• Journal of Mechanical Science and Technology
• /
• v.15 no.5
• /
• pp.671-680
• /
• 2001

Boundary condition is one of the major factors to influence the numerical stability and solution accuracy in numerical analysis. One of the most important physical boundary conditions in the flowfield analysis is the wall boundary condition imposed on the body surface. To solve a two-dimensional Euler equation, totally four numerical wall boundary conditions should be prescribed. Two of them are supplied by the flow tangency condition. The other two conditions, therefore, should be prepared additionally in a suitable way. In this paper, four different sets of wall boundary conditions are proposed and then applied to solve high-speed flowfields around a quarter circle geometry. A two-dimensional compressible Euler solver is prepared based on the finite volume method. This solver hires three different upwind schemes; Steger-Warmings flux vector splitting, Roes flux difference splitting, and Lious advection upstream splitting method. It is found that the way to specify the additional numerical wall boundary conditions strongly affects the overall stability and accuracy of the upwind schemes in high-speed flow calculation. The optimal wall boundary conditions should be also chosen very carefully depending on the numerical schemes used to solve the problem.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.9
• /
• pp.823-826
• /
• 2010

In this study, the control method of assistive robot was developed for the elderly. The control method of gait-assistant-robot was proposed considering the change of COP (Center of Pelves), BOS (Base of Support) and comparative analysis of the moving velocity for the elderly. We analyzed the movement of COP of the body and its velocity of the elderly equipped with manual walker and gait-assistant-robot. As a result, change in COP was greater from left to right than from anterior to posterior; also, the average velocity of the movement of COP and manual walker for manual walker gait was 0.7(m/s). Therefore, it is necessary to concern more on the left-right balance and synchronization of the velocity of COP.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.4
• /
• pp.821-827
• /
• 2009

Currently, with the development of web 2.0 knowledge sharing system became more and more important. In this paper, we proposed and implemented seminar assistant system using database system and knowledge sharing system on public seminar. We recorded speaker's voice and presentation files on our system and user can review past talks on our seminar review systems. Our database system is implemented using MS SQL, and Input/Output Completion Port(IOCP) socket model as our server side network module. Also we used presentation software using Direct Show with MFC and Windows Presentation Foundation(WPF). and our review system is based on WFP programmed with C# language.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.6
• /
• pp.837-844
• /
• 2001

Jet cutting technology currently makes use of a generic supersonic gas jet to improve the cutting speed and performance. In order to get a better understanding of the flow characteristics involved in the supersonic jet cutting technology, the axisymmetric Navier-Stokes equations have been solved using a fully implicit finite volume method. Computations have been conducted to investigate some major characteristics of supersonic coaxial turbulent jets. An assistant gas jet has been imposed on the primary gas jet to simulate realistic jet cutting circumstance. The pressure and the temperature ratios of the primary and assistant gas jets are altered to investigate the major characteristics of the coaxial jets. The total pressure and Mach number distributions, shock wave systems, and the jet core length which characterize the coaxial jet flows are strongly affected by the pressure ratio, but not significantly dependent on the total temperature ratio. The assistant gas jet greatly affects the basic flow characteristics of the shock system and the core length of under and over-expanded jets.

• English Language & Literature Teaching
• /
• v.17 no.4
• /
• pp.293-312
• /
• 2011

Many immersion programs have been established and managed throughout Korea in recent years in schools, English villages and camps. Research on the effects of various programs has been reported with focus on the program types or the benefits and learning outcomes for the participants. The purpose of this study is to find out the effects of participation at English camp as a teaching assistant by comparing some factors such as competence, English abilities, and connection to current studies/career before and after camp experience. The results show that all 17 competence rates rose with 'crisis management' showing prominent change. Also, the camp experience provides opportunity for improving English Test scores, conversational skills, teaching skills, and mostly language confidence. Lastly, the camp helped in setting career goals and was helpful in the preparation process of job seeking. Most of the subjects, the teaching assistants at camp, replied that the impact of camp experience is useful in current studies/career. In conclusion, the experience as camp teaching assistant is valuable in many aspects.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.9
• /
• pp.4264-4279
• /
• 2017

In this paper, maximum likelihood-based automatic lexicon generation using mixed-syllables is proposed for unlimited vocabulary voice interface for East Asian languages (e.g. Korean, Chinese and Japanese) in AI-assistant based interaction with mobile devices. The conventional lexicon has two inevitable problems: 1) a tedious repetition of out-of-lexicon unit additions to the lexicon, and 2) the propagation of errors during a morpheme analysis and space segmentation. The proposed method provides an automatic framework to solve the above problems. The proposed method produces a level of overall accuracy similar to one of previous methods in the presence of one out-of-lexicon word in a sentence, but the proposed method provides superior results with the absolute improvements of 1.62%, 5.58%, and 10.09% in terms of word accuracy when the number of out-of-lexicon words in a sentence was two, three and four, respectively.

