• Korean Journal of Crystallography
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• v.4 no.2
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• pp.100-104
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• 1993

Reduced glutathione (GSH) plays a vital role in the metabolism of all cells. Glutathions, a tripeptide cowfosed of glutamic acid, cysteane, and gtycina is synthesized by two synthesized reutions. The first is catalyzed by Y-glutamylcysteine synthetase (GSH-I) and the second by glutathione synthetase (GSH-ll). The glutathione biosynthetic pathway of E. coziis mainly controlled by nonallosteric feedback inhibition of GHS-I by GSH. Determination of the three-dimensional structure of GSH-I by X-ray crystallography is necessary in order to understand the structure-function relationship at the molecular level. As the (irst step toward its structure determination, crystallization of 5. coli V-glutamylcystfine synthetase (GSH-I) has been achived using the hanging drop vapor diffusion method and capillaw method. Crystals of GSH-I have been grown from ammonium sulfate solution. The crystals grew at room temperature within 10 days to dimensions of 0.2 m x 0.2 m x 0.2 ml by hanging drop vapor diffusion method and diffracted to about 4 A resolution using synchrotron X-rays. Another crystal, grown by the capillary method to dimensions of 0.25 mm x 0.25 mm x 0.3 mm within 40 days, diffracted to about 4 A resolution using X-rays from a rotating anode.

• Journal of Agricultural Extension & Community Development
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• v.24 no.2
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• pp.99-115
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• 2017

The purpose of this study is to analyze potential adoption rates and reusing patterns of the new rice direct seeding technology. The model constructed and employed in this study is a system dynamics model of farmer adoption and reusing patterns for this new technology over time. The model incorporates a causal loop diagram that explains interactions among rice cultivation subsystems with feedback loops and further attempts to build a causal loop model with stock-flow diagram for computer simulation. As one example of how the model can be used to provide insight to rice farmers, simulations are run over varying levels on the cultivation process of rice. The major finding is to demonstrate the utility of system dynamics simulation methodology in aiding the rice wet direct seeding farmers' decision making.

• Journal of Korea Game Society
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• v.15 no.4
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• pp.145-156
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• 2015

Existing researches have been limited to one-dimensional analysis of game experience (enjoyment, addictive user, usability). However, we considered to analyze complex sentiments of mobile game users due to diffusion of multitasking in these days. In this study, We focused on 'collective sentiments' of mobile game users and studied 'connected emotions and mental model' of them. To support theoretical assumption, we analyzed social data which reflect intention and unintended behavior of users. As a result, multiple consumption of service, diversified patterns of information recommendation and quest experience based on networking were critical to mobile game UX.

• Journal of The Korean Astronomical Society
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• v.36 no.3
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• pp.111-121
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• 2003

In order to explore the cosmic ray acceleration at the cosmological shocks, we have performed numerical simulations of one-dimensional, plane-parallel, cosmic ray (CR) modified shocks with the newly developed CRASH (Cosmic Ray Amr SHock) numerical code. Based on the hypothesis that strong Alfven waves are self-generated by streaming CRs, the Bohm diffusion model for CRs is adopted. The code includes a plasma-physics-based 'injection' model that transfers a small proportion of the thermal proton flux through the shock into low energy CRs for acceleration there. We found that, for strong accretion shocks with Mach numbers greater than 10, CRs can absorb most of shock kinetic energy and the accretion shock speed is reduced up to $20\%$, compared to pure gas dynamic shocks. Although the amount of kinetic energy passed through accretion shocks is small, since they propagate into the low density intergalactic medium, they might possibly provide acceleration sites for ultra-high energy cosmic rays of $E\ll10^{18}eV$. For internal/merger shocks with Mach numbers less than 3, however, the energy transfer to CRs is only about $10-20\%$ and so nonlinear feedback due to the CR pressure is insignificant. Considering that intracluster medium (ICM) can be shocked repeatedly, however, the CRs generated by these weak shocks could be sufficient to explain the observed non-thermal signatures from clusters of galaxies.

