• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.349-357
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• 2011

Purpose: In this study, for the reasons of observing the changes when using bonding agent with Ni-Cr alloy and Co-Cr alloy and using VM13 and Vintage MP ceramic which have the disparity in coefficient of thermal expansion, it is carried out to evaluate the characteristics of the bonding agent through the analysis of the interface between metal and ceramic and the analysis of bond strength by variable. Methods: The surface treatment was performed on the two kinds of alloy(Ni-Cr alloy and Co-Cr alloy) specimens, which were sandblasted and were treated with bonder application. The metal-ceramic interfaces were analyzed with EPMA in order to ionic diffusion, and the shear test was performed. Results: As a result of observation of metal-ceramic interfacial properties, it was observed that Cr atoms were spread from the alloy body to the ceramic floor in the specimen of Group B. It was also seen that Cr, W atoms were spread from the alloy body to the ceramic floor in the specimen of Group S. In consequence of observing Shear bond strength, it was calculated that the specimen of BSV was 27.75(${\pm}11.21$)MPa, BSM was 27.02(${\pm}5.23$)MPa, BCV was 30.20(${\pm}5.99$)MPa, BCM was 27.94(${\pm}10.76$)MPa, SSV was 20.83(${\pm}2.58$)MPa, SSM was 23.98(${\pm}3.94$)MPa, SCV was 32.32(${\pm}4.68$)MPa, and SCM was 34.54(${\pm}10.63$)MPa. Conclusion: In the metal-ceramic interface of Bellabond plus sample group, diffusion of Cr atoms was incurred and diffusion of C Cr atoms and W atoms in the sample group of $Starloy{(R)}\;C$ was observed. Using bonding agent showed the higher bond strength than using the sand blasting treatment. In the Bellabond plus alloys, the specimen group with the use of binding materials showed higher shear bond strength, but didn't show statistically significant differences (p>0.05). In the $Starloy{(R)}\;C$ alloys, the specimen group with the use of binding materials showed higher shear bond strength and statistically significant differences(p<0.05). In terms of VM13 ceramic, it was in the Bellabond plus alloys that the high shear bond strength was showed, but there's no statistically significant differences(p>0.05). In terms of Vintage MP ceramic, it was in the $Starloy{(R)}\;C$ alloys that the high shear bond strength was showed and statistically significant differences(p<0.05). Metal-ceramic to fracture of the shear strength measurements and an analysis of all aspects of military usage fracture of the composite, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.2
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• pp.185-196
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• 1997

By considering the definition and application of resolution as well as the concept and theory of SAR, the essential contents of the SAR design and analysis are described. This paper is to compare and analyze the resolution performance capability of three techniques for achieving azimuth resolution such as the real aperture, the unfocused and the focused techniques, through the simulation. Simulation is performed to make the restricted conditions for the unfocused technique that can be implemented by the less commputing load of signal processingand the lower cost. Through the mission analysis, the use of SAR image can be applied for estimation of whole situation at the regional area in the field of military demands for tactical purpose as well as civilian demands for the damage of disaster. RPV and sall or medium aircraft are selected to carry the SAR for these purposes and the proper resolution turns ou 5~15 m. The trade-off study of variables through the simulations results in the proper conditions such that range is less 3, 000 m, Wavelength is 1~10 m, and the raw signals and results processed by three techniques for two point targets are exhibited undr such conditions. Therefore, at some points, the result of this paper si proposed for useful applications of unforcused technique in the restricted conditions except the identification of the small target at a long range re- quired for high resolution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.48-54
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• 2020

DMSMS (Diminishing Manufacturing Sources and Material Shortage) is increased by developing the scientific technique and downsizing the military part market. DMSMS affects the increase in total life cycle costs and serviceability. Therefore, advance control for parts is important to reduce the cost, and a database is needed to share information on the DMSMS. A task needs to be performed continuously by setting the major control item to management more efficiently. The purpose of this study was to deduce the major control item for the DMSMS management system. Thus, the pre-control item basis of the DAPA (Defense Acquisition Program Administration) Manual and the SD-22 Manual were first selected, and the results of the survey were analyzed by AHP (Analytic Hierarchy Process) method. Fifteen of the detailed items were stratified into three criteria (Impact, Probability, and cost of the DMSMS), and each weight for the items was calculated using a nine-point scale survey. The AHP survey was executed with 25 specialists in the DMSMS management field, and the score of consistency ratio over 0.1 was excluded. The model explained the results and suggested future directions for development.

