• 제목/요약/키워드: region-specific materials

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한국인 연령에 따른 하악 치조골 골밀도 (The bone density of mandible as the aging process in Koreans)

  • 이철원;김철환
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제37권6호
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    • pp.496-504
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    • 2011
  • Introduction: This study compared the alveolar bone density of the mandible according to gender, age and position using Cone-beam computed tomography (CT). Materials and Methods: The maxillofacial CT scan data was obtained from 60 Korean patients. In addition, the alveloar bone density of 5 males and 5 females with normal occlusion aged from 10 to 70 years was measured at the buccal cortical bone, cancellous bone and lingual cortical bone, as well as at the position of the incisors, canines, premolars and molars. Results: The age-specific mean bone density was highest in patients in their third decade. The buccal cortical bone of the molars showed the highest bone density. Males in their fifties and sixties had a higher bone density in the cancellous bone in the region of the premolars and the buccal cortical bone of the molars, respectively, than females but there was no significant difference between males and females in the other parts. The cancellous bone density was highest in those in their twenties and thirties, and tended to decline up to their seventh decade. Conclusion: These results revealed a significantly different bone density according to gender, age and position in the Korean population. In addition, it is possible to predict the bone density based on these results.

도로제설 이력자료 기반 제설 인프라 분석 (Analysis of Road Snow-removal Infrastructure using Road Snow-removal Historical Data)

  • 김진국;김승범;양충헌
    • 한국도로학회논문집
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    • 제19권3호
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    • pp.83-90
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    • 2017
  • PURPOSES : In this study, systematic road snow-removal capabilities were estimated based on previous historical data for road-snowremoval works. The final results can be used to aid decision-making strategies for cost-effective snow-removal works by regional offices. METHODS : First, road snow-removal historical data from the road snow-removal management system (RSMS), operated by the Ministry of Land, Infrastructure and Transport, were employed to determine specific characteristics of the snow-removal capabilities by region. The actual owned amount and actual used amount of infrastructure were analyzed for the past three years. Second, the regional offices were classified using K-means clustering into groups "close" to one another. Actual used snow-removal infrastructure was determined from the number of snow-removal working days. Finally, the correlation between the de-icing materials used and infrastructure was analyzed. Significant differences were found among the amounts of used infrastructure depending on snowfall intensity for each regional office during the past three years. RESULTS:The results showed that the amount of snow-removal infrastructure used for low heavy-snowfall intensity did not appear to depend on the amount of heavy snowfall, and therefore, high variation is observed in each area. CONCLUSIONS:This implies that the final analysis results will be useful when making decisions on snow-removal works.

쌍롤식 박판 연속주조공정에 있어서 용탕과 냉각롤의 접촉 열저항을 고려한 전열해석 (Thermal Analysis on Twin-Roll Type Strip Continuous Casting Process Considering Contact Thermal Resistance between Molten Metal and Cooling Roll)

  • 김영도;강충길
    • 대한기계학회논문집A
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    • 제20권1호
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    • pp.189-205
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    • 1996
  • The twin-roll type strip continuous casting process(or direct rolling process) of steel materials is characterized by two rotating water cooled rolls receiving a steady supply of molten metal which solidifies onto the rolls. A solidification analysis of molten metal considering phase transformation and thermofluid is performed using finite diffefence method with curvilinear coordinate to reduce computing time and molten region analysis with arbitrary shape. An enthalpy-specific heat method is used to determine the temperatures inthe roll and the steel. The temperature distribution of cooling roll is calculated using two dimensional finite element method, because of complex roll shape due to cooling hole in rolls and improvemnt accuracy of calculation result. The energy equaiton of cooling roll is solved simultanuously with the conservation equaiton of molten metal in order to consider heat transfer through the cooling roll. The calculated roll temperature is compared to experimental results and the heat transfer coefficient between cooling roll surface and rolling material(steel) is also determined from comparison of measured roll temperature and calculated temperature.

익상견갑에 대한 전거근 운동: 증례 보고 1. (Serratus anterior muscle exercise for The Winging Scapula: Case Study)

  • 장준혁;구봉오;김선엽
    • 대한정형도수물리치료학회지
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    • 제9권2호
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    • pp.69-77
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    • 2003
  • Objective: The purpose of this study is to describe the effect of the serratus anterior muscle exercise in a patient with winging of the scapular. Background and Purpose: The patient was a 33-year-old man with an 3 years history of the left deltoid region. He had not responded to previous treatments of rest, TENS and medicine. Materials and Methods: After Surgical operation of the shoulder, the patient was treated for 6 months in 144 visits. treatment consisted of push-up with plus in the standing position with his hands against the wall and unique push-up with quadruped position at mat. Also, Sling exercise therapy was utilized to control scapular stabilization and reduce stress on the scapulohumeral joint. Result: Following 104 physical therapy visits, the patient was able to full range of motion of the shoulder without shrug motion. Conclusion and Discussion: Scapular winging and serratus anterior muscle function are important consider in the rehabilitation of the shoulder dysfunction. Therefore, specific exercise program for people with the winging scapular should be considered.

