1,721,148 research outputs found
A methodology of conjoint segmentation for Internet shopping malls using customer's surfing data
No full textConstructing tree decompositions of graphs with bounded gonality
No full textIn this paper, we give a constructive proof of the fact that the treewidth of a graph is at most its divisorial gonality. The proof gives a polynomial time algorithm to construct a tree decomposition of width at most k, when an effective divisor of degree k that reaches all vertices is given. We also give a similar result for two related notions: stable divisorial gonality and stable gonality.Accepted author manuscriptDiscrete Mathematics and Optimizatio
Algorithms for Aircraft Flight and Maintenance Scheduling in an Army Aviation Unit
No full textThis paper focuses on an aircraft flight and maintenance scheduling problem with the objective of maximizing the weighted sum of completed missions. We consider two types of maintenance activities: short-term maintenance activity to be performed when the cumulative flight time for an aircraft reaches a predetermined range; and long-term maintenance activity to be performed after a predetermined number of short-term maintenance activities. In the problem, both flight and maintenance schedules for each aircraft are to be determined. We present a mathematical formulation for the problem and develop heuristic algorithms. Performance of the proposed algorithms is evaluated with a series of tests on a number of problem instances, and results are reporte
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A Study on the Performance Evaluation of OpenGL-based Graphics Sub-System
Get PDFThe company, SGI, developed the new 3D API, OpenGL and opened the specification of OpenGL to the public. Many other companies which try to develop the graphic hardware system are maintaining and advancing the products related OpenGL with OpenGL specification.
The softwares which are accelerated by OpenGL show various results according to the detail function in the accelerating device, OpenGL. However, there is a loss in the performance of the system hardware because users are not fully prepared for understanding the graphic hardwares and 3D API.
In this thesis, 3D performance environmental settings supporting the OpenGL 3D API Graphic Sub-system were tested with SPECviewperf 7.1 based on Pro/Engineer 2001 which includes two models in shaded, wireframe, and hidden-line removal, three modes and seven viewsets.
Finally, this research aims for organizing the optimal environment of major application which used by users with the result of 3D performance analysis.1. 서 론 1
1.1 연구배경 1
1.2 연구내용 1
1.3 연구목적 2
2. OpenGL 3D API 성능 평가 환경 설정 3
2.1 Graphics Sub-system 3
2.2 OpenGL 3D API 4
2.3 Specviewperf 6
2.4 테스팅 플랫폼 12
3. OpenGL 3D 성능 SPECViewperf 테스트 13
3.1 OpenGL 3D Performance 테스트 13
3.1.1 테스트 계획 14
3.1.2 OpenGL Settings 테스트 17
3.1.3 Default Color Depth, Buffer-Flipping Mode, Vertical Sync 테스트 22
3.2 OpenGL 그래픽 서브시스템 최적화 성능테스트 27
3.3 OpenGL 그래픽 서브시스템 성능저하 환경테스트 29
4. SPECViewperf 테스트결과 분석 및 평가 31
5. 결 론 3
Natural history of malunion in sagittal plane in supracondylar fracture of the humerus in children
No full text의학과/석사[한글]
상완골 과상부 골절은 소아 주관절 골절 중 가장 흔한 형태로 치료 후 여러 가지 합병증이 발생할 수 있는데, 그 중에는 볼크만 허혈성 구축을 비롯하여 혈관, 신경 손상 및 내반주, 외반주를 포함한 각변형 등이 포함된다. 근래 K-강선을 이용한 수술적 치료를 시행하면서 볼크만 허혈성 구축의 발생률이 현저히 줄어들었고, 각변형 등에 의한 외형 및 기능장애가 더욱 중요하게 생각되고 있다. 이 중 내반주, 외반주 등 관상면에서의 변형에 대한 연구는 많이 보고 되었으나, 시상면에서의 부정 유합에 대한 임상적 연구는 많지 않다. 1995년부터 2003년까지 영동 세브란스 병원 정형외과에 내원한 소아 과상부 골절 환자에서 술 후 1년 이상 추시 가능하였던 환자 중 상완골-소두 각도(humerocapitellar angle)의 각변형이 있는 23 례를 대상으로 주관절 운동 범위와의 연관성을 상관 분석(correlation analysis)을 통해 분석하였다. 또한 상완골-소두 각도(humerocapitellar angle)의 재형성 정도를 윌콕슨 부호 순위합 검정(Wilcoxon signed rank sum test)를 통하여 분석하였다. 상완골-소두 각도(humerocapitellar angle)가 증가할수록 주관절 굴곡이 유의하게 감소하였고, 평균 2년 추시에서 상완골-소두 각도(humerocapitellar angle)의 재형성은 의미있게 나타나지 않았다. 또한 골절 유합 직후 측정값에서 상완골-소두 각도(humerocapitellar angle)가 증가 할수록 바우만각도(Baumann angle)가 통계적으로 의미있게 감소하여 관상면과 시상면의 변형이 상호 연관성을 가지고 있음을 시사하였다. 즉, 소아 상완골 과상부 골절에서 시상면의 전방 각 형성이 환자의 주관절 운동범위(굴곡 감소)와 밀접한 관련을 가지며 관상면에서의 내반 변형과도 서로 연관성을 가지므로 소아 상완골 과상부 골절을 치료하는데 있어 시상면 각교정에 대한 주의가 필요할 것으로 생각된다. 또한 상완골-소두 각도(humerocapitellar angle)의 변화에 대해서는 더 긴 추시 기간을 가지고 연구를 해야 할 것으로 생각된다.
[영문]Supracondylar fracture of the humerus is a common injury in children. It is associated with several complication including Volkmann''s ischemia, neurovascular injury and angular deformities. In recent years percutaneous pinning has reduced the incidence of Volkmann''s ischemia, and deformity and functional problem are now the major concerns. A survey of literature revealed many reports about deformity in coronal plane(cubitus varus, cubitus valgus), but there were few studies about malunion in sagittal plane. A retrospective study was undertaken to evaluate the correlation between sagittal malunion and range of motion of the elbow in 23 patients who admitted to the Young Dong Severance Hospital from 1995 to 2003 and who showed angular deformity in sagittal plane. Also, attempts were made to analyse the amount of remodeling of malunion in sagittal plane. Increased humerocapitellar angle had correlation with decrement of elbow flexion with statistical significance. Significant remodeling of humerocapitellar angle was not found during the average 2 year follow-up period. Humerocapitellar angle also showed significant correlation with Baumann angle. Humerocapitellar angle is an important factor to restore the range of motion(especially in flexion) and the reduction even in coronal plane. A longer follow-up period is needed to evaluate the remodeling of humerocapitellar angle.ope
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