• Title/Summary/Keyword: Large Display

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Effect of thread design on the marginal bone stresses around dental implant (임플란트 나사산 디자인이 변연골 응력에 미치는 영향)

  • Lee, Sang-Hyun;Jo, Kwang-Heon;Lee, Kyu-Bok
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.4
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    • pp.316-323
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    • 2011
  • Purpose: The purpose of this study was to investigate the effect of different thread designs on the marginal bone stresses around dental implant. Materials and methods: Standard ITI implant(ITI Dental Implant System; Straumann AG, Waldenburg, Switzerland), 4.1 mm in diameter and 10 mm in length, was selected as control. Test implants of four different thread patterns were created based on control implant, i.e. maintaining all geometrical design of control implant except thread pattern. Four thread designs used in test implants include (1) small V-shape screw (model A), (2) large V-shape screw (model B), (3) buttress screw (model C), and (4) trapezoid screw (model D). Surface area for unit length of implant was 14.4 $mm^2$ (control), 21.7 (small V-shape screw), 20.6 (large V-shape screw), 17.0 (buttress screw) and 28.7 $mm^2$ (trapezoid screw). Finite element models of implant/bone complex were created using an axisymmetric scheme with the use of NISA II/DISPLAY III (Engineering Mechanics Research Corporation, Troy, MI, USA). A load of 100 N applied to the central node on the crown top either in parallel direction or at 30 degree to the implant axis (in order to apply non-axial load to the implant NKTP type 34 element was employed). Quantification and comparison of the peak stress in the marginal bone of each implant model was made using a series of regression analyses based on the stress data calculated at the 5 reference points which were set at 0.2, 0.4, 0.6, 0.8 and 1.0 mm from implant wall on the marginal bone surface. Results: Results showed that although severe stress concentration on the marginal bone cannot be avoided a substantial reduction in the peak stress is achievable using different thread design. The peak marginal bone stresses under vertical loading condition were 7.84, 6.45, 5.96, 6.85, 5.39 MPa for control and model A, B, C and D, respectively. And 29.18, 26.45, 25.12, 27.37, 23.58 MPa when subject to inclined loading. Conclusion: It was concluded that the thread design is an important influential factor to the marginal bone stresses.

A Study of Korean Costume in the Collection of Overseas Museums (해외 박물관 소장 한국 복식문화재에 관한 연구)

  • 윤은재;임영자
    • Journal of the Korean Society of Costume
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    • v.36
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    • pp.219-238
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    • 1998
  • For the purpose of this Study, the situation of Korean costume properties in the collection of overseas museums was investigated through correspondence, interviews with their curators and persons in charge and survey. As results were made about the situation of museum science (conservation) and practical utilization of costume properties. So, the study result were drawn as follows : Krean costume properties unexplaind of 'Korean cultural Properties' could be found in the Metropolitan Museum of Art of New York(135 pieces), the Brooklyn Museum of New York(20 pieces), the Newark Museum of New Jersey(15 pieces), and the Victoria Albert Museum of London(100 pieces). Korean costume properties in the collection of over-seas museums mostly fall under the rang of period between the 19th century and the early 20th century and are classified into everyday clothing, wedding costume and armors for the most part. In 1900s, museum in several countries began to collected Korean cultural properties through foreign missionaries or diplomats as well as merchants or travellers in who bought Korean objects. Recently, scholars, traditional Korean costume designerss and diplomatic and consular offices in overseas have donated our Korean costume to many foreign museums. Korean costume properties were largely on display in the dependent display of folklore museums or in a part of exhibition gallery for Asian culture and there were the separate exhibition rooms in museums in the United Kingdom, Germany, Denmark, Austria, Japan and the United States America. But the size and level of display room for Korean cultural properties is one third as large as that for chinese or Japanese cultual properties. It was found in this study that the traditional Korean costume in the collection of overseas museums was largely recorded only as general items rather than given their proper names. The typical example of misnaming included bridal's Kimono for Wonsam(원삼) in the Metropolitan Museum of Art, Yeonroksaek-bumunsajeokori for Dangeui(당의) and Jissan-gryongwonmunsadurumagi for Kongdali(동달이) in the Okura collection of the Tokyo National Museum, and so on. And the Victoria Albert Museum modified the way of wearing Daenim(대님) and the National Museum of Ethnology in Osaka seemed to misplace the ornament of Keanggi(댕기) on Mubok(무복) and Josunjuk(조선족: Chinese-Korean) Museum also misplace hansam(한삼). On the one hand, the Newark museum of New Jersey mixed Chinese armor with the Korean one and the Photohraph of King Kojong(고종) with Chinese one. It is corrected to publish and disseminate the book concering Korean costume in order to inform foreign museums of thed proper names and wearing method of our traditional costumed. The repair of costume before cleaning in the process of conservation treatment can prevent damage likely to occur as the properties of fiber itself are weakened in liquid. It is recommended that western 8-figure stitch and tacking stitch is added to Korean traditional stitching method. Museums in the U.S.A and the U.K are concerned about the aftermath of cleaning it-self, specially conservation treatment may exert on remains and predominantly use the vacuuming method to remove dust or bits of straw before the exhibition beings. But in case of Korea, the dry cleaning and wet cleaning method are used according to the nature and state of a sample costume. This comprehensive cleaning method is gradually developing scientifically but it is expected that those concerned will make a chemical analysis of the solvent to be used and also the more precise test of costume properties will be conducted before cleaning them. A partial study was made here because the scope of study was too broad and vast. It is expected that more studies will be conducted concerning our costume culture under the long-term plan and active support at the government level.

