A genetic algorithm-based system for wireless mesh networks: analysis of system data considering different routing protocols and architectures

Wireless mesh networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in location science. In our previous work, we evaluated WMN-GA system which is based on genetic algorithms (GAs) to find an optimal location assignment for mesh routers. In this paper, we evaluate the performance of four different distributions of mesh clients for two WMN architectures considering throughput, delay and energy metrics. For simulations, we used ns-3, optimized link state routing (OLSR) and hybrid wireless mesh protocols (HWMP). We compare the performance for Normal, Uniform, Exponential and Weibull distributions of mesh clients by sending multiple constant bit rate flows in the network. The simulation results show that for HWM protocol the throughput of Uniform distribution is higher than other distributions. However, for OLSR protocol, the throughput of Exponential distribution is better than other distributions. For both protocols, the delay and remaining energy are better for Weibull distribution.     

Transactions and cross shareholdings in Mazda’s Keiretsu: a centrality analysis

Maintaining symbiotic inter-relationships with suppliers is an integral part of developing tightly interwoven vertical supply arrangements among members participating in a network of companies. This article reviews the relevant literature on network theory to test the interrelationships among transactions, cross shareholdings, and sales among all the firms in Mazda’s Yokokai Keiretsu. Rooted in graph theory, the degree of betweenness, cross shareholdings, and closeness indicators were used to compute the centrality index, which was then employed to explore the nature of the relationship between transactions and sales, as well as that between cross shareholdings and sales. The findings reveal statistically significant inter-correlations between transactions and sales, and between cross shareholdings and sales. Managerial implications are discussed and conclusions are presented.     

Parallel Turing machines on four-dimensional input tapes

The parallel Turing machine (PTM) proposed by Wiedermann is a set of identical usual sequential Turing machines (STMs) cooperating on two common tapes: storage tape and input tape. On the other hand, due to the advances in many application areas such as motion picture processing, computer animation, virtual reality systems, and so forth, it has become increasingly apparent that the study of four-dimensional patterns is of crucial importance. Therefore, we think that the study of four-dimensional automata as a computational model of four-dimensional pattern processing is also meaningful. In this article, we propose a four-dimensional parallel Turing machine (4-PTM), and investigate some of its properties based on hardware complexity.     

Relation between impressions of a touch panels’ coloration and operation

The relationships between the colors used in the design of touch panels and the operation of electronic devices are discussed, and experiments that investigated the effects of color in the designs of touch panel interfaces on their operation and on the impressions of users have been conducted. Subjects tried mental arithmetic tests on 12 types of screen which had different color images. The “time it took to perform the task,” the “number of correct answers,” the “number of incorrect answers,” and the “number of timeouts” were measured and counted. After the tasks were administered, the subjects answered questionnaires about their impressions of the interfaces. The average number of correct answers was higher when using “cool-casual” than when using the other colorations. Furthermore, there was a positive correlation between the number of correct answers and a preference for the display coloration. There was a strong relationship between the coloration of the interface and the speed and accuracy of the operation. The results of the study lead us to expect that both the usability and the accuracy of operations could be improved by designing the coloration of the touch panel interface appropriately.     

Fabrication, Mechanical Properties, and Electrical Conductivity of Co3O4 Ceramics

Well-densified Co₃O₄ ceramics (98.3% of theoretical) have been fabricated by the combined use of hot pressing (800°C/I h/30 MPa) and hot isostatic pressing (880°C/2 h/196 MPa). Their Vickers hardness and fracture toughness are 10.3 GPa and 4.2 MPa·m^1/2, respectively. They exhibit a high electrical conductivity of 3.35 × 10' S·cm⁻¹ at 800°C.     

Advanced Data Acquisition Methods for Quantitative Single Photon Emission CT

This paper proposes some advanced data acquisition methods for quantitative single photon emission CT. One example of such methods is the odd number angular sampling method over 360 degrees for a widely distributed object, and the other is fine angular sampling of 180 degrees for a nonsymmetrically localized small object in an attenuation cross section. The image quality, such as the spatial resolution and the signal-to-noise ratio, becomes better than that reconstructed from conventional conjugate projection data. The reconstruction technique used in computer simulation is the iterative correction matrix method, but other techniques are also applicable. Comparison between the weighted back projection method and the correction matrix method is also presented.     

Super‐short‐focus front projector with aspheric‐mirror projection optical system

Abstract— We have developed a new front projector with a super‐short projection distance of 0.65 m at 100 in. We installed a newly developed reflective‐type projection optical system in this projector, which was composed of only four aspheric mirrors that were free of color aberrations. Using this new system and a single‐chip DMD?, we projected a picture that had excellent sharpness and high contrast from 40 to 100 in. This paper describes the principles, design, and characteristics of the new WT600? front projector.     

Temperature dependence of electronic relaxation time in the Sondheimer size effect of copper

Measurements of the phonon-limited relaxation time _T are made in copper by means of the Sondheimer size effect. It is found that the relaxation rate 1/ _T varies approximately as T ⁵ when the magnetic field is directed in the [110] direction, while it varies approximately as T ⁵ below 8 K and as T ^3.3 above 8.5 K when the magnetic field is directed in the [100] direction. The results are discussed in terms of diffusive and catastrophic scattering.This work was supported by Grant-in-Aid for Scientific Research from the Ministry of Education of Japan.     

Semiological seizure classification

We propose an epileptic seizure classification based exclusively on ictal semiology. In this semiological seizure classification (SSC), seizures are classified as follows: a. Auras are ictal manifestations having sensory, psychosensory, and experiential symptoms. b. Autonomic seizures are seizures in which the main ictal manifestations are objectively documented autonomic alterations. c. "Dialeptic" seizures have as their main ictal manifestations an alteration of consciousness that is independent of ictal EEG manifestations. The new term "dialeptic" seizure has been coined to differentiate this concept from absence seizures (dialeptic seizures with a generalized ictal EEG) and complex partial seizures (dialeptic seizures with a focal ictal EEG). d. Motor seizures are characterized mainly by motor symptoms and are subclassified as simple or complex. Simple motor seizures are characterized by simple, unnatural movements that can be elicited by electrical stimulation of the primary and supplementary motor area (myoclonic, tonic, clonic and tonic-clonic, versive). Complex motor seizures are characterized by complex motor movements that resemble natural movements but that occur in an inappropriate setting ("automatisms"). e. Special seizures include seizures characterized by "negative" features (atonic, astatic, hypomotor, akinetic, and aphasic seizures). The SSC identifies in detail the somatotopic distribution of the ictal semiology as well as the seizure evolution. The advantages of a pure SSC, as opposed to the current classification of the International League Against Epilepsy (ILAE), which is actually a classification of electroclinical syndromes, are discussed.