• 제목/요약/키워드: different production process

검색결과 1,139건 처리시간 0.035초

고로내 열유동 현상의 수치해석 사례(I) (Numerical simulation of thermo-fluid flow in the blast furnace)

  • 진홍종;최상민
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.2038-2043
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    • 2007
  • Analysis of the internal state of the blast furnace is needed to predict and control the operating condition. Especially, it is important to develop modeling of blast furnace for predicting cohesive zone because shape of cohesive zone influences on overall operating condition of blast furnace such as gas flow, temperature distribution and chemical reactions. Because many previous blast furnace models assumed cohesive zone to be fixed, they can't evaluate change of cohesive zone shape by operation condition such as PCR, blast condition and production rate. In this study, an axi-symmetric 2-dimensional steady state model is proposed to simulate blast furnace process using the general purpose-simulation code. And Porous media is assumed for the gas flow and the potential flow for the solid flow. Velocity, pressure and temperature distribution for gas and solid are displayed as the simulation results. The cohesive zones are figured in 3 different operating conditions.

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Pronunciation of Sonorant Clusters in English for Korean Speakers: A Constraint-based Approach

  • Chung, Chin-Wan
    • 영어어문교육
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    • 제13권3호
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    • pp.23-40
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    • 2007
  • This paper discusses why Korean speakers have problems in pronouncing some medial sonorant clusters in English. We argue that the main reasons lie in the sonority sequence requirement difference between the two languages. English does not have any specific sonority sequence preference between the medial sonorant sequences while Korean has a strict requirement between the two sonorants over a syllable boundary. This sonority sequence requirement difference between the two languages acts as an interference for Korean speakers in learning English pronunciation. This barrier for Korean speakers in acquiring correct pronunciation is implemented in a constraint ranking difference in the Optimality Theory, which is not familiar for Korean speakers. Understanding the details of sonorant production mechanisms along with the different constraint ranking will facilitate the learning process of Korean speakers learning English.

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Comparison of two sampling intervals and three sampling intervals VSI charts for monitoring both means and variances

  • Chang, Duk-Joon
    • Journal of the Korean Data and Information Science Society
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    • 제26권4호
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    • pp.997-1006
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    • 2015
  • In industrial quality control, when engineers use VSI control procedure they should consider both required time to signal and switching behaviors together in the case of production process changed. Up to the present, many researchers have studied fixed sampling interval (FSI) chart and variable sampling interval (VSI) chart in the points of average number of samples to signal (ANSS) and average time to signal (ATS). However, ANSS and ATS do not provide any switching information between different sampling intervals of VSI schemes. In this study, performances of two sampling intervals VSI chart and three sampling intervals VSI chart are evaluated and compared. The numerical results show that ANSS and ATS values of two sampling intervals VSI chart and three sampling interval VSI chart are similar regardless the amount of shifts. However, the values of switching behaviors including ANSW are less efficient in three sampling intervals VSI charts than in two sampling intervals VSI chart.

사출성형 시 코어 형상과 웰드품질과의 관계 (Relation of weld-quality and core shape in injection molding)

  • 이규호;최우수;노건철;정영득
    • Design & Manufacturing
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    • 제8권1호
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    • pp.23-26
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    • 2014
  • The injection molding is used in more than 70% of total production of plastic products. Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but also mechanical property. In this study weld quality has been examined according to the injection processing temperature, materials and mold designs. We selected four different materials such as PA, PP, ABS and PS as experimental materials. Weld quality increased as injection processing temperature increases. It was more dependent on materials flow ability. As a result, weld quality incase of rectangular core is better than circular core.

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I. C. 유형별 전환곡선식의 도출에 관한 연구 (A Study on Deriving The Diversion Curve of I.C.s)

  • 손진현;이용재
    • 대한교통학회지
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    • 제8권2호
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    • pp.77-97
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    • 1990
  • Compared to modal split, the methods of forecasting traffic volumes diverted in various types of I.C.s have not been sufficiently studied. The purpose of this study is to derive a new diversion function that can represent the directional traffic volume in accordance with various geometrics of I.C.s. In general, knowing various traffic impedances and the amount of traffic production and attraction, one can estimate proper traffic volumes associated with directions by using a well-defined diversion function. This function is usually made by a series of process such as surveying directional traffic volumes on several I.C.s, analyzing with a regression method and verifying those results by statistical approaches. The function has been developed by rigorous statistical testings, mainly a regression analysis. This paper presents an effective method in planning and designing new roads, I.C.s and route choice of subway. Finally, some comparisons and improvements and suggested when one uses different types of relevant models and functions.

