• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2879-2884
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• 2007

Dynamic responses of electrorheological (ER) fluids in steady pressure flow to stepwise electric field excitations are investigated experimentally. The transient periods under various applied electric fields and flow velocities were determined from the pressure behavior of the ER fluid in the flow channel with two parallel-plate electrodes. The pressure response times were exponentially decreased with the increase of the flow velocity, but increased with the increase of the applied electric field strength. In order to investigate the cluster structure formation of the ER particles, it was verified using the flow visualization technique that the transient response of ER fluids in the flow mode is assigned to the densification process in the competition of the electric field-induced particle attractive interaction forces and the hydrodynamic forces, unlike that in the shear mode determined by the aggregation process.

• Journal of Korean Society of Transportation
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• v.14 no.1
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• pp.81-99
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• 1996

This study aims to assess the potential competition among road, rail, and coastal transport under various scenarios concerning the future inland container transport systems in Pusan-KyungIn corridor. For this SP approaches are adopted to collect data from shippers and carriers, and multinomial logit models are estimated at disaggragate level. The results of the analysis indicate that the SP data are reliable, and that the mode choice models estimated are valid. The results also indicate that the most effective policy to divert the freight volume from road to other modes is to reduce freight rates for the railway, and is to transport time for the coastal water with improved reliability.

• Korean Journal of Optics and Photonics
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• v.24 no.4
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• pp.168-175
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• 2013

An information display device is a key component in the information society. A liquid crystal display is the most widely used among information display devices. However, its performance still needs to be improved in order to survive in competition with other information display devices. In this paper, we explain the structure and the operation principle of a liquid crystal display device and introduce our recent research activities on liquid crystal mode technology.

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.246-254
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• 2010

This paper presents a multiagent system for microgrid operation in the grid-interconnected mode. An energy market environment with generation competition is adopted for microgrid operation in order to guarantee autonomous participation and meet the requirements of participants in the microgrid. The modified Contract Net Protocol (CNP) is used as a protocol for interactions among agents. The multiagent system for microgrid operation based on the modified CNP and the energy market environment is designed and implemented. To verify the feasibility of the suggested multiagent system, experiments on three operation conditions are carried out.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.138-138
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• 2000

Kinetic behaviors of homoepitaxial growth on Ni(110) surface was studied at the growth-temperature ranges 290~380 K with scanning tunneling microscopy. At low temperature (~290 K), deposited Ni grows layer-by-layer mode in the first several layers with one-dimensional islands but eventually (at > monolayers) forms three-dimensional islands througy the kinetic shortening of the average length of one-dimensional islands. At the intermediat temperature (~340 K), the three-dimensional islands were observed to be I) regular mesa-like structure with high aspect ratio (~1:10) at ~15 monolayer, ii) hut-like structure with low aspect ratio (~1:1.5) at ~35 monolayer, and iii) rounded mound structure at ~55 monolayers, due to the competition of kinetic and energetic terms. At the high temperature (~ 380 K), the flat surface with layer-by-layer mode was observed up to 50 monolayers. Microscopic orgins for the observations will be discussed on the basis of kinetic Monte Carlo simulations.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.104.1-104
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• 2003

To screen for potential biocontrol agents against postharvest disease of garlics caused by Penicillium hirsutum, a total of 933 isolates (432 fungi and 501 bacteria) were isolated from the rhizoshere or rhizoplane of garlics. Among them, Pantoea agglomerans isolate 59-4 (Pa 59-4) was selected for a potential biocontrol agent by in vivo wounded garlic bulb assay, When the spore suspension (10$\^$5/ spores/$m\ell$) of Penicillium hirsutum was co-inoculated with spore or cell suspension of each fungal or bacterial isolate on wounded garlics, the isolate highly suppressed disease development. Soaking garlic bulbs in the suspension of Pa 59-4 significantly reduced garlic decay from p. hirsutum. However, Pa 59-4 did not inhibit the mycelial growth of P. hirsutum in dual-culture with P. hirsutum on Tryptic soy agar. In order to elucidate mode of action of Pa 59-4 nutrient competition between Pa 59-4 and P. hirsutum was investigated using tissue culture plates with cylinder inserts containing defusing membrane reported by Janisiewicz et al. The results showed that Pa 59-4 effectively suppressed spore germination and mycelial growth of blue mold in the low concentration (0.5％) of garlic juice, but did not suppress those of blue mold in the higher concentration (5％) of garlic juice. This result suggests that the mechanism in biocontrol of garlic blue mold by Pa 59-4 may involve in nutrient competition with P. hirsutum on garlic bulbs.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.365-371
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• 2017

