• Title/Summary/Keyword: 자연형 하도

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Tooth color changes associated with the bracket bonding and debonding (교정치료 시 브라켓 부착 및 제거에 따른 치아색 변화)

  • Kim, Seok-Pil;Hwang, In-Nam;Cho, Jin-Hyoung;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.36 no.2 s.115
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    • pp.114-124
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    • 2006
  • The purpose of this study was to evaluate the tooth color changes of resin bonding sites and their adjacent sites on orthodontic bracket bonding. Sixty extracted sound premolars were used and the tooth color was recorded according to the CIE $L^*a^*b^*$ color system using a spectrophotometer. The tooth colors of the twenty premolars were measured and compared before bracket bonding and after removal. On a further twenty premolars, the tooth color was measured before and after only primer application. In the change of $L^*$ values, according to the bracket bonding and primer application, the lightness was decreased, and in the change of $a^*\;and\;b^*$ values, the color was changed into a more yellowish color The color differences $({\Delta}E^*)$ were calculated from the $L^*a^*b^*$ values and compared with the standard value of clinical detection $({\Delta}E^*=3.7)$. The color differences between before the bracket bonding and after removal noted exceeded the standard value and those of between before and after the primer application were not larger than the standard value. Toothbrushing was performed after application of the primer to evaluate the color changes according to the primer abrasion. As a control, toothbrushing was performed on the last twenty premolars. The color differences noted were larger than the standard value after toothbrushing. Also, to evaluate the color changes of the tooth which is exposed to sun irradiation after bracket removal, additional photoaging was performed and the color was measured for all teeth. The additional color differences after photoaging were smaller than the standard value. The above results suggest that the tooth color changes after fixed orthodontic treatment.

Writing and Sijo in new media culture age (새로운 매체문화시대의 글쓰기와 시조)

  • Jung Ki-chul
    • Sijohaknonchong
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    • v.22
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    • pp.27-55
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    • 2005
  • Visual media are taken the highest position in modem society, Modern poems also have been changed into visual poems, This aspect is the result of considering only individual talents ignoring traditions. Now, new Sigo should be concentrated on the mythological and historical voice from true nature and the body of human being, That is. ut should be converted into an ecological world view resolutely and restored a form of expression granted specific characteristics of our language. Advantages the computer media have brought. that is. equality freedom. human rights. harmony. pro-environmental value. can be maximized by positively accepting an ecological world view of Sijo which had included daily lives and spirits of the nation. Moreover. these all changes of new Sijo have to be established and recreated in the traditional expressions of Sijo. Aesthetic value of Sijo should be found in the expression forms such as phonetic harmony, rules of versification, rhythm, and etc. Then, we can overcome modern society's pathological phenomena such as severance, separation, dissolution, estrangement, psychiatric syndrome and etc. which visual media superiority brought. At the same time. it will cure ills of modern poems, Sijo and writing epochally and can establish true happiness and development.

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Methodologies for Enhancing Immersiveness in AR-based Product Design (증강현실 기반 제품 디자인의 몰입감 향상 기법)

  • Ha, Tae-Jin;Kim, Yeong-Mi;Ryu, Je-Ha;Woo, Woon-Tack
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.2 s.314
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    • pp.37-46
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    • 2007
  • In this paper, we propose technologies for enhancing the immersive realization of virtual objects in AR-based product design. Generally, multimodal senses such as visual/auditory/tactile feedback are well known as a method for enhancing the immersion in case of interaction with virtual objects. By adapting tangible objects we can provide touch sensation to users. A 3D model of the same scale overlays the whole area of the tangible object so the marker area is invisible. This contributes to enhancing immersion. Also, the hand occlusion problem when the virtual objects overlay the user's hands is partially solved, providing more immersive and natural images to users. Finally, multimodal feedback also creates better immersion. In our work, both vibrotactile feedback through page motors, pneumatic tactile feedback, and sound feedback are considered. In our scenario, a game-phone model is selected, by way of proposed augmented vibrotactile feedback, hands occlusion-reduced visual effects and sound feedback are provided to users. These proposed methodologies will contribute to a better immersive realization of the conventional AR system.

