A visual approach to simulation of icon‐based Chinese input method

Abstract

This paper presents a visual programming environment for users to develop their own defined icon‐based Chinese input methods. It will show the following four aspects. First, Chinese characters are concrete icons (decomposition graphs or webs). Second, a grammar that generates the above mentioned webs is a context‐free web grammar. Third, an icon‐based Chinese input method defines semantic rules to the production rules of the web grammar which then becomes an attributed web grammar. Fourth, a Chinese input simulator is a machine that accepts these webs. Developing such a simulator can be regarded as the construction of a user‐defined application program under the proposed visual programming environment. This paper also shows that form‐based visual languages included in the environment can be used to specify ways of evaluation and simulation in the user‐defined simulator.     

A new subliminal channel based on fiat‐Shamir's signature scheme

Abstract

This paper constructs a subliminal channel in a RSA‐like variant of the Fiat‐Shamir signature scheme to transfer any secret information. The proposed subliminal channel, unlike that in El‐Gamal signature scheme, can avoid the serious shortcoming that a subliminal receiver can undetectably forge a signer's signature. In addition, our channel also overcomes almost all shortcomings from which the subliminal channel in El‐Gamal signature scheme suffer.     

A microprocessor‐based electrohydraulic servo system

Abstract

A microprocessor‐based electrohydraulic servo system has been constructed and tested. It is implemented with an 8‐bit single‐chip microcomputer to control a hydraulic motor. The control algorithm is based on variable structure control principles. The experimental results show that the system is under good control and possesses a great potential for electrohydraulic servo control.     

A two‐layer cryptographic scheme for a service framework based on mobile agents

Abstract

In recent years, a new computation model, referred to as Service‐On‐Demand, has come into being gradually. This concept can be summarized as: the whole Net is a computer and one can have his/her tasks served using resources scattered around the Net. One technique that uses a similar concept is Web Service, which has been applied to many networks. However, Web Service is still confined to the Client‐Server paradigm and, in our opinion, does not wholly tally with the spirit of Service‐On‐Demand. Besides, there have not been many effective security schemes proposed for Web Services. This paper presents a mobile agent service framework, designed in reference to the service‐on‐demand concept, for the next generation of service‐based Internet applications. A two‐layer cryptographic security infrastructure is laid in the service framework to offer secured services. By separating the service functionality from its operating medium, the framework successfully prevents many security problems from happening. It also offers a most desirable benefit to both service providers and users. For service providers, deployment of a service is as easy as inserting a plug‐n‐play interface card and for service users, using a service is as easy as filling out a downloaded form. The main goal of this framework is to offer a total solution for providing secured services easily instead of doing difficult programming for services.     

Design of a double microprocessor‐based on‐line process control system

Abstract

A numerical technique for integrating the full Navier‐Stokes and diffusion equations through an initial value problem has been used to investigate the time development of a line buoyant source issuing in a density‐stratified environment. The basic physical features and some structures of the interactions of the motion at the intermediate mixing region are obtained. Results show that the stratification tends to inhibit the flow development of the buoyant source and to encourage the formation of a recirculatory vortex on the lower region near the source and the upper region.     

A grey‐based approach for distribution network reconfiguration

Abstract

This work presents a new concept for selecting restoration plans in power distribution systems using the Grey Relational Analysis (GRA) and the Analytical Hierarchy Process (AHP) approach. The GRA is used to analyze the preference ranking of each restoration plan, and the AHP is adopted to deal with assessing the weighting values of each objective function in a rational way. The proposed decision analysis framework can be applied to assist distribution system operators to make right decisions during a power system restoration process. The effectiveness of the proposed method is demonstrated through a numerical example. The test results show that the proposed method can rank each restoration plan in a quantitative way and obtain a preferable restoration plan correctly.     

A label‐based information flow control model for object‐oriented systems

Abstract

This paper proposes a label‐based information flow control model to prevent information leakage within object‐oriented systems. It offers the features of: (a) adapting to dynamic object state change, (b) adapting to dynamic role change, (c) preventing indirect information leakage, (d) detailing the control granularity to variables, (e) allowing purpose‐oriented method invocation, (f) controlling method invocation through argument sensitivity, (g) allowing declassification, and (h) allowing only trusted sources to write a variable.     

A frequency‐locked position servo control system by microprocessor‐based slope‐varied technique

Abstract

A microprocessor‐based slope‐varied frequency‐pumped controller (μP‐SVFPC) for improving the locking performance of the frequency‐locked position servo control system (FLPS) is presented. The presented slope‐varied pump technique is to perform the position control process fast for a long distance servo, while nearly similar acquisition times for different distance servos are obtained during the servo range. The motion profiles for system locking are adaptively generated according to the coming frequency error. No motion profiles are required to be pre‐installed in the controller. A prototype of μP‐FLPS is realized, simulated, and tested. Computer simulation and experimental result confirm that the system acquisition times of μP‐FLPS for short, middle, and long distance servos are nearly similar to each other. In comparison with the basic FLPS system, the acquisition times of the presented μP‐FLPS for the middle and long distance servos are improved by about 58% and 85%, respectively.     

