• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1869-1882
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• 1998

In this paper, we investigae convergence behaviors of a differential method for 2-D motion parameter estimation. While the differential method is widely studied for motion compensated prediction in video coding, little attention hs been paid to its convergence properties. Based on the nonseparable exponential covariance image model, we derive the estimates of update terms for the 2- and 6-parameter motion models. And, the effect of noise, spatial correlation, choice of spatial gradient measures, andthe size of a region, are quantitatively anlyzed in relation to the convergence speed. Some empirical results are presented to verify the analysis.

• Nuclear Engineering and Technology
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• v.31 no.1
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• pp.29-48
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• 1999

Local two-phase flow parameters of subcooled flow boiling in inclined annulus were measured to investigate the effect of inclination on the internal flow structure. Two-conductivity probe technique was applied to measure local gas phasic parameters, including void fraction, vapor bubble frequency, chord length, vapor bubble velocity and interfacial area concentration. Local liquid velocity was measured by Pilot tube. Experiments were conducted for three angles of inclination; 0$^{\circ}$(vertical), 30$^{\circ}$, 60$^{\circ}$. The system pressure was maintained at atmospheric pressure. The range of average void fraction was up to 10% and the average liquid superficial velocities were less than 1.3 m/sec. The results of experiments showed that the distributions of two-phase How parameters were influenced by the angle of channel inclination. Especially, the void fraction and chord length distributions were strongly affected by the increase of inclination angle, and flow pattern transition to slug flow was observed depending on the How conditions. The profiles of vapor velocity, liquid velocity and interfacial area concentration were found to be affected by the non-symmetric bubble size distribution in inclined channel. Using the measured distributions of local phasic parameters, an analysis for predicting average void fraction was performed based on the drift flux model and flowing volumetric concentration. And it was demonstrated that the average void fraction can be more appropriately presented in terms of flowing volumetric concentration.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.257-262
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• 2014

Risk information may be one of the most important factor for worker's safe behavior because that safe behavior can be oriented by attitude based on risk information. Traditionally KAP(knowledge, attitude and practice) model was useful frame for the change of human behavior. Knowledge is formed by information through experience and education. Worker's health may be prevented by his or her own active safe behavior based on risk information. This paper is to investigate the effect of labor union on the provirion of risk information by labor union. Data for analysis is the third Korean Working Conditions Survey done by Occupational Safety and Health Research Institute in 2011. The sample size is 50,032 economic active person surveyed by household interview survey with structure questionnaire by trained interviewer. The difference of risk information provision among employees was tested by mean difference test. The level of risk information of employees of companies with labor union is higher than that with non labour union. This paper has some implication for the promotion of safe behavior of employees through risk information provision mediated by labor union. Some limitation of this study may be considered because of using the cross sectional survey data.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.128-138
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• 2008

VE of the scripture season enterprises and it respected LCC analyzes from the research which it sees and to use AHP techniques and definite LCC techniques and probabilistic LCC techniques selects the optimum route the case study which it executed. It presented the quality rating model in about the resultant most route lascivious at the time of VE evaluation, in order to select the alternative of optimum AHP techniques which are one in decision-making technique and an evaluation item by weight and a grade it applied the mountaintop it did. Also the definite LCC analyzer law departments of existing together it applied the probabilistic LCC techniques which use Monte Carlo Simulation in about analytical prices and reliability height boil. The economical efficiency was excellent with VE/LCC analytical resultant route and facility size abridgment, the rivers most it will be able to minimize an environmental effect with short distance traverse, the selection this hit preparation LCC which separates from the land use side decreased, the value (V) above 22.0% with the fact that it improves. And, the reliability of the probabilistic LCC analytical resultant analytical results in compliance with Monte Carlo Simulation with 90.3% was very analyzed with the fact that it is a high level.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.375-380
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• 2014

To enhance biocompatibility between the orthopedic implant stem and obsteoblast cells, bone-forming cells, micro-size holes are patterned in Ti plate surface. Initially, the house built laser power stabilization system is applied to the laser micro patterning machine to convince repeatable result. Various pulse widths are irradiated Ti plate and relationship between diameters of patterned holes and pulsed width is derived. Effect of multi pulse is observed and optimal pulse number is considered to avoid heat affected zone. After MG-63 osbeoblast cells are cultured, micro patterned Ti plates are compared with control plates. In SEM image, cells are well aligned and aggregation is observed in both 60, and $100{\mu}m$ patterned plates. Finally, free form surface stem model is prepared to test micro hole patterning.

