• 제목/요약/키워드: technology

검색결과 275,050건 처리시간 0.14초

Evaluation of Static Spring Constant and Accelerated Life Prediction for Compression Set of Polyurethane Resilient Pad in Rail Fastening System

  • Lee, Seung-Won;Park, Jun-Young;Park, Eun-Young;Ryu, Sung-Hwan;Bae, Seok-Hu;Kim, Nam-Il;Yun, Ju-Ho;Yoon, Jeong-Hwan
    • Elastomers and Composites
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    • 제53권4호
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    • pp.220-225
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    • 2018
  • Resilient pads play a major role in reducing the impact of loads on a rail in a rail-fastening system, which is essentially used for a concrete track. Although a compression set test is commonly used to measure the durability of a resilient pad, the static spring constant is often observed to be different from the fatigue test. In this study, a modified compression set test method was proposed to monitor the variations in the compression set and static spring constant of a resilient pad with respect to temperature and time. In addition, the life of the resilient pad was predicted by performing an acceleration test based on the Arrhenius equation.

Technology 수렴가능성에 대한 실증적 고찰

  • 조상섭;이장우
    • 한국기술혁신학회:학술대회논문집
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    • 한국기술혁신학회 2003년도 춘계학술대회
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    • pp.19-29
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    • 2003
  • 본 연구는 우리나라 산업간에 Technology 수렴가능성에 대한 기존 선형(Linearity) 설정 관계식보다 비선형(Nonlinearity) 설정관계식에서 실증분석하는 데 연구목적이 있다. 본 연구목적을 위하여 장기적 시계열자료를 이용하여(1970∼2000), 우리나라 제조업과 총 산업(Grand Total)간에 Technology Gap에 대한 정상성(Stationarity)을 검증함으로써, Technology수렴 가능성을 검토하였다. 본 연구결과는 Technology수렴가설에 대한 두 가지 중요한 실증분석방향을 제공하고 있다. 첫째, 우리나라 산업간에 Technology 수렴가능성은 비선형관계에서 분석해야 한다는 결론을 얻었다. 따라서 우리나라 산업간에 Technology 수렴가능성은 단순 선형관계를 기반으로 할 경우, 설정오류에 따른 Technology 수렴가능성이 성립하지 않을 가능성이 높게 나타날 수 있었다. 둘째, 우리나라 경제의 경우, Technology 수렴가능성에 대한 분석결과는 비선형관계에서 Technology Regime별로 Technology 수렴가능성이 다르게 나타나고 있음으로 실증분석방법론 및 그 결과에 대한 시사점도출에 유의해야 한다.

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Technology 수렴가능성에 대한 실증적 고찰 (An Empirical Study on the Technology Convergence)

  • 조상섭;이장우
    • 기술혁신학회지
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    • 제6권2호
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    • pp.191-202
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    • 2003
  • The objective of this study is to examine the existence of technology gap convergence between manufacturing sector and Grand Total over 1970 to 2000 under nonlinearity relationship in Korea. We use the concept of technology convergence as the stationarity test of technology gap over the relevant periods. Our empirical results provide two important implications for the future study: First, our empirical results strongly support the nonlinearity for technology convergence in our country and an empirical tests based on the assumption of linearity will be biased and wrong industry and economic policy implications. Second, we find two regimes i.e. technology convergence and technology divergence between manufacture sector and Grand Total in our country over 1970 to 2000. These study results imply that the relevant industry and economic policies for technology and R&D implementations be with a causation.

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일본(日本)의 환경(環境) 복원(復元) 녹화(綠化) - 일본녹화공학회의 발자취와 과제 - (The Environmental Restoration and Revegetation Technology in Japan - The History of The Japanese Society of Revegetation Technology and the Problems of the Revegetation Technology in Japan -)

  • 마스다 타쿠로
    • 한국환경복원기술학회지
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    • 제1권1호
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    • pp.110-113
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    • 1998
  • It can be said that the revegetation technology in Japan was started in 1960's when Japan entered into the era of high-growth economy. In the beginning, the revegetation technology was mainly applied on the man made slopes, and with the time, the fields of the revegetation technology have been extended to the urban landscaping, ecosystem conservation, prevention of desertification and so on. With the progress of the revegetation technology and the expansion of its fields, new problems have occurred. In this paper, I introduced the history of The Japanese Society of Revegetation Technology and the present condition, and discussed about the problems of the revegetation technology in Japan.

