• 제목/요약/키워드: Chain Structure

검색결과 1,302건 처리시간 0.031초

디지털경제와 산업 전환: PC와 가전 산업의 사례 연구 (Industrial Transformation in digital economy: A Case Study on PC and Comsumer Industries)

  • 배영자
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 2002년도 제20회 동계학술발표회 논문집
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    • pp.133-149
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    • 2002
  • This study aims to investigate the impact of wide use of digital technology, in particular, the Internet, on innovation process and corporate strategy in electronics industry. The introduction of digital technology has changed innovation process, business model and organizational structure of the electronics companies. With the introduction of digital technology, the entire value chain of electronics industry from procurement, sales, and marketing to R&D and manufacturing has been restructured. E-commerce has been a major agenda for e-business. Recently, collaboration among electronics companies through e-marketplace has emerged as an important issue. A web-based e-commerce standard, so called RosettaNet, has been developed for facilitating e-transactions of electronics firms. The development of digital technology has dramatically increased the processing speed and sophisticated the virtual reality technology. As simulation becomes easier and more effective, the uncertainty and risk involved in R&D has decreased significantly. Another positive impact is closer cooperation between R&D and manufacturing functions. Taking advantage of automated and flexible production technology, has a new type of firm, so called, EMS (Electronics Manufacturing Services) emerged, whose strategic focus is on manufacturing only. The EMS can be seen as a kind of innovative organization, that is, a modular organization for production function. Digital technology has made convergence of computer and communication possible at early years but right now the convergence has been accelerated in extensive areas of communication, broadcasting, information appliances, software, contents, and services. Firms' effort for an innovative product and service has been intensified and the competition for a new standard product and service has become severe in electronics industry. Business activities are always realized in a specific organizational context. Accordingly building up innovation-friendly organization has emerged as a critical concern. Due to the striking decrease of transaction cost, a network type of organization has proliferated, and a business function turns into a modular organization. As a whole, digital technology has pushed electronics firms into developing their own business model, which takes consideration of standardization of business platform and their core competency.

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Structural Characterization of Physiologically Active Polysaccharides from Natural Products (Arabidopsis)

  • Shin, Kwang-Soon;Darvill, Alan G.
    • Food Science and Biotechnology
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    • 제15권3호
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    • pp.447-452
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    • 2006
  • To determine the functions of specific cell wall polysaccharides, polysaccharides of three mutants, mur3-1, mur3-2, and mur3-3, obtained from Arabidopsis wild type, underwent structural characterization. Upon sequential separation of pectins (RG-I and RG-II) and cross-linking glycans (xyloglucan, XG), only XG was affected by the mud mutation. Wild-type XG contained a considerable amount of fucose, whereas the fucose level in mur3 XGs was less than 20% that of wild type. Further analysis of XGs by matrix-assisted laser-induced/ionization time-of-flight (MALDI-TOF) mass spectrometry indicated that mud lines considerably or completely lost the fucosylated XG oligosaccharides such as XXFG and XLFG and the double-galactosylated oligosaccharide XLLG $^1H$-NMR spectroscopic analyses of the XG oligosaccharides from mur3-3 plant revealed the absence of fucose and a galactose level in the galactosylated side chain that was reduced by 40% compared to that of Arabidopsis wild-type plant. In contrast, 85% less fucose and a slight loss of galactose were observed in the mur3-1 and mur3-2 lines which show normal growth habit. Of the three Arabidopsis mur3 lines studied here, mur3-3 is disrupted by a T-DNA insertion in the exon of MUR3 which encodes XG-specific galactosyltransferase, and exhibits slight dwarfism. These results indicated that the T-DNA insertion at the MUR3 locus did not induce the complete loss of galactose in XG, and that galactose, rather than fucose, in the XG side chains made a major contribution to overall wall strength.

다양한 메탈로센 촉매를 이용한 폴리에틸렌 왁스의 중합 (Polymerization of polyethylene wax using various metallocene catalysts)

  • 한지웅;이영남;김성호;김인태
    • 한국응용과학기술학회지
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    • 제34권4호
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    • pp.857-865
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    • 2017
  • 본 연구는 폴리에틸렌 중합에 이용되는 Ziegler-Natta 촉매와는 다른 Indene및 Cyclopent adien을 기반으로 하는 다양한 메탈로센 촉매를 사용하여 폴리에틸렌 왁스를 중합하고 중합한 폴리에틸렌 왁스의 특성에 대해 분석하고 평가 하였다. 폴리에틸렌 왁스 중합은 각 다른 구조의 리간드를 포함하는 메탈로센 촉매에 대하여 중합온도, 연쇄이동제로 사용되는 수소와 에틸렌가스의 비율을 조정하여 다양한 조건하에서 중합을 시도 하였으며 그에 따른 분자량과 분자량 분포, 촉매 수율을 비교 분석하였다. 결과적으로 본 연구를 통하여 저분자량을 가지며 좁은 분자량 분포를 가지기에 적합한 메탈로센 촉매의 구조를 제안하였으며 이상적인 폴리에틸렌 왁스를 중합 할 수 있었다.

