• 제목/요약/키워드: Correct Expansion

검색결과 83건 처리시간 0.024초

임상가를 위한 특집 3 - 상악골 횡적 부조화의 외과적치료 (Surgical treatment of maxillary transverse deficiency)

  • 권용대;이현우
    • 대한치과의사협회지
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    • 제51권6호
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    • pp.322-329
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    • 2013
  • Among the occlusal discrepancies, maxillary transverse deficiency is quite common in several reasons. The reasons are comprised of maxillary hypoplasia, thumb sucking habits, non-syndromic palatal synostosis and syndromal patients including cleft patients. Orthodontic treatment is used routinely to correct a deficiency in young patients while it has limitations for a skeletally mature patient. Surgical treatments help provide effective maxillary expansion to correct a deficiency in adults. Surgical methods can be categorized to segmental Le Fort I osteotomy and surgically assisted rapid maxillary expansion(SARME). Both methods seem successful but each method would have its own indication. We give a review on transverse maxillary deficiency and two surgical methods.

정확한 경계 추출 및 수행시간 단축을 위한 개선된 워터쉐드 알고리즘 (Modified Watershed Algorithm for Extracting Correct Edge and Reducing Processing Time)

  • 박동인;김태원;고윤호;최재각
    • 한국멀티미디어학회논문지
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    • 제13권10호
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    • pp.1463-1473
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    • 2010
  • 본 논문에서는 정확한 경계 추출 및 수행시간 단축을 위한 개선된 워터쉐드 알고리즘을 제안한다. 본 논문에서는 두 가지 새로운 알고리즘을 제안한다. 첫 번째는 기존 강우방식과 침수방식의 워터쉐드 확장 방식을 복합적으로 적용한 것이다. 먼저 각 방식의 장점과 단점을 규명하고 장점은 유지하고 단점은 보완하여 정확한 경계를 추출하면서도 수행시간을 단축할 수 있는 새로운 확장방식을 제안한다. 두 번째는 보다 정확한 경계를 얻기 위한 새로운 우선순위 결정 알고리즘이다. 기울기의 영교차점은 경계로 예상되는 위치이지만 기존의 워터쉐드 알고리즘은 이러한 위치를 경계로 추출하지 못하는 한계를 가지고 있다. 따라서 보다 정확한 경계를 추출할 수 있도록 워터쉐드를 위한 새로운 우선순위 결정 알고리즘을 제안한다. 모의실험을 통해 제안된 알고리즘과 기존 알고리즘을 비교하고 제안된 방법이 보다 정확한 경계를 추출할 수 있음을 보인다.

질의응답시스템에서 정답 특징에 관한 실험적 분석 (Experimental Analysis of Correct Answer Characteristics in Question Answering Systems)

  • 한경수
    • 디지털콘텐츠학회 논문지
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    • 제19권5호
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    • pp.927-933
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    • 2018
  • 자연어 질문에 대해 답변을 찾아 제공하는 질의응답시스템의 오류에 가장 큰 영향을 미치는 요소 중 하나가 질문으로 정답을 포함하고 있을 만한 문서나 단락을 검색하는 단계이다. 검색의 성능 향상을 위해서는 정답 포함 문서 및 단락의 특징을 잘 이해해야 한다. 본 논문은 질문, 정답 포함 문서, 정답 미포함 문서로 구성된 말뭉치를 사용하여 정답 문서에는 질문 단어가 얼마나 많이 출현하는지, 출현 위치는 어떻게 분포하는지, 질문과 정답 문서의 주제는 얼마나 유사한지 등을 실험적으로 분석한다. 이를 통해 질의응답시스템을 위한 기존의 검색 연구 결과들에 대한 원인을 설명하고 효과적인 검색 단계의 필요 요소에 관해 논의한다.

Salvage rapid maxillary expansion for the relapse of maxillary transverse expansion after Le Fort I with parasagittal osteotomy

  • Lee, Hyun-Woo;Kim, Su-Jung;Kwon, Yong-Dae
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제41권2호
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    • pp.97-101
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    • 2015
  • Maxillary transverse deficiency is one of the most common deformities among occlusal discrepancies. Typical surgical methods are segmental Le Fort I osteotomy and surgically-assisted rapid maxillary expansion (SARME). This patient underwent a parasagittal split with a Le Fort I osteotomy to correct transverse maxillary deficiency. During follow-up, early transverse relapse occurred and rapid maxillary expansion (RME) application with removal of the fixative plate on the constricted side was able to regain the dimension again. RME application may be appropriate salvage therapy for such a case.

Surgery-first Approach for Facial Asymmetry with Transverse Discrepancy Using Hyrax-type Palatal Expansion Appliance

  • Youn-Kyung Choi;Sung-Hun Kim;Yong-Il Kim
    • Journal of Korean Dental Science
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    • 제16권1호
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    • pp.87-98
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    • 2023
  • This report presents a case of successful treatment of skeletal Class III malocclusion with transverse discrepancy in adult by surgery-first approach. Traditionally dental decompensation is necessary prior to surgery in 2-jaw surgery to correct transverse and rotational discrepancy. However, the hyrax-type palatal expansion appliance was used to improve maxillary expansion accuracy and postoperative stability in this surgery-first approach (segmental Le Fort I osteotomy and mandibular setback surgery). It was established to be an effective means of precisely predicting postoperative occlusion and achieving stable retention after surgery of skeletal Class III malocclusion with maxillary transverse discrepancy.