• The Research Journal of the Costume Culture
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• v.1 no.1
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• pp.33-68
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• 1993

The purpose of this paper is to survey the influence of the culture change on the dress and personal adornments, and to survey the change of factors from the August 15. 1945 to 1960, in connection with the social and cultural background, applying B. Malinowski′s "Theory of Culture Change" which means an acculturation is the change′s elements of the dress and its ornaments. It is remarkable that the dress and personal adornments of Korean women after August 15, 1945 has great change from the traditional dress of the thousands years. Through the Liveration on August 15, 1945, American military government and the establishment of the Korean government, American democracy has brought many changes on Korean society. Advancement of education, an society with developed economic life, and introduction of scientific skill have influenced on the women′s way of thinking and a style of behavior and the view of value. The acculturation, the supply of mass communication, introduction of new institution and the reorganization of the old institution, the change of the economic situation, the change of the educational system, the change of the point of value, the development of scientific skill have greatly influenced on the dress and personal adornments. Modern dress and personal adornments of Korean women has the following developing procedure. The Liberation from Japan on the 15th, of August, 1945, the stationing of American Soldiers during hte Koran War, returning of the oversea′s brethern, and the mass communication have the direct and indirect contact with western civilization, and bring the occasion of development of the modern dress of Korean women. The increase of mass communication, such as radio, TV, newspaper, magazines and the frequent fashion shows showed fine design and practical western style dress to the women. This was the real beginning of the western style dress in Korea. By the increase of employment and the improvement of the economic situation, the consumption of clothing and the adornments was increased, so that a wide variety of fashions was set, and numerous kind and form of dress came in. As the increase of the number of women students, their practical and free dress life demanded western style dress. After the Liberation from Japan, the open-door policy of sex, public morals and traditional ethics became lax, and in this disordered society, indecent expose of the body was common. By the different kind of technological development, the form, fabrics, colors and patterns in clothes were much influenced and the hair style, make up, shoes and adornments were much influenced too. As shown above, the change of the dress has the same connection with that of society and culture. This shows that the dress and personal adornments represent clearly the cultural phenomenon of the society and cultural change of the society.

• Journal of Korea Multimedia Society
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• v.11 no.9
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• pp.1204-1212
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• 2008

The vehicle simulation (flight simulator) in 1920's was the first in the virtual reality. With the development of precise optical and electromagnetic equipment, the virtual reality widened its application for other purposes than military one. Based on the realistic display technology, it is more and more common in the various areas such as entertainment, medical profession, learning, film, architectural design, tourism and etc. In 1989, Jaron Ranier was the first to use the terminology 'Virtual Reality'. With this term, all virtual projects could be classified in a single item. But even before the term was used, the virtual reality has been studied up to now. As a part of virtual reality, the human thirst for the impossible thing has led to the development of ride film. The ride film consists of the special technical elements as well as the psychological analysis of human being. The ultimate purpose of virtual reality is engrossment through interaction. Even though the real interaction requires interface, input sensor and reaction ability, the ride film is not an element of the typical interaction. The virtual reality is mostly defined in technical terms now. But in this study, we will analyze the concepts worked out by Professor Michael Haim who is called a philosopher in the cyberspace in aspect of experience-oriented definition. We will analyze the adaptability of virtual reality based on his concepts such as artificial reality/ interaction/ engrossment/ networked world/ remote display/ simulation/ onmon engrossment. And also, we aim to suggest the directions of developing the ride films for perfect engrossment and to draw optimized conclusion thereon. In this viewpoint, we consider that the study of ride film on which there were few case studies will contribute to level up the basic frameworks of IT technology and the digital image.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.311-316
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• 2020

The main cause of DMSMS is the rapid replacement cycle and short life cycle of parts, according to the development of science, compared to the long life cycle of weapons systems. In particular, the problem of the supply and demand of such parts becomes even more acute during the operation maintenance phase after the mass production and power generation stage. To eliminate DMSMS problems that arise continuously from development to the operation of weapon systems and select the most cost-effective countermeasures to obsolescence, this paper suggests a standard to determine the appropriate time for quantitative performance improvement by conducting total life cycle cost analysis. For such purpose, this study examined the domestic and overseas cost analysis methods and applied it to single domestic weapon system to verify the research. This study responds to the issue of discontinuing components and helps reduce the total life cycle cost of military products.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.3
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• pp.139-146
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• 2018

Underwater acoustic communication can be applied to various area such as scientific, commercial and military survey using Autonomous Underwater Vehicles and Unmanned Underwater Vehicles. Underwater communication is studying very actively by advanced country like United States. But differ from wireless communication in the air, underwater acoustic communication has some difficult problems, ISI(Inter Symbol Interference) due to multipath and limit of transmission bandwidth due to slow propagation of sound wave. In this paper, SC-FDE and OFDM transmission system for the cancellation of ISI in conjunction with underwater acoustic channel modeling are applied to the underwater simulation of communication. The performance of these methods in the simulation guide to possibility of adopting in underwater acoustic communication algorithm. For this purpose, we compare SER performance of SC-FDE with that of OFDM for modelled underwater channel. Underwater channel is generated by Bellhop model. Simulation results show above 5dB SNR gain at 10-3 SER. And it demonstrate SC-FDE is efficient method for underwater acoustic communication.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.147-163
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• 2013