Conformational Transition of Form II to Form Ⅰ PoLy(L-proline) and the Aggregation of Form Ⅰ in the Transition: Water-Propanol Solvent System

  • 김현돈
    • Bulletin of the Korean Chemical Society
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    • 제18권9호
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    • pp.922-928
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    • 1997
  • The conformational transition of poly(L-proline) (PLP), Form Ⅱ → Form Ⅰ and the intermolecular aggregation of the product, Form Ⅰ, during and after the transition in water-propanol (1:7, 1:9, 1:15.7, and 1:29 v/v) were studied. For the study, the viscosity change and excess light scattering intensity were measured in the course of the transition which was determined by the Form Ⅰ fraction, fI of the sample solution. For the PLP sample of molecular weight Mv=31,000 the experimental results show that the reaction course is roughly divided into three regions: in the first region [fI=0.27 to 0.40 (- [α]D=400 to 330)], the conformational change of Form Ⅱ → Form Ⅰ occurs with decrease of viscosity, in the second region [fI=0.40 to 0.80 (- [α]D=330 to 120)], a partial side-by-side (p-S-S) type aggregation in which Form Ⅰ blocks interact with each other, which induces the increase of viscosity, starts to occur, and in the third region [fI=0.80 to 1.00 (- [α]D=120 to 15)], a side-by-side type (raft like) aggregation of Form Ⅰ or an end-to-end (E-E) type aggregation occurs according to the solvent situation, i.e., in a water-rich medium [water-propanol (1:9 or 1:7 v/v)], the (S-S) type aggregation with a gross decrease in viscosity occurs while in a water-poor medium [water-propanol (1:29 or 1:15.7 v/v), the (E-E) type aggregation with a large increase in viscosity occurs. The (S-S) type aggregation was promoted at high temperatures. Based on the structure of PLP, a reasonable mechanism for the (p-S-S) and (S-S) aggregation which occurs with the transition of Form Ⅱ → Form Ⅰ is considered. The suggested mechanism was also supported by the result of chain length effect of PLP for the aggregation.

다양한 지구통계기법의 지하매질 예측능 및 적용성 비교연구 (Comparative Analysis of Subsurface Estimation Ability and Applicability Based on Various Geostatistical Model)

  • 안정우;정진아;박은규
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제19권4호
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    • pp.31-44
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    • 2014
  • In the present study, a few of recently developed geostatistical models are comparatively studied. The models are two-point statistics based sequential indicator simulation (SISIM) and generalized coupled Markov chain (GCMC), multi-point statistics single normal equation simulation (SNESIM), and object based model of FLUVSIM (fluvial simulation) that predicts structures of target object from the provided geometric information. Out of the models, SNESIM and FLUVSIM require additional information other than conditioning data such as training map and geometry, respectively, which generally claim demanding additional resources. For the comparative studies, three-dimensional fluvial reservoir model is developed considering the genetic information and the samples, as input data for the models, are acquired by mimicking realistic sampling (i.e. random sampling). For SNESIM and FLUVSIM, additional training map and the geometry data are synthesized based on the same information used for the objective model. For the comparisons of the predictabilities of the models, two different measures are employed. In the first measure, the ensemble probability maps of the models are developed from multiple realizations, which are compared in depth to the objective model. In the second measure, the developed realizations are converted to hydrogeologic properties and the groundwater flow simulation results are compared to that of the objective model. From the comparisons, it is found that the predictability of GCMC outperforms the other models in terms of the first measure. On the other hand, in terms of the second measure, the both predictabilities of GCMC and SNESIM are outstanding out of the considered models. The excellences of GCMC model in the comparisons may attribute to the incorporations of directional non-stationarity and the non-linear prediction structure. From the results, it is concluded that the various geostatistical models need to be comprehensively considered and comparatively analyzed for appropriate characterizations.