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Identification of Meat Species Using PCR-RFLP Marker of Cytochrome b Gene

  • Shin, Sung-Chul;Chung, Ku-Young;Chung, Eui-Ryong
    • 한국축산식품학회지
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    • 제26권3호
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    • pp.375-379
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    • 2006
  • Food labeling regulations require that the meat species in various meat products are accurately declared to the consumer. Substitution or adulteration of costly meat with a cheaper one is one of the most common problems in the meat industry. In this study, PCR-restriction fragment length polymorphism(RFLP) method of the mitochondrial cytochrome b(mt cyt b) gene has been applied for identification of the origin of six mammalian meat species(beef, port horse, goat, mutton and deer) and three poultry meat species(chicken, turkey and duck) as raw materials for meat products. PCR was used to amplify a variable region of mt cyt b gene. Meat species differentiation was determined by digestion of the amplified products with a 359 bp fragment using HaeIII and HinfI restriction enzymes, which generated species-specific RFLP patterns. This PCR-RFLP DNA marker of mt cyt b gene could be very useful for the accurate and reliable identification and discrimination of animal meat species in routine analysis.

지역경제 저성장의 구조적 요인에 관한 연구 (A Study on the Structural Causes of Underdevelopment of Regional Economy)

  • 유원근;최호영
    • 디지털융복합연구
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    • 제12권10호
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    • pp.45-59
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    • 2014
  • 특정 지역이 경제적 저성장을 보이는 구조적 원인에 대한 체계적이고 실증적인 분석은 향후 구조적 문제점을 해결하고 원활한 성장구조를 정착시키기 위한 중요한 작업이 된다. 본 연구는 강원도가 산업구조의 저위성과 영세 사업체들의 비중이 타 지역에 비해 높은 구조적 특성을 지녀 자본의 축적 구조가 취약하다는 점을 인식한다. 이러한 인식을 토대로 본 연구는 지역내총생산 및 지역산업연관표를 분석하여 지역의 입지여건과 특성을 고려한 발전전략을 수립할 수 있도록 논거를 제시하고 있다.

특이 지역 환경에 대한 야외 학습 연구 -초등과학 지질 영역을 중심으로- (A Study on Field Trip of Specific-Region Environment -Focus on 'Geological Unit' of Elementary Science-)

  • 홍승호
    • 한국환경교육학회지:환경교육
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    • 제21권3호
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    • pp.1-12
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    • 2008
  • This study is aimed at suggesting ways to develop field trip or learning materials focusing on environment of Jeju seashore in order to make an effective field trip. To perform these purposes, the contents and concepts were analyzed from environment-related 'geological unit' of elementary science textbook. Afterwards, the places having the geological features in coincidence with them are chosen, and investigated, and these regions can develop into geological teaming places for field trip. Each teaming spot focuses on understanding and finding out the characteristic geological environment of rock shore, gravel shore, sand shore, shellfish shore, and tideland shore among Jeju shores. When field trip is conducted at the preparatory stage, students can get advance knowledge on geological concepts from textbook. The activity record paper is presented at the field trip stage where students observe geological phenomena on their own. After field trip is finished, the summary stage is given to solve some problems on the basis of the observed contents. The developed data from this research have its regional limits, but is surely useful for teachers who try to plan field trip when they especially choose the right field trip spots, or plan to make the process for field trip preparation of the environmental education. Furthermore, with this survey and activities, students can take the chance to improve the learning effect through their own experience on environment of Jeju seashore.

