• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.60 no.4
• /
• pp.246-252
• /
• 2011

In this paper proposes the soft-switching boost converter and MPPT control for improving the efficiency of PV system. The proposed converter designed H-bridge auxiliary resonant circuit. By this circuit, all of the switching devices perform the soft switching under the zero voltage and zero current condition. Therefore the periodic switching losses can be decreased at turn on, off. The soft switching boost converter designs for 1.5[kW] solar module of the power conversion. Thus, this soft switching boost converter is simulated by MATLAB simulation using Newton-Method algorithm. As a result, Proposed Soft Switching Converter compared to a typical boost converter switching loss was reduced about 61%. And the overall system efficiency was verified to increase about 3.3%.

• The Journal of Korean Society of Virology
• /
• v.27 no.2
• /
• pp.257-260
• /
• 1997

Adenoviruses are icosahedral virions containing double-stranded linea DNA. They are 70 nm to 90 nm in diameter and capsid is composed of 252 capsomeres. Several members of this group, including types commonly associated with respiratory disease in man, are capable of producing malignant tumors in young hamsters and a few types have been shown to be oncogenic in young rat. Previous report involving effect of caffein on transformation induced by Adenovirus type 12 [9] has been carried out. The present report represents a continuation of previous study. To obtain evidence concerning the effect of MNNG (N-methyl-N'-nitro-N-nitroguanidine) on transformation, investigation of adenovirus type 12 of this group was undertaken. For practical consideration it was desirable to investigate the effect of MNNG on the adenovirus type 12 induced transformation in L cell. Results were as following 1. Adeno virus type 12 induced transformation was enhanced in the presence of MNNG. 2. Yields of adeno type 12 virus in L cell were slightly inhibited by treatment of MNNG.

• Journal of Computing Science and Engineering
• /
• v.4 no.3
• /
• pp.240-252
• /
• 2010

One of the important open problems in modeling plants is the extension of subdivision algorithms to branching structures. Most of the applications use the concept of L-system to produce branching structures as a sequence of lines and apply the subdivision scheme to appear as curves. In this paper, we explain how L-systems can be modified to produce branching structures. This is also very useful for generating the geometry of various shapes. The proposed technique, called an adaptive L-System, describes branching forms and leaves by making local curve without applying the subdivision steps. Advantages of the suggested algorithm over previous techniques are given. Validation of the algorithm are discussed, analyzed and illustrated by some experimental results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.252-255
• /
• 2014

The elevator rope is easy to oscillate and continue vibrating because the rope structure is flexible and inner damping is small. The vibration of elevator rope is caused by the building vibration excited by external disturbances such as winds and earthquake. This paper is concerned with the experimental verification of the elevator rope vibrations using a small-scale simulator. The elevator rope vibration coupled with the building vibration was modelled using the energy method in the previous study. In this study, the natural frequencies of the elevator rope were computed using the theoretical model and compared to experimental results. Also, the time-responses of the rope vibration during the cage motion were measured by laser sensors and compared to the theoretical predictions. Experimental results are in good agreement with theoretical predictions.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.2
• /
• pp.245-252
• /
• 2012

The biggest difficulty the small and small business currently face is not to have the effective cusomer management system that is the computerization of management. This suggests their will to introduce data marketing in order to differentiate 'Customer Marketing' and 'One to One Marketing'. The potential needs as well as visible needs of customer should be considered in order to research and analyze the customer data. At this point mayor enterprises are paying much attention to Customer Segmentation and their related markets are expanding rapidly. I'll give a brief introduction to the Multi Criteria Importance-Performance Analysis and go into the problems that should be considered and which phase to emphasize when building this system.

• Journal of Families and Better Life
• /
• v.14 no.2
• /
• pp.241-252
• /
• 1996

This study was designed to analysis a causal modeling between peer acceptance of children and the related variables. The subjects were 430 5th and 6th elemantary school children. Using questionnares data on peer acceptance aggression & withdrawal behavior rated by same-sex peers and mother-child attachment were gathered,. For the statiscal analyses multiple regression and path-analysis were used. The results show social behavior that effects peer acceptance is influenced by not only aggresive behavior but also withdrawal behavior, Peer acceptance was not affected directly by mother-child attachment and paternal education while academic achievement affected peer acceptance indirectly. Therefore children's peer acceptance is mainly determined by social behavior as well as academic achievement.