• Journal of Navigation and Port Research
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• v.33 no.3
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• pp.167-174
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• 2009

Recently, design technology of has been required such as catamaran yacht with high-speed according to expand a marine leisure industry. The domestic technical development for design and production of yacht is not actively than Canada, USA, Japan etc. However, with further development of yacht design & technology, it is need to develop a key technology related to increase the value of catamaran yacht. In the present paper, new guideline is suggest for catamaran yacht as like kinds of marine leisure ship in order for fundamental structure design and structural analysis for twin-hulled ship yacht and techniques for structural analysis as sea leisure ship in this research. The class of society has not been proposed formally about regulation and methodology for estimation of strength of small hight-speed craft with satisfying two conditions as noted; length less than 50meters, ratio of length to breadth less than 12. In the present study, we were adopted DNV (Yachts, Design Principles, Design Loads, Hull Structural Design) Rule and KR (FRP rule application guide) for scantling of structural members. Furthermore, ABS rule is used for structural calculation about application of loading conditions for catamaran yacht. This study can be available feedback role to manufacture of 38ft diffusion style for catamaran yacht. It is expected that this study will be a good reference in order to design of catamaran yacht with high-speed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.18-29
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• 2015

The purposes of this research and development are as follows: first, to provide pleasant driving environments inside tunnels; second, to improve the current illumination environments lacking in diffusion luminance meters to meet tunnel lighting standards; and, third, to reduce the consumption of tunnel lighting energy accounting for approximately 65% of tunnel maintenance costs because of inadequate visual environments and tunnel operations. Further details are listed below. Firstly, an image luminance meter for tunnels that can implement the L20-method which is a tunnel luminance method that follows the international standards of CIE88, which was developed in order to improve and change the existing illumination-based tunnel lighting operation system to a luminance-based system. (The margin of error of below 5% according to the results of a test by an authorized agency and field test). Secondly, early illumination control is possible since the lighting control system that can be operated based on luminance enables interlocking control of the inside and outside of a tunnel using ethernet communication. Thirdly, guidelines for field application of the system are proposed. In addition, the luminance inducers of tunnels are found and the reflexibility of each facility that may reduce luminance of the boundaries is also proposed. Fourthly, as a result of a test bed, power consumption of luminance-based lighting operations decreased by 15.6% compared to illumination-based operations. Applying the feedback controls and maintenance factors of internal/external luminance meters, it reduced by 36.4%. Therefore, we became able to provide a luminance-based lighting operation system that complies with tunnel lighting design standards and provides a visual environment for drivers.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.1
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• pp.5-19
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• 2015

Literatures on open innovation have two major limitations. First, either on a firm level or on an industry level did they analyze the open innovation issues. The results of a firm's innovation can be diffused through the whole network and the firm can learn back from the network knowledge. Prior literatures did not consider the feedback loop among firms and network in which the firms are involved. Second, most open innovation research had a static perspective on firm's innovation performance. Since the diffusion, spill-over and learning among network members are involved over time, the open innovation is intrinsically dynamic. From the dynamic perspective, we can appreciate the fundamental attributes of the open innovation network which involves diverse firms, research institutes, and universities. In order to overcome the limitations, we suggest a dynamic model for open innovation network. We build an agent-based model which consists of heterogeneous firms. The firms are connected through a scale-free network which is formed by preferential attachment. Through the diverse scenario of simulation, we collect massive data on the firm level and analyze them both on firm and industry level. From the analysis, we found that, on industry level, the overall performance of open innovation increases as the internal research capability, absorptive capacity, and learning curve coefficient increase. Noticeably, as the deprecation rate of knowledge increases, the variability of knowledge increases. From the firm level analysis, we found that the industry-level variables had a significant effect on the firm's innovation performance lasting through all the time, whereas the firm-level variables had only on the early phase of innovation.

• The Journal of Korean Medicine
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• v.37 no.3
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• pp.97-111
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• 2016

Objectives: This study aims to investigate the policy status of traditional medicine standardization between Korea and China as well as to derive a strategic development plan for Korean medicine standardization. Methods: The existing national plans and preceding studies on traditional medicine standardization in Korea and China were reviewed, and scope of the study was categorized as having three main aspects: infrastructure; standard development and standardization activities; and application and diffusion. Results: Nine development plans for Korean medicine standardization derived under the study were as follows: With regard to infrastructure of standardization, 1) standardization plan of Korean medicine shall be established based on involvement of multi-government ministries. 2) It shall be set with a consistent cooperation process among standardization-related organizations, as well as 3) encourage the industry to participate in standardization activities. To activate standards development, 4) launching the R&D-standardization-industrialization linked project, 5) supporting Korean medicine society and the mirror committee for motivation, and 6) planning the international joint research for development of standard and expanding standardization activities are recommended. In the aspect of application, there is a need for 7) expanding certification systems for the industry and 8) evaluation and feedback on the life-cycle of standardization. Lastly, 9) educational programs for training experts of standardization shall be developed and implemented. Conclusions: In order to invigorate standardization activities for Korean medicine, enhancement of planning and evaluation capacity, ensuring the strategic development of standards, broadening boundaries of international standardization activities, and training professionals are required.