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The Study on Risk Factors Analysis and Improvement of VDT Syndrome in Nuclear Medicine (핵의학과 Video Display Terminals Syndrome 유해 요인 조사 및 개선에 관한 연구)

  • Kim, Jung-Soo;Kim, Seung-Jeong;Lee, Hong-Jae;Kim, Jin-Eui;Kim, Hyun-Joo;Han, In-Im;Joo, Yung-Soo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.61-66
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    • 2010
  • Purpose: Recently, Department of Nuclear Medicine have an interest in Video Display Terminals (VDT) syndrome including musculoskeletal disorders, ophthalmologic disorders, trouble of electromagnetic waves and stress disorders occur to VDT workers as the growing number of users and rapid pace of service period supply in large amount. This study research on the actual condition for VDT syndrome in Nuclear Medicine, Seoul National University Hospital (SNUH), discover the problem and draw a plan of upcoming improvement. The aim of this study establish awareness about VDT syndrome and is to prevent for it in the long run. Materials and Methods: Department of Nuclear Medicine, SNUH is composed Principle part, Pediatric part and PET center. We estimated risk factors visit in each part directly. Estimation method use "Check list for VDT work" of Wonjin working environment health laboratory and check list is condition of VDT work, condition of work tables, condition of chairs, condition of keyboards, condition of monitors, working position, character of health management and other working environment. Analysis result is verified in Department of Occupational and Environment, Hallym University Sacred Heard Hospital. Results: As a result of analysis, VDT condition of Department of Nuclear Medicine, SNUH is rule good. In case of work tables, recent of things are suitable to users upon the ergonomical planning, but 15% of existing work tables are below the standard value. In case of chairs are suitable, but 5% of theirs lost optimum capacity become superannuated. The keyboards are suitable for 98% of standard value. In case of monitors, angle control of screen is possible of all, but positioning control is impossible for 38%. In case of working position, 10% is fixed positioning for long time and some of the items researched unsuitable things for standard. At health management point, needed capable of improvement. Also, other working condition as lighting, temperature, noise and ventilation, discovered the problem, but is sufficient to advice value. Conclusion: VDT syndrome is occurrences of possibility continuously, come economical expensive about improvement, is inherent in various causes and originate without your knowledge. So, there is need systematic management system. In Nuclear Medicine, VDT syndrome make it better that constant interest and effort as improvement of ergonomical working environment, improvement of working procedure, regular exercise and steady stretching, and can be prevented fairly. This promote physical and mental condition of worker in top form in comfortable working environment, so this is judged by enlargement of operations efficiency and rising of satisfaction ratings of the inside client.

