Introducing k-point parallelism into VASP

For many years ab initio electronic structure calculations based upon density functional theory have been one of the main application areas in high performance computing (HPC). Typically, the Kohn–Sham equations are solved by minimisation of the total energy functional, using a plane wave basis set for valence electrons and pseudopotentials to obviate the representation of core states. One of the best known and widely used software for performing this type of calculation is the Vienna Ab initio Simulation Package, VASP, which currently offers a parallelisation strategy based on the distribution of bands and plane wave coefficients over the machine processors. We report here an improved parallelisation strategy that also distributes the k-point sampling workload over different processors, allowing much better scalability for massively parallel computers. As a result, some difficult problems requiring large k-point sampling become tractable in current computing facilities. We showcase three important applications: dielectric function of epitaxially strained indium oxide, solution energies of tetravalent dopants in metallic VO₂, and hydrogen on graphene.     

Introducing Gravitational Force into Affinity Propagation Clustering

Clustering has long been an important data processing task in different applications. Typically, it attempts to partition the available data into groups according to their underlying distributions, and each cluster is represented by a center or an exemplar. In this paper, a new clustering algorithm called gravitational-force-based affinity propagation (GAP) is proposed, based on the well-known Newton''s law of universal gravitation. It views the available data points as nodes of a network (or planets of a universe) and the clusters and their corresponding exemplars can be obtained by transmitting affinity messages based on the gravitational forces between data points in a network. While GAP is inspired by the recently proposed affinity propagation (AP) clustering approach, it provides a new definition of the similarity between data points which makes the AP process more convincing and at the same time facilitates the differentiation of data points'' importance. The experimental results show that the GAP clustering algorithm, with comparable clustering accuracy, is even more efficient than the original AP clustering approach.     

The Need for Research into Creativity in Marketing

A convenience sample of 36 online journals was taken as the source of information for this study. Management and marketing journals at a major publishing house were analysed in order to find out what they had to say about creativity. A search over the period 1989–99 found 29 articles which included creativity as one of the keywords. The area of marketing revealed a range of applications for creativity thinking. It is suggested that marketing executives need to be creative in order to enable their organisations to match the activities of their competitors and meet the needs of a rapidly changing environment.     

Introducing XP into Greenfield Projects: lessons learned

ThoughtWorks introduced XP into an organization and successfully completed a bleeding-edge technology project with client staff that had no previous experience using an agile development approach. This article illustrates not only how XP helped make the project a success, but also gives other lessons learned regarding the introduction of XP at client sites.     

Introducing solid objects into a constraint modelling system

A constraint modelling system called RASOR allows the constraints between design parameters to be investigated by a designer. Some simple geometric entities are provided. The ACIS solid modeller provides procedures for handling solid objects. An integrated system in which ACIS solids are defined and manipulated by RASOR commands has been achieved. The use of constraints is illustrated with reference to the assembly of the links of a mechanical system.     

Introducing reuse of software designs into a company

There are various motivations for introducing reuse into a company. One company tries to lower its costs in the software production, another aims on improving the quality of their products, a third thinks of securing the know-how of experienced software engineers in case they leave the company. Each of these three goals causes a similiar situation demanding reuse.A longterm vision of an environment for software reuse and its possible support by tools is given in this paper. The starting point of the discussion is the ESPRIT-project PRACTITIONER (No. 1094). The results and the experience gained in this project are based on information retrieval, hypermedia, and CASE tools. This paper presents these results and the drawn conclusions. Furthermore, it explains the ongoing technical aspects of the installation of an environment supporting reuse.     

遗传算法中引入非自然规则的研究

遗传算法作为一种模拟自然生物进化的群体搜索计算模型,正被广泛应用于各种领域,然而未成熟收敛现象却是一个难于克服的现实问题。论文首先分析了未成熟收敛的原因以及自然进化规则解决此问题的先天不足,通过对变异算子引入非自然规则—低适应值个体高变异和当前最优点微变异等策略对传统遗传算法进行改造,仿真表明其作为一个独立算法通过自身很好地解决了未成熟收敛问题。     

Introducing object orientation into large and complex systems

The paper investigates the applicability of the object-oriented technique to large and complex systems as exemplified by the operating system BS2000 which has been under constant development for a number of years. The proposed system architecture ensures the harmonious coexistence of procedural and object-oriented parts of the system. New domains, which are implemented using the object-oriented paradigm, can be smoothly embedded in the existing system. The parallel usage of different implementation languages is rendered economically viable. In our framework some representative parts of the system were redesigned and implemented in a prototype. The extensibility of the design was checked by including further parts into this scheme. The results are encouraging, so that the object-oriented technique will be used in the further development process. The proposed technique can also be applied to systems with a different structure, even a monolithic one     

将硬件引入“面向对象程序设计”课程实验教学

针对“面向对象程序设计”课程实验内容的设置容易使学生产生学之无用的思想及学后不会用的问题,结合电子信息专业培养特色,压缩了传统的、基本的实验内容,增加了应用性强的实验项目,并将硬件引入实验教学。实践表明,改进后的实验教学模式效果良好。     

