• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.192-198
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• 1996

We present a theoretical formulation of diffusion process on solid surface based on multidimensional transition state theory (TST). Surface diffusion of single adatom results from hopping processes on corrugated potential surface and is affected by surface vibrations of surface atoms. The rate of rare events such as hopping between lattice sites can be calculated by transition state theory. In order to include the interactions of the adatom with surface vibrations, it is assumed that the coordinates of adatom are coupled to the bath of harmonic oscillators whose frequencies are those of surface phonon modes. When nearest neighbor surface atoms are considered, we can construct Hamiltonians which contain terms for interactions of adatom with surface vibrations for the well minimum and the saddle point configurations, respectively. The escape rate constants, thus the surface diffusion parameters, are obtained by normal mode analysis of the force constant matrix based on the Hamiltonian. The analysis is applied to the diffusion coefficients of W, Ir, Pt and Ta atoms on the bcc(110) plane of W in the zero-coverage limit. The results of the calculations are encouraging considering the limitations of the model considered in the study.

• Biodesign
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• v.6 no.4
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• pp.92-95
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• 2018

API5 is a unique oncogenic, non-BIR type IAP nuclear protein and is up-regulated in several cancers. It exerts several functions, such as apoptosis inhibition, cell cycle progression, cancer immune escape, and anticancer drug resistance. Although structural studies of API have revealed that API5 mediates protein-protein interactions, its detailed molecular functions remain unknown. Since FGF2 is one of API5's major interacting proteins, structural studies of the API5-FGF2 complex will provide insight into both proteins' molecular function. We overexpressed and purified API5 and FGF2 in Escherichia coli and crystallized the API-FGF2 complex using polyethylene glycol (PEG) 6000 as a precipitant. Diffraction data were collected to a $2.7{\AA}$ resolution using synchrotron X-rays. Preliminary diffraction analysis revealed that the API5-FGF2 complex crystal belongs to the space group $P2_12_12_1$ with the following unit cell parameters: a = 46.862, b = 76.523, $c=208.161{\AA}$. One asymmetric unit with 49.9% solvent contains one API5-FGF2 complex. Molecular replacement calculation, using API5 and FGF2 coordinates, provided a clear electron density map for an API5-FGF2 complex.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.21-29
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• 2020

In this paper, we propose quantitative evaluation method that enable security comparison between Security Container Runtimes. security container runtime technologies have been developed to address security issues such as Container escape caused by containers sharing the host kernel. However, most literature provides only a analysis of the security of container technologies using rough metrics such as the number of available system calls, making it difficult to compare the secureness of container runtimes quantitatively. While the proposed model uses a new method of combining the degree of exposure of host system calls with various external vulnerability metrics. With the proposed technique, we measure and compare the security of runC (Docker default Runtime) and two representative Security Container Runtimes, gVisor, and Kata container.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.470-475
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• 2017

Since the intake air of gas turbine engine of marine purpose contains water particles, inertial separator for separating the air and water particles are provided. Saw type and wave type separator are now used to separate inflow water particle from the gas. In this paper, the design parameters of saw type separator are studied by numerical simulations. Using the commercial CFD program, Star-CCM+, Lagrangian-Eulerian method was used to perform the analysis of two phase flow of the mist in the air. This method solves Reynolds-Averaged Navier-Stokes equations in Eulerian framework for the continuous phase, while solves equation of motion for individual particles in Lagrangian framework. Lagrangian multiphase method was applied to monitor the particles of different sizes and shapes and to verify collision between particles by chasing particles. Water particles were injected through injectors located at the inlet of the separator and escape mode was used which assumes that the particles attached on the surface of inertial separator were removed from the simulation, effectively escaping the solution domain. Through the numerical computations with the inlet condition of constant water particle size in the wetness fraction of 85%, efficiency of eliminating the water particle and the pressure drop between the inlet and outlet were examined.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.6
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• pp.79-91
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• 1998

Design principles for high-brightness ligh-temitting diodes have been derived by using escape cone concepts. Based on the design principles, some important high-brightness LED structures developed thus far have been reviewed and, in addition, their external coupling efficiencies have also been estimated. In AlGaAs or InGaAIP LEDs, in which photon absorption in the ohmic electrodes is known to be serious, photon shielding by the electrodes is minimized by using window layer (WL) as well as transparent substrate (TS) leading to significantly improved light-emitting efficiency. However, in InGaN LEDs emitting blue to green lights, the photon absorption in ohmic contact to wide bandgap GaN may be negligible and therefore, photon shielding by the electrodes would not lead to as significant problems as in conventional In AIGaAs or InGaAIP LEDs.

