• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.300-305
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• 2012

In this paper, a miniaturized bow-tie monopole UWB antenna with band rejection characteristic is proposed. To miniaturize the proposed antenna, a perfect magnetic wall(PMW) condition is applied to primitive bow-tie monopole antenna. An uneven ground patch, a tapered feeding structure and a edge-chopped main patch are adapted for impedance matching. A quater-lambda slot resonator is inserted at main patch to prevent interference in UWB band from another band. The proposed antenna is fabricated on Taconic RF60-A substrate with relative permittivity of 6.15. The size of the proposed antenna is $30.0{\times}39.7mm^2$, which is only 45 % of the conventional bow-tie monopole antenna. The proposed antenna covers full UWB band with return losses less than -10 dB and has band stop characteristic in 5 GHz WLAN band. The maximum gains are within -1.0~5.0 dBi, the group delay variations are within 1.0 ns and the radiation patterns show directivity characteristics in x-y plane.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.1
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• pp.1-11
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• 2011

The objective of this study was to investigate the landscape structures of the National and Provincial Forest Parks in the list of "100 Famous Forests of Korea" designated by Korea Forest Service by comparing them with those of the non-designated forests. Among the designated and the non-designated, 34 mountain forests were chosen respectively over all provinces of Korea. The spatial characteristics of forest landscapes were quantified as the landscape indices independently using FRAGSTATS and the two sets of results of analyses were compared each other. According to the results of the comparative study, the designated forests were found on the higher elevation with the higher average slope and the more complicated relief conditions rather than those of the non-designated. In terms of landscape structure, the designated forests show the larger average patch size, the lower edge density and the higher diversity of landscape components. These results indicate that the more hilly mountain forests with the more complicated spatial distribution patterns of patches are the characteristics of the designated forests. The indices of the forest landscape structure would be useful in understanding the perception of forest landscape.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2169-2175
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• 2009

This research aims to evaluate the concept of eco-efficient water infrastructure and provides a list of case studies in order to help understand the applicability of eco-efficient water infrastructure to Asia and the Pacific. A set of indicators have been explored to assess eco-efficiency in water infrastructure for the region on a micro and macro scale. The core idea of eco-efficiency, 'more value with less impact (on the environment)', has proven to be applicable in management of water infrastructure. The fundamental elements in eco-efficient water infrastructure should encompass physical infrastructure and non-physical infrastructure, which is more needed particularly in Asian countries. The case studies have demonstrated the applicability of the concept of eco-efficient water infrastructure. The Republic of Korea has provided the case of the eco-friendly approaches to enhance dam management and its innovative solutions how to use water more efficiently through state-of-art technologies. The experiences of Singapore are some of the best evidence to establish eco-efficient water infrastructure, for instance, the NEWater project via application of cutting edge technologies (recycled water) and institutional reform in water tariff systems to conserve water as well as enhance water quality. A list of indicators to assess eco-efficiency in water infrastructure have been discussed, and the research presents a myriad of project cases which are good to represent eco-efficiency in water infrastructure, including multipurpose small dams, customized flood defense systems, eco-efficient ground water use, and eco-efficient desalination plants. The study has presented numerous indicators in five different categories: 1) the status of water availability and infrastructure; 2) production and consumption patterns of freshwater; 3) agricultural products and sources of environmental loads; 4) damages from water-caused natural disaster; and 5) urban water supply and sanitation. There are challenges as well as benefits in such indicators, since the indicators should be applied very carefully in accordance with specific socio-economic, political and policy contexts in different countries in Asia and the Pacific Region. The key to success of establishment of eco-efficient water infrastructure in Asia primarily depends on the extent to which each country is committed to balancing its development of physical as well as non-physical water infrastructure. Particularly, it is imperative for Asian countries to transform its policy focus from physical infrastructure to non-physical infrastructure. Such shift will help lead to implementation of sustainable in Asian countries.

