• 산업경영시스템학회지
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• 제36권4호
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• pp.25-30
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• 2013

This article deals with the transient analysis in bicycle shifting using a discrete chain model. Among the various components of a bicycle, we focused in the power-transmissions on the contact points between the chain element and sprocket. And by imposing kinematic motions on the front and rear derailleurs, we analyzed the shifting mechanism for increasing the rotational speed of rear wheel. In order to build the dynamic analysis model, we first tore down the real bicycle and measured each component's design parameters. Then we made 3-dimensional CAD models for each component related to the power transmission of a bicycle. Using the converted 3-dimensional dynamic model for the simulation program, we performed non-shifting and shifting dynamic analysis. As a result, we investigated the dynamic behaviors of a discrete chain model focused on the interaction between the chain and sprocket wheel.

• 대한전자공학회논문지SD
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• 제44권2호
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• pp.127-138
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• 2007

본 논문에서는 최대길이 의사무작위 이진 시퀀스(m-시퀀스)의 쉬프트-덧셈 특성에 근거한 위상천이를 이용하여 회로 출력에 나타나는 X-값을 효과적으로 마스크 함으로써 내장된 자체 테스트를 실현할 수 있는 기법을 제안한다. 이 기법은 패턴생성기인 LFSR의 출력을 적절하게 위상천이 하여 마스크 패턴을 생성할 수 있는 위상천이 네트워크를 이용한다. 테스트 절차 동안에 각 스캔 체인에 인가되는 마스크 패턴의 위상 천이 수는 재구성 가능하다. LFSR의 출력을 적절하게 위상 천이하여 모든 스캔 체인 마스크 패턴을 생성할 수 있는 위상천이 네트워크 합성 알고리즘을 제안한다. 본 논문에서 제안하는 X-마스크 회로는 각 스캔 체인 마스크 패턴을 생성할 수 있는 후보 위상천이 수가 많기 때문에 하드웨어 오버헤드를 효과적으로 감축할 수 있다. 실험을 통하여 제안된 위상천이를 이용한 X-마스크 회로는 기존의 연구 결과보다 훨씬 적은 저장공간과 하드웨어 오버헤드를 필요로 함을 증명한다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.108-108
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• 2006

The role of conformational entropy of polymer chains in polymer crystallization is investigated by molecular modeling and theory. The entropy of folded loops dominates at experimentally relevant temperatures to dictate short equilibrium lamellar thicknesses, which are much smaller than the extended chain thickness. Also the entropic barriers control the kinetics of polymer crystallization. These results based on chain entropy are different from the classical views of how polymer chains crystallize.

• 대한안전경영과학회지
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• 제20권4호
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• pp.1-6
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• 2018

Recently, bicycle has means of effective healthy transportation, and riding the bicycles is considered as popular recreational and sporting activities. Also, the saddle, steering system, driving device and braking device are researched briskly because of consumer's need for driving performance and comfort. Especially, the importance of a cassette responsible for transmission function by transmitting power to the drive shaft through the chain is very focused. The writer conducted structural analysis for the sprocket of each level using the ANSYS widely used for the analysis. Speed shifting performance was enhanced by minimization / simplification of shifting point through a sort of tooth profile of the cassette. By partitioning a clear value type and other shifting point, it has been modified to enable smooth speed-shifting. In addition, as titanium precision forming process, this study studied the molding technique by blanking and dies forging for mass production of the cassette. so it could be expected that the entire drive train would utilize that in the future. The stamping process capability for thin materials for the mass production of the sprockets is applicable to producing automobile parts, so lightweight component production is likely to be possible through that, for the safety of driving.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권4호
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• pp.221-228
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• 2007

In this paper, we propose a new symbolic simulation for scan chain diagnosis to solve the diagnosis resolution problem. The proposed scan chain fault simulation, called the SF-simulation, is able to analyze the effects caused by faulty scan cells in good scan chains. A new scan chain fault simulation is performed with a modified logic ATPG pattern. In this simulation, we consider the effect of errors caused by scan shifting in the faulty scan chain. Therefore, for scan chain diagnosis, we use the faulty information in good scan chains which are not contaminated by the faults while unloading scan out responses. The SF-simulation can tighten the size of the candidate list and achieve a high diagnosis resolution by analyzing fault effects of good scan chains, which are ignored by most previous works. Experimental results demonstrate the effectiveness of the proposed method.

