Frame-sliced voxel representation: An accurate and memory-efficient modeling method for workpiece geometry in machining simulation

This paper presents a new and enhanced voxel representation format for modeling the machined workpiece geometry in simulating machining operations involving repeated update of the workpiece model volume. The modeling format is named as the Frame-Sliced Voxel representation (FSV-rep) as it uses a novel concept of frame-sliced voxels to represent the boundary of the workpiece volume. The FSV-rep uses a multi-level surface voxel representation for sparse and memory-efficient implementations. The utilization of frame-sliced voxels enables approximation of the workpiece surface to only loosely depend on the grid resolution but achieve sub-voxel resolution updates for the model volume. It can, thus, provide a boundary representation of the workpiece model at an accuracy that is much higher than a basic voxel model of the same grid resolution and a similar model size. Quantitative comparisons of the FSV-rep with the traditional voxel representations at the same finest grid resolution show improvement up to two orders of magnitude in accuracy with only marginal increases in the model size. This confirms the effectiveness of the FSV-rep in simulating machined workpiece geometry in complex machining processes such as multi-axis milling.     

Eigenspace compression: dynamic 3D mesh compression by restoring fine geometry to deformed coarse models

Multimedia Tools and Applications - Dynamic 3D mesh compression is of great practical important issues in computer graphics and multimedia applications. In this paper, an efficient compression...     

三维软件在大运量、长距离输煤管道设计中的应用

针对采用二维软件进行工艺管道布置存在的工作量大、易出错等问题,分析了国内设计领域所使用的各种三维软件的优缺点,并提出将Solidworks软件应用于大运量、长距离输煤管道设计中,详细介绍了Solidworks软件在输煤管道方案设计阶段、初步设计阶段、施工图设计阶段中的应用。     

Photo-electroforming: 3-D geometry and materials flexibility in aMEMS fabrication process

Photo-electroforming is a new manufacturing process for making microelectromechanical systems (MEMS). Photo-electroforming builds parts by an additive process which defines geometry by depositing powder in layers and creating regions of selective conductivity by laser-enhanced electroless plating. The conductive region is then joined by a second plating to form an integral part. The unmetallized portion is removed by selective etching in one step after all layers are defined and joined. Single-layer and two-layer stand-alone parts made of nickel/silicon carbide composites of overall size 75-100 μm and feature size 25 μm were created. Writing speeds of up to 24 cm/s and in-plane resolution of 15 μm were demonstrated. The high laser-induced plating rates were found to be due to elevated substrate temperatures under the laser spot and enhanced mass transfer due to pumping by the hydrogen bubbles resulting from the plating reaction. In the regimes studied, mass transfer defined the rate limit. The in-plane resolution was found to be limited by a combination of laser spot size, thermal conduction in the substrate, and laser divergence due to gas bubbles     

From on-line sketching to 2D and 3D geometry: a system based on fuzzy knowledge

The paper describes the development of a fuzzy knowledge-based prototype system for conceptual design. This real time system is designed to infer user's sketching intentions, to segment sketched input and generate corresponding geometric primitives: straight lines, circles; arcs, ellipses, elliptical arcs, and B-spline curves. Topology information (connectivity, unitary constraints and pairwise constraints) is received dynamically from 2D sketched input and primitives. From the 2D topology information, a more accurate 2D geometry can be built up by applying a 2D geometric constraint solver. Subsequently, 3D geometry can be received feature by feature incrementally. Each feature can be recognised by inference knowledge in terms of matching its 2D primitive configurations and connection relationships. The system accepts not only sketched input, working as an automatic design tool, but also accepts user interactive input of both 2D primitives and special positional 3D primitives. This makes it easy and friendly to use. The system has been tested with a number of sketched inputs of 2D and 3D geometry.     

