• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1410-1412
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• 1995

A high efficiency ozone generation using both of a electrode-edge discharge and a dielectric-harrier discharge from a modified silent type ozone generator has been proposed and studied for small scale applications. It is found that the output ozone concentration of the proposed generator depended greatly upon the air gap spacing and the applied power frequency and voltage on the ozone generation. The ozone generator showed higher ozone concentration than the same size of the ceramic type surface ozone generator(Masuda type one). And, it is found that the generator had a potential to be used as an ozone generator for small scale applications.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2242-2244
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• 1999

Recently, An important research field of pulsed power is high voltage, high power generation with exploding wire opening switch. Another point of view exploding wire effects have been researched for generation of the pulsed high pressure shock wave. Theoretical considerations of the shock pressure generation along with experiment results are presented in this paper and. Some experimental results of hard rock fracturing show the possibilities of commercial using.

• Tribology and Lubricants
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• v.33 no.3
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• pp.85-91
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• 2017

This work studies the flow behaviors in the gap between the friction pad and separator in wet-clutch systems. The fluid volume of the lubricant is modeled using the entire system of wet-clutch pack of a dual clutch transmission that has larger outer radius of odd gear shifts and smaller inner radius of even gear shifts. Flow behaviors in the gap of the clutch pad are computed using the gear shift modes that consider the real relative velocities between the friction pad and separator. Flow behaviors in the gap of the disengaged clutch pad are mainly investigated for the wet-clutch system, whereas the engaged clutch pad is modeled with no fluid rate through the contacting surfaces. The developed hydrodynamic fluid pressures and velocity fields in the clutch pad gap are computed to obtain the relevant information for managing flow rates in wet-clutch packs under dual operating conditions during gear shifts. These hydrodynamic pressures and velocity fields are compared on the basis of each gear level and gap location, which is necessary to determine the effects of groove patterns on the friction pad. Shear stresses in the gap locations are also computed on the basis of the gear level for the inner and outer clutch pads. The computed results are compared and used for the design of cooling capacity against frictional heat generation in wet-clutch pack systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1B
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• pp.60-70
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• 2011

IPTV was introduced as the new growth engine of the broadcasting and telecommunications industry and has experienced a high growth rate as its subscribers exceeded 2 million in early 2010. However there have been some doubts on if the IPTV market will keep current growth drift. One of such suspicions is that IPTV market has not been developed by the competitiveness of IPTV industry itself. In addition, the recent slowdown of subscribers' growth and IPTV players' operating at a loss has been suggested as obstacles to the IPTV market growth. This sort of phenomenon has been brought about by ambiguous proposition of IPTV's own value as well as IPTV service positioning gap. To resolve these problems this study empirically investigates what customers want to get from IPTV service by analyzing switching value of IPTV subscribers. This study also identifies which values must be strategically considered to develop next generation IPTV services, in particular mobile IPTV services. Following the investigation, this study analyzes the possible positioning gap of mobile IPTV. Through this analysis, this study suggests which sort of service values need to be reconciled.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.514-522
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• 2014

A new type of high precision electromagnetic suspension (EMS) which can support heavy tray along long stroke rail is proposed in this paper. Compared with the conventional EMS, the suggested moving-core typed EMS has the levitation electromagnets (EMs) on the fixed rail. This scheme has high load capability caused by iron-core and enables simple tray structure. Also it does not have precision degradation caused by heat generation from EMs, which is a drawback of conventional EMS. With these merits, the proposed EMS can be an optimal contactless linear bearing in next generation flat panel display (FPD) manufacturing process if the ability of long stroke movement is proved. So a special Section Switching Algorithm (SSA) is derived from the resultant force and moment equations of the levitated tray which enables long stroke movement of the tray. In order to verify the feasibility of the suggested SSA, a simple test-setup of the EMS with 2 Section-changes is made up and servo-controlled in the simulation and experiment. The simulation shows the perfect changeover the EMs, and the experiment shows overall control performance of under ${\pm}40{\mu}m$ gap deviations. These results reveal that the newly suggested contactless linear bearing can simultaneously achieve high load capability and precision gap control as well as long stroke.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.25-34
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• 2001

