• Title/Summary/Keyword: Evolve

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Importance Of Tribology in Positive-Displacement Type of Fluid Machinery and Heat Engine

  • Nakahara, Tsunamitsu
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.3-8
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    • 1998
  • The industrial revolution in England was based on the manufacturing systems by the power of water mill and rapidly progressed by the innovation of steam engine. It is no exaggeration to say that today's civilization is realized by the development of various types of power machinery, namely fluid machinery and heat engine. The electric energy is converted mainly from thermal energy (mainly steam) of mineral oil, coal and nuclear fuel through generator connected with steam turbine which is a kind of power machinery. There are various types of power machinery as shown in Tables 1a and 1b. They are classified into two types by use. One is absorption type of fluid and/or thermal energy, for examples, windmill and heat engine. The other is provision type of the energies for examples, pump, compressor and propulsion. By flow type, they are also classified by two types, turbo type and positive-displacement type. The turbo type began from water mill and windmill and evolve to steam turbine and finally to gas turbine. The positive-displacement type started from reciprocating water pump and developed into steam engine and changed to reciprocating combustion engine. The pumps and motors used in oil hydraulic system for power control are also positive-displacement type.

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우리 나라 중소기업의 전략변화와 기술능력 학습 - 우리나라 전자부품 산업에 대한 사례연구 -

  • 이병헌;김영배
    • Proceedings of the Technology Innovation Conference
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    • 1998.06a
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    • pp.57-90
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    • 1998
  • This study attempts to explore the evolution paths of Korean SMEs'strategies and their technological teaming processes. Several different evolution paths are identified based on a dynamic strategic group analysis of 115 SMEs'strategy in the Korean electronic component industry for the period of 1990-1995. Further, inadept case analyses on technological learning processes in 5 firms are undertaken. Major findings of this study can be summarized as follows : 1) There are three dominant evolution paths in SMEs'strategy. First path indicates the evolution from a subcontractor or petty imitator group(a strategic group with the narrow product/market domain and the low level of accumulated resource/capabilities) into an innovator group(a strategic group with the narrow domain but high level of technological capability) by accumulating technological capabilities. Second, some firms move from a subcontractor group into a generalizer group(a strategic group with broad product/market domain but relatively low level of technological capability) by simply adding product lines. Third path involves firms which evolve from a subcontractor group into a production focus group(a strategic group with high level of production capability) by investing in production capabilities. 2) An in-depth case analysis shows those who succeeded in technological learning are managed by CEOs, who have technological expertise and strategic vision, and have made an effort to establish management practices to support innovation, such employee educational program, performance-based reward system, etc. The successful firms also aggressively pursue diverse external linkages with outside technology sources to learn product and process technologies. Fiendly, this study discusses several implications of the findings for the theoretical development and strategic management of small firms in Korea.

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The Spectra Investigation of the Halo Planetary Nebula BoBn 1

  • Hyung, Siek;Otsuka, Masaaki;Tajitsu, Akito;Izumiura, Hideyuki
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.72.2-72.2
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    • 2010
  • The extremely metal-poor halo planetary nebula BoBn 1 has been investigated based on IUE archive data, Subaru/HDS spectra, VLT/UVES archive data, and Spitzer/IRS spectra. We have measured a heliocentric radial velocity of $+191.6\pm1.3\;kms^{-1}$ and expansion velocity 2Vexp of $40.5\pm3.3\;kms^{-1}$ from an average over 300 lines. The estimations of C, N, O, and Ne abundances from the optical recombination lines (ORLs) and Kr, Xe, and Ba from the collisional excitation lines (CELs) are also done. We have detected 5 fluorine and several slow neutron capture elements (the s-process). The amounts of [F/H], [Kr/H], and [Xe/H] suggest that BoBn 1 is the most F-rich among F detected PNe and is a heavy s-process element rich PN. The photo-ionization models built with non-LTE theoretical stellar atmospheres indicate that the progenitor was a 1-1.5 $M_\bigstar$ that would evolve into a white dwarf with an $0.62M_{\odot}$ core mass and $0.09M_{\odot}$ ionized nebula. Careful examination implies that BoBn 1 has evolved from a binary and experienced coalescence during the evolution to become a visible PN. The elemental abundances except N could be explained by a binary model composed of $0.75M_{\odot}+1.5M_{\odot}$ stars.

