• Title/Summary/Keyword: Channel forming

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A Study on the Channel forming Discharge Estimation and the Hydraulic Geometry Characteristics of the Alluvial Stream (충적하천의 하도형성유량 산정과 수리기하특성에 관한 연구)

  • Lee, Hee-Chul;Lee, Eun-Tae
    • Journal of Korea Water Resources Association
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    • v.36 no.5
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    • pp.823-838
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    • 2003
  • For many rivers and streams, it has been observed that a single representative discharge may be used to determine the hydraulic geometry of a stable channel. This representative channel forming discharge has been given several names by different researchers, including bankfull, specified recurrence interval, and effective discharge. Therefore, The purpose of this study is to estimate channel forming discharge for study areas using the hydrological characteristic parameters and recording data, and to determine the hydraulic geometry relationships for the relating bankfull dimensions to bankfull discharge. In the Munmak and Seomyun gauging stations, the estimated bankfull discharges are found to have a return period of 1.8 and 1.5 years on the maximum annual series, respectively. The estimated effective discharges at those stations are largely different from bankfull discharges. The hydraulic geometry relationships between bankfull discharge and bankfull width, bankfull depth, velocity, bed slope are established. But the statistical parameters, such as R2, are calculated lower.

Structural Design and Characterization of a Channel-forming Peptide

  • Krittanai, Chartchai;Panyim, Sakol
    • BMB Reports
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    • v.37 no.4
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    • pp.460-465
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    • 2004
  • A 16-residue polypeptide model with the sequence acetyl-YALSLAATLLKEAASL-OH was derived by rational de novo peptide design. The designed sequence consists of amino acid residues with high propensity to adopt an alpha helical conformation, and sequential order was arranged to produce an amphipathic surface. The designed sequence was chemically synthesized using a solid-phase method and the polypeptide was purified by reverse-phase liquid chromatography. Molecular mass analysis by electro-spray ionization mass spectroscopy confirmed the correct designed sequence. Structural characterization by circular dichroism spectroscopy demonstrated that the peptide adopts the expected alpha helical conformation in 50% acetonitrile solution. Liposome binding assay using Small Unilamellar Vesicle (SUV) showed a marked release of entrapped glucose by interaction between the lipid membrane and the tested peptide. The channel-forming activity of the peptide was revealed by a planar lipid bilayer experiment. An analysis of the conducting current at various applied potentials suggested that the peptide forms a cationic ion channel with an intrinsic conductance of 188 pS. These results demonstrate that a simple rational de novo design can be successfully employed to create short peptides with desired structures and functions.

The Influence of Omni-channel Propensity and Regulatory Focus on Consideration Set Formation (옴니채널 성향, 조절초점과 고려상표군 형성에 관한 연구)

  • HAN, Sang-Seol
    • The Journal of Industrial Distribution & Business
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    • v.10 no.5
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    • pp.49-58
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    • 2019
  • Purpose - Consumer behaviors or decision-making process has been changing recently as the consumer environment, including mobile everyday life, has changed. In view of this changing consumer smart environment, this study aims to investigate structural relation about the influence omni-channel propensity and regulatory focus on consideration set formation. Research design, data, and methodology - In order to proceed with this study, we review previous studies and setting hypotheses. The hypothesis was verified through a survey that was conducted for university students with experience in purchasing in less than three months. With reference to previous studies, operational definition was made for the questionnaire design. From 2018 Nov. to 2019 Feb. Survey was conducted on the panel consumers who purchase item within that period. 315 collected survey data were used to verify hypotheses except the data that had incorrect values. This data were used for SPSS/AMOS for confirm hypothesis which developed by researcher. Results - The results of this study are as follows. First, Consumers were considering a more heterogeneous alternatives if they were more omni-channel propensity in the process of forming consideration set. Second, Consumers were more conscious of the price if they were more omni-channel propensity Third, Consumers were considering a more newness alternatives if they were more omni-channel propensity in the process of forming consideration set. Meanwhile, The results of the study on regulatory focus and consideration set relationships are as follows. Consumers were considering a more heterogeneous alternatives if they were more promotion focus tendency in the process of forming consideration set. Second, Prevention focus tendency were more conscious of the price in the process of considering alternatives. Third, Consumers were considering a more newness alternatives if they were more promotion focus tendency. Conclusions - Depending on the changing consumer environment, the omni-channel propensity was shown to influence the formation of the consideration set. Also, Regulatory focus of consumers significantly influence to formation of consideration set. this study also contributes to the development of the theory as well as the practical approach with understanding consumer decision process on smart(mobile) environment.