The purpose of this study is to compare precipitation distributions in precipitation data sets over South Korea produced by three interpolation methods. The differences of precipitation caused by interpolation methods is an important information when the interpolated precipitation data sets were used in researches such as ecological and hydrological modeling as well as regional climate impact studies. In this study, the precipitation data sets were produced by IDW(Inverse Distance Weighting) and Cokriging in this study and the PRISM(Precipitation-elevation Regressions on Independent Slopes Model) data set obtained from Climate Change Information Center of Korea. The spatial resolution of the precipitation data is 1km. As a result, there was a great precipitation difference caused by interpolation methods in data of mountainous watersheds in general. Especially the difference of monthly precipitation was 10~20% or more in the mountainous watersheds near the Military Demarcation Line dividing North and South Korea, Mt. Sobaik, Mt. Worak, Mt. Deogyu, Mt. Jiri and Taeback Mountain Range. It means that a final result of a research can be affected by adopted interpolation method when an interpolated precipitation data set is used in the research for the these study sites.

• Journal of the Korea Fashion and Costume Design Association
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• v.7 no.3
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• pp.181-188
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• 2005

This study attempted to investigate the plastic characteristics of cyber punk fashion with a focus on fashion in the cyber punk movies in order to inquire into how the influence of the cyber punk taking the lead in the spiritual culture and way of life of the humankind in the 21th century would be expressed in fashion. For this purpose, it sought to analyze the beauty of new fashion creating the cyber environment and identify its contemporary meaning. An attempt was made to investigate the image of cyber punk fashion with a focus on fashion expressed in the cyber punk movies. As a result, the following findings were obtained: First, the image of cyber punk fashion expressed in the cyber punk movies was simplicity, which was to express the modest silhouette and details exclusive of decoration. In addition to clean and smooth gloss, it contained the modest image of resistance', not 'revolt' by borrowing the partial motive and image from existing punk fashion. The change of cyber punk fashion into the characteristic of concise, smooth external appearance brought about the restraint of its image and symbolism as well as its plastic characteristic. Second, it was characterized by the Eroticism nature of emphasizing the body line while expressing the future and modest image or exposing the body. Cyber punk fashion expressed the avant-garde image by using materials that gave a mysterious and future feelings, as well as unsymmetrical silhouette, the slit of body-conscious line, coarse cutting, the method of do-constructing and reconstructing the silhouette, the method of applying diverse underwears such as corset, brassiere and the like. Third, cyber punk fashion was marked by the nature of mined sex. It had the masculine image by using the black color containing the image of masculinity and resistance in female clothing and expressing the suit, coat and military looks giving an masculine impression. And it expressed the image of mixed sexes with the masculine image in male clothing by borrowing feminine images such as body-conscious line, widely cut neckline, floral decoration, leggings and the like. Fourth, cyber punk fashion was marked by naturalness. It was expressed as clothing made from silhouette, knit, cotton and the like in the atmosphere expressing love, comfortableness and truth. This contained the image of naturalness, a return to the primitive, that human being wanted to return to their original figure in the future element. The cyber punk movie may contain a dismal, gloomy future image on the whole, which can be overcome, and shows the possibility that it may grow into the alternative culture, not the revolting culture. The movie of 'The Fifth Element' demonstrates the meaning and role that shows the bright future image. It is thought that designers should make efforts for cyber punk fashion to perform its role in changing the gloomy future image into the bright image of society

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.2
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• pp.161-164
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• 2006

Purpose: Meniscal injuries are very common sports problems and indications for knee surgery. We analyzed the effectiveness of joint line tenderness retrospectively. Materials and Methods: From May 2005 to June 2006, 76 knees which were diagnosed meniscal injury and performed arthroscopic surgery by same surgeon at military hospital were included. We analyzed sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of joint line tenderness in meniscal diagnosis. Results: The joint line tenderness gave such results (78.8%, 32.6%, 52.6%, 47.3%, 66.7% for sensitivity, specificity, accuracy, positive predictive value, negative predictive value respectively). We got similar results in analyses with medial meniscal lesion, lateral meniscal lesion, and combined instability patients. Conclusion: The joint line tenderness is a easy and comfortable maneuver but, it's effectiveness is low when it is used lonely The composite examinations including MRI and diagnostic arthroscopy for meniscal injuries of the knee perform much better than joint line tenderness alone.