The future threat to computers and composition: Nontenured instructors, intellectual property, and distance education

In this article, I argue that recent initiatives concerning the use of computer-mediated instruction to improve writing skills in large lecture classes often work to undermine the professional status of composition teachers in North American universities. I trace the use of computer-assisted instruction, specifically distance-education initiatives. To further the cause of a just implementation of CAI, I discuss recent contractual language and explore the current practice of hiring computers and writing specialists into nontenurable staff positions. I posit that writing program administrators need to fight for stable, long-term positions for faculty who teach with computers and within computer-mediated spaces. I also argue that compositionists must seek to regulate and control the ownership of their intellectual property and course materials.     

Predicting the distance between antibody’s interface residue and antigen to recognize antigen types by support vector machine

In this paper, a machine learning approach, known as support vector machine (SVM) is employed to predict the distance between antibody’s interface residue and antigen in antigen–antibody complex. The heavy chains, light chains and the corresponding antigens of 37 antibodies are extracted from the antibody–antigen complexes in protein data bank. According to different distance ranges, sequence patch sizes and antigen classes, a number of computational experiments are conducted to describe the distance between antibody’s interface residue and antigen with antibody sequence information. The high prediction accuracy of both self-consistent and cross-validation tests indicates that the sequential discovered information from antibody structure characterizes much in predicting the distance between antibody’s interface residue and antigen. Furthermore, the antigen class is predicted from residue composition information that belongs to different distance range by SVM, which shows some potential significance.     

The price of free software: Labor, ethics, and context in distance education

The use, development, and dissemination of open-source software (OSS) appears to be more in line with the liberatory, collaborative, epistemological ideals of institutions of higher learning than does commercial software. However, our primary and secondary research reveals that due largely to institutional pressures and labor issues, open source software options are often not explored or considered when teaching distance-learning writing courses. In this article, we compare open source and commercial content/course management options and demonstrate the benefits and problems of specific applications. Additionally, we discuss our results from case studies of four instructors who teach distance-learning writing courses. We detail what types of applications they use, the level of institutional support they receive, and the motivations for their choices of applications.     

RETRACTED ARTICLE: Correlation between Amount-of-Reuse Metrics and Other Software Measures with Respect to Programming Code in C++

In recent years, there have been several proposals for amount-of-reuse metrics. However, it is not clear if these metrics measure anything different from other software metrics that are often generally used. Besides, the relationship between these metrics is also unclear. Without a clear understanding, the true added value provided by these metrics remains unknown. In this paper, an analysis of the existing amount-of-reuse metrics is presented and a subset of these is selected, on the basis of their industrial applicability, for further investigation. These metrics are then applied to a collection of different software products to obtain an understanding of the level of correlation that exists between them and other well-known software metrics such as cyclomatic complexity, volume and lines of code. Our analysis suggests that the selected subset of amount-of-reuse metrics provides a relatively independent view of the analyzed code.     

Variation in spectral response of soybeans with respect to illumination,view and canopy geometry

Comparisons of the spectral response for incomplete (well-defined row structure) and complete (overlapping row structure) canopies indicated that there was a greater dependence on Sun and view geometry for the incomplete canopies. This effect was more pronounced for the highly absorptive red (0.6-0.7 μm) wavelength band than for the near-infrared (IR) (0.8-1.1 μm) based on relative reflectance factor changes.

Red and near-IR reflectance for the incomplete canopy decreased as solar zenith angle increased for a nadir view angle until the soil between the plant rows was completely shaded. Thereafter for increasing solar zenith angle the red reflectance levelled off and the near-IR reflectance increased. A ‘hot-spot’ effect was evident for the red and near-IR reflectance factors, especially when the Sun-sensor view directions were perpendicular to the rows. The ‘hot-spot’ effect was more pronounced for the red band based on relative reflectance value changes. The effect of Sun angle was more pronounced for view angles perpendicular to the row direction.

An analysis of the ratios of off-nadir- to nadir-acquired data revealed that off-nadir red band reflectance factors more closely approximated straight-down measurements for time periods away from solar noon. Near-IR and greenness responses showed a similar behaviour. Normalized difference generally approximated straight-down measurements during the middle portion of the day. An exception occurred near solar noon when sunlit bare soil was present in the scene.     

