We present a new family of algorithms that solve the bias problem in the equation-error based adaptive infinite impulse response (IIR) filtering. A novel constraint, called the constant-norm constraint, unifies the quadratic constraint and the monic one. By imposing the monic constraint on the mean square error (MSE) optimization, the merits of both constraints are inherited and the shortcomings are overcome. A new cost function based on the constant-norm constraint and Lagrange multiplier is defined. Minimizing the cost function gives birth to a new family of bias-free adaptive IIR filtering algorithms. For example, two efficient algorithms belonging to the family are proposed. The analysis of the stationary points is presented to show that the proposed methods can indeed produce bias-free parameter estimates in the presence of white noise. The simulation results demonstrate that the proposed methods indeed produce unbiased parameter estimation, while being simple both in computation and implementation.

Using the chirped grating with temperature control, we demonstrated the adaptive dispersion compensation at 40 Gbit/s RZ transmission. The simple monitoring of the 40 GHz frequency component enables us to automatic control of the adaptive dispersion compensator.

Adaptation of software components to the requirements is one of the key concerns in Component Based Software Development (CBSD). In this paper, we propose a formal approach to compose component based systems which are adaptable to the requirements. We focus on the functional aspects of software components and requirements, which are expressed in S-sorted functions. Those S-sorted functions are transformed into Colored Petri Nets (CPN) models in order to evaluate connectivity between the components, and to evaluate adaptability of composed systems to the requirements. The connectivity is measured based on colors or data types in CPN, while the adaptability is measured based on functional equivalency. We introduce simple glue codes to connect the components each other. The paper focuses on business applications, however the proposed approach can be applied to any other domains as far as the functional adaptability is concerned.

Using the chirped grating with temperature control, we demonstrated the adaptive dispersion compensation at 40 Gbit/s RZ transmission. The simple monitoring of the 40 GHz frequency component enables us to automatic control of the adaptive dispersion compensator.

In this paper, a digital processing method is described for modifying tone contrast that is defined as the greatest difference in frequencies between peaks and valleys of pitch curves in monosyllable utterances. Under quiet and noisy backgrounds, modified Mandarin tone words were presented to hearing-im- paired Chinese listeners with moderate to severe sensorineural hearing loss. The listeners were asked to identify four alternative monosyllable words which were distinguishable by tones 1, 2, 3 and 4 respectively. Employing this method, it was found that modified speech with enhanced tone contrast yielded moderate gains in the percentage of correct identification of the tones when compared to unmodified speech tones with only compression amplification. It was likewise found that reducing tone contrast generally reduced the degree of correct tone identification. These findings therefore offer support to the assertion that a hearing aid with tone modifications is indeed effective for hearing-impaired Chinese.

This paper describes the evaluation of a fiber-optic reflective displacement sensor that is compensated for variations in light source intensity, pressure, temperature and opacity of ambient medium. Additionally, the distance information is averaged over several points on the target surface, which reduces signal fluctuations due to inhomogeneities. Furthermore, a practical optical fiber reflective sensor model of measuring oil film thickness for thrust bearing is set up in this paper. Actual measurements were made with HEC 3000 tons' thrust bearing and the results were in good agreement with theoretical calculations.

We propose middleware which works on widely-used commercial off-the-shelf platforms (UDP/IP, FastEthernet, and Windows NT or commercial real-time kernels) to realize real-time distributed services for plant monitoring and control systems. It is not suitable to use TCP/IP for the systems because of its unpredictable re-transmission, while, as well known, UDP/IP does not guarantee certain arrivals of packets and it is also not acceptable for the systems. With UDP/IP, packets are lost mainly because of collisions in a network and buffer overflows. To avoid these packet losses, the middleware controls scheduling of all the packets transmitted between the nodes in a distributed system and prevents excessive collisions and buffer overflows. The middleware provides a necessary set of functions for plant monitoring and control applications. The middleware on each node in a distributed system consists of library functions and run-time modules. An application program on the node is required to use these library functions according to the rules the middleware provides. In this way the middleware can manage all the traffic among the nodes in the system. Receiving requests from the application via library functions, the run-time module of the middleware schedules transmission of messages to other nodes, avoiding unexpected delivery delays or buffer overflows. The module also guarantees application-to-application quality of service (QoS), such as transmission period and delivery deadline, required by the applications. This is achieved by assigning the resources not shared by other services to each distributed service and scheduling these resources so as not to violate the assignment. Here, resources include maximum numbers of packets which a node can receive or send in a specific period (20 msec, for example). We show implementation of the middleware to make it clear how to guarantee application-to-application QoS with some application examples.