Metagenomic Insight into Lignocellulose Degradation of the Thermophilic Microbial Consortium TMC7

  • Wang, Yi;Wang, Chen;Chen, Yonglun;Chen, Beibei;Guo, Peng;Cui, Zongjun
    • Journal of Microbiology and Biotechnology
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    • 제31권8호
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    • pp.1123-1133
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    • 2021
  • Biodegradation is the key process involved in natural lignocellulose biotransformation and utilization. Microbial consortia represent promising candidates for applications in lignocellulose conversion strategies for biofuel production; however, cooperation among the enzymes and the labor division of microbes in the microbial consortia remains unclear. In this study, metagenomic analysis was performed to reveal the community structure and extremozyme systems of a lignocellulolytic microbial consortium, TMC7. The taxonomic affiliation of TMC7 metagenome included members of the genera Ruminiclostridium (42.85%), Thermoanaerobacterium (18.41%), Geobacillus (10.44%), unclassified_f__Bacillaceae (7.48%), Aeribacillus (2.65%), Symbiobacterium (2.47%), Desulfotomaculum (2.33%), Caldibacillus (1.56%), Clostridium (1.26%), and others (10.55%). The carbohydrate-active enzyme annotation revealed that TMC7 encoded a broad array of enzymes responsible for cellulose and hemicellulose degradation. Ten glycoside hydrolases (GHs) endoglucanase, 4 GHs exoglucanase, and 6 GHs β-glucosidase were identified for cellulose degradation; 6 GHs endo-β-1,4-xylanase, 9 GHs β-xylosidase, and 3 GHs β-mannanase were identified for degradation of the hemicellulose main chain; 6 GHs arabinofuranosidase, 2 GHs α-mannosidase, 11 GHs galactosidase, 3 GHs α-rhamnosidase, and 4 GHs α-fucosidase were identified as xylan debranching enzymes. Furthermore, by introducing a factor named as the contribution coefficient, we found that Ruminiclostridium and Thermoanaerobacterium may be the dominant contributors, whereas Symbiobacterium and Desulfotomaculum may serve as "sugar cheaters" in lignocellulose degradation by TMC7. Our findings provide mechanistic profiles of an array of enzymes that degrade complex lignocellulosic biomass in the microbial consortium TMC7 and provide a promising approach for studying the potential contribution of microbes in microbial consortia.

미얀마와 한·중·일의 무역패턴 분석 (The pattern of trade between Myanmar and Korea, China and Japan)

  • 최영준;이가은
    • 국제지역연구
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    • 제20권4호
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    • pp.3-22
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    • 2016
  • 본 논문은 미얀마의 개혁과 개방이후의 무역패턴을 분석하고 동아시아의 한국과 중국 및 일본과의 무역패턴을 분석하였다. 미얀마의 비교우위구조와 국제분업구조를 RCA지수와 TSI지수를 이용하여 분석하였다. 분석기간은 개방 직후인 2012부터 자료 확보가 가능한 최근 2014으로 하였으며, 무역자료는 UN comtrade를 사용하였다. 분석결과 미얀마는 개방이후에 무역의 급격한 성장을 이루고 있을 뿐만 아니라 분업의 구조도 변화되고 있었다. 개방으로 2차산품의 무역비중이 증가하였을 뿐만 아니라 비교우위도 1차산품에서 2차 노동집약산업으로 이동하고 있었다. 한국과 중국 및 일본과의 무역에 있어서도 주로 1차산품과 노동집약재 중심으로 수출이 이루어졌다. 동아시아 3국간의 무역의 구조를 비교하면, 한국은 아직 미얀마와 초기단계의 무역구조를 보이고 있는 것으로 분석되었다. 즉 중국과 일본은 미얀마와 무역 관계가 안정적인데 반해, 한국과 미얀마의 무역은 비교우위 패턴이 안정적이지 않은 것으로 나타났다.

Effects of short-term fasting on in vivo rumen microbiota and in vitro rumen fermentation characteristics

  • Kim, Jong Nam;Song, Jaeyong;Kim, Eun Joong;Chang, Jongsoo;Kim, Chang-Hyun;Seo, Seongwon;Chang, Moon Baek;Bae, Gui-Seck
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권6호
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    • pp.776-782
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    • 2019
  • Objective: Fasting may lead to changes in the microbiota and activity in the rumen. In the present study, the effects of fasting on rumen microbiota and the impact of fasting on in vitro rumen fermentation were evaluated using molecular culture-independent methods. Methods: Three ruminally cannulated Holstein steers were fed rice straw and concentrates. The ruminal fluids were obtained from the same steers 2 h after the morning feeding (control) and 24 h after fasting (fasting). The ruminal fluid was filtrated through four layers of muslin, collected for a culture-independent microbial analysis, and used to determine the in vitro rumen fermentation characteristics. Total DNA was extracted from both control and fasting ruminal fluids. The rumen microbiota was assessed using denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction. Microbial activity was evaluated in control and fasting steers at various intervals using in vitro batch culture with rice straw and concentrate at a ratio of 60:40. Results: Fasting for 24 h slightly affected the microbiota structure in the rumen as determined by DGGE. Additionally, several microorganisms, including Anaerovibrio lipolytica, Eubacterium ruminantium, Prevotella albensis, Prevotella ruminicola, and Ruminobacter amylophilus, decreased in number after fasting. In addition, using the ruminal fluid as the inoculum after 24 h of fasting, the fermentation characteristics differed from those obtained using non-fasted ruminal fluid. Compared with the control, the fasting showed higher total gas production, ammonia, and microbial protein production (p<0.05). No significant differences, however, was observed in pH and dry matter digestibility. Conclusion: When in vitro techniques are used to evaluate feed, the use of the ruminal fluid from fasted animals should be used with caution.