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Eclectic Sociocultural Traditions of the Baba Nyonya of George Town, Penang, Malaysia

  • OOI, Keat Gin
    • 수완나부미
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    • 제9권2호
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    • pp.51-89
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    • 2017
  • Strategically situated between the East-West maritime crossroads, the peoples of Southeast Asia over the centuries witnessed the comings and goings of traders from territories from East Asia, South Asia, West Asia and Europe. There were also those from North America that crossed the Pacific for commercial profits in this region. Foreign traders undoubtedly in the course of their visits and sojourns had liaisons with local women, some engaged in marriages. Offspring of these interracial miscegenation possessed rather unique characteristics. As a community, they were identified with the Malay term, peranakan, from the root word, "anak" meaning "child," hence "offspring" or "descendent". Specific terms - Baba Nyonya, Tionghoa-Selat, Chitty, Jawi Pekan, Pashu, Kristang - referred to particular groups. Although socially they appeared 'neither here nor there', members of mixed parentage were able to carve an especial niche in the local environment throughout Southeast Asia, conspicuously in urban, port-cities where trade and commerce predominated. Following in the footsteps of their progenitor, the Peranakan acted as intermediaries, comprador between foreign and indigenous enterprises, profiting financially and socially from trade and commerce. Tapping on the author's personal experiences and first-hand observations, complementing with oral sources, and support from secondary materials, this present essay explores, discusses, and analyzes the eclectic sociocultural practices and traditions of the Baba Nyonya of George Town, Penang. Purposeful intention is to further enlighten our understanding, and in turn, our appreciation, of these ever increasingly diminishing communities and their cultures across Southeast Asia.

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Feasibility study of spent fuel internal tomography (SFIT) for partial defect detection within PWR spent nuclear fuel

  • Hyung-Joo Choi;Hyojun Park;Bo-Wi Cheon;Hyun Joon Choi;Hakjae Lee;Yong Hyun Chung;Chul Hee Min
    • Nuclear Engineering and Technology
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    • 제56권6호
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    • pp.2412-2420
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    • 2024
  • The International Atomic Energy Agency (IAEA) mandates safeguards to ensure non-proliferation of nuclear materials. Among inspection techniques used to detect partial defects within spent nuclear fuel (SNF), gamma emission tomography (GET) has been reported to be reliable for detection of partial defects on a pin-by-pin level. Conventional GET, however, is limited by low detection efficiency due to the high density of nuclear fuel rods and self-absorption. This paper proposes a new type of GET named Spent Fuel Internal Tomography (SFIT), which can acquire sinograms at the guide tube. The proposed device consists of the housing, shielding, C-shaped collimator, reflector, and gadolinium aluminum gallium garnet (GAGG) scintillator. For accurate attenuation correction, the source-distinguishable range of the SFIT device was determined using MC simulation to the region away from the proposed device to the second layer. For enhanced inspection accuracy, a proposed specific source-discrimination algorithm was applied. With this, the SFIT device successfully distinguished all source locations. The comparison of images of the existing and proposed inspection methods showed that the proposed method, having successfully distinguished all sources, afforded a 150 % inspection accuracy improvement.

참조점의 불규칙적 배치를 통한 PIC보의 하중 충실도 향상에 관한 연구 (Load Fidelity Improvement of Piecewise Integrated Composite Beam by Irregular Arrangement of Reference Points)

  • 함석우;조재응;전성식
    • Composites Research
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    • 제32권5호
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    • pp.216-221
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    • 2019
  • Piecewise Integrated Composite (PIC) 보는 하중 유형에 따라 구간을 나누어, 각 구간마다 하중 유형에 강한 복합재료의 적층 순서를 배열한 보이다. 본 연구에서는 보의 거동을 고려하여 PIC 보의 구간을 머신 러닝을 통해 나누어 기존에 제시되었던 PIC 보에 비해 우수한 굽힘 특성을 갖게 하는 것이 목적이다. FE 모델의 240개 요소가 참조점으로 선택되었다. 선행 유한요소해석은 머신 러닝의 학습데이터 생성을 위하여 규칙적으로 분포된 참조점에서 3축 특성 값(Triaxiality)으로 나타냈다. 3축 특성 값은 인장, 압축 그리고 전단의 하중유형을 나타낸다. 머신 러닝 모델은 하이퍼파라미터(Hyperparameter)와 학습데이터로 구성되었으며, 하이퍼파라미터 튜닝을 통해 적절한 하중 충실도를 도출하였지만, 거동이 큰 보의 옆면에서는 적절하지 않은 하중 충실도가 도출되었다. 이를 해결하기 위하여 고르게 배치한 참조점을 보의 거동에 따라 배치하여 학습 데이터를 얻었고, 머신 러닝 모델이 생성되었다. 앞서 생성된 머신 러닝 모델을 통하여 보가 매핑 되었고, PIC 보에 대하여 유한요소 해석을 진행한 결과, 기존에 제시되었던 PIC 보에 비해 최대하중과 흡수 에너지가 커지는 특성이 나타났다.