• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.405-415
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• 2019

Excessive tooth wear can cause irreversible damage to the occlusal surface and can alter the anterior occlusal relationship by destroying the structure of the anterior teeth needed for esthetics and proper anterior guidance. The anterior deep bite is not a morbid occlusion by itself, but it may cause problems such as soft tissue trauma, opposing tooth eruption, tooth wear, and occlusal trauma if there are no stable occlusal contacts between the lower incisal edge against its upper lingual surface. The most important goal of treatment is to form stable occlusal contact in centric relation. In this case report, patients with decrease in vertical dimension and anterior deep bite due to maxillary posterior tooth loss and excessive tooth wear were treated full mouth rehabilitation with increased vertical dimension to regain the space for restoration and improve anterior occlusal relationship and esthetics. The functional and aesthetic problems of the patient could be solved by the equal intensity contact of all the teeth in centic relation (CR), anterior guidance in harmony with the functional movement, and restoration of the wear surface beyond the enamel range.

• Korean journal of communication and information
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• v.76
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• pp.92-123
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• 2016

This paper aims to examine systematically how audiences' exposure to crime news influences their multicultural acceptability. In particular, the analysis has focused on how the variance in the effects of contacts with crime news on foreigners takes place, according to the types of media and communication favored among the audiences. Also, with perceived risk toward crime as a mediating variable, this research scrutinizes the way crime news on foreigners comes to influence multicultural acceptability among the audiences. While various news sources and communication channels are influential in strengthening the perceived possibility of crime on the individual level, the results show, television seems to be particularly more effective with regards to the perceived prevalence of crime on the social level (RQ 1). Also, while contacts with crime news through 'dialogic' media rarely influence multicultural acceptability significantly, 'discursive' media and face-to-face contacts have negative impacts on the multicultural acceptability (RQ 2). Consequently, perceived risk on the social level seems to play the role of full mediation in the process where audiences' contact with crime news through discursive media influences their multicultural acceptability (RQ 3). Based on these findings, both theoretical and practical implications were discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.4
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• pp.337-346
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• 2014

This study aimed to understand the mode characteristics of a droplet subject to periodic forced vibration and the detachment of a droplet placed on a plate surface. An surface was coated with Teflon to clearly observe the behavior of a droplet. The contact angle between the droplet and surface and the hysteresis were found to be approximately $115^{\circ}C$ and within $25^{\circ}C$, respectively. The coating process was performed in a clean room that had an environment with a low level of contaminants and impurities such as air dust, detergents, and particles. To predict the resonance frequency of a droplet, theoretical and experimental approaches were applied. Two high-speed cameras were configured to acquire side and top views and thus capture different characteristics of a droplet: the mode shape, the detachment, the separated secondary droplet, and the waggling motion. A comparison of the theoretical and experimental results shows no more than 18 discrepancies when predicting the resonance frequency. These differences seem to be caused by contact line friction, nonlinear wall adhesion, and the uncertainty of the experiment. For lower energy inputs, the contact line of the droplet was pinned and the oscillation pattern was axisymmetric. However, the contact line of the droplet was de-pinned as the oscillation became more vigorous with increased energy input. The size of each lobe at the resonance frequency is somewhat larger than that at the neighboring frequency. A droplet in mode 2, one of the primary mode frequencies, exhibits vertical periodic movement as well as detachment and secondary ejection from the main droplet.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.341-347
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• 1987

The behavior of conger eel, Astroconger myriaster (Brevoort), to the bamboo and plastic pots with baits was investigated alternately in two experimental water tanks. One of the pots being dropped on the tank bottom, the eels touched it to obtain the bait probably by their sense of smell, and increased rapidly in the number of touch to show a maximum within 30 minutes. But the touch was made mainly to the pot wall at which the bait was located and quite accidentally to the pot mouth. The eels touched the pot mouth retreated frequently without attempting to enter the pot and their entering was very hampered by the bamboo funnel constituting the pot mouth. However, a entering, if made, encouraged other touches and the touches ascribed other enterings. But, if 30 minutes elapsed, the number of touch decreased gradually and so the enterings were little made. The ability of pots attracting the eels into them was varied with their inclination to the tank bottom and the bait position in them. That is, the pot which was laid horizontally showed high ability of attracting in case in which the bait was fixed in the vicinity of its mouth. The pot, inclined by $30^{\circ}$ by lifting its tail and had a bait left free, showed almost equal ability to the horizontal pot with a bait in the vicinity of mouth. But the pot, inclined by $30^{\circ}$ by lifting its mouth and had a bait left free, showed a very low attracting. A comparison between the bamboo and plastic pots gave only that the entering of the eels became later several minutes in the latter.