In this paper, discharge lamp ozonizer(DLO) of a new discharge type using superposition of gaseous electrical discharge for environment improvement was designed and manufactured. DLO is equipped with 3 electrodes(central ground electrode of discharge lamp type internal high voltage electrode of mesh type and external high voltage electrode of spiral type), and it is composed of double gap(gap between discharge lamp and internal electrode, gap between discharge lamp and external electrode). Internal and external electrodes are respectively applied AC high voltage which has 180[$^{\circ}$] phase difference. Ozone is generated by overlaying of each silent discharge which is respectively came from two gaps. At the moment discharge characteristics and ozone generation characteristics of DLO were investigated in accordance with quantity of supplied gas, discharge power and the number of DLO. When ozone generated by DLO was in contact with NO gas, removal characteristics was excellent, so it confirmed that DLO could be used as air environment improvement facility.

• Journal of Technology Innovation
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• v.13 no.1
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• pp.169-191
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• 2005

By analyzing a national survey of public understanding of science and technology, this paper attempts to examine public perceptions of scientists and engineers in Korea. A special attention is given to the gap in the view of scientists and engineers across generation, gender, and class fields (or major fields). This paper shows that generation has the strongest effect on public perceptions of scientists and engineers among all the socio-demographic factors examined in this study. Those over 50 are more likely to have the conventional idealized images of scientists and the stereotypical negative images of scientists simultaneously, while the 20s are less likely to accept the idealized image of scientists. The survey result thus may suggest that the younger generation began to depart from a patriotic and moral description of scientists and engineers-for the younger generation, science and engineering is losing moral respect but becomes perceived as an ordinary occupation. Contrary to the popular belief, however, gender has little effect on public perceptions of scientists and engineers. This finding questions the assertion that female students possess more negative attitudes toward scientists and engineers than male students, and thus are reluctant to develop careers related to science and engineering. By uncovering that class fields (or major areas) have no effect on the image of scientists, this study also call into question the assertion in the science wars that the inadequate appreciation of science particularly among those who do not major in science and engineering is responsible for inadequate support for science and technology.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.586-595
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• 2016

The difference of generation is the main cause of society transition. If we know about the gap of generations, then we know where we go in future. This study focus on the differences of a regulation recognition among the generations. When we understand the differences of regulation recognition among the generations, we can realize the trait of regulation in society. In result, there are a lot of differences of regulation recognition among the generations. The older they are, the more they are positive to regulation. And the younger they are, the more they are negative to regulation. In particular, 50's generation have the opposite regulation recognition to 20's generation in specialty of regulation and in a conglomerate regulation.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.294-302
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• 2018

The regulation of the game industry by the Korean government is closely related to the specific regulatory behavior from their parents' generation regarding gaming behavior of their children. This is because there exists a gap in terms of digital culture experience between parents and children. This study examined the differences in how moral values affect the awareness or perceptions of the game users. In the results, the norm conformity was found to have a negative influence on the fondness for game users. Age was also shown to have a negative influence on the fondness for the game users. Based on these findings, we also found the mediating effect of age existed specifically with regard to the relation of norm conformity and the fondness for the game users. The results suggest that the game industry promotion policies of Korea should change their existing targets from focusing on everyone to just the elderly.

• Current Applied Physics
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• v.18 no.12
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• pp.1473-1479
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• 2018

Recently multiferroic materials have attract great interest for the applications on memorial, spintronic and magneto-electric sensor devices for their spontaneous magneto-electric coupling properties. Research and development of the various kinds of multiferroics are indispensable factor for a new generation multifunctional materials. In this research, mechanical, electronic, magnetic and nonlinear optical properties of La modified $BiLaFe_2O_6$ (BLFO) and Mn modified $Bi_2FeMnO_6$ (BFMO) were studied as new members of multiferroic $BiFeO_3$ (BFO) series by first-principles calculations, and compared with the pure BFO to discover the optimized properties. Our results show that BLFO and BFMO have good mechanical stability as revealed by elastic constants that satisfy the stability criteria. All these compounds exhibit anisotropic and ductile nature. The enhanced properties by La and Mn substitution, such as increased hardness, improved magnetism, decreased band gap and comparable second harmonic generation responses reveal that the new multiferroic members of BLFO and BFMO would get wider application than their BFO counterpart. Our study is expected to providing an appropriate mechanical reference data as guidance for engineering of high efficiency multifunctional devices with the BFO series.