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기술가치 평가시스템을 이용한 기술가치 전략 분석 (Analysis of Technology Value Strategy using Technology Valuation System)

  • 권방현;황규승
    • 경영정보학연구
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    • 제5권1호
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    • pp.129-146
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    • 2003
  • 기술 투자와 거래의 증가는 기술가치 평가에 대한 관심을 증대시키고 있으나 평가의 전문성과 기술가치의 다양성으로 인해 객관적인 기술 가치 평가가 용이하지 않은 문제점을 가지고 있다. 이 연구는 웹 기반의 대화형 기술가치 평가(WITV) 시스템을 개발하고 이 시스템을 이용한 기술가치의 평가 및 기술가치의 전략 분석에 그 목적을 두고 있다. WITV 시스템은 내적 기술가치(IVT)와 외적 기술가치(EVT)로 구성 된 기술가치 매력도(TVA) 모형을 이용하여 기술가치를 평가하고 해당 산업에서 기술의 가치를 제고하기 위한 전략을 분석하는데 이용되고 있다. 이 연구는 코스닥에 등록된 IT산업 의 중소 제조기업을 대상으로 TVA 모형과 WITV 시스템의 타당성과 적용가능성을 실험하였으며, 실험결과에 의해 그 효용성을 검증하였다.

The rs196952262 Polymorphism of the AGPAT5 Gene is Associated with Meat Quality in Berkshire Pigs

  • Park, Woo Bum;An, Sang Mi;Yu, Go Eun;Kwon, Seulgi;Hwang, Jung Hye;Park, Da Hye;Kang, Deok Gyeong;Kim, Tae Wan;Park, Hwa Chun;Ha, Jeongim;Kim, Chul Wook
    • 한국축산식품학회지
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    • 제37권6호
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    • pp.926-930
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    • 2017
  • High-quality meat is of great economic importance to the pig industry. The 1-acylglycerol-3-phosphate-O-acyltransferase 5 (AGPAT5) enzyme converts lysophosphatidic acid to phosphatidic acid in the mitochondrial membrane. In this study, we found that the porcine AGPAT5 gene was highly expressed in muscle tissue, influencing meat characteristics, and we also identified a non-synonymous single-nucleotide polymorphism (nsSNP) (rs196952262, c.673 A>G) in the gene, associated with a change of isoleucine 225 to valine. The presence of this nsSNP was significantly associated with meat color (lightness), lower cooking loss, and lower carcass temperatures 1, 4, and 12 h after slaughter (items T1, T4, and T12 on the recognized quality scale, respectively), and tended to increase backfat thickness and the water-holding capacity. These results suggest that nsSNP (c.673A>G) of the AGPAT5 gene is a potential genetic marker of high meat quality in pigs.

A Fiber Optic Sensor for Determination of 2,4-Dichlorophenol Based on Oxygen Oxidation Catalyzed by Iron(III) Tetrasulfophthalocyanine

  • Tong, Yilin;Li, Dapeng;Huang, Jun;Zhang, Cong;Li, Kun;Ding, Liyun
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3307-3311
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    • 2013
  • A new fiber optical sensor was developed for the determination of 2,4-dichlorophenol (DCP). The sensor was based on DCP oxidation by oxygen with the catalysis of iron(III) tetrasulfophthalocyanine (Fe(III)PcTs). The optical oxygen sensing film with $Ru(bpy)_3Cl_2$ as the fluorescence indicator was used to determine the consumption of oxygen in solution. A lock-in amplifier was used for detecting the lifetime of the oxygen sensing film by measuring the phase delay change of the sensor head. The different variables affecting the sensor performance were evaluated and optimized. Under the optimal conditions (i.e. pH 6.0, $25^{\circ}C$, Fe(III)PcTs concentration of 0.62 mg/mL), the linear detection range and response time of the sensor are $1.0{\times}10^{-6}-9.0{\times}10^{-6}$ mol/L and 250 s, respectively. The sensor displays high selectivity, good repeatability and stability, and can be used as an effective tool in analyzing DCP concentration in practical samples.

Bioconversion of Untreated Corn Hull into L-Malic Acid by Trifunctional Xylanolytic Enzyme from Paenibacillus curdlanolyticus B-6 and Acetobacter tropicalis H-1

  • Duong, Thi Bich Huong;Ketbot, Prattana;Phitsuwan, Paripok;Waeonukul, Rattiya;Tachaapaikoon, Chakrit;Kosugi, Akihiko;Ratanakhanokchai, Khanok;Pason, Patthra
    • Journal of Microbiology and Biotechnology
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    • 제31권9호
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    • pp.1262-1271
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    • 2021
  • L-Malic acid (L-MA) is widely used in food and non-food products. However, few microorganisms have been able to efficiently produce L-MA from xylose derived from lignocellulosic biomass (LB). The objective of this work is to convert LB into L-MA with the concept of a bioeconomy and environmentally friendly process. The unique trifunctional xylanolytic enzyme, PcAxy43A from Paenibacillus curdlanolyticus B-6, effectively hydrolyzed xylan in untreated LB, especially corn hull to xylose, in one step. Furthermore, the newly isolated, Acetobacter tropicalis strain H1 was able to convert high concentrations of xylose derived from corn hull into L-MA as the main product, which can be easily purified. The strain H1 successfully produced a high L-MA titer of 77.09 g/l, with a yield of 0.77 g/g and a productivity of 0.64 g/l/h from the xylose derived from corn hull. The process presented in this research is an efficient, low-cost and environmentally friendly biological process for the green production of L-MA from LB.