• Progress in Medical Physics
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• v.4 no.2
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• pp.49-58
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• 1993

The complex glow curves were split into isolated glow curves to be calculated the values of kinetic order, activation energy, escape frequency and density of initial trap from the independent glow curves using the mathematical method of thermally stimulated processes. The minimization of the intensity difference between measured and theoretical glow curve was done by the nonlinear least-square program. The results of the fitted curves were almost equal to the actual values of the parameters. Thermoluminescence from gamma ray irradiated ${\alpha}$-Al$_2$ $O_3$ over the range of 300K to 600K was split into six glow curves. The kinetic order, activation energy and escape frequency of first glow curve were obtained as 1, 1.12eV and 6.79X10$\^$12/sec$\^$-1/, respectively, which were similar to the results of other method. Also the parameters of the second and the third glow curve and so forth were calculated.

• Fire Science and Engineering
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• v.27 no.4
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• pp.35-40
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• 2013

This study investigated the evacuation characteristics of student of elementary school with single unit fireproof shutter. In particular, we gathered the data about fireproof shutter and checked the data. And we made comparison and did an analysis of the evacuation characteristics of elementary school student according to working of single unit fireproof shutter for fires. As a result, it took the last occupant 130 seconds to escape from the school with no fire shutter case. But it took time 190 seconds to escape when the single unit fireproof shutter worked. Some of elementary school students could not open the door installed on the shutter when the single unit fireproof shutter worked. Considering this circumstance, it can be led to time delays of escaping when the single unit fireproof shutter work. And many students can be exposed to the fire hazards. Therefore, the study on the power to open the door installed on the shutter must be done in the future.

• Journal of the Korea Institute of Building Construction
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• v.4 no.1
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• pp.97-103
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• 2004

In case of a fire in road or railway tunnel it is always necessary to keep the escape condition as good as possible. Most of the victims of major fires in tunnels are because they couldn't leave the tunnel in time and were trapped by smoke, or rescue teams couldn't reach the place of the accident due to low visibility and high temperature. In spring 2003 a comprehensive field experiment was undertaken in a large scaled tunnel in Youngin City to test the effectiveness of a new water spray curtain system, designed to the air qualify inside of a tunnel in case of fire during passenger's escape to safe routes, In order to control the smoke propagation, fixed water sprayed nozzles were used to make water curtain system, which can be installed or hanging water piping line below ceiling. The experiment was accompanied by an extensive measurement campaign in order to measure temperature dropping effect and flow conditions as well as CO concentration for various water sprayed curtains produced by sprinkler heads or water spray nozzle. Eventually comparison analysis were undertaken to investigate the performance of water curtains under fixed water pressure. Therefore most effective water curtain system was presented on the basis of water droplet size in long tunnel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4167-4173
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• 2010

ICT education guidelines revised in 2005 reinforce computer science elements such as algorithm, data structure, and programming covering all schools. It means that goal of computer education is improving problem-solving abilities not using of commercial software. So this paper suggests problem-solving method of maze escape through robots' cooperation in an effort of learning these elements. Problems robots should solve are first-search and role-exchange. First-search problem is that first robot searches maze and send informations about maze to the second robot in real time. Role-exchange problem is that first robot searches maze, but loses its function at any point. At this time second robot takes a role of first robot and performs first robot's missions to the end. To solve these two problems, it goes through four steps; problem analysis, algorithm description, flowchart and programming. Additional effects of our suggestion are chance of cooperation among students and use of queue in data structure. Further researches are use of more generalized mazes, application to real field and a talented curriculum.

• Psychiatry investigation
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• v.15 no.11
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• pp.1019-1029
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• 2018

Objective We investigated how mental health awareness among North Korean refugees transformed depending on temporal-spatial context changes. Methods In 2013, we conducted interviews with 10 refugees (eight women) who had been in South Korea for over a year and performed a qualitative analysis of the change in mental health awareness in the differences between living in North Korea, escape (a related period of forced sojourn in a third country), and settlement in South Korea. Results We classified 39 concepts into five main categories. The first two categories (while living in North Korea) were "a mindset for the system, but not for individual mental health" and "being confined in a social environment that was indifferent to mental health." A third category appeared during escape: "focusing on survival amid continuity of intense suffering." The final two categories appeared when settling in South Korea: "recognition of mental health amid cultural shock" and "introspection and sorting oneself out." Conclusion This qualitative study enabled a better multi-dimensional understanding of the social and cultural aspects involved in improving mental health awareness among North Korean refugees in South Korea. It is desirable to integrate mental health as a part of daily life and to expand training for North Korean settlers.