• Journal of Digital Convergence
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• v.11 no.1
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• pp.339-347
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• 2013

Recently, Korean medium-sized medical organizations require innovative strategies. Network-driven concerns in Korean medical organization have been a front burner issue to enhance economic and managerial efficiencies. Effective network-driven collaboration depends upon effective processes and economics strategies among medical providers group. From this motivation, we studied and provided the systems' theoretical background and networked hospital system structures. The aim of suggested research model in this paper is to overcome demerit of stand-alone medium-sized hospitals and analyze a system dynamics model to measure managerial performances. The developed system dynamics model is to quantify the effects of network strategy based on the historical financial data of real-life hospitals network experiences. The network effects are resulted in efficiencies and effectiveness enhancements in competitiveness through advertisement and effective education system. The simulations of system dynamics results can explain the improvement in financial outcome by joining in the network group. The network effects are shown more effective in dental hospital than other groups. In conclusion, it is expected that network effects have a critical influence of managerial, marketing, and medical collaboration performance for any type of medical hospitals.

• ETRI Journal
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• v.30 no.1
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• pp.59-67
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• 2008

The necessity for the precise time synchronization of measurement data from multiple sensors is widely recognized in the field of global positioning system/inertial navigation system (GPS/INS) integration. Having precise time synchronization is critical for achieving high data fusion performance. The limitations and advantages of various time synchronization scenarios and existing solutions are investigated in this paper. A criterion for evaluating synchronization accuracy requirements is derived on the basis of a comparison of the Kalman filter innovation series and the platform dynamics. An innovative time synchronization solution using a counter and two latching registers is proposed. The proposed solution has been implemented with off-the-shelf components and tested. The resolution and accuracy analysis shows that the proposed solution can achieve a time synchronization accuracy of 0.1 ms if INS can provide a hard-wired timing signal. A synchronization accuracy of 2 ms was achieved when the test system was used to synchronize a low-grade micro-electromechanical inertial measurement unit (IMU), which has only an RS-232 data output interface.

• Nuclear Engineering and Technology
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• v.41 no.6
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• pp.753-764
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• 2009

JAEA started the LSTF experiments in 1985 for the fourth stage of the ROSA Program (ROSA-IV) for the LWR thermal-hydraulic safety research to identify and investigate the thermal-hydraulic phenomena and to confirm the effectiveness of ECCS during small-break LOCAs and operational transients. The LSTF experiments are underway for the ROSA-V Program and the OECD/NEA ROSA Project that intends to resolve issues in thermal-hydraulic analyses relevant to LWR safety. Six types of the LSTF experiments have been done for both the system integral and separate-effect experiments among international members from 14 countries. Results of four experiments for the ROSA Project are briefly presented with analysis by a best-estimate (BE) code and a computational fluid dynamics (CFD) code to illustrate the capability of the LSTF and codes to simulate the thermal-hydraulic phenomena that may appear during SBLOCAs and transients. The thermal-hydraulic phenomena dealt with are coolant mixing and temperature stratification, water hammer up to high system pressure, natural circulation under high core power condition, and non-condensable gas effect during asymmetric SG depressurization as an AM action.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.78-82
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• 2014

Power Transformers with more than one secondary winding are not uncommon in industrial applications. But new classes of applications where very large number of independent secondaries are used are becoming popular in controlled converters for medium and high voltage applications. Cascade H-bridge medium voltage drives and Pulse Step Modulation (PSM) based high voltage power supplies are such applications. Regulated high voltage power supplies (Fig. 1) with 35-100 kV, 5-10 MW output range with very fast dynamics (${\mu}S$ order) uses such transformers. Such power supplies are widely used in fusion research. Here series connection of isolated voltage sources with conventional switching semiconductor devices is achieved by large number of separate transformers or by single unit of multi-secondary transformer. Naturally, a transformer having numbers of secondary windings (~40) on single core is the preferred solution due to space and cost considerations. For design and simulation analysis of such a power supply, the model of a multi-secondary transformer poses special problem to any circuit analysis software as many simulation softwares provide transformer models with limited number (3-6) of secondary windings. Multi-Secondary transformer models with 3 different schemes are available. A comparison of test results from a practical Multi-secondary transformer with a simulation model using magnetic component is found to describe the behavior closer to observed test results. Earlier models assumed magnetising inductance in a linear loss less core model although in actual it is saturable core made-up of CRGO steel laminations. This article discusses a more detailed representation of flux coupled magnetic model with saturable core properties to simulate actual transformers very close to its observed parameters in test and actual usage.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.3
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• pp.43-53
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• 2004

The vibration of a rolling piston type rotary compressor for air-conditioning use is analyzed numerically and experimentally. Multibody dynamic analysis methods to predict the vibration are given. The compressor is modeled as a multibody system composed of bodies, joints, and force elements. Experimental results are shown to compare with simulation results. A sensitivity study using different variables that affect the compressor vibration is also carried out. It is found that the mass of the weight balancer plays an important role in acceleration.

