• Title/Summary/Keyword: B-Rep

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Hybrid Representations for Enveloping Modeling in Gearing

  • Voznyuk, Roman
    • International Journal of CAD/CAM
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    • v.3 no.1_2
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    • pp.13-17
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    • 2003
  • Hybrid method of representing geometric entities as combination of boundary (B-rep) and functional (F-rep) representations is presented which can be used as a basis of solid modeling kernel. It contains whole functionality of classic B-rep kernel, and also supports enveloping (sweep of solid body). Principles and keysolutions are considered. Example of a real task that comes from gearing is provided.

Development of smart CAD/CAM system for machining center based on B-Rep solid modeling techniques(l) (A study on the B-Rep solid modeler using half edge data structure) (B-Rep 솔리드모델을 이용한 머시닝센터용 CAD/CAM시스템 개발(I))

  • Yang, Hee-Goo;Kim, Seok-Il
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.3
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    • pp.150-157
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    • 1996
  • In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interfer- ence check between solids, the structural design of machine tools and robots and so on.

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Development of Smart CAD/CAM System for Machining Center Based on B-Rep Solid Modeling Techniques (I) (A Study on the B-Rep Solid Modeler using Half Edge Data Structure) (B-Rep 솔리드모델을 이용한 머시닝 센터용 CAC/CAM 시스템 개발(1): 반모서리 자료구조의 B-Rep 솔리드모델러에 관한 연구)

  • 양희구;김석일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.689-694
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    • 1994
  • In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interference check between solids, the structural design of machine tools and robots and so on.

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Current Classification of the Bacillus pumilus Group Species, the Rubber-Pathogenic Bacteria Causing Trunk Bulges Disease in Malaysia as Assessed by MLSA and Multi rep-PCR Approaches

  • Husni, Ainur Ainiah Azman;Ismail, Siti Izera;Jaafar, Noraini Md.;Zulperi, Dzarifah
    • The Plant Pathology Journal
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    • v.37 no.3
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    • pp.243-257
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    • 2021
  • Bacillus pumilus is the causal agent of trunk bulges disease affecting rubber and rubberwood quality and yield production. In this study, B. pumilus and other closely related species were included in B. pumilus group, as they shared over 99.5% similarity from 16S rRNA analysis. Multilocus sequence analysis (MLSA) of five housekeeping genes and repetitive elements-based polymerase chain reaction (rep-PCR) using REP, ERIC, and BOX primers conducted to analyze the diversity and systematic relationships of 20 isolates of B. pumilus group from four rubber tree plantations in Peninsular Malaysia (Serdang, Tanah Merah, Baling, and Rawang). Multi rep-PCR results revealed the genetic profiling among the B. pumilus group isolates, while MLSA results showed 98-100% similarity across the 20 isolates of B. pumilus group species. These 20 isolates, formerly established as B. pumilus, were found not to be grouped with B. pumilus. However, being distributed within distinctive groups of the B. pumilus group comprising of two clusters, A and B. Cluster A contained of 17 isolates close to B. altitudinis, whereas Cluster B consisted of three isolates attributed to B. safensis. This is the first MLSA and rep-PCR study on B. pumilus group, which provides an in-depth understanding of the diversity of these rubber-pathogenic isolates in Malaysia.

DNA fingerprinting of Brucella abortus isolated from bovine brucellosis outbreaks by repetitive element sequence (rep)-PCR

  • Suh, Dong Kyun
    • Korean Journal of Veterinary Research
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    • v.45 no.2
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    • pp.199-205
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    • 2005
  • DNA fingerprint patterns of 8 Brucella reference strains and 15 B. abortus field isolates were characterized by repetitive element sequence-based PCR (rep-PCR) using BOX- and ERIC-primers in this study. AMOS PCR differentiated all Brucella field isolates from B. abortus RB51, a vaccine strain by producing a B. abortus-specific 498 bp band. Rep-PCR using BOX-primer produced 13 to 18 bands with sizes of between 230 and 3,300 bp, and discriminated Brucella strains to the species level except B. canis and B. suis. PCR products amplified with ERIC primers were, however, not appropriate for differentiating the Brucella isolates. DNA fingerprint patterns for all B. abortus field isolates were identical among them and were put on one cluster with B. abortus biovar 1 reference strain in the dendrogram, indicating they were highly clonal. These results suggested that rep-PCR using BOX primer might to be a useful tool for calculating genetic relatedness among the Brucella species and for the study of brucellosis epidemiology.

The Development of Converting Program from Sealed Geological Model to Gmsh, COMSOL for Building Simulation Grid (시뮬레이션 격자구조 제작을 위한 Mesh 기반 지질솔리드모델의 Gmsh, COMSOL 변환 프로그램 개발)

  • Lee, Chang Won;Cho, Seong-Jun
    • Journal of the Korean earth science society
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    • v.38 no.1
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    • pp.80-90
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    • 2017
  • To build tetrahedra mesh for FEM numerical analysis, Boundary Representation (B-Rep) model is required, which provides the efficient volume description of an object. In engineering, the parametric solid modeling method is used for building B-Rep model. However, a geological modeling generally adopts discrete modeling based on the triangulated surface, called a Sealed Geological Model, which defines geological domain by using geological interfaces such as horizons, faults, intrusives and modeling boundaries. Discrete B-Rep model is incompatible with mesh generation softwares in engineering because of discrepancies between discrete and parametric technique. In this research we have developed a converting program from Sealed Geological Model to Gmsh and COMSOL software. The developed program can convert complex geological model built by geomodeling software to user-friendly FEM software and it can be applied to geoscience simulation such as geothermal, mechanical rock simulation etc.