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Three Dimensional Simulation Model of Fuel Delivery Jet Pump (연료 송출용 제트펌프 3차원 전산해석 모델)

  • PARK, DAIN;YUN, JIN WON;YU, SANGSEOK
    • Journal of Hydrogen and New Energy
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    • v.28 no.3
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    • pp.308-314
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    • 2017
  • Jet pump in automotive fuel tank module is used to deliver fuel to fuel pump so that the pump is operated without aeration in suction side. In this study, three dimensional simulation model of jet pump is developed to understand performance variation over design parameters. Performance of jet pump is also investigated experimentally in terms of operating pressures. The experimental data is used to verify the three dimensional simulation model of jet pump. Verification results show that the three dimensional simulation model of jet pump is about 1% error with experiment. The simulations are conducted in terms of throat ratio and primary flow induction angle. As the throat ratio is increased, the flux ratio is trade-off at 3 times of throat diameter. On the other hand, as primary flow induction angle is increased, vapor pressure inside the nozzle is decreased. In summary, the results show that liquid jet pump has to be optimized over design parameters. Additionally, high velocity of induced flow is able to evolve cavitation phenomena inside the jet pump.

Evaluation on Optimal Height of the Bin Wall using Stability Analysis (안정해석을 통한 공동 일체식 옹벽의 최적높이 평가)

  • Bae, Woo-Seok
    • Journal of the Korean Society of Safety
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    • v.24 no.2
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    • pp.48-54
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    • 2009
  • Structures to support against slop failures or resist earth pressure like masonry retaining walls or retaining walls have continued to advance and evolve to new eco-friendly, easy-to-construct, crib retaining walls with varied forms and construction methods, meeting the needs of the times. Researches until now, however, have focused on the analyses of site displacement or stability of the whole site including structures like retaining walls, and thus, researches on rational design or method for stability analysis are lacking. Therefore, this study was conducted on a number of stability analyses, such as the visual power line or stability on sliding, being presented for bin walls, which enable vegetation to grow and were developed and applied in varied forms, meeting the development demands for eco-friendly retaining wall structures. This study compared the results of stability analyses, determined their feasibility, and evaluated their stability according to the height and facade slope of retaining walls. According to the results of this study, traditional masonry retaining wall analysis showed rather conservative stability evaluation results in the stability evaluation of bin walls, and the method using the visual power line seems to be objective because it produced similar results to the stability evaluation method on sliding or turnover.

CONSIDERATIONS IN THE DEVELOPMENT OF FUTURE PIG BREEDING PROGRAM - REVIEW -

  • Haley, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.4 no.4
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    • pp.305-328
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    • 1991
  • Pig breeding programs have been very successful in the improvement of animals by the simple expedient of focusing on a few traits of economic importance, particularly growth efficiency and leanness. Further reductions in leanness may become more difficult to achieve, due to reduced genetic variation, and less desirable, due to adverse correlated effects on meat and eating quality. Best linear unbiased prediction (BLUP) of breeding values makes possible the incorporation of data from many sources and increases the value of including traits such as sow performance in the breeding objective. Advances in technology, such as electronic animal identification, electronic feeders, improved ultrasonic scanners and automated data capture at slaughter houses, increase the number of sources of information that can be included in breeding value predictions. Breeding program structures will evolve to reflect these changes and a common structure is likely to be several or many breeding farms genetically linked by A.i., with data collected on a number of traits from many sources and integrated into a single breeding value prediction using BLUP. Future developments will include the production of a porcine gene map which may make it possible to identify genes controlling economically valuable traits, such as those for litter size in the Meishan, and introgress them into nucleus populations. Genes identified from the gene map or from other sources will provide insight into the genetic basis of performance and may provide the raw material from which transgenic programs will channel additional genetic variance into nucleus populations undergoing selection.

Glucose transport 1 deficiency presenting as infantile spasms with a mutation identified in exon 9 of SLC2A1