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A New Approach to Mobile Device Design - focused on the Communication Tool & it's GUI for Office Workers in the Near Future - (모바일 기기 디자인의 새로운 접근 - 근 미래 작업환경에서의 커뮤니케이션 도구 디자인과 GUI 연구를 중심으로 -)

  • Yang, Sung-Ho
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.31-42
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    • 2006
  • This study originates from the following critical mind; what will the office of the future be like? and what technology will we rely upon most to communicate with colleagues or to access business information. In the office environment today, new technology has compelled new work paradigm and has greatly affected the capabilities of the individual to work in a more productive and efficient manner. However, even though new computer technology has changed the business world so rapidly, it is very difficult to see the changes that have been taken place. As an aim of the study, creating a mobile tool for office workers that successfully supports their work and communication was explored, and this study explored future work environment with a 5 years technological and social perspective. As a result of this study, the bON brings new visions to the mobile professionals via various interfaces. The bON, a mobile device, is both a system of work and of communication for office workers. The bON, as an integrated tool for working and communicating, forms the basis for a mobile information gateway that is equally capable of functioning as a mobile desk. The basic underlying idea is that all formal meeting places and hallways in the office are equipped with large wall-mounted screens. The bON collaborates with these media in various ways to enhance productivity and efficiency. The main challenge for the bON to enhance both mobility and quality of information is using new technology including bendable and flexible display and soft material display and sensors. To answer for the strong needs for mobility, the whole size of the device is fairly small while the screen is rolled inside the device. For Graphical User Interface, moreover, a new technique called Multi-layering Interface was adopted to stretch user's visual limits and suggests new direction in designing mobile device, equipped with small size display.

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A Study on the description of Puppet Performance History (인형연행사 기술의 새로운 모색)

  • Heo, Yong-ho
    • (The) Research of the performance art and culture
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    • no.19
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    • pp.379-418
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    • 2009
  • This study is a link in a chain which grope for the description of puppet performance history. This study imply my intention which is not a description of puppet performance 'history' but a description of 'puppet performance' history. Object materials of this study is materials connected with puppet performance from ancient times to Chosun dynasty. Object materials of this study include not only records but also remains and pictures. Discussion start with regulation of puppet performance materials and establishment of a classification criterion. As a result of that discussion, the age of puppet performance is as follows: 'the age of diverse use of puppet', 'the age of ritual puppet performance of worship', 'the age of play puppet performance of handling', 'the age of ritual puppet performance of display', 'the age of ritual puppet performance of expulsion', 'the age of ritual puppet performance of handling', 'the age of play puppet performance of display', 'the age of play puppet performance of handling and voice-acting'. According to the internal division of age, the description of puppet performance history which is spread chronologically is attempted. As a result of the description, I confirm that puppet performance reveal a one's unfolding process. And a distinct aspect from the general cultu! re history is found. The development process which is a changeover that is 'from ritual puppet performance to play puppet performance' is amended by a circulation of ritual puppet performance and play puppet performance'. And the development process which is a changeover 'from static puppet to dynamic puppet' is amended by a circulation of static puppet and dynamic puppet'. Like this the thing which is laid in the inside which is not a one sided changeover but is a circulation is said that from one age of puppet performance to other age of puppet performance is not a close of former puppet performance tradition. Unfolding from one age to other age, on the other hand former puppet performance reveal aspect which is a continuance and change with a one's vitality. And a relation of mutual influence is exist between the ritual puppet performance and the play puppet performance on a large scale, among the puppet performance types on a small scale. this also don't overlook in cas! e of a groping of puppet performance history.

Construction and Application of Intelligent Decision Support System through Defense Ontology - Application example of Air Force Logistics Situation Management System (국방 온톨로지를 통한 지능형 의사결정지원시스템 구축 및 활용 - 공군 군수상황관리체계 적용 사례)