• Journal of the Korean Society of Costume
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• v.35
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• pp.17-44
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• 1997

Medieval European practical art and style of costume is studied through referring to the literatures. The type of clothing that was seen on tapestries arts and crafts paintings and wall paintings and appeared in the architecture such as church. There were symbolic aspects of color motifs at this period and some restraints for clothing according to the social class, It was a period that draped garments due to the War of Crusades is appeared. Be-cause the medieval taste and decorative character is not only 'formative art' but also the taste beyoud 'mode' and atomsphere of that times it could be seen the strong reflec-tion of customs in the clothing of that times which is shown in works of art. 1) The purpose of Christian art which was found in mosaics stained glasses wall pain-tings and statues of architecture was not just the revival of natural phenomena but visuali-zation of sacred and invisible things. It was valuable to understandin of the spiritual through the sense organ It was a monumental art that was combined with decorative func-tion and role of the Bible. It revealed what was about the religious spiritual miracle, 2) In the medieval European painting characteristic and beautiful creativity was the basis of an argument. Both "Worship of East-ern" that is painted ion a parchment and "Cor-onation of Charles VI" were described decor-ation motifs on the edge of buildings geo-metric patterns and others with outstanding skill. there were precise technologic skill of architect and glassmen and lots of patience of craftsmen. " The Labour of the Months" and the scene of"A Trial at the Court" is also de-scribed elaborately. 3) Tapestry was developed in France Ger-many Swiss at the 14th century. Religionary and historical themes unicorn lady bird flowering plants and others were major motifs. It was very important as decorative wall coverings and as practical door arch and bed hangings. It was made through patient hard work with simple technique and it was con-sidered as an art for practical use. Tapestry was what everyone wish to have. It is reckoned for the item of the best gift. The royalty and nobility ordered and used custom-made tapestries. Sometimes the subject of motifs consisted of series which were deeply related to living 4) Decorative arts and crafts was the art that used materials such as precious metals jewels and others and that accorded with the luxurious and gorgeous taste of the royalty and nobility. Christian considered splendid and beautiful color of light as a symbol of glory. They used also for church appliances, There were metal crafts wood crafts textile crafts and others, As was stated above the costume appeared on the arts and crafts for living revealed the process of changes saw how the politic econ-omic and social organizations were developed.and social organizations were developed.

• Progress in Medical Physics
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• v.14 no.3
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• pp.151-160
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• 2003

The application of more complex radiotherapy techniques using multileaf collimation (MLC), such as 3D conformal radiation therapy and intensity-modulated radiation therapy (IMRT), has increased the significance of verifying leaf position and motion. Due to thier reliability and empirical robustness, quality assurance (QA) of MLC. However easy use and the ability to provide digital data of electronic portal imaging devices (EPIDs) have attracted attention to portal films as an alternatives to films for routine qualify assurance, despite concerns about their clinical feasibility, efficacy, and the cost to benefit ratio. In this study, we developed method for daily QA of MLC using electronic portal images (EPIs). EPID availability for routine QA was verified by comparing of the portal films, which were simultaneously obtained when radiation was delivered and known prescription input to MLC controller. Specially designed two-test patterns of dynamic MLC were applied for image acquisition. Quantitative off-line analysis using an edge detection algorithm enhanced the verification procedure as well as on-line qualitative visual assessment. In conclusion, the availability of EPI was enough for daily QA of MLC leaf position with the accuracy of portal films.

• Archives of design research
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• v.18 no.1 s.59
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• pp.135-144
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• 2005

Consumers' awareness of product value, and their product preferences, are becoming increasingly influential in product development, particularly in corporations' efforts in manufacturing products with a competitive edge. Corporations conduct surveys on consumers' product satisfaction and preferences and conduct in-depth studies on consumer needs. They then manufacture products in accordance with the results of these surveys and studies. With the necessity and demand for digital door lock products recently growing, this research sought to explore product competitiveness reinforcement factors that could facilitate market penetration, and to formulate corresponding design strategies. In-depth consumer interviews were also conducted to identify consumer lifestyles and needs. Furthermore, consumer preference images, purchase and use-related patterns, and the status of door lock markets were studied. In the past, to design and manufacture consumer-oriented products, corporations primarily resorted to the improvement of the products' technological features. At present, the users' product preferences and the ways that they use these products are the factors that determine product design. Consumers today tend to adjust their lifestyles according to available products, and prefer products that have greater value in terms of lifestyle and culture. Strategic points for reinforcing competitiveness were presented in this study: first, offering different values that will enhance consumer satisfaction, second, positively developing bio-recognizable methods that will boost consumer preference, third, meeting the consumers' expectations that door lock products should not be mere 'entrance and exit control' systems, but network security systems and fourth, adopting convenient authentication methods backed by advanced technologies.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.211-220
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• 1998

