Teaching meshes, subdivision and multiresolution techniques

In recent years, geometry processing algorithms that directly operate on polygonal meshes have become an indispensable tool in computer graphics, CAD/CAM applications, numerical simulations, and medical imaging. Because the demand for people that are specialized in these techniques increases steadily the topic is finding its way into the standard curricula of related lectures on computer graphics and geometric modeling and is often the subject of seminars and presentations. In this article we suggest a toolbox to educators who are planning to set up a lecture or talk about geometry processing for a specific audience. For this we propose a set of teaching blocks, each of which covers a specific subtopic. These teaching blocks can be assembled so as to fit different occasions like lectures, courses, seminars and talks and different audiences like students and industrial practitioners. We also provide examples that can be used to deepen the subject matter and give references to the most relevant work.     

A study on information security management system evaluation—assets, threat and vulnerability

The security of information system is like a chain. Its strength is affected by the weakest knot. Since we can achieve 100% Information Security Management System (ISMS) security, we must cautiously fulfill the certification and accreditation of information security. In this paper, we analyzed, studied the evaluation knowledge and skills required for auditing the certification procedures for the three aspects of ISMS—asset, threat, and vulnerability.     

A GUI for Jess

The paper describes JessGUI, a graphical user interface developed on top of the Jess expert system shell. The central idea of the JessGUI project was to make building, revising, updating, and testing Jess-based expert systems easier, more flexible, and more user friendly. There are many other expert system building tools providing a rich and comfortable integrated development environment to expert system builders. However, they are all either commercial or proprietary products. Jess and JessGUI are open-source freeware, and yet they are well suited for building even complex expert system applications, both stand-alone and Web-based ones. An important feature of JessGUI is its capability of saving knowledge bases in XML format (in addition to the original Jess format), thus making them potentially easy to interoperate with other knowledge bases on the Internet. Jess and JessGUI are also used as practical knowledge engineering tools to support both introductory and advanced university courses on expert systems. The paper presents design details of JessGUI, explains its links with the underlying Jess knowledge representation and reasoning tools, and shows examples of using JessGUI in expert system development. It also discusses some of the current efforts in extending Jess/JessGUI in order to provide intelligent features originally not supported in Jess.     

Normal vector compression of 3D mesh model based on clustering and relative indexing

As the transmission of 3D shape models through Internet becomes more important, the compression issue of shape models gets more critical. While the compressions of topology and geometry have been explored significantly, the same issue for normal vectors has not yet been studied as much as it deserves.

Presented in this paper is an approach to compress the normal vectors of a 3D mesh model using the concept of clustering and relative indexing. The model is assumed to be manifold triangular mesh model with normal vectors associated with vertices. The proposed scheme clusters the normal vectors of given model and the representative normal vector of each cluster is referred to via a mixed use of relative as well as absolute indexing concepts. It turns out that the proposed approach achieves a significant compression ratio (less than 10% of the original VRML model files) without a serious sacrifice of the visual quality.     

Managing service level agreements in Premium IP networks: a business-oriented approach

This paper presents a market-enabling framework where users, content providers and network operators can interact in the seamless, transparent sale and delivery of a wide range of services. The framework allows for dynamic creation, configuration and delivery of services with quality assurance, via automated management of Service Level Agreements (SLAs). We propose an approach relying on a systemic treatment of business, service and network layer issues, which translates into a layered architecture where components belonging to different levels interact on the basis of a mediation paradigm. We use mediation as a generic term for a combination of negotiation, brokerage and state notification, jointly concurring to the realization of the entire life-cycle of a service.     

Optical CO2 sensor with the combination of colorimetric change of α-naphtholphthalein and internal reference fluorescent porphyrin dye

A new optical CO₂ sensor based on the overlay of the CO₂ induced absorbance change of pH indicator dye α-naphtholphthalein with the fluorescence of tetraphenylporphyrin (TPP) was developed. The observed luminescence intensity from TPP at 655 nm increased with increasing the CO₂ concentration. The ratio I₁₀₀/I₀ values of the sensing films consisting of α-naphtholphthalein in ethyl cellulose layer and TPP in polystyrene layer, where I₀ and I₁₀₀ represent the detected luminescence intensities from a layer exposed to 100% nitrogen and 100% CO₂, respectively, that the sensitivity of the sensor, are more than 53.9. The response and recovery times of the sensing films consisting of α-naphtholphthalein in ethyl cellulose layer and TPP in polystyrene layer were less than 5 s for switching from nitrogen to CO₂, and for switching from CO₂ to nitrogen. The signal changes were fully reversible and no hysterisis was observed during the measurements. The highly sensitive optical CO₂ sensor based on fluorescence intensity changes of TPP due to the absorption change of α-naphtholphthalein with CO₂ was achieved.     

Co(-Fe)-B-Si-Nb块体非晶合金

利用团簇线方法和微合金化原理研究了Co基Co(-Fe)-B-Si-Nb多组元合金体系中块体非晶合金的形成。首先,确定Co-B-Si三元体系为基础体系,利用团簇线(体现在三元体系中为二元特殊团簇与第三组元的连线)在Co-B-Si体系中确定基础合金成分;然后添加少量的Nb对基础三元成分进行合金化以提高合金的玻璃形成能力。利用铜模吸铸法制备直径为3mm的合金棒,结果表明能够形成块体非晶的合金成分为(Co8B3-Si)100-xNbx(x=4～5at%),其中,Co8B3为密堆附半八面体的阿基米德反棱柱团簇结构。并且这些非晶成分可近似地用(团簇)1(胶粘原子)1模型表达,为(Co8B3)1M1(M=(Si,Nb)),即非晶成分由一个团簇连接一个胶粘原子组成,其中胶粘原子M为Si和Nb原子的组合。最后用Fe替代部分Co可进一步提高合金的玻璃形成能力,得到的Co-Fe-B-Si-Nb五元块体非晶合金具有很好的软磁性能,其饱和磁化强度(Ms)最大可达0.98T,矫顽力(Hc)低于6A/m。     

Pencil curve detection from visibility data

The trajectory of the ball-center point of a ball-end mill slid along a concave-edge region on a part surface becomes a pencil curve, and the ball-end milling along the pencil curve is called pencil curve machining. Presented in the paper is a procedure for computing pencil curves for 3-axis sculptured surface machining. The proposed algorithm traces pencil curves from an offset triangular mesh having numerous intersections (self-intersections). Since the outer skin of an offset triangular mesh makes the valid CL-surface, pencil curves can be obtained by connecting valid intersections lying on the outer skin of the offset mesh. The underlying concept of the proposed algorithm is that visible intersections are always valid for pencil curves. To obtain the visibility data of intersections, the proposed algorithm uses a graphics board, which performs hidden surface removal at a rate of up to a million polygons per second. Various examples have been tested with implementation of the algorithm, and some examples are presented for illustration.