A Hybrid Prefix Cashing Scheme for Efficient IP Address Lookup

  • Kim, Jinsoo;Kim, Junghwan
    • 한국컴퓨터정보학회논문지
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    • 제20권12호
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    • pp.45-52
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    • 2015
  • We propose a hybrid prefix caching scheme to enable high speed IP address lookup. All prefixes loaded in a prefix cache should not be overlapped in address range for correct IP lookup. So, every non-leaf prefix needs to be expanded not so as to be overlapped. The shorter expanded prefix is more preferable because it can cover wider address range just as an single entry in a prefix cache. We exploits advantages of two dynamic prefix expansion techniques, bounded prefix expansion technique and bitmap-based prefix expansion technique. The proposed scheme uses dual bound values whereas just one bound value is used in bounded prefix expansion. Our elaborated technique make the dual bound values be associated with several subtries flexibly using bitmap information, rather than with fixed subtries. We evaluate the performance of the proposed scheme in terms of the average length of the expanded prefixes and cache miss ratio. The experiment results show the proposed scheme has lower cache miss ratio than other previous schemes including both bounded prefix expansion and bitmap-based expansion irrespective of the cache size.

트롬본 장치를 이용한 하악궁 확장 (Expansion of the mandibular arch using a trombone appliance)

  • Sabuncuoglu, Fidan Alakus;Karacay, Seniz;Olmez, Huseyin
    • 대한치과교정학회지
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    • 제41권3호
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    • pp.211-218
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    • 2011
  • Objective: This case report describes orthodontic treatment of contracted mandibular arch using a trombone appliance. Methods: A 14-year-old girl with Class II division 2 malocclusion, retroclined maxillary incisors, and buccally displaced maxillary canines required dental expansion in 3 spatial directions to correct the contracted maxillary and mandibular arches. In the initial phase of treatment, the maxillary arch was expanded and distalized using a quad-helix appliance and cervical headgear. Following the expansion and leveling of the maxillary arch, a trombone appliance was used to expand the mandibular arch. On correction of the mandibular arch and provision of sufficient space to level the mandibular teeth, fixed orthodontic treatment phase was initiated. Results: A trombone appliance proved effective in correcting the contracted mandibular arch. Because of labiolingual and transversal expansion, the mandibular dental arch perimeter was increased by 7.4 mm; the misalignment of the mandibular teeth was corrected successfully. Conclusions: A trombone appliance may serve as an appropriate clinical alternative for treating moderate mandibular arch crowding caused by the contraction of the dental arch.

조직확장술및 장골이식을 이용한 하악골 결손부의 재건 (MANDIBULAR RECONSTRUCTION BY TISSUE EXPANSION AND ILIAC BONE GRAFT)

  • 이계영;민경인;정수일;박재범;안재진;김도균;김철환
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제22권4호
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    • pp.449-453
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    • 2000
  • 저자등은 하악 복잡골절 정복후 골과 연조직 결손을 보이는 환자에게 internal resorvoir를 이용한 연조직 확장 후 장골 이식으로 골결손 수복을 함으로써 양호한 안모개선을 얻었기에 문헌고찰과 함께 보고하는 바이다.

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공작기계용 볼 베어링의 억지끼워맞춤과 내부틈새변화에 관한 해석적 연구 (FE-analysis of Shrink Fits and Internal Clearance for Ball Bearing of Machine Tool)

  • 김웅;이춘만;황영국
    • 한국정밀공학회지
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    • 제26권5호
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    • pp.135-141
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    • 2009
  • The bearing clearance is influenced by shrink fit and thermal expansion during operation. The designer must take into account the reduction of clearance after installation to the interference fits, and thermal expansion must be considered. The purpose of this study is to grasp the internal clearance variation and behavior of a bearing which is a deep connected with fatigue life of bearing and performance of spindle through FEM(Finite Element Method). Finite element analysis is performed by using commercial code ANSYS according to variation of thermal condition and rotational speeds. This paper presents correct negative internal clearance according to temperature during operation. Furthermore, interrelation between thermal expansion and contraction are presented to maintain adequate contact force for three type of spindle system (HSK-A60, HSK-40E, HSK-32E). The influence of the centrifugal force and Internal clearance variation of bearing is studied to operating rotational speed.

내장형 프로세서를 위한 IEEE-754 고성능 부동소수점 나눗셈기의 설계 (IEEE-754 Floating-Point Divider for Embedded Processors)

  • 정재원;홍인표;정우경;이용석
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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    • pp.353-356
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    • 2000
  • In this paper, a high-performance and small-area floating-point divider, which is suitable for embedded processors and supports all rounding modes defined by IEEE 754 standard, is designed using the series expansion algorithm. This divider shares and fully utilizes the two MAC units for quadratical convergence to the correct quotient. The area increase of two MAC units due to the division is minimized in this design, so that it can be suitable for embedded processors. The tested HDL codes are synthesized and optimized with 0.35$\mu\textrm{m}$ CMOS standard celt libraries. The results show that the latency of the synthesized divider is 17.43 ㎱ in worst condition. But, the divider calculates the correct rounded quotient through only 6 cycles.

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