Design and Implementation of a Novel Spherical Mobile Robot

In this paper, the design, modeling and implementation of a novel spherical mobile robot is presented. The robot composes of a spherical outer shell made of a transparent thermoplastic material, two pendulums, two DC motors with gearboxes, two equipments for linear motion and two control units. It possesses four distinct motional modes including: driving, steering, jumping and zero-radius turning. In driving and steering modes, the robot moves along straight and circular trajectories, respectively. The robot performs these motional modes using movable internal masses. In the jumping mode, it can jump over obstacles and in the zero-radius turning mode, the robot can turn with zero-radius to improve the motion flexibility. Furthermore, the attempts to establish the dynamic models of some motional modes are made and finally, the accuracy of the obtained dynamic models is verified by simulation and experimental results.     

On the effect of multirate co-simulation techniques in the efficiency and accuracy of multibody system dynamics

Dynamic simulation of complex mechatronic systems can be carried out in an efficient and modular way making use of weakly coupled co-simulation setups. When using this approach, multirate methods are often needed to improve the efficiency, since the physical components of the system usually have different frequencies and time scales. However, most multirate methods have been designed for strongly coupled setups, and their application in weakly coupled co-simulation is not straightforward due to the limitations enforced by commercial simulation tools used in mechatronics design. This work describes a weakly coupled multirate method intended to be a generic multirate interface between block diagram software and multibody dynamics simulators, arranged in a co-simulation setup. Its main advantage is that it does not enforce equidistant or synchronized communication time-grids and, therefore, it can be easily applied to set up weakly-coupled co-simulations using off-the-shelf commercial block diagram simulators while giving the user a great flexibility for selecting the integration scheme for each subsystem.     

Implementation and performance evaluation of a payment protocol for vehicular ad hoc networks

Vehicular ad hoc networks (VANETs) are envisioned to support the development of a wide range of attractive applications such as payment services which require the design of payment systems that satisfy additional requirements associated with VANETs. The wide range of scenarios (with or without connectivity restriction) arising from vehicle-to-vehicle and vehicle-to-roadside communications have opened up new security challenges which must be considered by payment system designers to achieve the same security capabilities independent of the scenario where payment occurs. We propose and implement a new payment protocol (called KCMS-VAN protocol) for those scenarios where the client cannot communicate directly with the credit card issuer (the client’s financial institution) for authentication. Our proposed protocol uses symmetric-key operations which require low computational power and can be processed much faster than asymmetric ones. We also present a performance evaluation of the proposed payment protocol and the results obtained demonstrate that optimal performance can be achieved with it.     

Improving performance and energy efficiency of embedded processors via post-fabrication instruction set customization

Encapsulating critical computation subgraphs as application-specific instruction set extensions is an effective technique to enhance the performance and energy efficiency of embedded processors. However, the addition of custom functional units to the base processor is required to support the execution of custom instructions. Although automated tools have been developed to reduce the long design time needed to produce a new extensible processor for each application, short time-to-market, significant non-recurring engineering and design costs are issues. To address these concerns, we introduce an adaptive extensible processor in which custom instructions are generated and added after chip-fabrication. To support this feature, custom functional units (CFUs) are replaced by a reconfigurable functional unit (RFU). The proposed RFU is based on a matrix of functional units which is multi-cycle with the capability of conditional execution. To generate more effective custom instructions, they are extended over basic blocks and hence, multiple-exits custom instruction and intuition behind it are introduced. Conditional execution capability has been added to the RFU to support the multi-exit feature of custom instructions. Because the proposed RFU has limitations on hardware resources (i.e., connections and processing elements), an integrated mapping-temporal partitioning framework is proposed to guarantee that the generated custom instructions can be mapped on the RFU (mappable custom instructions). Experimental results show that multi-exit custom instructions enhance the performance and energy efficiency by an average of 32% and 3% compared to custom instructions limited to one basic block, respectively. A maximum speedup of 4.9, compared to a single-issue embedded processor, and an average speedup of 1.9 was achieved on MiBench benchmark suite. The maximum and average energy saving are 56% and 22%, respectively. These performance and energy efficiency are obtained at the cost of 30% area overhead.     

Implementation of wide-field integration of optic flow for autonomous quadrotor navigation

Insects are capable of robust visual navigation in complex environments using efficient information extraction and processing approaches. This paper presents an implementation of insect inspired visual navigation that uses spatial decompositions of the instantaneous optic flow to extract local proximity information. The approach is demonstrated in a corridor environment on an autonomous quadrotor micro-air-vehicle (MAV) where all the sensing and processing, including altitude, attitude, and outer loop control is performed on-board. The resulting methodology has the advantages of computation speed and simplicity, hence are consistent with the stringent size, weight, and power requirements of MAVs.     