A swept volume approach based on hermite interpolation for optimization in collision‐free motion planning

Abstract

The recursive quadratic programming (RQP) technique has been successfully applied for the motion planning problem. This paper inherits the RQP optimization formulation to solve collision‐free motion planning problems. The focus of the paper is to develop a more accurate approach to represent the swept volume based on Hermite interpolation. The non‐convex swept volume may be described by parametric representation. Based on this idea, the non‐convex limitation of the motion planning by the previous RQP technique can be overcome and it has yielded accurate answers in distance calculation. Also, have been presented to illustrate and demonstrate this approach in the paper.     

Analysis on the removal mechanism of disc grinding based on dynamic thermal–mechanical coupling

International Journal of Mechanics and Materials in Design - Disc grinding is a commonly-utilized removal technology to generate the machining surface with higher precision. The material removal is...     

A new scheme for ID‐based cryptosystems and signatures

Abstract

This paper proposes a new ID‐based cryptographic scheme for implementing public‐key cryptosystems and signatures. Instead of generating and publishing a public key for each user, the ID‐based scheme permits each user to choose his name or network address as his public key. This eliminates the need of a large public‐file and the exchange of private or public keys. The major advantage of the ID‐based cryptosystems is that the number of users can be exteneded to t*L users without decreasing the system security when users conspire, where L is the number of the system's secrets and t is the number of factors in p ‐ 1.     

A CTPN‐based scheduler for a flexible manufacturing cell

Abstract

This paper first presents hierarchical scheduling and control architecture for a flexible manufacturing cell (FMC) that is currently set up at the Mechanical Industrial Research Laboratories of the Industrial Technology Research Institute at Hsinchu, Taiwan. With this architecture, we focus on the scheduling problem of the FMC and present a scheduling mechanism based on a colored timed Petri net (CTPN) model. The CTPN model has three functions in the proposed mechanism: the first one is to formally describe pallet flows and resource constraints in the FMC by the event‐condition relation; the second one is to analyze conflict points among the pallet flows; the third one is to evaluate the used dispatching rules concerned with the selection of machine routings, the selection of work‐in‐process pallets in inter‐medium buffers and the assignment of the commonly used material‐handling device. Using the CTPN‐based scheduler, an appropriate combination of dispatching rules for each given batch can be selected to fit given criteria, e.g. minimum batch completion time, maximum resource utilization or minimum tardiness, etc. Moreover, real‐time status of the FMC can be represented in the mechanism for obtaining the on‐line scheduling effect.     

Speaker identification over telephone system based on channel‐effect cancellation

Abstract

This paper presents a method of speaker identification over telephone system based on channel‐effect cancellation. A set of inverse channel spectra is chosen as the basis for generating a channel‐effect‐cancellation filter. The speaker identification scheme is based on vector quantization where the codebooks of each speaker are trained without channel effect. When the speech signal of a speaker goes through the telephone system, a proper channel‐effect‐cancellation filter is generated to minimize the channel effect on the speech signal. The experiments show that the channel effect is mostly contributed by telephone handsets rather than by the transmission lines. By using the proposed method, an identification rate of 93.8% can be achieved for 100 speaker tests.     

Performance analyses of multi‐attribute files based upon multiple key hashing functions and haphazard files

Abstract

In this paper, a new multi‐attribute file, called haphazard file, is introduced. We derive two formulas for the average number of buckets to be examined over all possible partial match queries for multi‐attribute files based upon multi‐key hashing functions and haphazard files respectively. Theoretical results show that the performance of multi‐attribute files based upon multiple key hashing functions is always superior to that of haphazard files.     

A study of the feature‐based digital image stabilization system

Abstract

This article presents a digital image stabilization scheme that uses image processing techniques to compensate for undesirable image jitter due to vehicle or platform vibration to obtain a stabilized image display. The developed digital image stabilization system is based on the image combination approach combined with advanced image selection, feature detection, feature matching and pre‐rotation processing to produce crisp images. Using the Sobel edge detector, we calculate the magnitude of edge response as the judgment criteria for image transformation. To demonstrate the validity of the proposed technique, experimental results are given for some synthetic images.     

A parity-time symmetry single-mode laser based on graphene

The development of advanced optical systems, especially coherent optical systems demands high-performance single-mode lasers. Here, we proposed a parity-time symmetry single-mode laser based on graphene with superior performance over the widely utilized technologies of the index-coupled DFB laser working at telecommunication wavelength. The unique properties of graphene have been used to tune the III-V/Silicon hybrid laser to the PT symmetry broken phase where the lasing mode has a minimum overlap with graphene nanostructures while all other modes have been suppressed by the loss in graphene. Our results suggest a high-performance silicon-based laser source for photonic integrated circuits. Such a compact single-mode laser source can be widely used in some applications, such as on-chip optical interconnects, optical spectrometry, biochemical sensing and imaging.