Classificiation of Boundary Information for Non-manifold B-rep Solid Modeler (복합다양체 솔리드 표현을 위한 경계정보의 분류)

  • 최국헌;한순홍
    • Korean Journal of Computational Design and Engineering
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    • v.4 no.2
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    • pp.121-126
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    • 1999
  • Existing data structures for non-manifold solid modelers use basic dat entities, such as vertex, edge, loop, face, shell, and region to find adjacency relationships. But, no one clearly identified what additional types of data entitles are necessary to represent incidence relationships. In this paper, we classified the boundary information of vertex, edge, face , and region from the 3-D space view. As the results we can clearly define the boundary information required for adjacency relationships. The existing B-rep data structures for solid modeler are compared whether they have the required boundary information.

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A Performance Comparison of 3-D Spatial Operation between Prism Model and B-Rep Model (프리즘 모델과 B-Rep 모델의 3차원 공간 연산 성능 비교)

  • Jang, Dae-Sung;Kim, Ho-Chul;Kim, Ji-Hyun;Kim, Joon-Seok;Li, Ki-Joune
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2010.06a
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    • pp.303-305
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    • 2010
  • 실내공간의 특성을 고려하여 u-GIS 서비스를 제공하기 위해서는 그에 맞는 적절한 모델과 질의처리 방법이 필요하다. 프리즘 모델은 실내공간을 표현하기 위한 3차원 기하 모델이며, 이에 대한 질의처리 방법이 제안된 바 있다. 하지만 이에 대한 실험적 근거가 부족하므로, 본 논문에서는 프리즘 모델의 질의 처리 방법을 적용한 시스템과 B-Rep 기반의 3차원 공간 DBMS 시스템간의 연산 수행을 비교 실험하였다. 그 결과 프리즘 모델 기반의 질의처리 방법이 B-Rep 기반의 공간 DBMS 보다 질의 처리 성능이 우수한 것으로 검증되었다.

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Role of CopA to Regulate repABC Gene Expression on the Transcriptional Level (전사 수준에서 repABC 유전자 발현을 조절하는 CopA 단백질의 역할)

  • Sam Woong Kim;Sang Wan Gal;Won-Jae Chi;Woo Young Bang;Tae Wan Kim;In Gyu Baek;Kyu Ho Bang
    • Journal of Life Science
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    • v.34 no.2
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    • pp.86-93
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    • 2024
  • Since replication of plasmids must be strictly controlled, plasmids that generally perform rolling circle replication generally maintain a constant copy number by strictly controlling the replication initiator Rep at the transcriptional and translational levels. Plasmid pJB01 contains three orfs (copA, repB, repC or repABC) consisting of a single operon. From analysis of amino acid sequence, pJB01 CopA was homologous to the Cops, as a copy number control protein, of other plasmids. When compared with a CopG of pMV158, CopA seems to form the RHH (ribbon-helix-helix) known as a motif of generalized repressor of plasmids. The result of gel mobility shift assay (EMSA) revealed that the purified fusion CopA protein binds to the operator region of the repABC operon. To examine the functional role of CopA on transcriptional level, 3 point mutants were constructed in coding frame of copA such as CopA R16M, K26R and E50V. The repABC mRNA levels of CopA R16M, K26R and E50V mutants increased 1.84, 1.78 and 2.86 folds more than that of CopA wt, respectively. Furthermore, copy numbers owing to mutations in three copA genes also increased 1.86, 1.68 and 2.89 folds more than that of copA wt, respectively. These results suggest that CopA is the transcriptional repressor, and lowers the copy number of pJB01 by reducing repABC mRNA and then RepB, as a replication initiator.

The Terminal and Internal Hairpin Loops of the ctRNA of Plasmid pJB01 Play Critical Roles in Regulating Copy Number

  • Kim, Sam Woong;Jeong, In Sil;Jeong, Eun Ju;Tak, Je Il;Lee, John Hwa;Eo, Seong Kug;Kang, Ho Young;Bahk, Jeong Dong
    • Molecules and Cells
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    • v.26 no.1
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    • pp.26-33
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    • 2008
  • The plasmid pJB01, a member of the pMV158 family isolated from Enterococcus faecium JC1, contains three open reading frames, copA, repB, and repC. Plasmids included in this family produce counter-transcribed RNA (ctRNA) that contributes to copy number control. The pJB01 ctRNA, a transcript which consists of 54 nucleotides (nts), is encoded on the opposite strand from the copA/repB intergenic region and partially overlaps an atypical ribosome binding site (ARBS) for repB. The ARBS is integrated by the two underlined conserved regions: 5'-TTTTTGTNNNNTAANNNNNNNNNATG-3', and the ctRNA is complementary only to the 5' conserved sequence 5'-TTTTTGT-3'. This complementary sequence is located at a distance from the terminal loop of the ctRNA secondary structure. The ctRNA structure predicted by the mfold program suggests the possible generation of a terminal and an internal hairpin loop. The amount of in vitro translation product of repB mRNA was inversely proportional to the ctRNA concentration. Mutations in the terminal and internal hairpin loops of the ctRNA had inhibitory effects on its binding to the target mRNA. We propose that the intact structures of the terminal and internal hairpin loops, respectively, play important roles in forming the initial kissing and extending complexes between the ctRNA and target mRNA and that these regulate the copy number of this plasmid.