Characteristics of the Strains Selected from Crosses between Introduced Interspecific Hybrids and Cultivars in Hibiscus Species (종간교잡 유래 도입 무궁화와 국내 선발 품종과의 교잡에 의해 육성된 계통들의 특성)

  • Kang, Ho-Chul;Ha, Yoo-Mi;Kim, Dong-Yeob;Han, In Song;Noh, Kwang-Mo
    • FLOWER RESEARCH JOURNAL
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    • v.19 no.1
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    • pp.55-63
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    • 2011
  • This study was carried out to develop new cultivars of Hibiscus species from crosses between introduced interspecific hybrids and cultivars in Hibiscus species. Fruit setting of interspecific crosses of Hibiscus strains was less than 10% and the number of seeds in the fruit was also in low level. Three individuals of specific flower and leaf characteristics were selected from crosses between introduced interspecific hybrid, 'Fujimusme'(♀), and H. syriacus 'Namwon'(♂) in 2004. A new strain, Hibiscus ${\times}$ 'W-26', was selected from the crossing of interspecific hybrid, 'Fujimusme'(♀), and H. syriacus 'Namwon'(♂), which had white flower and narrow separated petal. Hibiscus ${\times}$ 'WRB-2' was selected from the crossing of interspecific hybrid, 'Fujimusme'(♀), and H. syriacus 'Namwon'(♂), which had white flower and blue eye spot. Hibiscus ${\times}$ 'R-141' was selected from crosses between introduced interspecific hybrid, 'Shichisai'(♀) and H. syriacus 'Namwon'(♂), which had large flowers over 13 cm diameter and revealed tall tree type. Hibiscus ${\times}$ 'R-142' was selected from the crossing of interspecific hybrid, 'Shichisai'(♀), and H. syriacus 'Namwon'(♂), which had large flowers over 13 cm diameter and revealed tall tree type. The characteristics were succeded after grafting. Flower of 'R-142' had reddish violet color with red eye spot, whereas its parent had blue and purple flowers.

Optimization and Application Research on Triboelectric Nanogenerator for Wind Energy Based High Voltage Generation (정전발전 기반 바람에너지 수확장치의 최적화 및 고전압 생성을 위한 활용 방안)

  • Jang, Sunmin;Ra, Yoonsang;Cho, Sumin;Kam, Dongik;Shin, Dongjin;Lee, Heegyu;Choi, Buhee;Lee, Sae Hyuk;Cha, Kyoung Je;Seo, Kyoung Duck;Kim, Hyung Woo;Choi, Dongwhi
    • Korean Chemical Engineering Research
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    • v.60 no.2
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    • pp.243-248
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    • 2022
  • As the scope of use of portable and wearable electronic devices is expanding, the limitations of heavy and bulky solid-state batteries are being revealed. Given that, it is urgent to develop a small energy harvesting device that can partially share the role of a battery and the utilization of energy sources that are thrown away in daily life is becoming more important. Contact electrification, which generates electricity based on the coupling of the triboelectric effect and electrical induction when the two material surfaces are in contact and separated, can effectively harvest the physical and mechanical energy sources existing in the surrounding environment without going through a complicated intermediate process. Recently, the interest in the harvest and utilization of wind energy is growing since the wind is an infinitely ecofriendly energy source among the various environmental energy sources that exist in human surroundings. In this study, the optimization of the energy harvesting device for the effective harvest of wind energy based on the contact electrification was analyzed and then, the utilization strategy to maximize the utilization of the generated electricity was investigated. Natural wind based Fluttering TENG (NF-TENG) using fluttering film was developed, and design optimization was conducted. Moreover, the safe high voltage generation system was developed and a plan for application in the field requiring high voltage was proposed by highlighting the unique characteristics of TENG that generates low current and high voltage. In this respect, the result of this study demonstrates that a portable energy harvesting device based on the contact electrification shows great potential as a strategy to harvest wind energy thrown away in daily life and use it widely in fields requiring high voltage.

Distribution and Host Plants of Parasitic Weed Cuscuta pentagona Engelm. (기생식물 미국실새삼의 분포 및 기주식물상)

  • Hwang, Sunmin;Kil, Jihyon;Lee, Chang-Woo;Kim, Youngha
    • Korean Journal of Plant Resources
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    • v.26 no.2
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    • pp.289-302
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    • 2013
  • Surveys were conducted to study nationwide distribution and identify habitats and host plants of Cuscuta pentagona Engelm. as a parasite. The major habitat types were arable land near agricultural waterways (54.3%), open field near roadside (41.3%) and artificial grassland (4.3%). The investigated host plants of Cuscuta pentagona consist of total 130 taxa: 10 varieties, 1 subspecies, 119 species, 95 genera, and 37 families. Among them, 30 taxa were alien plants. As for the useful plants, there were 59 taxa of edible ones (45.4%), 54 taxa of medicinal ones (41.5%), 13 taxa of ornamental ones (10%), 13 taxa of industrial ones (10%), and 9 taxa of pasture ones (6.9%). On arable land, it caused damage particularly to the growth of agricultural crops such as Oryza sativa L. (Rice) and fruits such as Malus pumila Mill. (Apple) etc. Its growth and distribution may cause economic loss for crops because of the close location of the arable land.