• Clean Technology
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• v.6 no.1
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• pp.17-25
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• 2000

Catalytic oxidation of volatile organic compounds(benzene, toluene, xylene) over transition metals/ALO-6 catalysts was investigated in a fixed bed flow reactor system at atmospheric pressure. The orders of catalytic activities for the complete oxidation of toluene were Cu>Mn>Fe>V>Mo>Co>Ni>Zn for 15% transition metals/ALO-6 catalyst system. Increasing the calcination temperature resulted in decreasing the specific surface areas of catalyst, subsequently the catalytic activity. The loading of Cu on ALO-6 had a great effect on the catalytic activity and 5% Cu/ALO-6 catalyst showed higher catalytic activity, which may be contributed to the uniformly distributed active sites. Benzene, toluene and xylene were completely oxidized to carbon dioxide over 5% Cu/ALO-6 catalyst at over $380^{\circ}C$ and 4.5 g-cat.hr./g-mole. The orders of the kinds of reactants for catalytic activity over 5% Cu/ALO-6 were toluene>xylene>benzene. As the concentration of reactant increased, the catalytic activity decreased due to self-poison of reactant.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.1
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• pp.43-50
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• 2008

The analysis and results of flexural behavior for steel composite beam with built-up cross-section considering bolt deformation are presented in this paper. The bolt deformation and the restrict effect due to bolt-connection and friction are considered to investigate the flexural behavior of steel composite beam. Nonlinear spring element in ABAQUS is used to consider bolt deformation, also the results are compared with those in case bolt deformations are ignored. The displacement, bending stresses and shear stresses are calculated by F.E. model, and these results are compared with the analytical value of no interaction beam, partial interaction beam and full interaction beam. As a result of analysis, the behavior of composite beam is more dependant on the composite rate than the friction of the steel. When the composite rate is more than 50%, the behavior of composite beam considering the effects of bolt deformation is similar to that of fully composite beam.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.1-6
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• 2005

Injury of permanent teeth by trauma usually occurs to $8{\sim}10\;years$ old children, in mixed dentition. Fracture, dislocation, intrusion, extrusion, avulsion are the common types of trauma in teeth. The injuries which teeth are dislocated from the alveolar sockets can be treated by reduction and fixation. In this case report two children visited Wonkwang University Dental Hospital after the emergency treatment of tooth injury by other medical institutes. In these cases the injured teeth were not reducted properly and showed premature contact. So the teeth were dislocated from the alveolar sockets intentionally and fixed again in the proper position. Unproper reduction can cause premature contact, delay of healing, difficulty of mastication, and malocclusion. For this reason emergency rooms or local dental clinics where patients with dental trauma can be examined first, must know well about the treatment procedure of the injured teeth and should be consulted to the profession when necessary.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.6
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• pp.533-539
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• 2009

In this study, the femur, the tibia, the articular cartilage and the menisci are three dimensionally reconstructed using MR images of healthy knee joint in full extension of 26-year-old male. Three dimensional finite element model of the knee joint is fabricated on the reconstructed model. Also, the FE models of ligaments and tendons are attached on the biologically suitable position of the FE model. Bones, articular cartilages and menisci are considered as homogeneous, isotropic and linear elastic materials, and ligaments and tendons are modeled as truss element and nonlinear elastic springs. The numerical results show the contact pressure and the von Mises stress distribution in the soft tissues such as articular cartilages and menisci which can be regarded as important parameters to estimate the failure of the tissues and the pain of the patients.

• Journal of the Korean Regional Science Association
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• v.35 no.1
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• pp.19-31
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• 2019

This study examines the effect of national identity and threat awareness on the multi-cultural acceptability and whether contact theory actually work. For the analysis, this study used '2013 Korea General Social Survey' data and compared two groups divided according to whether or not they live in ethnic places using structural equation modeling. The empirical analysis shows that national identity does not have a direct effect on multi-cultural acceptability, and threat awareness has a full mediating effect between national identity and multi-cultural acceptability. In addition, the negative effect of the threat awareness on multi-cultural acceptability was greater in groups living in ethnic places. The findings suggest that multi-cultural awareness education is necessary to reduce the threat awareness toward foreigners, and that community-level programs are needed to prevent and coordinate conflicts arising from contact between foreigners and Koreans.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.238-244
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• 1990

The behavior of conger eel, Astroconger myriaste(Brevoort), to the net pots with baits was investigated alternately in two experimental water tanks. One of the pots being dropped on the tank bottom, the eels increased rapidly in number of touching the pot to show a maximum whithin 30 minutes and then decreased gradually. The enterings of eels into the pots were also made mainly within 30 minutes and easier in pots with lower entrances. But the complete enterings were decided by the passage of eel tails through the pot entrances and so the eels retreated frequently after attemping to enter the pots, especially in pots small in the interval between the entrances and the baits or in pots with flappers. However, most of enterings encouraged the touches and earlier enterings ascribed earlier production of maximum touch. The eels, if entered the pots without flappers, got out of the pots relatively easily and the getting-out was easier in pots with lower entrances. On the other hand, the eels entered the pot with flappers could not get out of the pots. A comparison between the circular and square pots gave that the guidance of eels to the entrances was easier in the former and the passing of eels through the entrances in the latter, not only at the inside of pots but also at the outside. The general behavior of eels in touching or entering the net pots in the above results was almost equal to that on the bamboo and plastic pots in the previous paper.