ComputerAided_Design_Engineering_amp_Manufactur.pdf

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primarily uses the bounding-box, point-in-polyhedra query, polyhedral proximity, and polyhedral and surface intersection algorithms for the reasoning purposes. • Size tolerance module: This module retrieves information from the function decomposition, process planning, and optimization modules in order to arrive at a set of size tolerance assignments on the surfaces of the part. This is done by transforming the PFM assignment on the part surface into equivalent design tolerance limits and determining the optimal size tolerance limits with regard to other constraints (such as manufacturing and quality considerations). The component function-functional tolerance limit knowledge base and the process-tolerance limit data base provide support to the size tolerance module. • Form tolerance module: This module works in a similar fashion to the size tolerance module. In this module, the form tolerance type (such as flatness, circularity, etc.), along with the form tolerance zone, is assigned for the different surfaces of the part. During the synthesis phase, the component function-functional tolerance limit and geometric entity-process error relationship knowledge bases, and the process-tolerance limit data base assist in the assignment of tolerances. • Process planning module: This module is used for creating the process model of the part using a blackboard architecture-based process planner. 15 • Optimization module: In this module, the different optimization formulations that are encountered in tolerance synthesis are evaluated in order to assign the tolerances. This module offers an integrated platform for solving linear programming (LP) and nonlinear programming (NLP) optimization-related problems. • Datum specification module: This module takes as its input the information from the geometric reasoning module, the PFM model of the surfaces, and the process model of the part in order to assign a set of data for referencing different features in the part. The datum assignment algorithm is provided in Reference 16. • Position tolerance specification module: In this module, the position tolerances on the location of different features of the part are assigned on the basis of the component functions, the process model, and the inter-relationships between the location of different part features. The component function-functional tolerance limit and geometric entity-process error relationship knowledge bases along with the process-tolerance limit data base provide support to the position tolerance module. • Information aggregation module: In this module, the size, form, and position tolerances assigned to the part are retrieved for presentation in a useful manner to the user. In addition, this module assists in transformation of some of the tolerances into other types as required (e.g., some of the form tolerance assignments are transformed into orientation tolerances, depending on the specified functional and assembly requirements). Case Study: Tolerance Assignment for a Spindle Assembly A spindle assembly consisting of three parts (shaft, hub, and key) as shown in Figure 1.16 is used for demonstrating the working of TSS. In Table 1.10, the user-specified inputs to TSS are shown. The input consists of (a) part geometry specification, part location in assembly with respect to a global coordinate reference frame, location, and type of feature in the part, and size dimensions of the features, (b) surface finish specifications (Ra values) for the faces of the features, (c) part function specification denoting the functions performed by the part, and (d) assembly-graph of the spindle assembly. Next, TSS generates the geometric models of the three parts and instantiates the respective product models (Figure 1.15). With reference to Figures 1.15 and 1.16, face interactions involving surface contact take place among the following faces: (a) face 3 (F6-3) of feature F6 is pressed against face 3 (F3-3) of feature F3, (b) face 4 (F6-4) of feature F6 is pressed against face 4 (F5-4) of feature F5, (c) face 2 (F4-2) of feature F4 is pressed against face 2 (F2-2) of feature F2, (d) face 5 (F6-5) of feature F6 is pressed against face (F3-5) and face (F5-5), and (e) face 6 (F6-6) of feature F6 is pressed against face (F3-6) and face (F5-6). In accordance with the proposed tolerance synthesis schema, the PFM model for the individual faces of the three parts is generated for the specified part functions and assembly configuration. © 2001 by CRC Press LLC