The stochiometric composition of $AgGaS_2$polycrystal source materials for the single crystal thin films were prepared from horizontal furnace. From the extrapolation method of X-ray diffraction patterns, it was found that the polycrystal $AgGaS_2$has tetragonal structure of which lattice constant $a_0\;and \;c_0$ were 5.756 $\AA$ and 10.305 $\AA$, respectively. $AgGaS_2$single crystal thin film was deposited on throughly etched GaAs(100) substrate from mixed crystal $AgGaS_2$by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $590^{\circ}C$ and $440^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about 0.5 $mu \textrm{m}$/h. The crystallinity of the grown single crystal thin films was investigated by the DCRC (double crystal X-ray diffraction rocking curve). The optical energy gaps were found to be 2.61 eV for $AgGaS_2$single crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation, then the constants in the Varshni equation are given by${\Alpha};=;8.695{\times}10^{-4};eV/K,and;{\beta};=;332;K$. from the photocurrent spectra by illumination of polarized light of the $AgGaS_2$single crystal thin film, we have found that crystal field splitting $\Delta$Cr was 0.28 eV at 20 K. From the PL spectra at 20 K, the peaks corresponding to free and bound excitons and a broad emission band due to D-A pairs are identified. The binding energy of the free excitons are determined to be 0.2676 eV and 0.2430 eV and the dissociation energy of the bound excitons to be 0.4695 eV.

• The korean journal of orthodontics
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• v.41 no.4
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• pp.268-279
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• 2011

Objective: The purpose of this study was to compare self-drilling orthodontic mini-implants of different surfaces, namely, machined (untreated), etched (acid-etched), RBM (treated with resorbable blasting media) and hybrid (RBM + machined), with respect to the following criteria: physical appearance of the surface, measurement of surface roughness, and insertion pattern. Methods: Self-drilling orthodontic mini-implants (Osstem implant, Seoul, Korea) with the abovementioned surfaces were obtained. Surface roughness was measured by using a scanning electron microscope and surface-roughness-testing machine, and torque patterns and vertical loadings were measured during continuous insertion of mini-implants into artificial bone (polyurethane foam) by using a torque tester of the driving-motor type (speed, 12 rpm). Results: The mini-implants with the RBM, hybrid, and acid-etched surfaces had slightly increased maximum insertion torque at the final stage ($p$ < 0.05). Implants with the RBM surface had the highest vertical load for insertion ($p$ < 0.05). Testing for surface roughness revealed that the implants with the RBM and hybrid surfaces had higher Ra values than the others ($p$ < 0.05). Scanning electron microscopy showed that the implants with the RBM surface had the roughest surface. Conclusions: Surface-treated, self-drilling orthodontic mini-implants may be clinically acceptable, if controlled appropriately.

• Research in Plant Disease
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• v.12 no.3
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• pp.189-196
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• 2006

Crown gall on lower stem of weeping fig(Ficus benjamina Roxb.) was first observed at Daejon in 2003. Tumors were about 15 cm in size and semi-round with rough surface texture of dark brown color. Two virulent isolates among ten bacteria isolated from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge, and white or tannish cream in color on potato dextrose agar supplemented with 0.5% $CaCO_3$. They were rod shape with peritrichous flagellae, gram-negative, aerobic growth, oxidase-positive, and grew on D1M agar. The isolates were identified as Agrobacterium larrymoorei and A. tumefaciens based on biochemical and physiological characteristics, fatty acid profiles and substrate utilization patterns. Seedlings of some host plants excepting grapevine produced typical galls two to three weeks after inoculation with cell suspensions of the virulent strains. This is the first report on crown gall of weeping fig in Korea.

• Research in Plant Disease
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• v.12 no.3
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• pp.197-204
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• 2006

Crown gall on lower stem and root of chrysanthemum(Dendranthema grandiflorum Kitamura) was observed at Hwasung and Gumi in 2001 and 2004, respectively. Tumors were semi-round with rough surface texture of dark brown color. Nine isolates inducing gall formation on lower stem of chrysanthemum among twenty isolates from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge and whitish or tannish cream in color on potato dextrose agar supplemented with 0.5% $CaCO_3$. The virulent isolates were rod-shaped with peritrichous flagellae, gram negative, aerobic and growing on D1M agar. Among nine virulent isolates, one isolate was identified as Agrobacterium rubi and eight isolates were A. tumefaciens based on biochemical and physiological characteristics, fatty acid profiles and substrate utilization patterns. A. tumefaciens had strong pathogenicity and broad host range compared with A. rubi. This is the first report on crown gall of chrysanthemum in Korea. To our knowledge, crown gall of chrysanthemum caused by A. rubi is first report in this study worldwide.