• Journal of The Korean Astronomical Society
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• v.45 no.5
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• pp.127-138
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• 2012

We explore how wave-particle interactions affect diffusive shock acceleration (DSA) at astrophysical shocks by performing time-dependent kinetic simulations, in which phenomenological models for magnetic field amplification (MFA), Alfv$\acute{e}$nic drift, thermal leakage injection, Bohm-like diffusion, and a free escape boundary are implemented. If the injection fraction of cosmic-ray (CR) particles is ${\xi}$ > $2{\times}10^{-4}$, for the shock parameters relevant for young supernova remnants, DSA is efficient enough to develop a significant shock precursor due to CR feedback, and magnetic field can be amplified up to a factor of 20 via CR streaming instability in the upstream region. If scattering centers drift with Alfv$\acute{e}$n speed in the amplified magnetic field, the CR energy spectrum can be steepened significantly and the acceleration efficiency is reduced. Nonlinear DSA with self-consistent MFA and Alfv$\acute{e}$nic drift predicts that the postshock CR pressure saturates roughly at ~10 % of the shock ram pressure for strong shocks with a sonic Mach number ranging $20{\leq}M_s{\leq}100$. Since the amplified magnetic field follows the flow modification in the precursor, the low energy end of the particle spectrum is softened much more than the high energy end. As a result, the concave curvature in the energy spectra does not disappear entirely even with the help of Alfv$\acute{e}$nic drift. For shocks with a moderate Alfv$\acute{e}$n Mach number ($M_A$ < 10), the accelerated CR spectrum can become as steep as $E^{-2.1}$ - $E^{-2.3}$, which is more consistent with the observed CR spectrum and gamma-ray photon spectrum of several young supernova remnants.

• Journal of Yeungnam Medical Science
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• v.17 no.2
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• pp.108-122
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• 2000

Background: Models of attention deficit hyperactivity disorder(ADHD) that have proposed a hypodopaminergic state resulting in hypofunction of the prefrontal circuitry have assumed a unitary dopamine system, which largely ignores the distinct functional differences between mesocortical dopamine system and nigrostriatal dopamine system. Purpose: The author's goal was to develop a pathophysiological model for ADHD with greater explanotory power than dopaminergic hypofunction hypothesis in prefronal circuitry. Material and Methods: Published clinical findings on ADHD were integrated with data from genetic, pharmacological, neuroimaging studies in human and animals. Results: Molecular genetic studies suggest that three genes may increase the susceptibility to ADHD. The three candidate genes associated with ADHD are each involved in dopaminergic function, and this consistent with the neurobiologic studies implicating catecholamines in the etiology of ADHD. Pharmacological data also provide compelling support for dopamine and noradrenergic hypothesis of ADHD. Neuroimaging studies lend substantial support for the hypothesis that right-sided abnormalities of prefrontal-basal ganglia circuit would be found in ADHD. Conclusions: The present hypothesis takes advantage of the major differences between the two pertinent dopamine systems. Mesocortical dopamine system, which largely lacks inhibitory autoreceptors, is ideally positioned to regulate cortical inputs, thus improving the signal-to-noise ratio for biologically valued signals. In this circuit, therapeutic doses of stimulants are hypothesized to increase postsynaptic dopamine effects and enhance executive functions. By contrast, symptoms of hyperactivity/impulsivity in ADHD are hypothesized to be associated with relative overactivity of nigrostriatal circuit. This nigrostriatal circuit is tightly regulated by inhibitory autoreceptoors as well as by long distance feedback from the cortex, and slow diffusion of therapeutic doses of stimulant via oral administration is hypothesized to produce a net inhibition of dopaminergic neurotransmission and improves hyperactivity.