• Journal of the Korean Home Economics Association
• /
• v.48 no.2
• /
• pp.95-111
• /
• 2010

We examined gender-specific behaviors in children and classified types of bullying behavior among 1,181 fifth and sixth grade elementary schools students. Differences were identified in individual variables, family environment variables, and school environment variables. Furthermore the behavioral tendencies of those variables towards bullying were also investigated. Collected data were subjected to descriptive and comparative statistical analysis using the SPSS program(Ver 15.0). Results showed that tendency towards bullying was gender specific. Bullying behavior, reinforcing behavior, assistant behavior, and onlooking behavior in boys were influenced by individual factors only. However, defending behavior in boys was influenced by individual and school factors, while victimizing behavior was influenced by individual and family factors. In girls, onlooking behavior was only influenced by individual factors, while reinforcing behavior was influenced by individual and family factors. Bullying behavior, defending behavior, assistant behavior, and victimizing behavior in girls were influenced by individual, family, and school factors.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.8
• /
• pp.603-609
• /
• 2016

This paper presents an optimally designed master device mechanism for teleoperated interventional robotic system. The interventional procedures using the teleoperated robotic system and the physicians' requirements are summarized. The master device should implement 5-DOF motion including 2-DOF translational motion for the entry position control, 2-DOF rotational motion for the orientation control, and 1- DOF translational motion for needle insertion. The handle assembly includes a 1-DOF translational mechanism for needle insertion and buttons for operation mode selection. The mechanisms for the 2-DOF translational motion and the 2-DOF rotational motion are designed using motors and brakes based on the various mechanisms to satisfy all the above requirements, respectively. Absolute position sensors are adopted to implement automatic initial positioning and orientation matching at the first step of needle insertion.

• The Korean Journal of Emergency Medical Services
• /
• v.23 no.3
• /
• pp.29-40
• /
• 2019

Purpose: This study was conducted to identify the effects of educational intervention on pre-test and post-test tidal volume, endotracheal peak pressure, and ventilation interval measurements during single-rescuer respiratory-assistant therapy by paramedic students. Methods: The present study, with a quasi-experimental design, included a pre-test and post-test nonequivalent control group. A total of 62 paramedic students (31, experimental group; 31, control group) participated in this study. The intervention lasted 80 minutes. Data were collected from each student before the intervention and two weeks after the intervention, between September 3 and 21, 2018. The collected data were analyzed using IBM SPSS Statistics for Windows, Version 25.0. Results: Tidal volume (p<.001) and endotracheal peak pressure (p=.002) measurements after the intervention were significantly different between the two groups. Analysis of covariance was used to control the variance (the pretest value of endotracheal peak pressure) in order to identify the effect of the intervention in the two groups. Endotracheal peak pressure was not significantly different between the two groups. Conclusion: Education and training of paramedic students in emergency medical services on single-rescuer respiratory-assistant therapy is necessary for the emergency care of patients with respiratory arrest.

• Journal of the Korean Institute of Rural Architecture
• /
• v.10 no.4
• /
• pp.9-16
• /
• 2008

The purpose of this study is to compare and seize the type of the path of flow for nurses and living assistant, of the path of flow for evacuation and walking practice by analysis plan for the care facilities in the out-of-home service. It supposed many problem for living in the care facilities for the aged get down activity, especially their relates with difficulty in walking. And services of nurses and living assistant get mixed properties by that problem for the aged with difficulty in walking. It classified into T type, L type, H type, ${\Box}$ type, - type all the path of flow for nurses and living assistant on the longest from nursing station to each bedroom, the path of flow for evacuation from each room to exit, the path of flow for walking practice on the corridor and lobby. The three path of flow are influenced by an inner court, especially passable court is the important primary factor in the communication between the aged, a course and time required of flow.