An Efficient Newton-Krylov Implementation of the Constrained Runs Scheme for Initializing on a Slow Manifold

The long-term dynamic behavior of many dynamical systems evolves on a low-dimensional, attracting, invariant slow manifold, which can be parameterized by only a few variables (“observables”). The explicit derivation of such a slow manifold (and thus, the reduction of the long-term system dynamics) is often extremely difficult or practically impossible. For this class of problems, the equation-free framework has been developed to enable performing coarse-grained computations, based on short full model simulations. Each full model simulation should be initialized so that the full model state is consistent with the values of the observables and close to the slow manifold. To compute such an initial full model state, a class of constrained runs functional iterations was proposed (Gear and Kevrekidis, J. Sci. Comput. 25(1), 17–28, 2005; Gear et al., SIAM J. Appl. Dyn. Syst. 4(3), 711–732, 2005). The schemes in this class only use the full model simulator and converge, under certain conditions, to an approximation of the desired state on the slow manifold. In this article, we develop an implementation of the constrained runs scheme that is based on a (preconditioned) Newton-Krylov method rather than on a simple functional iteration. The functional iteration and the Newton-Krylov method are compared in detail using a lattice Boltzmann model for one-dimensional reaction-diffusion as the full model simulator. Depending on the parameters of the lattice Boltzmann model, the functional iteration may converge slowly or even diverge. We show that both issues are largely resolved by using the Newton-Krylov method, especially when a coarse grid correction preconditioner is incorporated.     

Comparison of parallel multi-objective approaches to protein structure prediction

Protein structure prediction (PSP) is an open problem with many useful applications in disciplines such as medicine, biology and biochemistry. As this problem presents a vast search space and the analysis of each protein structure requires a significant amount of computing time, it is necessary to take advantage of high-performance parallel computing platforms as well as to define efficient search procedures in the space of possible protein conformations. In this paper we compare two parallel procedures for PSP which are based on different multi-objective optimization approaches, i.e. PAES (Knowles and Corne in Proc. Congr. Evol. Comput. 1:98–105, 1999) and NSGA2 (Deb et al. in IEEE Trans. Evol. Comput. 6:182–197, 2002). Although both procedures include techniques to take advantage of known protein structures and strategies to simplify the search space through the so-called rotamer library and adaptive mutation operators, they present different profiles with respect to their implicit parallelism.     

R-Technology of Programming: Basic Notions and Implementation

This paper presents a kind of visual programming,which is called R-technology of programming,The R-technology is independent of any programming language or operating system and the R-chart is in accord with international standard(ISO 8631H).The package of R-technology has been applied to the high level languages such as PASCAL.C,ASSEMBLER,FORTRAN,PL/1,MODULA-2 and RTRAN,This package is applied to computers ranging from mainframes(IBM370) and minis(VAX) to micros(IBM/PC).     

A Design and Implementation of Secure Login System

According to the secure problems existing in the login system, a new secure scheme on login system is proposed. This scheme encryptedly transmits the input information after filtration and digestion so that it can efficiently avoid the replay-attack and the man-in-the-middle attack.     

Improvement and Implementation of Network Intrusion Detection System

Current network intrusion detection systems （NIDSes） are confronted with some problems. In addition to high false positive ratio and high false negative ratio, their own performances are difficult to be adapted to the need of increasing network traffic. To improve the speed and accuracy of detection, this paper analyzes the NIDS firstly, and secondly presents and implements two improved schemes from string matching algorithms and the structure of intrusion signature library. Experimental results show that our schemes are feasible.     

R-Technology of Programming: Basic Notions and Implementation

This paper presents a kind of visual programming, which is called R-technology of programming.The R-technology is independent of any programming language or operating system and the R-chart isin accord with international standard (ISO 8631H). The package of R-technology has been applied tothe high level languages such as PASCAL, C, ASSEMBLER, FORTRAN, PL/1, MODULA-2 andRTRAN. This package is applied to computers ranging from mainframes (IBM 370) and minis (VAX)to micros (IBM/PC).     

