• 제목/요약/키워드: Technical change

검색결과 1,383건 처리시간 0.038초

Model Algorithmic Control for Paper Mills Using Neural Networks

  • Park Jong Ho;Yeo Yeong Koo;Park See Han;Sohn Chang Man
    • 펄프종이기술
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    • 제36권5호
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    • pp.11-20
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    • 2004
  • In this work the Model Algorithmic Control (MAC) method is applied to control the grade change operations in paper mills. The neural network model for the grade change operations is identified first and the impulse model is extracted from the neural network model. Results of simulations for MAC control of grade change operations are compared with plant operation data. The major contribution of the present work is the application of MAC in the industrial plants based on the identification of neural network models. We can confirm that the proposed MAC method exhibits faster responses and less oscillatory behavior compared to the plant operation data in the grade change operations.

건축 사유체계 변화에 의한 색채사용 특성에 관한 연구 (A study on the characteristics of color by change in architectural thinking system)

  • 이선민
    • 한국실내디자인학회논문집
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    • 제15권2호
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    • pp.166-173
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    • 2006
  • Architectural color has been preserved the multiple characteristics reflected the change of social value criteria and technical development. Especially, the change of technical paradigm has led to variation from simple and fixed color system, as through the considerable change of architect's subject thinking, favored and symbolic system. Now, architectural color has also been revealed as the timely, moving, behavioral and existent color by anthropolatric thinking system. Therefore, it could be transformed expressive system reflected from abstract-pictorial characteristics, from the fixed to non-determining system, constructive to non-constructive system, context to expressive system, reasonal to emotional system, respectively. So, the range of architectural color has been extended as a element in reinforced the planned concept of the architect beyond the past decorated and symbolic color scope. As thereinafter, future's architectural color could be expected to concrete to the public-friendly relation system, developed widely to the system for reinforcing the concept not introduction of meaningless, fragmental and instinct color through the relational adaptation with design concept.

제지공정의 모델예측제어 (Dynamic Matrix Control of Grade Change Operations in Paper Mills)

  • 박종호;여영구;강홍
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2004년도 추계학술발표집
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    • pp.212-220
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    • 2004
  • In this work the Dynamic Matrix Control method is applied to control the grade change operations in paper mills. Paper process trained by neural network regards a real-plant. The model obtained with operation data is used to achieve DMC. Results of simulations for DMC control of grade change operations are compared with plant operation data response. From the comparison, we can see that the proposed DMC method exhibits faster response for the grade change of paper and achieves stable steady-state.

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Quantification of Crystallinity Change in Celluloses during Refining

  • Kim, Chul-Hwan;Yang, Jae-Kyung;Park, Jong-Yawl
    • 펄프종이기술
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    • 제32권5호
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    • pp.8-13
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    • 2000
  • X-ray diffraction technique was used to quantify change of cellulose crystallinity during refining. XRD data confirmed that fiber wall delamination was caused by the structural conversion of celluloses which occurred in a liquid medium during refining. The quantified crystallinity of celluloses in pulp fibers was closely associated with the change of fiber wall delamination, which was defined by measurement of fiber wall thickness. In particular, it was well recognized that low intensity beating showed a better response in the change of crystallinity than high intensity one. The decrease o cellulose crystallinity during refining considerably enhanced the improvement of interfiber bonding ability of a dried sheet.

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IPCC 제5차 과학평가보고서 고찰 (In-depth Review of IPCC 5th Assessment Report)

  • 박일수;장유운;정경원;이강웅;;권원태;윤원태
    • 한국대기환경학회지
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    • 제30권2호
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    • pp.188-200
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    • 2014
  • The IPCC 5th Assessment Report (Climate Change 2013: The Physical Science Basis) was accepted at the 36th Session of the IPCC on 26 September 2013 in Stockholm, Sweden. It consists of the full scientific and technical assessment undertaken by Working Group I. This comprehensive assessment of the physical aspects of climate change puts a focus on those elements that are relevant to understand past, document current, and project future of climate change. The assessment builds on the IPCC Fourth Assessment Report and the recent Special Report on Managing the Risk of Extreme Events and Disasters to Advance Climate Change Adaptation. The assessment covers the current knowledge of various processes within, and interactions among, climate system components, which determine the sensitivity and response of the system to changes in forcing, and they quantify the link between the changes in atmospheric constituents, and hence radiative forcing, and the consequent detection and attribution of climate change. Projections of changes in all climate system components are based on model simulations forced by a new set of scenarios. The report also provides a comprehensive assessment of past and future sea level change in a dedicated chapter. The primary purpose of this Technical Summary is to provide the link between the complete assessment of the multiple lines of independent evidence presented in the main report and the highly condensed summary prepared as Policy makers Summary. The Technical Summary thus serves as a starting point for those readers who seek the full information on more specific topics covered by this assessment. Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of $CO_2$ since 1750. Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system. Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions. The in-depth review for past, present and future of climate change is carried out on the basis of the IPCC 5th Assessment Report.