  • Lee, Hyun Hee;Hur, Yun Jung
    • Clinical and Experimental Pediatrics
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    • v.59 no.sup1
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    • pp.29-31
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    • 2016
  • Glucose transport 1 (GLUT-1) deficiency is a rare syndrome caused by mutations in the glucose transporter 1 gene (SLC2A1) and is characterized by early-onset intractable epilepsy, delayed development, and movement disorder. De novo mutations and several hot spots in N34, G91, R126, R153, and R333 of exons 2, 3, 4, and 8 of SLC2A1 are associated with this condition. Seizures, one of the main clinical features of GLUT-1 deficiency, usually develop during infancy. Most patients experience brief and subtle myoclonic jerk and focal seizures that evolve into a mixture of different types of seizures, such as generalized tonic-clonic, absence, myoclonic, and complex partial seizures. Here, we describe the case of a patient with GLUT-1 deficiency who developed infantile spasms and showed delayed development at 6 months of age. She had intractable epilepsy despite receiving aggressive antiepileptic drug therapy, and underwent a metabolic workup. Cerebrospinal fluid (CSF) examination showed CSF-glucose-to-blood-glucose ratio of 0.38, with a normal lactate level. Bidirectional sequencing of SLC2A1 identified a missense mutation (c.1198C>T) at codon 400 (p.Arg400Cys) of exon 9.

Virtual Assembly Analysis Tool and Architecture for e-Design and Realization Environment

  • Kim, K.Y.;Nnaji, Bart-O.;Kim, D.W.
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.1
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    • pp.62-76
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    • 2004
  • Many customers are no longer satisfied with mass-produced goods. They are demanding customization and rapid delivery of innovative products. Many companies are now realizing that the best way to reduce life cycle costs is to evolve a more effective product development paradigm using Internet and web based technologies. Yet there remains a gap between current market demands and product development paradigms. The existing CAD systems require that product developers possess all the design analysis tools in-house making it impractical to employ all the needed and newest tools. Hence, this paper addresses how assembly operation analysis can be embedded transparently and remotely into a service-oriented collaborative assembly design environment. A new assembly operation analysis framework is introduced and a relevant architecture and tools are developed to realize the framework. Instead of the current sequential process for verifying and validating an assembly design, a new Virtual Assembly Analysis (VAA) method is introduced in the paper to predict the various effects of joining during actual collaborative design. As a case study, arc welding and riveting processes are investigated. New service-oriented VAA architecture and its VAA components are proposed and implemented on prototype mechanical assemblies.

UK Social Housing and Housing Market in England: A Statistical Review and Trends

  • Schmickler, Arno;Park, Kenneth Sungho
    • Land and Housing Review
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    • v.5 no.3
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    • pp.193-201
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    • 2014
  • Around 80% of the 63 million people in the UK live in urban areas where demand for affordable housing is highest. Supply of new dwellings is a long way short of demand and with an average annual replacement rate of 0.5% more than 80% of the existing residential housing stock will still be in use by 2050. A high proportion of owner-occupiers, a weak private rental sector and lack of sustainable financing models render England's housing market one of the least responsive in the developed world. As an exploratory research the purpose of this paper is to examine the provision of social housing in the United Kingdom with a particular focus on England, and to set out implications for housing associations delivering sustainable community development. The paper is based on an analysis of historical data series (Census data), current macro-economic data and population projections to 2033. The paper identifies a chronic undersupply of affordable housing in England which is likely to be exacerbated by demographic development, changes in household composition and reduced availability of finance to develop new homes. Based on the housing market trends analysed in this paper opportunities are identified for policy makers to remove barriers to the delivery of new affordable homes and for social housing providers to evolve their business models by taking a wider role in sustainable community development.

Research on the design paradigm shift of hospital lobby space that pursues emotional identity - Mainly on the lobby space in the private hospital of dermatology/plastic surgery in metropolitan circle - (감성적 아이덴티티를 지향하는 병원 로비공간 디자인 패러다임 변화에 관한 연구 - 수도권 피부과/성형외과 개인병원 로비공간을 중심으로 -)

  • Choo, Jin
    • Korean Institute of Interior Design Journal
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    • v.19 no.3
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    • pp.234-241
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    • 2010
  • Avoiding the unified productivity that was caused by the mechanical and technical development due to Industrial Revolution in the past, modern design is incessantly evolving in search of new motive, namely, diversity. Further, we live in the age when the propensity that serves public interest and purpose and sometimes shows quite individual character should be considered. As a result, the comprehensive and harmonious trend of emotional design is being highlighted more remarkably. Involving the social background that further respects human dignity, this is closely related to diverse issues such as human right which should be guaranteed and pursued for individual. While the tradition and innovation caused by the encounter of machine and art had confrontation and conflict in the past, the direction has changed to incessant evolution and interaction where paradigm of technical progress and development is newly composed and changed in modern times. The meaning of service in medical area is expanding and developing from the simple treatment to the more comprehensive healing. Medical space will evolve to the healing space that attaches importance to emotional aspect of human dimension which further understands and respects human being in the future.