Exact Minkowksi Sums of Polyhedra and Exact and Efficient Decomposition of Polyhedra into Convex Pieces

We present the first exact and robust implementation of the 3D Minkowski sum of two non-convex polyhedra. Our implementation decomposes the two polyhedra into convex pieces, performs pairwise Minkowski sums on the convex pieces, and constructs their union. We achieve exactness and the handling of all degeneracies by building upon 3D Nef polyhedra as provided by Cgal. The implementation also supports open and closed polyhedra. This allows the handling of degenerate scenarios like the tight passage problem in robot motion planning. The bottleneck of our approach is the union step. We address efficiency by optimizing this step by two means: we implement an efficient decomposition that yields a small number of convex pieces, and develop, test and optimize multiple strategies for uniting the partial sums by consecutive binary union operations. The decomposition that we implemented as part of the Minkowski sum is interesting in its own right. It is the first robust implementation of a decomposition of polyhedra into convex pieces that yields at most O(r ²) pieces, where r is the number of edges whose adjacent facets comprise an angle of more than 180 degrees with respect to the interior of the polyhedron. This work was partially supported by the Netherlands’ Organisation for Scientific Research (NWO) under project no. 639.023.301.     

A Substitution Based Model for the Implementation of PROLOG——The Design and Implementation of LPROLOG

Since PROLOG has been chosen as the Fifth Generation Computer's Kernal Language,it ispresently one of the hottest topics among computer scientists all over the world.Recently,theimplementation technique and the application of PROLOG have been developed rapidly.In thispaper,a new implementation scheme for PROLOG is proposed.The scheme is based on thesubstitution of instantiated veriable values.It has many advantages,such as a higher runningspeed,less main memory requirement,and easier to be implemented.The scheme has beenimplemented by the authors on IBM4341.     

Research and Implementation of the Practical Texture Synthesis Algorithms

How to generate pictures real and esthetic objects is an important subject of computer graphics.The techniques of mapping textures onto the surfaces of an object in the 3D space are efficient approaches for the purpose.We developed and implemented algorithms for generating objects with appearances stone,wood grain,ice lattice,brick,doors and windows on Apollo workstations.All the algorithms have been incorporated into the 3D grometry modelling system (GEMS) developed by the CAD Center of Tsinghua University.This paper emphasizes the wood grain and the ice lattice algorithms.     

Design and Implementation of a Heterogeneous Distributed Database System

This paper introduces a heterogeneous distributed database system called LSZ system,where LSZ is an abbreviation of Li Shizhen,an ancient Chinese medical scientist.LSZ system adopts cluster as distributed database node(or site).Each cluster consists of one of several microcomputers and one server.Te paper describes its basic architecture and the prototype implementation,which includes query processing and optimization,transaction manager and data language translation.The system provides a uniform retrieve and update user interface through global relational data language GRDL.     

The Design and Implementation of an OA System ZGL1

ZGLI,an office automation system for municipal administration,is presented.It is a distributedmicrocomputer system based on OMNINET.Each node of it is an IBM PC/XT microcomputer with Chinesecharacter facilities.The system consists of a distributed database management system,a Chinese characterelectronic mail system,a Chinese word processor and others.Its functions include document management,report form management,research project management,finance management and information access.     

Implementation and Application of Visual Simulation System for Digital Campus

Fundamental conception and technological features of Digital Campus as well as the general framework of its visualization subsystem are introduced. A practical case of visual campus simulation system of Huazhong University of Science and Technology is described. The key issues of simulation application based on Creator and Vega are discussed in detail and some applications of the visual campus system are also given.1     

Research and Implementation of a Graphic System for Doppler Radar

Doppler radar have become one of the most important instruments for weather now casting, and for meso-scale weather research because of its higher spatial and temporal resolutions. A dealing system for Doppler radar graphic was researched and implemented so as to providing a convenient tool for users. We research and realized CINRAD/XD Doppler radar＇s graphic system. It contains three important parts： reading, standardization and pretreatment. It can be used very easily and conveniently. Besides, the system can be expanded and transplanted simply.     

Minimum Augmentation of Edge-Connectivity between Vertices and Sets of Vertices in Undirected Graphs

Given an undirected multigraph G=(V,E), a family $\mathcal{W}Given an undirected multigraph G=(V,E), a family W\mathcal{W} of areas W⊆V, and a target connectivity k≥1, we consider the problem of augmenting G by the smallest number of new edges so that the resulting graph has at least k edge-disjoint paths between v and W for every pair of a vertex v∈V and an area W ? WW\in \mathcal{W} . So far this problem was shown to be NP-complete in the case of k=1 and polynomially solvable in the case of k=2. In this paper, we show that the problem for k≥3 can be solved in O(m+n(k ³+n ²)(p+kn+nlog n)log k+pkn ³log (n/k)) time, where n=|V|, m=|{{u,v}|(u,v)∈E}|, and p=|W|p=|\mathcal{W}| .