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복식에 있어서의 근대성의 의미 (Modernity in Costume)

  • 이재윤
    • 복식
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    • 제61권1호
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    • pp.124-131
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    • 2011
  • Modernity is commonly defined as a reflection of the features of modern society based on the historical experience of the West. As such, modernity includes involvement with political, economic, and social changes, a changing world-view, and changing trends in equality, gender roles, a desire for "the new," consumption, distribution based on mass production, and rational reform in fashion and dress. First and foremost, however, modernity in costume has been driven by the functional requirements of industrial capitalism. But while modernity has popularly been regarded as some sort of universal standard, in fact the West and the other societies have vastly different, unique, and particular experiences with their own respective histories of modernization. For this reason, cultural changes in the modernization process should be-indeed, must be-analyzed in the context of a country's own unique historical and cultural circumstances, rather than through the prism or strict adaptation of generalized Western concepts of modernization. Moreover, a "periodization" of the modernization of fashion and dress can be established by examining the characteristics of modernity in costume.

독일의 농업부산물을 이용한 바이오가스 생산시스템 (State-of-the-art of Production and Utilization of Biogas in Germany)

  • Oechsner, Hans
    • 한국유기농업학회:학술대회논문집
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    • 한국유기농학회 2009년도 상반기 학술대회
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    • pp.343-366
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    • 2009
  • Biogas can be generated out of a variety of organic substances and is suitable for different utilizations. It is very efficient in technical application and has a good balance between energy input and output (1 : 7). Moreover there is a great reduction of carbon dioxide (6 - 7 t $CO_2$/ ha). By means of biogas energy can be produced locally and allows maximum energy utilization. Therefore in the next years biogas will become more important in Germany, also for the scientific research area. In the future we have to deal with questions about the improvement of efficiency of the biogas process intensified.

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에너지부문(部門) 정책분석(政策分析)을 위한 계량모형적(計量模型的) 접근(接近)에 관한 연구(硏究) - 에너지수급(需給) 및 산업구조개편연관분석(産業構造改編聠関分析) - (Study on the Application of Quantitative Economic Modeling for Energy Policy Analysis - Energy/Economy Interaction for Energy Demand/Supply Analysis and Industry Infrastructure Change -)

  • 김형욱;안병훈
    • 대한산업공학회지
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    • 제8권1호
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    • pp.40-60
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    • 1982
  • Since the first oil embargo (1973), there have been developed many different types of energy-economy interaction models based upon various aspects of energy impact mechanism. We will propose to develop an integrated energy-economy interaction analysis system for less developed countries' energy policy analysis, especially for investment analysis toward constructing energy-saving industry infrastructure ; which is based on the motivation of combined energy models by John P. Weyant. This modeling system can cover the economic growth, inter-industry transactions including production features, and process analysis of energy sector in the total network scheme of general equilibrium, so that it can give many political implications as well as the modeling concept to be used for analyzing various political issues and making decisions related to national energy environment.

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Emergy Perspectives of Ecosystem Restoration in Korea

  • Kang, Dae-Seok
    • Ocean and Polar Research
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    • 제24권1호
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    • pp.87-92
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    • 2002
  • The emergy (spelled with an 'm') concept was introduced to provide a new insight into ecosystem restoration efforts in Korea. The emergy is defined as the available energy of one kind previously required directly and indirectly to make a product or service. It is an effort to evaluate the true contributions of natural resources to our economy. It tries to include both contributions from natures free works and human services to develop and process natural resources. The emergy evaluation can be used to select a restoration alternative that yields more to the economy with less stress to the environment, by comparing different alternatives with indices expressed in emergy. It can also be used to assess the success of ecosystem restoration projects. Pulsing dynamics in which a slow build-up of production is followed by a frenzied consumption in relatively short time period seems to be a general feature of all systems. Any ecosystem restoration effort, therefore, should consider the whole pulsing cycle for a successful implementation.

Biomineralization of Calcium Carbonate Polymorphs by the Bacterial Strains Isolated from Calcareous Sites

  • Dhami, Navdeep Kaur;Reddy, M. Sudhakara;Mukherjee, Abhijit
    • Journal of Microbiology and Biotechnology
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    • 제23권5호
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    • pp.707-714
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    • 2013
  • Microbially induced calcium carbonate precipitation (MICCP) is a naturally occurring biological process that has various applications in remediation and restoration of a range of building materials. In the present investigation, five ureolytic bacterial isolates capable of inducing calcium carbonate precipitation were isolated from calcareous soils on the basis of production of urease, carbonic anhydrase, extrapolymeric substances, and biofilm. Bacterial isolates were identified as Bacillus megaterium, B. cereus, B. thuringiensis, B. subtilis, and Lysinibacillus fusiformis based on 16S rRNA analysis. The calcium carbonate polymorphs produced by various bacterial isolates were analyzed by scanning electron microscopy, confocal laser scanning microscopy, X ray diffraction, and Fourier transmission infra red spectroscopy. A strain-specific precipitation of calcium carbonate forms was observed from different bacterial isolates. Based on the type of polymorph precipitated, the technology of MICCP can be applied for remediation of various building materials.