Kurosawa, Obana, and Ogata proposed a (k,n) threshold scheme such that t cheaters can be identified, where t (k-1)/3. Their scheme is superior to previous schemes with respect to the number of participants for identifying cheaters and the size of a share. In this paper, we improve the detectability of their scheme. By using erasure decoding and the authentication code, we show that cheaters less than k/2 can be identified. Although the size of a share is larger than that of their scheme, it is independent of n.

The common packet channel (CPCH) adopted by 3GPP is used to carry small and medium sized packets, such as SMS (short message service) and web data. We analyze the system performance of the non-real time channel monitoring scheme when the periodic broadcast method is deployed. If user equipment (UE) can continuously monitor the CPCH status, the performance of the channel monitoring scheme is satisfactory. However, in practice, a CPCH status broadcast period exists and, therefore, an UE can request a CPCH channel based on incorrect CPCH status information. This incorrect CPCH status information results in performance degradation in the channel monitoring scheme. We analyze this performance degradation and show the relationship between system performance and the status broadcast period.

In this paper, we consider a mobile, multimedia, multihop (M3) ad hoc network. Key characteristics of this system are the mobility of users, energy constraints, and the need to operate without a fixed (wired or wireless) infrastructure. In this environment, with the advent of multimedia communications, the use of the cluster architecture has been revisited to support the resource reservation and Quality-of-Service routing. We proposed an access-based clustering protocol (ABCP) that allows the network to self-organize into a cluster architecture. Three advantages are claimed by ABCP. First, by the access-based criterion, it minimizes the overhead on cluster formation so that the protocol has short execution time and good scalability. Second, ABCP unifies the algorithms for cluster initialization and maintenance, i.e., the same set of clustering functions are used by a node regardless of whether it just becomes active or is in leaving its current cluster. Third, simulation results demonstrate that the cluster structure behaves stably amid topology changes compared with techniques previously proposed. Together with the access-based criterion, a multiple access scheme is also proposed for the broadcast of control messages.

Recently many researches concerning heart sound analysis are being processed with development of digital signal processing and electronic components. But there are few researches about recognition of heart sound, especially full cardiac cycled heart sound. In this paper, three new recognition methods about full cardiac cycled heart sound were proposed. The first method recognizes the characteristics of heart sound by integrating important peaks and analyzing statistical variables in time domain. The second method builds a database by principal components analysis on training heart sound set in time domain. This database is used to recognize new input of heart sound. The third method builds the same sort of the database not in time domain but in time-frequency domain. We classify the heart sounds into seven classes such as normal (NO) class, pre-systolic murmur (PS) class, early systolic murmur (ES) class, late systolic murmur (LS) class, early diastolic murmur (ED) class, late diastolic murmur (LD) class and continuous murmur (CM) class. As a result, we could verify that the third method is better efficient to recognize the characteristics of heart sound than the others and also than any precedent research. The recognition rates of the third method are 100% for NO, 80% for PS and ES, 67% for LS, 93 for ED, 80% for LD and 30% for CM.

This paper presents a simple and cost-effective bidirectional antenna using a probe excited circular ring. The structure of the antenna is simple i.e., a linear electric probe surrounded by the circular ring. The principle of the antenna design is easy and straightforward. A choice of the ring radius is first chosen to achieve the condition that only the dominant mode can be propagated. Furthermore, it is found that for a specific ring radius, the radiation patterns of the antenna are varied as the ring width. Then, the optimum ring width that provides the maximum directivity is determined. The criterion of the selection of the ring width for various ring radii is illustrated as the guidelines for the antenna design. The fabricated antennas at the operating frequency of 1.9065 GHz are measured and compared with the theoretical predictions. It is apparent that these results are in reasonable agreement. The bidirectional pattern with the gain of 5.4 dBi over the bandwidth of 17% is obtained. Moreover, the antenna can be easily fabricated with the low production cost. Therefore, this antenna is suitable for installing at the base station in the street cell.

Fuzzy inference abilities were implemented to electromagnetic problems for the first time by the authors. After very successful results of applying the developed fuzzy modeling method to input impedance of a general monopole antenna, in this paper classifying the engineering electromagnetic problems simply, we apply the abilities of the proposed fuzzy inference method to make a qualitative model for transmission lines as a general example for a certain category of problems. The proposed approach starts from observing the problem through the window of human direct understandings and uses some parameters (as calculation base) evaluated basic for modeling process. It is shown that because of using this novel view point, a very simple fuzzy system based on new parameters may model the behavior of a transmission line in general form. The knowledge of each variable can be extracted and saved as simple curves individually, through continuing to make several models considering the desired variable as parameter. Finally, it is shown that the proposed method works even in highly nonuniform transmission line cases without changing in structure and complexity.