Token-based approach in distributed mutual exclusion algorithms: a review and direction to future research

The Journal of Supercomputing - The problem of mutual exclusion is a highly focused area in the distributed architecture. To avoid inconsistency in data, mutual exclusion ensures that no two...     

传统与现代的对话:书法在艺术设计中的应用

目前国内的艺术设计作品越来越脱离民族文化性和精神性。面对这种状况,借鉴传统艺术式样是解决这个问题的可行方法之一。在中国传统艺术中,书法具有其他艺术式样所没有的抽象性,在现代艺术设计中发挥着重要的作用。本文在探讨书法艺术特征和审美取向的同时,就书法在现代艺术设计中的表现形式,传统书法与现代艺术设计的关系进行探讨。并对今后艺术设计中书法元素的利用进行探析。     

Reducing the spatial distance between printed and online information sources by means of mobile technology enhances learning: Using 2D barcodes

Online information sources, such as pictures and animations on web pages are frequently used for complementing printed course material in educational contexts. The concurrent use of online and printed information sources by students, however, requires going back and forth between physically separated course material, such as a course book and a computer screen, thus leading to suboptimal learning outcomes. Compatible with the principles identified by the recent theoretical frameworks for multimedia learning, mobile technology provides learners with the opportunity to bring online and printed course material close together. Mobile phones make online information available within a small desktop space, in close proximity to printed course material. The challenges that are relevant to text input methods can be overcome by the 2D barcode technology. This study investigates the use of camera-equipped mobile phone and 2D barcode technology as an alternative to the use of computer screen for complementing printed course material. The results of the experimental investigation suggest that, by facilitating the access to online information sources by 2D barcode tags on course books, mobile phones have the potential to enhance learning.     

Database development and 3D modeling of textural variations in heterogeneous,unconsolidated aquifer media: Application to the Milan plain

The textural and hydrogeologic properties of loose deposits are closely connected to the sedimentary processes occurring in fluvial and glacio-fluvial systems. The proposed procedure combines geologic knowledge, coded well data logs stored in a hydrogeologic georeferenced database, geographic information system (GIS) and 3D calculation software to reconstruct the detailed distribution of the subsoil's hydrogeologic parameters. The calculations may apply to any subsoil part, bounded by one or more surfaces. This methodological approach may be applied to diverse investigation depths, vertical intervals detailed to varying extents, on a local or regional scale. Employing great quantities of well data logs, recorded in different ways and distributed across large areas, has enabled significant spatial sedimentologic reconstruction. Two groups of parameters were considered: textural (percentages of gravel, sand and clay) and hydrogeologic (hydraulic conductivity and porosity). In terms of sedimentology, the method reconstructs spatial heterogeneity both along cross-sections and for an entire user-defined volume to analyze the sediments’ energy functions and their distribution; deposition rates are proportional to process intensity and distribution with time. In terms of hydrogeology, detailed 3D hydrogeologic structural data provide detailed input for hydrogeologic models in groundwater resource management and planning, such as for transport models.     

The Hellinger distance in Multicriteria Decision Making: An illustration to the TOPSIS and TODIM methods

Due to the difficulty in some situations of expressing the ratings of alternatives as exact real numbers, many well-known methods to support Multicriteria Decision Making (MCDM) have been extended to compute with many types of information. This paper focuses on the information represented as probability distribution. Many of the methods that deal with probability distribution use the concept of stochastic dominance, which imposes very strong restrictions to differentiate two probability distributions, or uses the probability distributions to obtain a quantity that will be used to rank the alternatives. This paper brings the Hellinger distance concept to the MCDM context to assist the models to deal with probability distributions in a direct way without any transformation. Transformations in the data or summary quantities may miss represent the original information. For direct comparisons among probability distributions we use the stochastic dominance degree (SDD). We illustrate how simple it can be to adapt the existing methods to deal with probability distributions through the Hellinger distance and SDD by adapting the TOPSIS and TODIM (an acronym in Portuguese of Interactive and Multicriteria Decision Making) methods.