Pathological Study of Tumors Occurring in Dog (견종양(犬腫瘍)의 병리학적(病理學的) 검색(檢索))

  • Lim, Chang Hyeong
    • Korean Journal of Veterinary Research
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    • v.15 no.1
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    • pp.27-38
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    • 1975
  • The following tumors occurring naturally in the dog were studied pathologically and discussed briefly. Tumors of the skin and subcutis: Fibroma, Lipoma, Epidermal cyst, Melanosarcoma, Sweat gland adenoma, Mastocytoma (2 cases), Mastosarcoma, and Sebaceous gland carcinoma. Tumors of the spleen and lymph node: Fibrosarcoma of the capsule of spleen, Leiomysarcoma of the spleen, and Lymphosarcoma of the lymph node (2 cases). Tumors of the lung: Bronchogenic carcinoma (3 cases), Adenocarcinoma type, Squamous carcinoma type, and Undifferentiated (round cell) carcinoma type respectively. Tumors of the alimentary tract and liver: Fibroma of the stomach, Hemangioma of the liver, Bile duct carcinoma, Liver cell carcinoma, and Myelogenous leukemia manifested in the liver. Tumor of the peritoneum: Fibrosarcoma. Tumors of the urogenital system: Fibroma of the uterus, Fibroma of the prepuce, Follicular cyst of the ovary, Transmissible venereal tumor of the vagina (6 cases), Carcinoma of the kidney, Adenoma of the prostate (2 cases), and Seminoma of the testis. Tumors of the mammary gland: Mixed tumor (2 cases), and Myoepithelioma. Tumor of the nervous system: Neurofibrosarcoma of the thigh.

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A Study on the Welding Amount Estimation System combined with 3D CAD Tool (3차원 CAD 통합형 용접물량 산출 시스템에 관한 연구)

  • Ruy, Won-Sun;Kim, Ho-Kyeong;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3184-3190
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    • 2013
  • These days, the great part of design processes in the field of ship or offshore manufacturing are planed and implemented using the customized CAD system for each ship-building companies. It means that all information for design and production could be extracted and reused at the useful other area cost considerable time and efforts. The representative example is the estimation of welding length and material amount which is demanded during the construction of ship or offshore structures. The proper estimation of welding material to be used and the usage of them at the stage of schedule planning is mostly important to achieve the seamless process of production and expect the costing in advance. This study is related to the calculation of welding length and needed material amount at the stage of design complete utilizing the CAD system. The calculated amount are classified according to welding position, stage, block, bevel and welding type. Moreover it is possible to predict the working time for welding operation and could be used efficiently for the cost management using the results of this research.

On the Topographies and Recovery of Vegetation in the Hillside Erosion Control Districts (산복사방공사시공지(山腹砂防工事施工地)에 있어서 지형(地形)과 식생회복(植生回復))

  • Kang, Wi Pyung
    • Journal of Korean Society of Forest Science
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    • v.64 no.1
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    • pp.42-46
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    • 1984
  • This study was carried out to obtain the advanced basic data for hillside erosion control works. Recovery of vegetation in the hillside erosion control districts depends on various factors i.e., topographies, soil qualities, rain conditions and erosion control methods. The only relations between topographies and vegetation coverage were surveyed, since the other factors were equal in all those surveyed areas. The results obtained are summarized as follows; 1) Mean coverage values were decreased in order of 80%, 78.7%, 64.0% and 56.5%r in concave slope, uniform slope, compound slope and convex slope respectively. The mean coverage of all aspects was 69.8%. The slope pattern have a influence on formation of coverage. 2) Moisture ratio in soil and mean slope have an effect on the mean coverage value. 3) In the beginning of the hillside erosion control working, coverage (14.8%) by arbor species was too low comparing with that by herb. 4) It is more desirable to recover regetation by artificial planting or seed planting than by the natural vegetation in the barren hillside. In the beginning of the hillside erosion control working, it is difficult to expect vegetation recovery by natural species.

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A Study on the Possibility of Self-Correction in the Market for Protecting Internet Privacy (인터넷 개인정보보호의 시장자체해결가능성에 대한 연구)

  • Chung, Sukkyun
    • Journal of Digital Convergence
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    • v.10 no.9
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    • pp.27-37
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    • 2012
  • Internet privacy has become a significant issue in recent years in light of the sharp increase in internet-based social and economic activities. The technology which collects, processes and disseminates personal information is improving significantly and the demand for personal information is rising given its inherent value in regard to targeted marketing and customized services. The high value placed on personal information has turned it into a commodity with economic worth which can be transacted in the marketplace. Therefore, it is strongly required to approach the issue of privacy from economic perspective in addition to the prevailing approaches. This article analyzes the behaviors of consumers and firms in gathering personal information, and shielding it from unauthorized access, using a game theory framework in which players strive to do their best under the given conditions. The analysis shows that there exist no market forces which require all firms to respect consumer privacy, and that government intervention in the form of a nudging incentive for information sharing and/or strict regulation is necessary.