• Journal of Institute of Control, Robotics and Systems
• /
• v.3 no.3
• /
• pp.252-258
• /
• 1997

This paper presents neural networks for hybrid position/force control which is a type of position and force control for robot manipulators. The performance of conventional hybrid position/force control is excellent in the case of the exactly-known dynamic model of the robot, but degrades seriously as the uncertainty of the model increases. Hence, the neural network control scheme is presented here to overcome such shortcoming. The introduced neural term is designed to learn the uncertainty of the robot, and to control the robot through uncertainty compensation. Further more, the learning rule of the neural network is derived and is shown to be effective in the sense that it requires neither desired output of the network nor error back propagation through the plant. The proposed scheme is verified through the simulation of hybrid position/force control of a 6-dof robot manipulator.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.11 no.1
• /
• pp.13-20
• /
• 2004

Purpose: This study was conducted to evaluate the effect of open laboratory self-directed practice in improving nursing skill competency. Method: This study was a one group posttest only design that examined the competency in basic nursing skills after traditional education and open laboratory self-directed practice. Students participated in traditional education and open laboratory practice through self-study. Whenever practice was done, the item of practice and time were measured and documented. Collected data were analyzed by frequency, percentages, averages and standard deviations, and Pearson correlation coefficients. Result: 1 The average number of students who participated in the open lab self-directed practice was 53.9 (64.2%) and the total number of hours of participation was 1567.5 minutes per year. Each student participated for an average of 29.1 minutes per year. 2. Analysis showed a statistically positive correlation between practical skill and open laboratory self-study (r=0.252, p=0.048).

• Journal of Microbiology
• /
• v.33 no.3
• /
• pp.252-259
• /
• 1995

The PCR was employed to detect and characterize the bovine immunodeficiency-like virus (BIV), which is a newly recognized member of the I entivirinae of the retroviruses. Degenerate primers representing the conserved regions in the pol genes of the Lentivirinae, were used to detect proviral DNA obtained from the bovine embryonic spleen cell cultures infected with BIV. The PCR amplified DNA fragment was molecularly cloned and sequenced. The BIV DNA fragment contained a sequence identical to that reported by Garvey et al. (Garvey et al., 1990. Virology, 175, 391-409). With the degenerate primers, peripheral blood mononuclear cells (PBMCs) of sick cattle and cells cultured with BIV were tested to determine genetic variation of BIV pol conserved sequence. We found the sequence heterogeneity within cultures and most variations occurred at the third base of codons that would not lead to amino acid substitutions. Another change was GAG (Glu) to AAG (Lys) within the BIV isolates. Interestingly, the altered sequence is also found in other lentiviruses such as HIV-2, SIV mac, CAEV and EIAV.

• Journal of Korean Society of Rural Planning
• /
• v.15 no.4
• /
• pp.59-74
• /
• 2009

This study reviews and modifies general IS success models to find success factors of WIS(Web-based Information Systems) and to confirm the relationship between WIS success and user's satisfaction of web use. A WISSM(Web-based Information Success Model extended to include EQ(E-Quality) is developed to anticipate user's intention to use Web-based Agricultural Information System and fit into the survey data from 252 WIS users of RDA(Rural Development Administration). PLS is applied to estimate a structural model based on EQ-WISSM to test hypotheses including 1) users reach a high level of intention to use Web-based Information Systems when they feel a high level of interactivity among an 'E-Quality', 'Decision Making Support Satisfaction' and 'Task Support Satisfaction', and E-Quality boosts intention to use Web-based Information Systems. The results show high path coefficients and $R^2$ values and find followings; First, the EQ-WISSM explains the user's intention to use WAIS quite well. Second, E-Quality can be used well in web-based IS environment to predict IS Success. Finally, this research finds the importance of 'Task Support Satisfaction' as a mediator between 'Decision Making Support Satisfaction', 'E-Quality' and 'Intention to Use'.