Introducing dynamic diversity into a discrete particle swarm optimization

Particle swarm optimization (PSO) is an evolutionary metaheuristic inspired by the flocking behaviour of birds, which has successfully been used to solve several kinds of problems, although there are few studies aimed at solving discrete optimization problems. One disadvantage of PSO is the risk of a premature search convergence. To prevent this, we propose to introduce diversity into a discrete PSO by adding a random velocity. The degree of the introduced diversity is not static (i.e. preset before running PSO) but instead changes dynamically according to the heterogeneity of the population (i.e. if the search has converged or not). We solve the response time variability problem (RTVP) to test these two new ideas. The RTVP is an NP-hard combinatorial scheduling problem that has recently appeared in the literature. It occurs whenever products, clients or jobs need to be sequenced in such a way that the variability in the time between the instants at which they receive the necessary resources is minimized. The most efficient algorithm for solving non-small instances of the RTVP published to date is a classical PSO algorithm, referred to by the authors as PSO-M1F. In this paper, we propose 10 discrete PSO algorithms for solving the RTVP: one based on the ideas described above (PSO  -_c3dyn$c_3\text{<italic>dyn</italic>}$) and nine based on strategies proposed in the literature and adapted for solving a discrete optimization problem such as the RTVP. We compare all 11 PSO algorithms and the computational experiment shows that, on average, the best results obtained are due to our proposal of dynamic control mechanism for introducing diversity.     

Introducing an expert systems course into the operations research curriculum

In order to keep pace with the changing times, it is important that an expert systems course be included in the operations research curriculum. The operations research community was instrumental in producing automated aids, namely decision support systems, to help the decision maker. Another type of aid which operations research can impact is expert systems. This paper stresses the need for an expert systems course as part of the operations research curriculum, and then discusses such a course as taught in the Management Science Department at George Washington University.     

Introducing rotation invariance into the Neocognitron model for target recognition

This model introduces rotation invariance into the Neocognitron model by way of rotation layers. The most likely orientation of the target is detected and used for further pattern classification using an algorithm similar to that for the Neocognitron model. The visual target recognition capability of this model is demonstrated.     

高校课堂引入手机评测系统研究

在中国,手机网民规模已达到9.32亿,其在整个网民中占比达99.2％.其中,我国高校学生的智能手机普及率接近100％,这使得在高校内利用智能手机APP辅助教学成为可能.论文研究在高校课堂中引入手机APP进行学习评测和管理的方法,即将传统的课程、班级管理及部分评价方法融入手机APP中,以提高高校课堂学习管理的效率和学生学习知识的积极性.论文对3门课程16个班级的884名学生进行了手机课堂测验应用,并对其中两门课4个班级的165名学生进行了手机课堂测验和纸质测验的对比试验,同时对124名学生进行针对手机测验的课堂调查.结果表明,手机测验相较于传统纸质测验得到更低的测试成绩,但是从主观上却引起学生极大的兴趣,增加了课堂活跃度.总体而言,大多数学生认可手机考试形式是一种趋势,在将来的教学中可能会成为一种重要的教学评价手段.但是,课堂手机评价系统还属于新兴事物,具有强大的生命力,还需要进一步研究.     

Computer Vision Methodologies

In this paper we address the problem of methodologies for computer vision. In the first part we will present a brief survey of the Marr paradigm, e.g., what David Marr called his philosophy. We will emphasize the sequence of hypotheses which progressively makes the scene recovery approach explicit as well as the limitations of this approach. We then present the goal-directed approach as an alternative to the recovery school: behaviorism versus reconstructionism. We show that this dichotomy is not the only possible one and introduce the idealism versus empiricism dichotomy. We propose some directions toward a new methodology in a systemic framework involving another, higher-level, methodological dichotomy: systemism versus reductionism. In this new framework we try to exploit of all the sources of constraints, and, thereby, to reconcile some of the previous approaches like recovery school and purposive vision.     

多核技术在数据结构课程中的引入与探讨

多核技术是当前计算机学科发展的热门方向,针对将多核技术融入到操作系统、编译原理等课程中出现的学生对基础算法并行化了解甚少的问题,文章提出将多核技术引入到前导课程数据结构中的实施方案,包括课堂教学内容的扩展,多核技术实践大纲及实例,并引入基于多核的课程设计。实践证明,新的教学方法增进了学生对多核技术和并行算法的了解。     

Introducing artificial evolution into peer-to-peer networks with the distributed remodeling framework

A peer-to-peer (P2P) network is a complex system whose elements (peer nodes, or simply peers) cooperate to implement scalable distributed services. From a general point of view, the activities of a P2P system are consequences of external inputs coming from the environment, and of the internal feedbacks among nodes. The reaction of a peer to direct or indirect inputs from the environment is dictated by its functional structure, which is usually defined in terms of static rules (protocols) shared among peers. The introduction of artificial evolution mechanisms may improve the efficiency of P2P networks, with respect to resource consumption, while preserving high performance in response to the environmental needs. In this paper, we propose the distributed remodeling framework (DRF), a general approach for the design of efficient environment-driven peer-to-peer networks. As a case study, we consider an ultra-large-scale storage and computing system whose nodes perform lookups for resources provided by other nodes, to cope with task execution requests that cannot be fulfilled locally. Thanks to the DRF, workload modifications trigger reconfigurations at the level of single peers, from which global system adaptation emerges without centralized control.