Browsing by Author "Perng, DB"

Now showing 1 - 13 of 13

A new feature-based design system with dynamic editing
(1997-04-01)
Perng, DB
;
Chang, CF
;
交大名義發表
;
工業工程與管理學系
;
National Chiao Tung University
This paper proposes a feature-based design system for prismatic parts in which predefined 3D features, instead of low-level 2D lines and points, are used as entities for representation and manipulation. Two special sets of functions, a new construction function and a dynamic editing function, enable designers to freely construct and modify parts. The parts are saved as feature-based files in CSG form, while a B-rep form is also created. The feature-based file allows the proposed 3D part-design system to be easily integrated into CAPP/CAM systems without complex feature-recognition and -extraction processes. Object-oriented concepts are used in implementing the proposed system, and examples are given to show its feasibility and effectiveness. (C) 1997 Elsevier Science Ltd.
A new feature-based design system with dynamic editing
(1997-04-01)
Perng, DB
;
Chang, CF
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This paper proposes a feature-based design system for prismatic parts in which predefined 3D features, instead of low-level 2D lines and points, are used as entities for representation and manipulation. Two special sets of functions, a new construction function and a dynamic editing function, enable designers to freely construct and modify parts. The parts are saved as feature-based files in CSG form, while a B-rep form is also created. The feature-based file allows the proposed 3D part-design system to be easily integrated into CAPP/CAM systems without complex feature-recognition and -extraction processes. Object-oriented concepts are used in implementing the proposed system, and examples are given to show its feasibility and effectiveness. (C) 1997 Elsevier Science Ltd.
A novel vision system for CRT panel auto-inspection
(2005)
Perng, DB
;
Chou, CC
;
Chen, WY
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
The defects of a 3-D translucent hull CRT panel may include scratches, blemishes, cracks, bubbles, or collapsed portions. Defects may occur on the inside surface, outside surface, or interior of the glass. We designed and developed three sets of vision systems which can automatically inspect defects in CRT panels. The first system inspects the front-surface and two turn-segments, the second system inspects the other two turn-segments, while the third system inspects the side-wall defects. Two different kinds of lighting environments were developed to highlight the CRT panels and to simplify the image-capturing process. Meanwhile, a set of image processing methods were devised which can reliably detect the defects within the expected processing time. Experimental results demonstrate that the developed vision systems can be used to inspect CRT panels in the production line.
A reference standard of defect compensation for leather transactions
(2005-06-01)
Yeh, C
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Defects exist on natural leather surfaces and they usually cannot be eliminated during processing. No international criterion specifies the compensatory counting for calf leather surface defects. So complicated negotiation causes additional cost and argument between suppliers and purchasers. The objective of this article is to establish a compensatory standard of leather defects for finished leather transactions. We start by collecting 170 samples of defective leather and classify the leather defects into seven types. By using digital image processing techniques, we can identify the defects and group nearby defects into a larger scrap area. The area of leather falling into disuse can be calculated. The compensatory standard corresponding to each type of leather defect is then defined. The established compensatory standard for finished leather transactions is evaluated for simulated practical leather transaction. Simulation results showed that the proposed approach is useful and beneficial for practical leather transactions.
A systematic approach for developing a foot size information system for shoe last design
(1999-11-29)
Cheng, FT
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
The property of a shoe last design significantly impacts the fitness of the shoes thus produced. Traditionally, a shoe last is designed by using numerous foot measure data. Among all the items of foot measure information, the foot length and joint girth are further identified as principle factors affecting shoe last design. In this paper, foot length and joint girth are analyzed by using a bi-variate normal distribution to obtain a more efficient foot size grading system. A set of 2486 adult male samples collected in Taiwan area are used in this analysis to establish the norm for the foot length and joint girth. A foot size information system (FSIS) providing shoe last related information such as the percentage of population that a last can fit in is established from the analysis results. This study contributes designers the grading information that is helpful for shoe last design. Relevance to industry Shoe last design is the basis for footwear design. The foot size information system derived in this paper provides shoe making industry with a more efficient and economical size grading system to design shoe lasts. This grading system also promotes customer satisfaction with better fitness in foot size. (C) 1999 Elsevier Science B.V. All rights reserved.
An intuitive and device-independent method of generating color atlases for electronic displays
(1998-01-01)
Tsai, JL
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
We propose a HCL mix color system that can describe accurate colors on different electronic displays. Algorithms for computing the threshold values of chroma and lightness are devised so that the HCL mix color system can create the 3D color gamut of a display. We propose an intuitive and device-independent method of generating a color atlas in the HCL mix color system. Users can find the desired colors in the 3D color gamut by using perceptually descriptive items for hue names, color tones, and lightness levels. The system is helpful for color schemes of computer-designed products. Simulation results of generated color atlases are given to show the feasibility and effectiveness of the method.