• Journal of Magnetics
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• v.16 no.2
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• pp.157-160
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• 2011

The magnetostrictive material is magnetized in magnetic field and produces a nonuniform demagnetizing field inside and outside it. The demagnetization is decided by the permeability of magnetostrictive material and its size. The magnetoelectric performances are determined by the synthesis of the applied and demagnetizing fields. An analytical model is proposed to predict the magnetoelectric voltage coefficient (MEVC) of magnetostrictive/piezoelectric laminate composite using equivalent circuit method, in which the nonuniform demagnetizing field is taken into account. The theoretical and experimental results indicate that the MEVC is positively connected with the permeability and the piezomagnetic coefficient of magnetostrictive material. To obtain the maximum MEVC, both the permeability and the piezomagnetic coefficient of magnetostrictive material should be taken into account in selecting the suitable magnetostrictive material.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1603-1605
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• 1994

Recently, Gas Circuit Breakers are rapidly replacing Vacuum Circuit Breakers in the medium voltage switchgear. This is due to the improved performance of - GCB in interrupting capability, price, weight, size etc., while the countermeasure to suppress the switching surges of VCB has not been satisfactory. Intensive research works on the GCB have been conducted in the world widely since 1980. Nowadays it is well known that the thermal expansion type GCB can provide- better performance than puffer type in the distribution power system. KERI has conducted researches in the GCB rated at 25.8kV 25kA with Jinkwang Co. using the thermal expantion principle since 1993. In this paper, the calculated results of electric and magnetic fields for the model GCB are presented and analyzed. The effect of permanent magnet used to improve the interruption capabilty at the low current level is also investigated. The design parameters for the interrupter inspected through the short-circuit tests conducted at high power laboratory of KERI.

• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.123-129
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• 1998

A numerical study has been conducted to investigate the effect of shock waves on the mixing and the recirculation zone of a hydrogen jet diffusion flame in a supersonic combustor. The general trends are compared with the experimental results obtained from the supersonic combustor at the University of Michigan. For the numerical simulation of supersonic diffusion flames, multi-species Navier-Stokes equations and detailed chemistry reaction equations of $H_2$-Air are considered. The $K-{\omega}/k-{\varepsilon}$ blended two equation turbulent model is used. Roe's FDS method and MUSCL method are used for convection fluxes in governing equations. Numerical results show that when slender wedges are mounted at the combustor wall the mixing and the combustion are enhanced and the size of recirculation zone is increased . The flame shape of supersonic flames is different in the flame-tip; it is not closed but open. The flame shape is shown to be greatly affected by shock waves.

• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.91-105
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• 2008

Nowadays, circulation industry is taking charge of important role in improvement of competitive power on the manufacturing industry and public welfare increase of consumer, price stabilization, employment creation and so on. A lot of research have been progressing for formation of total circulation complex, but decision making for selection of location on some facility is only calculated the optimum value when correct data values are inserted. However, a lot of decision making is accomplished in situation that have little knowledge of objective and constraints and as real world is also evaluated inclusive of analyst's subjectivity about variable, indefinite and fuzzy part, so it is decreasing a reliability on evaluation result and complicating objective evaluation on various effect and negative impact. Accordingly, from under like this situation, this study is to develop location decision model of circulation complex using fuzzy theory from the intention for the most reasonable decision making in fuzzy situation based on decision making problem on conventional location and size decision that did to be satisfactory constraints necessarily.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.2
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• pp.246-256
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• 2011

Purpose: With the decrease in available clinical sites, a decrease in adequately prepared clinical faculty, and demand to prepare health care students to begin work, we need alternative methods to teach clinical skills for health care professionals. The use of simulation as an educational process that can replicate clinical practices is becoming popular in nursing. Therefore, this study was conducted to review directions of simulation-based learning in nursing education. Methods: A systematic review of quantitative studies was undertaken using Medline, KERIS, and KISS. The primary search terms were simulation and nursing. Reference lists from relevant papers and the websites of relevant nursing organizations were also searched. Nine studies met inclusion criteria and were analyzed in detail. Results: All studies reported simulation as a valid teaching/learning strategy. Six of the studies (66.7%) showed that simulation technology was a practical and successful model to use in teaching a variety of clinical skills for nursing students and nurses. Conclusion: Simulation may have some advantages over other teaching methods, depending on the scenario, context, topic, and method. Further study is needed to determine the effect of team size on learning and to develop a universal method of outcome measurement.