  • Jo, Wongi;Kim, Hak-Jin
    • Journal of Intelligence and Information Systems
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    • v.25 no.2
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    • pp.77-97
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    • 2019
  • The large amount of data that emerges from the initial connection environment of the Fourth Industrial Revolution is a major factor that distinguishes the Fourth Industrial Revolution from the existing production environment. This environment has two-sided features that allow it to produce data while using it. And the data produced so produces another value. Due to the massive scale of data, future information systems need to process more data in terms of quantities than existing information systems. In addition, in terms of quality, only a large amount of data, Ability is required. In a small-scale information system, it is possible for a person to accurately understand the system and obtain the necessary information, but in a variety of complex systems where it is difficult to understand the system accurately, it becomes increasingly difficult to acquire the desired information. In other words, more accurate processing of large amounts of data has become a basic condition for future information systems. This problem related to the efficient performance of the information system can be solved by building a semantic web which enables various information processing by expressing the collected data as an ontology that can be understood by not only people but also computers. For example, as in most other organizations, IT has been introduced in the military, and most of the work has been done through information systems. Currently, most of the work is done through information systems. As existing systems contain increasingly large amounts of data, efforts are needed to make the system easier to use through its data utilization. An ontology-based system has a large data semantic network through connection with other systems, and has a wide range of databases that can be utilized, and has the advantage of searching more precisely and quickly through relationships between predefined concepts. In this paper, we propose a defense ontology as a method for effective data management and decision support. In order to judge the applicability and effectiveness of the actual system, we reconstructed the existing air force munitions situation management system as an ontology based system. It is a system constructed to strengthen management and control of logistics situation of commanders and practitioners by providing real - time information on maintenance and distribution situation as it becomes difficult to use complicated logistics information system with large amount of data. Although it is a method to take pre-specified necessary information from the existing logistics system and display it as a web page, it is also difficult to confirm this system except for a few specified items in advance, and it is also time-consuming to extend the additional function if necessary And it is a system composed of category type without search function. Therefore, it has a disadvantage that it can be easily utilized only when the system is well known as in the existing system. The ontology-based logistics situation management system is designed to provide the intuitive visualization of the complex information of the existing logistics information system through the ontology. In order to construct the logistics situation management system through the ontology, And the useful functions such as performance - based logistics support contract management and component dictionary are further identified and included in the ontology. In order to confirm whether the constructed ontology can be used for decision support, it is necessary to implement a meaningful analysis function such as calculation of the utilization rate of the aircraft, inquiry about performance-based military contract. Especially, in contrast to building ontology database in ontology study in the past, in this study, time series data which change value according to time such as the state of aircraft by date are constructed by ontology, and through the constructed ontology, It is confirmed that it is possible to calculate the utilization rate based on various criteria as well as the computable utilization rate. In addition, the data related to performance-based logistics contracts introduced as a new maintenance method of aircraft and other munitions can be inquired into various contents, and it is easy to calculate performance indexes used in performance-based logistics contract through reasoning and functions. Of course, we propose a new performance index that complements the limitations of the currently applied performance indicators, and calculate it through the ontology, confirming the possibility of using the constructed ontology. Finally, it is possible to calculate the failure rate or reliability of each component, including MTBF data of the selected fault-tolerant item based on the actual part consumption performance. The reliability of the mission and the reliability of the system are calculated. In order to confirm the usability of the constructed ontology-based logistics situation management system, the proposed system through the Technology Acceptance Model (TAM), which is a representative model for measuring the acceptability of the technology, is more useful and convenient than the existing system.

The Ultrastructure of Leydig Cells in the Testis of Korean Native Chickens (한국 재래 닭 고환 간질세포의 미세구조에 관한 연구)

  • Jang, B.G.;Tae, H.J.;Choi, C.H.;Park, Y.J.;Yang, H.H.;Kim, N.S.;Park, S.Y.;Kang, H.S.;Park, B.Y.;Lee, Y.H.;Ahn, D.C.;Kim, I.S.
    • Korean Journal of Poultry Science
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    • v.33 no.3
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    • pp.181-188
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    • 2006
  • Changes in the fine structure of testicular Leydig cell from hatching to adulthood were studied in Korean native chickens of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 24, 28, 32, 44, 52 and 64 weeks (n=13 chickens per group) of age. The objective of this study were to elucidate Leydig cell ultrastructure during testicular development. Testes of chickens were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using $1{\mu}m$ sections stained with methylene blue-azure II, qualitative and quantitative(stereological) morphological studies were performed. The ultrastructural changes of the Leydig cell were investigated by ultrathin section with the transmission electron microscope. The stages of the Leydig cell development described focus on mitochondria, endoplasmic reticulum, and lipid droplets which are involved in androgens as fullows. 1) Approaching puberty. The closely packed Leydig cells and sparse intercellular space. The nucleus occupied a large portion of the Leydig cell volume. The population of Leydig cells contained two types of cells that differed in the appearance of their nuclei which were either highly electron-opaque or relatively electron-lucid. The cytoplasm was characterized by large amounts of lipid droplets, relatively few spherical mitochondria, and sparse smooth endoplasmic reticulum. 2) Puberty to adult. The Leydig cells which display features compatible with significant androgen synthesis: large volume of cytoplasm containing extended smooth endoplasmic reticulum, abundant mitochondria, and reduction of lipid droplets.

