used to derive optimal process conditions for improving the thickness uniformity of a 0.40 mm, 3.5 inch light guide panel. Process mapping and expert group analysis were used to identify factors that influence the thickness of injection molded products. The key factors identified were mold temperature, mold temperature, injection speed, packing pressure, packing time, clamp force, and flash time. Considering the resin manufacturer's recommended process conditions and the process conditions for similar light guide plates, a three-level range was selected for the identified influencing factors. L27 orthogonal array process conditions were generated using the Taguchi method. Injection molding was performed using these L27 orthogonal array to mold the 3.5 inch light guide plates. Thickness measurements were then taken, and the results were analyzed using the signal-to-noise ratio to maximize the CpK value, leading to the determination of the optimal process conditions. The thickness uniformity of the product was analyzed by applying the derived optimum process conditions. The results showed a 97.5% improvement in the Cpk value of 3.22 compared to the process conditions used for similar light guide plates.

The effect of film morphology by bar-coating process for large area perovskite solar modules

  • Ju, Yeonkyeong;Kim, Byeong Jo;Lee, Sang Myeong;Yoon, Jungjin;Jung, Hyun Suk
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.416-416
    • /
    • 2016
  • Organic-inorganic metal halide perovskite solar cells have received attention because it has a number of advantages with excellent light harvesting, high carrier mobility, and facile solution processability and also recorded recently power conversion efficiency (PCEs) of over 20%. The major issue on perovskite solar cells have been reached the limit of small area laboratory scale devices produced using fabrication techniques such as spin coating and physical vapor deposition which are incompatible with low-cost and large area fabrication of perovskite solar cells using printing and coating techniques. To solution these problems, we have investigated the feasibility of achieving fully printable perovskite solar cells by the blade-coating technique. The blade-coating fabrication has been widely used to fabricate organic solar cells (OSCs) and is proven to be a simple, environment-friendly, and low-cost method for the solution-processed photovoltaic. Moreover, the film morphology control in the blade-coating method is much easier than the spray coating and roll-to-roll printing; high-quality photoactive layers with controllable thickness can be performed by using a precisely polished blade with low surface roughness and coating gap control between blade and coating substrate[1]. In order to fabricate perovskite devices with good efficiency, one of the main factors in printed electronic processing is the fabrication of thin films with controlled morphology, high surface coverage and minimum pinholes for high performance, printed thin film perovskite solar cells. Charge dissociation efficiency, charge transport and diffusion length of charge species are dependent on the crystallinity of the film [2]. We fabricated the printed perovskite solar cells with large area and flexible by the bar-coating. The morphology of printed film could be closely related with the condition of the bar-coating technique such as coating speed, concentration and amount of solution, drying condition, and suitable film thickness was also studied by using the optical analysis with SEM. Electrical performance of printed devices is gives hysteresis and efficiency distribution.

  • PDF

A Study on the Costume of the Gods in the Ancient Roman Myths (고대 로마 신화에 등장한 신들의 복식 연구)

  • 임상임;추미경
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.25 no.5
    • /
    • pp.945-956
    • /
    • 2001
  • The costume for gods in the Ancient Roman myth was studied by examining in the embossed-carving, sculptures, mural-painting and various documents of the period. The clothes item, hairstyle, symbol & ornaments and shoes of the gods in the Roman myths were analyzed to understand the formative process in the religious costumes, and results are as follows. First, the costumes for male gods are the same as those for ordinary men lived in ages, including toga, paludamentum, tebenna, tunica. The costumes for female gods are also the same as those for ordinary women lived in ages, including stola, palla, tunica. Second, the hairstyle of male gods is short curled-hair, twisty roll-up hair and braid long-hair due to the influence of Etrurian in the early days. Another hairstyle is appeared in form of the laurelled-crown. The hairstyle of female gods is curled long-hair, chignon style and braid roll-up hair decorated with hairband. Third, the symbol & ornaments which represent the responsible possession of male gods, are appeared in beard, a stick of the message, arrow-case, offering-dish, antlered-glass, shield, spear-handle, as the superhuman forms, such as the lightning shape. For female gods they are is appeared plastron, a stick of the message, flower. some female gods wear necklace, foot-ring, bracelet. Fourth, male gods wear shoes in forms of sandal, buskin, boots, but all female gods are in barefoot. It could be explained by the fact that a man-centered society in the ancient roman is reflected in the world of gods. As mentioned, Gods costume in Roman myths was very similar to or nothing different from the ordinary peoples in Rome. However, they used corps, sacrifices or sepcific symbols depending on the fields that they were responsible for in order to be distinguished from the ordinary people. This is the result from the peoples expression that they should keep a close relationship with Gods hoping to be protected, and rely on them under whatever circumstances.

  • PDF