Solving the error correcting code is an important goal with regard to communication theory. To reveal the error correcting code characteristics, several researchers have applied a statistical-mechanical approach to this problem. In our research, we have treated the error correcting code as a Bayes inference framework. Carrying out the inference in practice, we have applied the NMF (naive mean field) approximation to the MPM (maximizer of the posterior marginals) inference, which is a kind of Bayes inference. In the field of artificial neural networks, this approximation is used to reduce computational cost through the substitution of stochastic binary units with the deterministic continuous value units. However, few reports have quantitatively described the performance of this approximation. Therefore, we have analyzed the approximation performance from a theoretical viewpoint, and have compared our results with the computer simulation.

A state space compression method based on multivariate analysis was developed and applied to reinforcement learning for high-dimensional continuous state spaces. First, useful components in the state variables of an environment are extracted and meaningless ones are removed by using multiple regression analysis. Next, the state space of the environment is compressed by using principal component analysis so that only a few principal components can express the dynamics of the environment. Then, a basis of a feature space for function approximation is constructed based on orthonormal bases of the important principal components. A feature space is thus autonomously construct without preliminary knowledge of the environment, and the environment is effectively expressed in the feature space. An example synchronization problem for multiple logistic maps was solved using this method, demonstrating that it solves the curse of dimensionality and exhibits high performance without suffering from disturbance states.

We have developed an optical connector assembly method that allows the rapid on-site installation of an optical connector. To simplify this on-site assembly process we fabricated built-in parts that enable us to install the optical connector using pre-assembled optical connector parts. Moreover, we have established an advanced method for applying a solidifying agent that adheres to the inner wall of a ferrule flange. With our assembly method, we can complete on-site optical connector installation, other than the polishing process, in two steps, namely bonding agent application and fiber insertion.

The mechanism of dark bridge formed with very slow contact separating speed was empirically shown with some discussions from the experimental results which the authors have obtained by using the cantilever system for controlling contact gap. By analyzing the obtained results, we will assume some concept of formation mechanism of dark bridge. Since the thermal effect is inevitable in the bridge formation, this will be inferred from two points; one is the a-spot change at initial state of bridge forming, and another one is the thermal expansion due to bridge current that affects the shape of bridge. This paper will show from these two points the conceptual bridge formation mechanism in case of non-melting state of contact bridge which is called here dark bridge.

This investigation proposes a modified equivalent circuit of single complementary split-ring resonator (CSRR) in planar transmission media and a dual-mode ring bandpass filter (BPF) that uses periodic CSRRs to suppress the spurious response. The proposed modified equivalent circuit consists of lumped elements that can be easily extracted from the measured S parameters. The proposed dual-mode ring BPF has exhibits a wide stopband characteristic owing to the bandgap resonant characteristic of CSRRs in the harmonic frequency of the dual-mode ring BPF. Good agreement with EM simulation and measurement is demonstrated.

We consider the problem of dynamically apportioning resources among a set of options in a worst-case online framework. The model we investigate is a generalization of the well studied online learning model. In particular, we allow the learner to see as additional information how high the risk of each option is. This assumption is natural in many applications like horse-race betting, where gamblers know odds for all options before placing bets. We apply Vovk's Aggregating Algorithm to this problem and give a tight performance bound. The results support our intuition that it is safe to bet more on low-risk options. Surprisingly, the loss bound of the algorithm does not depend on the values of relatively small risks.

Field assembly of optical connectors is demanded because of the wide use of optical fiber in telecommunications systems. We propose a new assembling techniques that enable us to assemble connectors anywhere quickly and cost effectively. The key points are an adhesive technique and a polishing technique. In this report, we focus mainly on our a new polishing machine, which is suitable for optical connector ends machining on-site. The machine which is small and light weight can finish optical connector ends easily in a short time with enough low cost.

A method which uses the moving time and the over travel time of contact to discover the characteristics of contact and the reliability of aerospace relay is proposed. The Gauss-Newton method and its improved form (Macalto method) are used to identify the nonlinear mathematical model of the parameter during armature initial moving period, which is from the coil is energized at a rated voltage to the moment the armature begins to move. The validity of the method is verified by results of actual experiments and analysis.

Breaking arcs occurring between silver electrical contacts are observed in DC42 V resistive circuit using a high-speed camera. The motion and current densities of the cathode and anode spot regions are investigated for different interrupt currents (I=7 A, 10 A and 14 A). Results indicate that the arc length at which the motion of arc spots becomes stable depends on the interrupt current, and the current densities of the cathode spot region are almost constant immediately before arc extinction for each interrupt current.

In modern CMOS digital design, the noise immunity has come to have an almost equal importance to the power consumption. In the last decade, many low power design schemes have been presented. However, no one can simply judge which one is the best from the noise immunity point of view. In this paper, we investigate the noise immunity of the static CMOS low power design schemes in terms of logic and delay errors caused by different kinds of noise existing in the static CMOS digital circuits. To fulfill the aims of the paper, first a model representing the different sources of noise in deep submicron design is presented. Then the model is applied to the most famous low power design schemes to find out the most robust one with regard to noise. Our results show the advantages of the dual threshold voltage scheme over other schemes from the noise immunity point of view. Moreover, it indicates that noise should be carefully taken into account when designing low power circuits; otherwise circuit performance would be unexpected. The study is carried out on three circuits; each is designed in five different schemes. The analysis is done using HSPICE, assuming 0.18 µm CMOS technology.