A Rate Separating Multi-Channel Protocol for Improving Channel Diversity and Node Connectivity in IEEE 802.11 Mesh Networks (IEEE 802.11 메쉬 네트워크에서 채널 다양성과 노드 연결성 향상을 위한 레이트 분할 멀티 채널 프로토콜)

  • Kim, Sok-Hyong;Suh, Young-Joo;Kwon, Dong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12A
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    • pp.1152-1159
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    • 2010
  • Wireless Mesh Networks (WMNs) provides Internet accesses to users by forming backbone networks via wireless links. A key problem of WMN is network capacity. For this, multi-channel and multi-rate functions of IEEE 802.11 can be utilized. Depending on channel assignments, multi-channel determines node connectivity and channel diversity. Also, in IEEE 802.11 multi-rate networks, the rate anomaly problem occurs, the phenomenon that low-rate links degrades the performance of high-rate links. In this paper, we propose rate separating multi-channel (RSMC) protocols that improves the node connectivity and channel diversity, and mitigates the rate anomaly problem. RSMC increases the channel diversity by forming tree-based WMNs and decreases the rate anomaly by separating different rate links on the tree via channels. In addition, it uses network connectivity (NC) algorithm to increase the node connectivity. Through simulations, we demonstrate that the RSMC shows improved performance than existing multi-channel protocols in terms of aggregate throughput, node connectivity, channel diversity.

Improvement of Smart Antenna System Performance Using virtual antennas (가상안테나를 이용한 스마트 안테나의 성능개선)

  • 임채현;문성훈;한동석
    • Proceedings of the IEEK Conference
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    • 2001.06a
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    • pp.49-52
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    • 2001
  • A virtual antenna system is presented to increase the channel capacity of a smart antenna in cdma2000. Although a smart antenna system can increase channel capacity by forming a beam to a desired user direction, an increase of channel capacity is limited by the number of antenna elements. A virtual antenna is proposed to improve the channel capacity by increasing the degree of freedom. The results show that the proposed system has a larger channel capacity than a conventional smart antenna system for the same number of antenna elements.

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Springback Control in the Forming Processes for High-Strength Steel Sheets (고강도 강판 성형 공정의 스프링백 제어)

  • 양우열;이승열;금영탁;황진영;윤치상;신철수;조원석
    • Transactions of Materials Processing
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    • v.12 no.8
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    • pp.718-723
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    • 2003
  • Tn order to develop springback control technology for high-strength steel sheets, several studies have been conducted: dome stretching test, stepped s-rail forming and springback measurement, and optimally shaped initial blank design. First, to find out the formability of TRIP60, dome stretching test was performed. Next, the stepped s-rail die, which was designed to form a channel type panel with large twist and wall curl, was manufactured and used to evaluate the effect of controlling forming variables, such as blank holding force and flange amount on the springback. Furthermore, new measurement method of the springback was introduced to define wall curl and twist in geometrically complex panels. Finally, the optimally shaped initial blank was employed to verify one of the best ways to control the springback in channel type. high-strength sheet panels.

Split Die Design for ECAP with Lower Loads (등통로각압축 공정용 저하중 분리형 금형 설계)

  • Jin, Young-Gwan;Kang, Seong-Hoon;Son, Il-Heon;Im, Yong-Taek
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.3
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    • pp.217-222
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    • 2008
  • Equal channel angular pressing (ECAP) is one of the effective methods to produce bulk-nano materials by accumulating plastic strain into the workpiece without changing its cross-sectional shape in the multi-pass processing. However, the forming load becomes higher for manufacturing large specimens using conventional solid or split dies because of friction, flash formation, and usage of dummy specimen. In the present investigation, better split die was designed to reduce the forming loads and improve the geometrical accuracy of the specimen in the multi-pass ECAP. The new die exit channel was also designed to reduce the friction effect. Experiments with AA1050 specimens with a square cross-section were carried out to examine the design goal using the proposed split dies for routes A and C up to four passes. The numerical forming simulations were used to determine the effective geometry of various die models in the present work.

Effect of Forming Factor on Springback in U-bended and Drawn Channel (굽힘과 드로잉에서 성형인자가 탄성복원에 미치는 영향)

  • 한영호;송윤준;김형진;정영혁
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.90-93
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    • 2002
  • Assuring required dimensional tolerance after spingback becomes the main concern of sheet-forming die designers when formability is secured through previous tryout. As a part to build a guideline to control springback in automobile frame forming, experiments are carried out to show the effects of process parameters, such as holding force, blank size, and lubrication, on corner angles of channels formed by U-bending or by square-cup drawing and trimming. The results are resented in the viewpoint of evaluating parameters.

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Development of Manufacturing Technology for Center Floor Cross Member with Roll Forming Process (롤 포밍 공법을 이용한 고강도 차체 부품 제작 기술 개발)

  • Kim, D.K.;Park, S.E.;Cho, K.R.;Lee, K.H.;Kim, K.H.;Lee, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.297-300
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    • 2009
  • The roll forming process is often used to manufacture long, thin-walled products such as a pipe. The final cross-section is a comparatively simple open-channel, a closed tube section or a complex profile with several bends. In recent years, that process is often applied to the bumper beam in the automotive industries. In this study, a optimal Center Floor Cross Member manufacturing technology, model deign and proper roll-pass sequences can be suggested by forming number of roll-pass and bending angle, and also effects of the process parameters on the final shape formed by roll forming defects were evaluated.

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