This paper proposes a new heuristic algorithm FMDB for the minimum initial marking problem MIM of Petri nets: "Given a Petri net and a firing count vector X, find an initial marking M0, with the minimum total token number, for which there is a sequence δ of transitions such that each transition t appears exactly X(t) times in δ, the first transition is firable on M0 and the rest can be fired one by one subsequently. " Experimental results show that FMDB produces better solutions than any known algorithm.

We have developed a new traffic measuring tool and applied it to the real-time simulation of a network. It monitors IP traffic on an ATM link and continuously transfers the length and timestamp of each IP packet to a post-processing system. The post-processing system receives the data, estimates the cell's arrival epoch at the transmission queue of the ATM link, and simulates the queueing behavior on-line if conditions differ from those of the actual system. The measuring tool and real-time simulation represent a new approach to traffic engineering. A new estimation problem, the arrival sequence estimation, is shown and some algorithms are proposed and evaluated. Also, a new dimensioning algorithm called the queue decay parameter method, which is expected to be robust and applicable to real-time control, is proposed and evaluated.

A secret sharing scheme allows a secret to be shared among a set of participants, P, such that only authorized subsets of P can recover the secret, but any unauthorized subset can not recover the secret. It can be used to protect important secret data, such as cryptographic keys, from being lost or destroyed without accidental or malicious exposure. In this paper, we consider secret sharing schemes based on interpolating polynomials. We show that, by simply increasing the number of shares held by each participant, there is a multiple assignment scheme for any monotone access structure such that cheating can be detected with very high probability by any honest participant even the cheaters form a coalition in order to deceive him.

A multimedia content is usually read-only and composed of multimedia objects with their spatial and temporal specifications. These specifications given by its author can enforce the display of objects to be well organized for its context. When multimedia contents are serviced in network environment by an on-demand basis, the temporal relationship among the objects can be used to improve the performance of the service. This paper models the temporal relationship as a scenario that represents the presentation order of the objects in a scenario and proposes several scheduling methods that make it possible to rearrange the transmission order of objects in a scenario. As a result, system resources such as computing power and network bandwidth can be highly utilized. Since the temporal relationship of a scenario is static, it is possible to reduce the scheduling overhead of a server by pre-scheduling currently servicing scenarios. In addition, several simulation results are presented in order to compare and analyze the characteristics of the proposed methods.

We have proposed a new string-based haptic interface device in this paper. It is a kind of device that allows a user to use both hands and multi-fingers to direct manipulate the virtual objects in the computer simulated virtual environment. One of the advantages of the device is to allow the user to use both hands to perform the cooperative works of hands, such as holding a large object that cannot be grasped or held by single hand. In addition, the haptic feedback sensation provided by the device at the fingertips makes possible for the user to perform dexterous manipulation, such as manipulating small size of objects. We have discussed about the design of the proposed device and have elaborated the methods of fingertip positions measurement and force feedback generation. The experiments had been carried out to verify the capabilities of the proposed device.

Many experimentally and theoretically based models have been proposed to predict, quantitatively evaluate, and combat the fading phenomenon in mobile communication systems. However, to the best of the authors' knowledge, up to now there is no objective method to determine which is the most suitable distribution to model the fading phenomenon based on experimental data. In this work, the Minimum Description Length (MDL) criterion for model selection is proposed for that purpose. Furthermore, the MDL analysis is performed for some of the most widely used fading models based on measurements taken in a sub-urban environment.

Most scheduling applications have been classified into NP-complete problems. This fact implies that an optimal solution for a large scheduling problem is extremely time-consuming. A number of schemes are introduced to solve NP-complete scheduling applications, such as linear programming, neural network, and fuzzy logic. In this paper, we demonstrate a new approach, fuzzy Hopfield neural network, to solve the scheduling problems. This fuzzy Hopfield neural network approach integrates fuzzy c-means clustering strategies into a Hopfield neural network. In this investigation, we utilizes this new approach to demonstrate the feasibility of resolving a multiprocessor scheduling problem with no process migration, limited resources and constrained times (execution time and deadline). In the approach, the process and processor of the scheduling problem can be regarded as a data sample and a cluster, respectively. Then, an appropriate Lyapunov energy function is derived correspondingly. The scheduling results can be obtained using a fuzzy Hopfield neural network clustering technique by iteratively updating fuzzy state until the energy function gets minimized. To validate our approach, three scheduling cases for different initial neuron states as well as fuzzification parameters are taken as testbed. Simulation results reveal that imposing the fuzzy Hopfield neural network on the proposed energy function provides a sound approach in solving this class of scheduling problems.