An intuitive and device-independent method of generating color atlases for electronic displays
(1998-01-01)
Tsai, JL
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
We propose a HCL mix color system that can describe accurate colors on different electronic displays. Algorithms for computing the threshold values of chroma and lightness are devised so that the HCL mix color system can create the 3D color gamut of a display. We propose an intuitive and device-independent method of generating a color atlas in the HCL mix color system. Users can find the desired colors in the 3D color gamut by using perceptually descriptive items for hue names, color tones, and lightness levels. The system is helpful for color schemes of computer-designed products. Simulation results of generated color atlases are given to show the feasibility and effectiveness of the method.
Assembly-part automatic positioning using high-level entities of mating features
(1997-07-01)
Chang, CF
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
We present a new and convenient method for automatically positioning parts in an assembly. High-level entities of mating features and mating relations are used to describe the composed state of parts in an assembly. The characteristics of volume, reference origin, and boundary face of mating features and parts are used to determine automatic part-positioning operations. Using the proposed approach, a hierarchical model of the assembly can be constructed more easily with fewer input data. This approach thus makes computer-aided assembly design systems more user-friendly and greatly reduces the amount of input data required, An example is presented to demonstrate the simplicity and effectiveness of the proposed approach. (C) 1998 Elsevier Science Ltd. All rights reserved.
Assembly-part automatic positioning using high-level entities of mating features
(1997-07-01)
Chang, CF
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
We present a new and convenient method for automatically positioning parts in an assembly. High-level entities of mating features and mating relations are used to describe the composed state of parts in an assembly. The characteristics of volume, reference origin, and boundary face of mating features and parts are used to determine automatic part-positioning operations. Using the proposed approach, a hierarchical model of the assembly can be constructed more easily with fewer input data. This approach thus makes computer-aided assembly design systems more user-friendly and greatly reduces the amount of input data required, An example is presented to demonstrate the simplicity and effectiveness of the proposed approach. (C) 1998 Elsevier Science Ltd. All rights reserved.
Establishing a demerit count reference standard for the classification and grading of leather hides
(2001)
Yeh, C
;
Perng, DB
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Leather hide, as a natural material, may have many types of undesirable surface defects. No analytical method has been devised for classifying and grading wet blue hide surface defects. A high return rate and disputes between the customer and manufacturing company usually cause additional costs. This paper proposes a semi-automatic machine vision method to measure the unusable surface defect areas in wet blue hides and a clear reference standard for the demerit count for graders to classify and grade wet blue hides. A statistical comparative evaluation of the grade deviation rate and a practical demerit count method for tannery performance are given to show the usefulness of the proposed approach.
Resolving feature interactions in 3D part editing
(1997-10-01)
Perng, DB
;
Chang, CF
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Feature-based design approach has been regarded as a promising approach for 3D parts design. However, the critical issues of modifying a part design by 3D features have not yet evoked sufficient discussion. This paper aims to address issues of feature interaction, especially for enclosure and intersection, among the modified feature and the other existing features. An efficient new approach to solve the feature interaction problems encountered in part-editing is proposed. The parts are assumed to consist of subtractive volume-features only. A set of rules that facilitate updating the B-rep data and feature-based representation of the part are devised. Computer simulation examples are given to show that the proposed approach is both feasible and effective. This research contributes to several aspects of feature-based design research, especially to the area of providing simple feature-based commands. (C) 1997 Elsevier Science Ltd.
Resolving feature interactions in 3D part editing
(1997-10-01)
Perng, DB
;
Chang, CF
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Feature-based design approach has been regarded as a promising approach for 3D parts design. However, the critical issues of modifying a part design by 3D features have not yet evoked sufficient discussion. This paper aims to address issues of feature interaction, especially for enclosure and intersection, among the modified feature and the other existing features. An efficient new approach to solve the feature interaction problems encountered in part-editing is proposed. The parts are assumed to consist of subtractive volume-features only. A set of rules that facilitate updating the B-rep data and feature-based representation of the part are devised. Computer simulation examples are given to show that the proposed approach is both feasible and effective. This research contributes to several aspects of feature-based design research, especially to the area of providing simple feature-based commands. (C) 1997 Elsevier Science Ltd.
Special issue on production automation
(1999-12-01)
Wu, DMC
;
Perng, DB
;
Chen, JJW
;
工業工程與管理學系
;
Department of Industrial Engineering and Management