Study on the Relationships Among Perceived Shopping Values, Brand Equity, and Store Loyalty of Korean and Chinese Consumers: A Case of Large Discount Store (한국과 중국 소비자의 쇼핑 경험가치 지각과 브랜드자산 및 점포충성도의 관계에 관한 비교 연구: 대형 할인점을 중심으로)

  • Hwang, Soonho;Oh, Jongchul;Yoon, Sungjoon
    • Asia Marketing Journal
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    • v.14 no.2
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    • pp.209-237
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    • 2012
  • 1. Research Purpose Consumers rely on various clues to evaluate their decision to patronize a retail store, and store brand is one of them (Dodds 1991; Grewal et al. 1998). As consumers find ever increasing variety of contact points connecting them to specific store, the value of experiential shopping as a means of increasing store's brand equity warrants greater attention from scholars of retail management. Retail shopping values are credited for creating not only cognitive experiences like brand knowledge but also emotional experiences such as shopping pleasure and pride (Schmitt 1999). This may be because today's consumers place emphasis on emotional values associated with shopping pleasure, lifestyle brought to life, brand relationship, and store atmosphere more than utilitarian values such as product quality and price. Many previous literature found this to be true (Ahn and Lee 2011; Mathwick et al. 2001). This brings forth important research issues and questions regarding the roles of shopping experiential values and brand equity with regard to consumer's retail patronage choice. However, despite this importance, research on this area remains quite inadequate (Hwang 2010). For this reason, this study aims to verify the relationships among experiential shopping values, retail store brand equity and tries to link that with customer loyalty by surveying large-scale discount store shoppers in Korea and China. 2. Research Contents In order to carry out the research objective, this study conducted comprehensive literature survey on previous literature by discussing major findings and implications with regard to shopping values and retail brand equity and store loyalty. For data collection, researcher employed survey-based research method where data were collected in two major cities of Korea (Seoul) and China (Bejing) and sampling frame was based on patrons of large discount stores in both countries. Specific research questions raised in this study are as follows; RQ1: How do Korean and Chinese consumers differently perceive of shopping values regarding shopping at large-sclae discount stores? RQ2: Are there differences in consumers' emotional consumption propensities? RQ3: Do Korean and Chinese consumers display different perceptions of brand equity towards large-scale discount stores? RQ4: Are there differences in relationships between shopping values and brand equity for Korean and Chinese consumers? For statistical analysis, SPSS17.0, AMOS17.0 and SmartPLS were employed. 3. Research Results The data collected through face-to-face survey conducted in Seoul and Bejing revealed appropriate data validity and reliability as a result of exploratory/confirmatory factor analysis and reliability tests, andh SEM model yielding satisfactory model fitness. The result of the study may be summarized by three main points. First, as a result of testing differences in consumption dispositions, Chinese consumers showed higher scores in aesthetic and symbolic dispositions, whereas Korean consumers scored higher in hedonic disposition. Second, testing on perceptions toward brand equity of large discount stores showed that Korean consumers exhibited more positive perceptions of brand awareness and brand image than Chinese counterparts. Third, the result of exploratory factor analysis on the experiential shopping values revealed different factors for each country. On Korean side, consumer interest value, aesthetic value, and hedonic value were prominent, whereas on Chinese side, hedonic value, aesthetic value, consumer interest value, and service excellence value were found salient. 4. Research Implications While many previous studies on inter-country differences in retailing area mainly focused on cultural dispositions or orientations to explain the differences, this study sets itself apart by specifically targeting individual consumer's shopping values from an experiential viewpoint. The study result provides important theoretical as well as practical implications for large-scale discount store, especially the impotance of fully exploring the linkage between shopping values and brand equity, which has significant influence on loyalty. Therefore, the specific implications deriving from the result shed some important insights upon the consumption values based on shopping experiences and brand equity. The differences found in store shoppers between the two countries may also provide useful insights for Korean and Chinese retailers who plan to expand their operations globally. Related strategic implications derived from this study is the importance of localizing retail strategy which is based on the differences found in experiential shopping values between the two country groups. Especially the finding that Chinese consumers value consumer interest and service excellence, whereas Koreans place importance on hedonic or aesthetic values indicates the need to differentiate the consumer's psychographical profiles when it comes to expanding retail operations globally. Particularly important will be to pursue price-orienated strategy in China in consideration of the high emphasis on consumer interests and service excellence, but to emphasize the symbolic aspects of brand equity in Korea by maximizing the brand equity associated with aesthetic values and hedonic orientations. 5. Recommendations This study focused on generic retail branded discount stores in both countries, thus making it difficult to tease out store-specific strategies based on specific retail brands. Future studies may benefit fro employing actual brand names in survey questionnaire to verify relationship between shopping values and brand-based store strategy. As with other studies of this nature, this study needs to strengthen the result's generalizability by selecting respondents from a wider spectrum of respondents.