TABLE 1.10 User Input for the Tolerance Synthesis System Part and Feature Geometry Description Part No. F type (F-id) F Geometry F Dimension � 10 mm F . Loc‡ Surface Finish Part-1 Bff(F1) Base-Cylinder [2.75,1.5] (R � H) [0,0,0] 0.01 Nff(F2) Hole-Cylinder [1.75,1.5] (R � H) [0,0,0] 0.004 Nff(F3) Slot-Block [1.5,0.5,0.5] (L � B � H) [0,0,15] 0.009 Part-2 Bff(F4) Base-Cylinder [1.75,7] (R � H) [0,0,0] 0.01 Nff(F5) Slot-Block [1.5,0.5,0.5] (L � B � H) [0,0,15] 0.009 Part-3 Bff(F6) Base-Block [1,1,0.5] (L � B � H) [0,0,15] 0.009 Part No. Part/Function Part Function Specification Function Description Assembly Graph Part Contact, self-rotary Contact pressure: 30 kg/mm motion 2 , Speed: 350 RPM, Load: NIL, Pa1 → (Part-2 �) Torque: 65 kg�mm Part Contact, self-rotary Contact pressure: 30 kg/mm motion 2 , Speed: 350 RPM, Pa2 → (Pa1 Part-3) Load: 0.45 kg, Torque: 65 kg�mm Part Contact Contact pressure: 30 kg/mm2 2 Pa3 → (Pa2 Part-1) †� 3 † 1 † F � Feature, Bff � Base form feature, Nff � Negative form feature, R � H � Radius � Height, L � B � H � Length � Breadth � Height, Loc. � Locations, Assy. � Assembly, Pax � Partial assembly state x. ‡ All locations are with respect to a global coordinate reference frame surface finish for each face of F is in �. † Part material is C-14 Steel and part has additional part function of nonpermanent assembly. � Additional part function—House (for explanation refer to Reference 22). In the next step, the appropriate size and form tolerances, and data and position tolerances for the features are identified in conjunction with component function-functional tolerance limit knowledge base (size, form, and position), geometric entity-process error relationship knowledge base, and process-tolerance limit data bases. In Table 1.11, the size, form, and orientation tolerances associated with all the different faces along with the data and position tolerances associated with the different form features of the three parts are shown. For instance, based on the PFM specifications of Face 3 (F3-3) and in conjunction with rules similar to those shown in Table 1.8, size tolerance limits (upper limit � 7 mm, lower limit � 0 mm) and orientation tolerance (perpendicularity) of 0.001 mm are assigned (Table 1.11) on the face. The size tolerance limits are derived by first identifying the type of fit between the two mating faces. In this case, face F3-3 maintains an interference fit with the mating face. The amount of interference between the two mating faces is determined using Rule 1 provided in Table 1.8 by using the values of the function specifications associated with the mating faces and material properties of the part material (Table 1.10). Using the ISO standard fit tables, 23 the appropriate tolerance limits associated with the desired amount of interference are identified for the specified dimensions of the mating faces and are further restricted by manufacturing constraints in order to obtain the above size tolerance limits. A similar procedure was adopted for the assignment of orientation tolerance to face F3-3. Similarly, the feature (F3) containing face F3-3 was assigned a position tolerance of 0.002 mm with Face 1 (F1-1) of feature 1 (F1) and feature 2 (F2) serving as the data (Table 1.11). On a similar note, feature F2 is assigned a position tolerance of 0.0015 mm with Face 1 (F1-1) and feature 1 (F1) serving as the data based on the values of the part behavior specifications (N � 350 RPM, T � 65 kg/mm), which are assigned to the PFM model of face F2-2. Any change in the values of the part behavior specifications associated with face F2-2 (i.e., values of N or T) would affect the value of position tolerance (i.e., eccentricity associated with rotation of hub). The tolerance values and required datum assignments are assigned to the product model of the individual faces and features at the end of this stage. In Figure 1.17, the technological information (including tolerance information) associated with a face of the key part is displayed. The TSS has been tested for a variety of cases and the tolerances synthesized by the system suggest the viability of our proposed tolerance model and tolerance synthesis schema. © 2001 by CRC Press LLC
Page 1 and 2: COMPUTER-AIDED DESIGN, ENGINEERING,
Page 3 and 4: Library of Congress Cataloging-in-P
Page 5 and 6: Editor Cornelius T. Leondes, B.S.,
Page 7 and 8: Chapter 1 Chapter 2 Chapter 3 Chapt
Page 9 and 10: the implementation of the IPD syste
Page 11 and 12: In our IPD system implementations,
Page 13 and 14: 2. Specification of analysis-specif
Page 15 and 16: FIGURE 1.2 base or the design insta
Page 17 and 18: FIGURE 1.4 System architecture of t