The main factor determining for both friction and contact resistance is the true contact area in the contact interface. Contact resistance depends on the size of the true contact area and contaminant films interposed between the contact areas of the interface. Moreover, friction force also depends on the true contact area. In particular, the formation of metallic junctions in the true contact area strongly effects the friction force. Therefore, since both electrical contact and friction force are related to the size of the true contact area, the contact resistance and friction force are considered to be interrelated through true contact areas. For electromechanical devices with sliding contacts such as connector and sliding switches, the contact resistance and friction are important characteristics. In order to obtain low contact resistance, contact load should be higher, but the friction force increases. These are opposite-side problems. In this study, as the contact resistance and friction occur in the same true contact area, the relationship between the contact resistance and friction was expressed in an equation. Moreover, this relationship was examined experimentally on a variety of contact surfaces under different surface conditions.

This letter proposes a fast k nearest neighbors search algorithm based on the wavelet transform. This technique exploits the important information of the approximation coefficients of the transform coefficient vector, from which we obtain two crucial inequalities that can be used to reject those vectors for which it is impossible to be k nearest neighbors. The computational complexity for searching for k nearest neighbors can be largely reduced. Experimental results on texture classification verify the effectiveness of our algorithm.

Anode activity in vacuum arc plays a very important role in both characteristics of vacuum arc and the interruption capacity of vacuum interrupters. In this paper, the transient thermal processes of anode in vacuum arc in a half of arc current cycle with frequency of 50 Hz are simulated by finite element analysis software, ANSYS. Some important phenomena of anode, e.g., the melt and solidification, mass loss due to evaporation, are investigated.

An instance of the classical stable marriage problem requires all participants to submit a strictly ordered preference list containing all members of the opposite sex. However, considering applications in real-world, we can think of two natural relaxations, namely, incomplete preference lists and ties in the lists. Either variation leaves the problem polynomially solvable, but it is known that finding a maximum cardinality stable matching is NP-hard when both variations are allowed. It is easy to see that the size of any two stable matchings differ by at most a factor of two, and so, an approximation algorithm with a factor two is trivial. A few approximation algorithms have been proposed with approximation ratio better than two, but they are only for restricted instances, such as restricting occurrence of ties and/or lengths of ties. Up to the present, there is no known approximation algorithm with ratio better than two for general inputs. In this paper, we give the first nontrivial result for approximation of factor less than two for general instances. Our algorithm achieves the ratio for an arbitrarily positive constant c, where N denotes the number of men in an input.

Arranging n points as uniformly as possible is a frequently occurring problem. It is equivalent to packing n equal and non-overlapping circles in a unit square. In this paper we generalize this problem in such a way that points are inserted one by one with uniformity preserved at every instance. Our criterion for uniformity is to minimize the gap ratio (which is the maximum gap over the minimum gap) at every point insertion. We present a linear time algorithm for finding an optimal n-point sequence with the maximum gap ratio bounded by in the 1-dimensional case. We describe how hard the same problem is for a point set in the plane and propose a local search heuristics for finding a good solution.

Chen and Kanj considered the VERTEX COVER problem for graphs with perfect matchings (VC-PM). They showed that: (i) There is a reduction from general VERTEX COVER to VC-PM, which guarantees that if one can achieve an approximation factor of less than two for VC-PM, then one can do so for general VERTEX COVER as well. (ii) There is an algorithm for VC-PM whose approximation factor is given as 1.069+0.069 where is the average degree of the given graph. In this paper we improve (ii). Namely we give a new VC-PM algorithm which greatly outperforms the above one and its approximation factor is roughly . Our algorithm also works for graphs with "large" matchings, although its approximation factor is degenerated.

We consider the problem of triangulating an x-monotone polygon with a small number of different edge lengths using Steiner points. Given a parameter α, where 0<α<1, we shall present an algorithm for finding an almost uniform triangular mesh with 3π/8α2+o(1/α2) different edge lengths such that every edge length is between l and (2+α)l. Experiments demonstrate the effectiveness of this algorithm.

In this paper, the separation of heat generation and heat transfer related to temperature rise of silver palladium contact was investigated experimentally in order to predict the temperature rise of contact by the use conditions such as voltage range between 25 to 40 V, current range between 3.2 to 5.0 A and silver palladium alloy (AgPd) materials. Firstly, relationship between temperature rise of contact and supply power was discussed. The effects of heat generation and heat transfer on temperature rise were separated and quantified by least squares method. Secondly, effects of durations and integral powers of bridge and arc on temperature rise were also discussed by changing supply power. Results show that the integral power of the bridge increases when supply power increases. As the supply power increases, integral power of arc also increases. The temperature rise is dominated by integral power of bridge. Remarkable difference of bridge duration can not be seen in the five materials (AgPd30, AgPd40, AgPd50, AgPd70 and Pd). The supply power is increased, arc duration gets longer. As weight percent of Pd content increases, the effect of supply power on arc duration becomes larger. Consequently, the integral power of arc increases. This study is a basic consideration to realize methods predicting temperature rise of contact.

In this paper, we propose a new robust model predictive control (MPC) technique for linear parameter varying (LPV) systems expressed as linear systems with feedback parameters. It is based on the minimization of the upper bound of finite horizon cost function using a new parameter dependent terminal weighting matrix. The proposed parameter dependent terminal weighting matrix for norm-bounded uncertain models provides a less conservative condition for terminal inequality. The optimization problem that satisfies the terminal inequality is solved by semi-definite programming involving linear matrix inequalities (LMIs). A numerical example is included to illustrate the effectiveness of the proposed method.

In this paper an analysis of component and system reliability for lattice systems is proposed when component failures are not statistically independent. We deal the case that the failure rate of a component depends on the number of the adjacent failed components. And we discuss the maintainability of the system when a failed component is replaced by a spare component. At first we discuss the approximated reliability of each component. Then we estimate the mean number of failed components. Furthermore, the system reliability is approximated by using the component reliability.