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Beam Shaping by Independent Jaw Closure in Steveotactic Radiotherapy (정위방사선치료 시 독립턱 부분폐쇄를 이용하는 선량분포개선 방법)

  • Ahn Yong Chan;Cho Byung Chul;Choi Dong Rock;Kim Dae Yong;Huh Seung Jae;Oh Do Hoon;Bae Hoonsik;Yeo In Hwan;Ko Young Eun
    • Radiation Oncology Journal
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    • v.18 no.2
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    • pp.150-156
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    • 2000
  • Purpose : Stereotactic radiation therapy (SRT) can deliver highly focused radiation to a small and spherical target lesion with very high degree of mechanical accuracy. For non-spherical and large lesions, however, inclusion of the neighboring normal structures within the high dose radiation volume is inevitable in SRT This is to report the beam shaping using the partial closure of the independent jaw in SRT and the verification of dose calculation and the dose display using a home-made soft ware. Materials and Methods : Authors adopted the idea to partially close one or more independent collimator jaw(5) in addition to the circular collimator cones to shield the neighboring normal structures while keeping the target lesion within the radiation beam field at all angles along the arc trajectory. The output factors (OF's) and the tissue-maximum ratios (TMR's) were measured using the micro ion chamber in the water phantom dosimetry system, and were compared with the theoretical calculations. A film dosimetry procedure was peformed to obtain the depth dose profiles at 5 cm, and they were also compared with the theoretical calculations, where the radiation dose would depend on the actual area of irradiation. Authors incorporated this algorithm into the home-made SRT software for the isodose calculation and display, and was tried on an example case with single brain metastasis. The dose-volume histograms (DVH's) of the planning target volume (PTV) and the normal brain derived by the control plan were reciprocally compared with those derived by the plan using the same arc arrangement plus the independent collimator jaw closure. Results : When using 5.0 cm diameter collimator, the measurements of the OF's and the TMR's with one independent jaw set at 30 mm (unblocked), 15.5 mm, 8.6 mm, and 0 mm from th central beam axis showed good correlation to the theoretical calculation within 0.5% and 0.3% error range. The dose profiles at 5 cm depth obtained by the film dosimetry also showed very good correlation to the theoretical calculations. The isodose profiles obtained on the home-made software demonstrated a slightly more conformal dose distribution around the target lesion by using the independent jaw closure, where the DVH's of the PTV were almost equivalent on the two plans, while the DVH's for the normal brain showed that less volume of the normal brain receiving high radiation dose by using this modification than the control plan employing the circular collimator cone only. Conclusions : With the beam shaping modification using the independent jaw closure, authors have realized wider clinical application of SRT with more conformal dose planning. Authors believe that SRT, with beam shaping ideas and efforts, should no longer be limited to the small spherical lesions, but be more widely applied to rather irregularly shaped tumors in the intracranial and the head and neck regions.

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Generation of Progressively Sampled DTM using Model Key Points Extracted from Contours in Digital Vector Maps (수치지도 등고선의 Model Key Point 추출과 Progressive Sampling에 의한 수치지형모델 생성)

  • Lee, Sun-Geun;Yom, Jae-Hong;Lim, Sae-Bom;Kim, Kye-Lim;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.6_2
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    • pp.645-651
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    • 2007
  • In general, contours in digital vector maps, which represent terrain characteristics and shape, are created by 3D digitizing the same height points using aerial photographs on the analytical or digital plotters with stereoscopic viewing. Hence, it requires lots of task, and subjective decision and experience of the operators. DTMs are generated indirectly by using contours since the national digital maps do not include digital terrain model (DTM) data. In this study, model key points which depict the important information about terrain characteristics were extracted from the contours. Further, determination of the efficient and flexible grid sizes were proposed to generate optimal DTM in terms of both quantitative and qualitative aspects. For this purpose, a progressive sampling technique was implemented, i.e., the smaller grid sizes are assigned for the mountainous areas where have large relief while the larger grid sizes are assigned for the relatively flat areas. In consequence, DTMs with multi-grid for difference areas could be generated instead of DTMs with a fixed grid size. The multi-grid DTMs reduce computations for data processing and provide fast display.