• ALGAE
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• 제36권4호
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• pp.285-298
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• 2021

The amount of CO₂ absorbed by the oceans continues to rise, resulting in further acidification, altering some functional traits of phytoplankton. To understand the effect of elevated partial pressures of CO₂ (pCO₂) on functional traits of dinoflagellates Alexandrium affine and A. pacificum, the cardinal temperatures and chain formation extent were examined under two pCO₂ (400 and 1,000 µatm) over the range of temperature expected to be associated with growth. The growth rate and chain formation extent of A. affine increased with higher pCO₂, showing significant changes in cardinal temperatures and a substantial increase in middle chain-length (4-8 cells) fractionation under elevated pCO₂ condition. By contrast, there were no significant differences in specific growth rate and any chain-length fractionation of A. pacificum between ambient and elevated pCO₂ conditions. The observed interspecies variation in the functional traits may reflect differences in ability of species to respond to environmental change with plasticity. Moreover, it allows us to understand the shifting biogeography of marine phytoplankton and predict their phenology in the Korea Strait.

• 한국수산과학회지
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• 제40권6호
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• pp.337-342
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• 2007

The formation of lysinoalanine (LAL) in protein recovered from the belanger's croaker, Johnius grypotus, using a pH shifting process was measured by amino acid analysis. The LAL peak was detected at 49.24 min, between phenylalanine and histidine peaks in the amino acid analyzer. LAL was not detected in the fish muscle or in protein recovered using the alkaline pH shifting process. LAL was not formed in protein recovered after storage for up to 9 hrs at pH 11, but was detected in the soluble protein fraction at pH 11, followed heating at $90\;^{\circ}C$. The myosin heavy chain decreased with storage time at pH 11. The results suggest that the alkaline shifting process for recovering fish muscle protein is safe, and that no LAL forms.

• Transactions on Electrical and Electronic Materials
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• 제18권4호
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• pp.211-216
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• 2017

The dielectric properties of two polyurethanes (PUs) with different hard segments, i.e., aromatic methylene di-p-phenyl diisocyanate (MDI) and aliphatic hexamethylene diisocyanate (HDI), were investigated in the temperature range of -100 to $100^{\circ}C$ and in the frequency range of 1 Hz to 3 kHz. The ${\alpha}$-relaxations induced by the glass transition of the equivalent soft segments in the two PUs occurred at relaxation times of ${\tau}=3.46{\times}10^{-3}s$ for MDI-PU and ${\tau}=3.39{\times}10^{-2}s$ for HDI-PU at $-20^{\circ}C$, in accord with the temperature-frequency superposition principle, resulting in similar shifting factors. However, different I-relaxations were observed for the two PUs. The I-relaxation of MDI-PU occurred due to the mobility of the chain extenders near $80^{\circ}C$ with a slower shifting rate than the ${\alpha}$-relaxation. On the other hand, I-relaxation arising from both the extender and the unconstrained hard segments of HDI-PU occurred at $70{\sim}100^{\circ}C$, indicating complicated dielectric behavior due to partial interaction with the ${\alpha}$-relaxation at high frequencies. Thus, the I-relaxation of HDI-PU did not follow the superposition principle. The dielectric behaviors of the PUs were mainly influenced by their phase transitions, which were affected by the structure and components of the materials.

• Agribusiness and Information Management
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• 제4권2호
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• pp.32-41
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• 2012

Studies have shown that the future of the wine market rests on the effective and efficient changes in technology to the supply chain used by most of the major global players. In today's wine industry, companies are faced with the ever-shifting demand for their products, strict regulation and increasing price competition. Even at that, mature companies in the wine industry are succeeding by scaling up production, streamlining their supply chains, expanding into new geographic areas, implementing more efficient processes, cleverly marketing products, and focusing on ever closer relationships with suppliers, partners and customers. However, this paper looks at supply chain challenges in the wine industry from a global perspective presented in the inbound, manufacturing and outbound processes as well as offer effective solutions in order for companies to gain a competitive advantage and succeed on a global level.

• 산업경영시스템학회지
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• 제27권4호
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• pp.59-68
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• 2004

Recently, shifting channel power is forcing supply chain to take back products. As you can imagine returned product has always been a problem for all parties in the supply chain due to the disruption in operations and a headache in processing returned products. Therefore, every member of supply chain should respond to reverse logistics activities particularly for the return handling process. Under such a strong demand of efficient and cost effective reverse logistics activities, particularly for the return handling process, the information system should be implemented and participated in intensively. This study analyzed the reverse logistics information factors for environmental conscious logistics system limited to returns from customers/consumers. The results provide reverse logistics information factors based on the return handling process which can be used as benchmarking for companies seeking implementation of an efficient return handling system.