CO2 고정화된 CFBC 석탄재를 활용한 저강도 고유동 채움재의 특성평가 (Characterization of Controlled Low-Strength Materials Utilizing CO2-Solidified CFBC Coal Ash)

  • 조용광;남성영;이용무;김춘식;서신석;조성현;이형우;안지환
    • 한국환경과학회지
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    • 제26권11호
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    • pp.1267-1274
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    • 2017
  • A Controlled Low-Strength Materials (CLSM) is suitable for mine backfilling because it does not require compaction owing to it high fluidity and can be installed quickly. Therefore, a CLSM utilizing $CO_2$-solidified Circulating Fluidzed Bed Combustion (CFBC) coal ash was developed and it's properties were investigated, since. $CO_2$-solidification of CFBC coal ash can inhibit exudation of heavy metals. The chemical composition and specific surface area of Pulverized coal Combustion fly ash and CFBC fly ash were analyzed. The water ratio, compressive strength and length change ratio of CLSM were confirmed. The water ratios differed with the specific surface area of the CLSM. It was confirmed that the porosity of CLSM affected its compressive strength and length change ratio.

High Efficiency Thin Film Photovoltaic Device and Technical Evolution for Silicon Thin Film and Cu (In,Ga)(Se,S)

  • 신명훈
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.88-88
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    • 2012
  • High efficiency thin film photovoltaic device technology is reviewed. At present market situation, the industrial players of thin film technologies have to confront the great recession and need to change their market strategies and find technical alternatives again. Most recent technology trends and technical or industrial progress for Silicon thin film and CIGS are introduced and common interests for high efficiency and reliability are discussed.

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맘퀴스트 생산성지수를 이용한 수산물 가공식품 도매업의 생산성 분석에 관한 연구 (Productivity Analysis in Fisheries Processed Wholesale Products Using Malmquist Productivity Index)

  • 표희동;김종천
    • Ocean and Polar Research
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    • 제32권4호
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    • pp.387-396
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    • 2010
  • This paper estimates changes in the total factor productivity and technical efficiency change index and the technical change index using the Malmquist productivity index (MPI) in fishery-processed wholesale products over the time period spanning 2006-2008. The model considers a number of employees and operating costs as input factors, and sales and EBIT (earnings before tax and interest) as output factors. The results demonstrate that, between 2006 and 2007, there has generally been no technical progress, although a small improvement in productivity was detected in the sales scale of 10 billion won-50 billion won. Between 2007 and 2008, there was technical progress in the majority of DMU, except within the range of 20 million won-10 billion won. Wilcoxon's rank-sum test, however, demonstrates no statistically significant differences in productivity between the two periods.

한·중·일 연구개발투자의 효율성 및 생산성변화 비교 분석 (R&D Efficiency and Productivity in Korea, Japan and China)

  • 조윤기
    • 국제지역연구
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    • 제14권2호
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    • pp.43-60
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    • 2010
  • 본 연구는 비모수적 추정방법인 DEA와 맴퀴스트지수를 통해 한 중 일 3국의 연구개발투자의 효율성과 생산성 변화를 측정하였다. 분석결과는 다음과 같다. 첫째, 분석기간 동안 한국과 일본의 효율성지수는 0.837과 0.834로서 OECD 평균 0.809를 상회하는 효율성을 보인 반면 중국의 경우는 0.420으로 가장 낮은 효율성을 보이고 있다. 둘째, 맴퀴스트지수에 의한 연구개발투자의 생산성 변화를 분석한 결과 일본과 중국은 각각 1.9%와 0.9%의 생산성감소를 보인 반면 한국의 경우 연평균 25%의 생산성증가를 시현하고 있다. 셋째, 생산성 변화를 기술의 변화와 효율성의 변화로 분해한 결과 분석기간 동안 연평균 1.9%의 생산성하락을 나타낸 일본의 경우는 기술진보 1.006, 기술효율성변화 0.975로서 생산성 감소는 기술효율성 하락에 의해 발생하고 있다. 한편 연평균 0.9%의 생산성하락을 보인 중국의 경우는 기술진보와 기술효율성변화가 각각 0.966과 1.026으로 나타나 기술진보보다는 기술효율성이 생산성을 견인하는 전형적인 기술추격형 개도국의 모습을 보이고 있다. 반면 한국의 경우는 효율성의 증가가 18.2% 기술진보가 5.9%로 나타나고 있어 선진국 따라잡기형 효율성증가가 생산성증가를 견인하고 기술진보가 이를 뒷받침하는 선진국형과 개도국형의 중간적인 모습을 보이고 있다.