IEEE 802.11 Wireless Local Area Network (WLAN) adopts Power Saving Mode(PSM) to save the power. Unlike existing PSM, this paper proposes a new scheme for the power saving of the Mobile Host(MH) when a MH performs the data transmission after the competition-based DCF(Distributed Coordination Function) and competition free-based PCF(Point Coordination Function). In this paper, The proposed scheme estimates the distance between the MH with the authority of data transmission and the Access Point(AP) and then adaptively controls the power of the MH considering the distance. Through the simulation result, we find that the proposed scheme consumes the smaller transmission power and has the similar success rate of packet transmission when it is compared to the existing scheme which uses the same power without the consideration of the distance.

• Journal of Technology Innovation
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• v.11 no.1
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• pp.177-193
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• 2003

This paper examines empirically if the increase of funding uncertainty in government supported R&D institutes(GSRIs) in Korean cause managers to use more effective management control practices. Recently government introduced a new government R&D budget management system, based on competition, named PBS(Project Base System). Government requires GSRIs to be self-supporting and compete for funding from government. The introduction of new budget management system named PBS, has resulted in the increase of funding uncertainty in GSRIs. According to institutional theory, government organizations gain legitimacy by conforming to external expectations regarding management control practices, In contrast, contingency theory proposes that management control practices are driven by the fit between the technical features of the environment and the management control practices. The contingency literature provides that one external factor expected to motivate government managers to use more efficient control practices is the presence of competition and funding uncertainty. This paper use both theoretical perspective to develop hypotheses and examine the influence of funding environment on management control practices. Results show that the more institutionalized environment, the more managers in GSRIs rely on bureaucratic mode of control for conforming to external requirements, and the greater the funding uncertainty, the more managers use results and personal modes of control to improve research team performance.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1706-1714
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• 2016

In the 21th century, with the development of the economic global progress, the competition is more stiff. During the fierce competition, 85% of the world's trade volume is root from the sea transportation, that means the harbor trade is becoming an important part in the world's trade. With the strong support of the Chinese national ministries, Tianjin Dongjiang Bonded Port Area had made a series of encouraging results and now becoming a positive mode of the chinese harbor trade port. In the meanwhile, the Dongjiang Bonded Port Area is also searching for the change and a better development. From this year, the Dongjiang Bonded Port Area is apply for the experimental unit to change from the Bonded Port Area to the Free Trade Zone. This paper focus on the Tianjin Dongjiang Bonded Port Area which is the largest port area in the northern part of China. The development progress of the Dongjiang Bonded Port Area is concerned and studied in the paper. This paper expected to research on the transformation progress from the Bonded Port Area to the Free Trade Zone, to find out appropriate ways for the blossom of the harbor trade and the bonded area.

• Wind and Structures
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• v.26 no.5
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• pp.267-277
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• 2018

Numerical simulations are performed of a long flexible cylinder undergoing vortex-induced vibration at a Reynolds number of 500. The cylinder is pinned at both ends, having an aspect ratio of 100 (cylinder length to cylinder diameter) and a mass ratio of 4.2 (structural mass to displaced fluid mass). Temporal and spatial information on the cross-flow (CF) and in-line (IL) vibrations is extracted. High modal vibrations up to the $6^{th}$ in the CF direction and the $11^{th}$ in the IL direction are observed. Both the CF and IL vibrations feature a multi-mode mixed pattern. Mode competition is observed. The $2^{nd}$ mode with a low frequency dominates the IL vibration and its existence is attributed to a wave group propagating back and forth along the span. Distributions of fluid force coefficients are correlated to those of the CF and IL vibrations along the span. Histograms of the x'-y motion phase difference are evaluated from the total simulation time and a complete vibration cycle representing the standing or travelling wave pattern. Correlations between the phase difference and the vibrations are discussed. Vortex structures behind the cylinder show an interwoven near-wake pattern when the standing wave pattern dominates, but an oblique near-wake pattern when the travelling wave pattern prevails.