Page 19 and 20: of a beam is considered for FEA. Th
Page 21 and 22: FIGURE 1.7 through the control expe
Page 23 and 24: 2. machining facility (e.g., gang m
Page 25 and 26: from the FBDS. The user also specif
Page 27 and 28: Depending on the type of feature to
Page 29 and 30: TABLE 1.6 Tolerance synthesis is de
Page 31 and 32: FIGURE 1.12 Display of the NC tool
Page 33 and 34: component geometric entities and va
Page 35: FIGURE 1.14 The system architecture
Page 39 and 40: TABLE 1.11 Tolerance Specifications
Page 41 and 42: 7. Z. Young and I. R. Groose. A rul
Page 43 and 44: FIGURE 2.1 Tool paths generated for
Page 45 and 46: FIGURE 2.2 sented by instances of f
Page 47 and 48: TABLE 2.1 A CAD-Generated Hole Conf
Page 49 and 50: FIGURE 2.6 mounted on the rotary ta
Page 51 and 52: FIGURE 2.8 fixture for the machinin
Page 53 and 54: FIGURE 2.10 or best-fit, or the cur
Page 55 and 56: FIGURE 2.11 Linear approximation of
Page 57 and 58: FIGURE 2.13 Circular approximation
Page 59 and 60: FIGURE 2.14(b) Circular approximati
Page 61 and 62: FIGURE 2.16 Types of biarcs. FIGURE
Page 63 and 64: FIGURE 2.18 Approximation of scanne
Page 65 and 66: FIGURE 2.20 A touch trigger probe c
Page 67 and 68: TABLE 2.4 Substitute Elements in CM
Page 69 and 70: FIGURE 2.21 CMM planning requiremen
Page 71 and 72: Product Model Representation for Co
Page 73 and 74: © 2001 by CRC Press LLC TABLE 2.5
Page 75 and 76: TABLE 2.7 Partial Listing of Dimens
Page 77 and 78: 24. Makinouchi, S., Okamoto, M., an
Page 79 and 80: Bijan Shirinzadeh Monash University
Page 81 and 82: FIGURE 3.1 Trends in flexible manuf
Page 83 and 84: FIGURE 3.3 and constrain different
Page 85 and 86: Other Fixturing Techniques There ar
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FIGURE 3.6 contact point. The geome
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FIGURE 3.8 The vertical support fix
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and moments about the contact point
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een identified, the normals are use
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one of choosing the variables: such
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Fixture Module Location An importan
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FIGURE 3.15 Illustration of functio
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FIGURE 3.18 Minimum separation test
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direction) the face, respectively.
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FIGURE 3.21 Software structure for
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3.8 Conclusion A reconfigurable fix
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Heui Jae Pahk Seoul National Univer
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FIGURE 4.1(b) Conceptual framework
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4.3 Measurement Points Sampling and
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Surface S2 Measurement Path FIGURE
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FIGURE 4.4 Rough phase alignment ba
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deviation between the nominal CAD d
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FIGURE 4.6(a) Sum of squares distan
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FIGURE 4.7(c) Trailing edge. (c) th
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FIGURE 4.8(a) Profile tolerance of
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The calculated minimum form error i
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FIGURE 4.11(a) A typical mold havin
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FIGURE 4.11(d) Inspection results f
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FIGURE 4.12(c) Maximum deviation (p
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5.1 Introduction Developments in th
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process plan for a part (Figure 5.3
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FIGURE 5.5 leading to the developme
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the previously stored process plan
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FIGURE 5.7 Techniques of defining a
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Feature Recognition and Extraction
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in relation to another feature (e.g
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FIGURE 5.9 Framework for building a
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FIGURE 5.10 Process plan content.