Changes in the ruminal fermentation and bacterial community structure by a sudden change to a high-concentrate diet in Korean domestic ruminants

  • Lee, Mingyung;Jeong, Sinyong;Seo, Jakyeom;Seo, Seongwon
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권1호
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    • pp.92-102
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    • 2019
  • Objective: To investigate changes in rumen fermentation characteristics and bacterial community by a sudden change to a high concentrate diet (HC) in Korean domestic ruminants. Methods: Major Korean domestic ruminants (each of four Hanwoo cows; $545.5{\pm}33.6kg$, Holstein cows; $516.3{\pm}42.7kg$, and Korean native goats; $19.1{\pm}1.4kg$) were used in this experiment. They were housed individually and were fed ad libitum with a same TMR (800 g/kg timothy hay and 200 g/kg concentrate mix) twice daily. After two-week feeding, only the concentrate mix was offered for one week in order to induce rapid rumen acidosis. The rumen fluid was collected from each animals twice (on week 2 and week 3) at 2 h after morning feeding using an oral stomach tube. Each collected rumen fluid was analyzed for pH, volatile fatty acid (VFA), and $NH_3-N$. In addition, differences in microbial community among ruminant species and between normal and an acidosis condition were assessed using two culture-independent 16S polymerase chain reaction (PCR)-based techniques (terminal restriction fragment length polymorphism and quantitative real-time PCR). Results: The HC decreased ruminal pH and altered relative concentrations of ruminal VFA (p<0.01). Total VFA concentration increased in Holstein cows only (p<0.01). Terminal restriction fragment length polymorphism and real-time quantitative PCR analysis using culture-independent 16S PCR-based techniques, revealed rumen bacterial diversity differed by species but not by HC (p<0.01); bacterial diversity was higher in Korean native goats than that in Holstein cows. HC changed the relative populations of rumen bacterial species. Specifically, the abundance of Fibrobacter succinogenes was decreased while Lactobacillus spp. and Megasphaera elsdenii were increased (p<0.01). Conclusion: The HC altered the relative populations, but not diversity, of the ruminal bacterial community, which differed by ruminant species.

Genetic diversity of grapevine (Vitis vinifera L.) as revealed by ISSR markers

  • Basheer-Salimia, Rezq;Mujahed, Arwa
    • Journal of Plant Biotechnology
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    • 제46권1호
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    • pp.1-8
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    • 2019
  • The main goal of this study was to determine the genetic diversity among 36 grape cultivars grown in Palestine by using ISSR-polymerase chain reaction (PCR) fingerprints. Among the tested primers, 17 produced reasonable amplification products with high intensity and pattern stability. A total of 57 DNA fragments (loci) separated by electrophoresis on agarose gels were detected and they ranged in size, from 150 to 900 bp. Out of these fragments, 55 (88%) were polymorphic and 2 (3.5%) monomorphic. Our results also revealed an average of 3.1 loci per primer. A minimum of 1 and maximum of 10 DNA fragments were obtained (S-17, #820 and #841) and (S-31) primers, respectively. Therefore, the later primer (S-31) is considered to be the most powerful primer among the tested ones. The genetic distance matrix showed an average distance range of between 0.05 and 0.76. The maximum genetic distance value of 0.76 (24% similarity) was exhibited between the (Shami and Marawi.Hamadani.Adi) as well as (Bairuti and Marawi.Hamadani.Adi) genotypes. On the other hand, the lowest genetic distance of 0.05 (95% similarity) was exhibited between (Jandali.Tawel.Mofarad and Jandali. Kurawi.Mlzlz) along with (Shami.Aswad and Shami.mtartash. mlwn) genotypes. Furthermore, the UPGMA dendrogram generally clusters the grape cultivars into eight major clusters in addition to an isolated genotype. Based on these figures, the cultivars tested in this study could be characterized by large divergence at the DNA level. This is taking the assumption that our region has a very rich and varied clonal grape genetic structure.