• Honam Mathematical Journal
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• v.40 no.2
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• pp.265-280
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• 2018

In this study, we firstly define equations of motion based on the traditional model Newtonian mechanics in terms of the Frenet frame adapted to the trajectory of the moving particle in Lie groups. Then, we compute energy on the moving particle in resultant force field by using geometrical description of the curvature and torsion of the trajectory belonging to the particle. We also investigate the relation between energy on the moving particle in different force fields and energy on the particle in Frenet vector fields.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.643-646
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• 2016

Fishes usually form a group in water to minimize drag coefficient and this fish schooling is one of representative problems in computational fluid dynamics. In this research, we simulated two fishes as a rectangle. We arranged rectangle horizontal and vertical, then we changed distance between two rectangles and simulated pressure of fluid and drag coefficient. We could find the best distance and position of two fishes that makes minimum drag coefficient.

• Health Policy and Management
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• v.9 no.3
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• pp.95-112
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• 1999

The objectives of this study were to develop the therapeutic recreation programs for relieving depressive symptoms of the elderly and to verify the effect on their psychological condition. The key elements of these programs, which consisted of 9 sessions. were aerobic exercises, group dynamics. and making fun. These programs were developed through a multidisciplinary approach with social workers and the faculties of preventive medicine. The social workers gave these programs to fifteen elderly people at the community center, so called noinjung, for 9 weeks. Before intervention of this program for the experimental group, the baseline was measured by GDS(geriatric depression scale). After intervention for 9 weeks, GDS as an outcome was measured to evaluate the effects of the program. This data was analyzed by $X^2$-test and Wilcoxon signed rank test. and the results were as follows: 1. Based upon the cutting point(GDS = 5) which could distinguish between depression group and normal group, the number for the normal group increased, while the number for the depression group decreased slightly after intervention with the therapeutic recreation programs, however, there was no significant change(p〉0.05). 2. The score of GDS decreased significantly after intervention with the therapeutic recreation programs(p〈0.05). 3. The scores of GDS decreased in widow(or) group and in female group compared to those of the married group and the male group, respectively(p〈0. 05). 4. The score of GDS increased in groups with similar labor and emotional support compared to those of groups with sufficient or less support, respectively(p〈0.05), These findings indicate that the therapeutic recreation programs might be effective for relieving depressive symptoms of the elderly. It is, therefore, suggested that this program be modified and standardized through review of the intervening process, experimental results, and responses of clients for appling in other noinjungs.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.423-427
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• 2003

In this paper, it is to development of brake system with ABS function for aircraft. The test of brake system is required before applying on aircraft. The real-time dynamic simulator with 5-D.O.F. aircraft dynamic model is developed for braking performance test of ABS (Anti-skid Brake System) control h/w with anti-skid brake functions. The dynamic simulator is real-time interface system that is composed of dynamic simulation parts, master control parts, digital and analog in/out interface parts, and user interface parts. The 5-D.O.F. aircraft dynamic model is composed of a big contour and a little contour by simulation s/w. The big contour represents the interactions of forces in airframe, nose and main landing gear, and engines on the center of gravity. The little contour represents interactions of wheel, braking units, hydraulic units and a control unit. ABS control h/w unit with ABS control algorithm is also developed and is tested with simulator under the some conditions of gripping coefficient. We have known that ABS control h/w unit on wet or snowy runway as well as dry runway very well protects wheel skid.

• Journal of the Korean Mathematical Society
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• v.53 no.4
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• pp.795-834
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• 2016

The main purpose of this paper is to propose a scheme of a proof of the nonsimpleness of the group $Homeo^{\Omega}$ ($D^2$, ${\partial}D^2$) of area preserving homeomorphisms of the 2-disc $D^2$. We first establish the existence of Alexander isotopy in the category of Hamiltonian homeomorphisms. This reduces the question of extendability of the well-known Calabi homomorphism Cal : $Diff^{\Omega}$ ($D^1$, ${\partial}D^2$)${\rightarrow}{\mathbb{R}}$ to a homomorphism ${\bar{Cal}}$ : Hameo($D^2$, ${\partial}D^2$)${\rightarrow}{\mathbb{R}}$ to that of the vanishing of the basic phase function $f_{\underline{F}}$, a Floer theoretic graph selector constructed in [9], that is associated to the graph of the topological Hamiltonian loop and its normalized Hamiltonian ${\underline{F}}$ on $S^2$ that is obtained via the natural embedding $D^2{\hookrightarrow}S^2$. Here Hameo($D^2$, ${\partial}D^2$) is the group of Hamiltonian homeomorphisms introduced by $M{\ddot{u}}ller$ and the author [18]. We then provide an evidence of this vanishing conjecture by proving the conjecture for the special class of weakly graphical topological Hamiltonian loops on $D^2$ via a study of the associated Hamiton-Jacobi equation.