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FIGURE 5.12 Schematic sketch of the
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Several techniques of defining a fe
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TABLE 5.1 Data Structure for Repres
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FIGURE 5.16 Classification of the t
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system to ensure that the part bein
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FIGURE 5.19 Graphical model of the
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TABLE 5.4 Data Structure for Repres
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FIGURE 5.20 Mapping between machini
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algorithms. (Some details of the pr
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FIGURE 5.24 An example rotational p
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FIGURE 5.26 Down_face-turn-up_face
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FIGURE 5.27 Procedure for machine t
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FIGURE 5.28 Determining the number
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DL is needed to be set only if the
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FIGURE 5.31 Operation sequencing co
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Cutting Tool Selection Selection of
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1. A tool is searched for in the da
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FIGURE 5.32 Inputs to optimization
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When these values are substituted,
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Usually, maximum and minimum speed
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FIGURE 5.33 Solution methodology.
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TABLE 5.6 Process Plan Internal Rep
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In a strict theoretical perspective
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18. Domazet, D. S. and Lu, S. C. Y,
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63. Prasad, A. V. S. R. K., Rao, P.
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CAD systems. The sample consists of
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learn to master the new system. An
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Although researchers appear to agre
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Link and Zmud28 found that organic
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Informal Training Informal CAD trai
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informal training programs, felt th
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6. C. A. Beatty, Tall Tales and Rea
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A.Y.C. Nee National University of S
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FIGURE 7.1 Planning, design, and ma
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A metal stamping can have the follo
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FIGURE 7.3 Strips used to notch out
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A Skeletal Approach for the Recogni
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These findings can be used to devel
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Semi-Direct Piloting In cases where
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a larger value, the die operations
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FIGURE 7.9 Symbolic relationship be
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FIGURE 7.11 The shape of the envelo
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TABLE 7.1 Schema for the Generation
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strong reasons to support a move to
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FIGURE 7.16 3-D CAD model of a part
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References Cheok, B.T. et al. (1994
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include the once forbidden generati
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A temporal matrix (T-Matrix) is pro
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FIGURE 8.1 A basic process. (From R
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FIGURE 8.4(a) Generate a new IG usi
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Note if the pair of nodes are both
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TABLE 8.1 Summary of the Rules Cond
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The correctness of these rules is e
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needs to show that after each full
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ule is violated, a warning should b
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Π1 Π3 Π4 FIGURE 8.8(a) After add
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
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A ik � ‘U’ and is in a cycle
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FIGURE 8.12(a) Add [p2 t7 p7 t8 p4]
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FIGURE 8.12(c) Add a token to p8 vi
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FIGURE 8.12(e) Add [p8 t9 p14 t10 p
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FIGURE 8.13 An example of rule TT.0
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FIGURE 8.14 A GPN model of a machin
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FIGURE 8.15(b) The first exclusive
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FIGURE 8.15(d) The last exclusive T
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FIGURE 8.15(f) After entering the a
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FIGURE 8.15(h) Completion of Compon
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FIGURE 8.15(j) Two PP-generations:
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FIGURE 8.15(l) The last exclusive T
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t1 t5 p1 p5 t6 (a) t2 t3 t4 2 2 p2
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FIGURE 8.17 An example of partial f
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Theorem 10: If pi → pk in a synth
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Note that control transitions are o
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t j than the lower at , it indicate
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• Programming logic and VLSI arra
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7. Chao, D. Y. and D. T. Wang, Appl
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53. Villaroel, J. L., J. Martinez,
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q u : the numerator of the least ra
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geometric modeling, engineering ana
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In dimension driven or parametric d
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FIGURE 9.3 configuration of bodies
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FIGURE 9.6 FIGURE 9.7 Geometric Int
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FIGURE 9.8 Intersection of degrees
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will introduce a way to propagate p
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Completeness of Dimensions Complete
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FIGURE 9.12 3-D constraints. © 200
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The distance constraint from pt �
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therefore: Now merge the lists and
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Quantity analysis methods have the
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y a revolute joint. By selecting al
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