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Uiwang, South Korea

Matin M.A.,Brunei Institute of Technology | Fattah A.,Digital Solution Inc.
International Journal of Innovative Computing, Information and Control | Year: 2015

The reason for the birth of cognitive radio (CR) is to utilize the spectrum resources efficiently by allowing secondary (unlicensed) users to access licensed frequency bands without harmful inference to the licensed (primary) users. In this paper, we discuss the tradeoff among the spectrum sensing ability, the throughput of the CR system and the interference to the primary users. In conventional frame structure, the secondary system has to sense the licensed frequency bands within the allocated sensing time before data transmission. During spectrum sensing, the transmission of data is not allowed which makes the sensing-throughput tradeoff problem, in the cognitive system. To solve this tradeoff, this paper proposed joint, beamforming and power control, method with optimal, target detection probability. The proposed approach ensures the protection to the primary system as well as overcoming the sensing throughput tradeoff problems in CR. system. The simulation result, demonstrates that the optimal transmit, power and optimal target, detection probability maximize the throughput. © 2015 ICIC International. Source

Hattori-Hara E.,Tokushima University | Mitsui S.N.,Tokushima University | Mori H.,Tokushima University | Arafurue K.,Digital Solution Inc. | And 6 more authors.
Journal of Cranio-Maxillofacial Surgery | Year: 2014

Objectives To investigate the influence of unilateral disc displacement (DD) in the temporomandibular joint (TMJ) on the stress in the contralateral joint, with a normally-positioned disc, during clenching. Study design A finite element model of the TMJ was constructed based on MRI and 3D-CT of a single patient with a unilateral DD. A second model with bilateral normally-positioned discs served as a reference. The differences in stress distribution in various TMJ components during clenching were predicted with these models.Results In the unaffected joint of the unilateral DD model, the largest von Mises stress at the start of clenching was predicted in the inferior surface of the disc and increased by 30% during clenching. In the connective tissue the largest stress (1.16 MPa) did not reduce during clenching, in contrast to the (unaffected) joints of the reference model. In the affected joint, the largest stress was predicted in the temporal cartilage throughout clenching. In the surrounding connective tissue, the largest stress (1.42 MPa) hardly changed during clenching indicating no, or negligible, stress relaxation.Conclusions This suggested that a unilateral DD could affect the stresses in the unaffected (contralateral) joint during clenching, where it may lead to weakening of the tissues that keep the disc on the top of the condyle. The results may be helpful in counseling worried patients, since they give insight into possible future developments of the disorder. Source

Kim Y.,Andong National University | Jung S.,Green A Inc. | Jung S.,Andong National University | Kim Y.,Digital Solution Inc. | Lee Y.,Andong National University
Journal of Asia-Pacific Entomology | Year: 2011

A fusion of information technology (IT) and sex pheromone monitoring provides a remote sensing IT-pheromone trap to monitor Oriental fruit moth, Grapholita molesta, populations in apple orchards. Once a male of G. molesta is attracted to its sex pheromone lure in the trap, an infrared sensor installed at the funnel-shaped orifice generates an electric signal. The signal is processed in a central processor and then transferred to an internet site via a code division multiple access protocol. The signal also contains information about when each male is caught. Daily trapping information from different localities is archived in a website. The accuracy of IT-pheromone traps in detecting male catches was shown by a high correlation (r=0.956) between the generated IT signals and actual numbers of males caught in the trap in apple orchards. Using this IT-pheromone trap, G. molesta in apple orchards was monitored for one year. These data were compared with monitoring data obtained from a conventional wing type-based sticky trap containing the identical sex pheromone lure. Both showed four characteristic adult peaks from April to September and were significantly correlated (r=0.695). IT-pheromone traps also gave real-time signals of male catches in the field. These real-time signals of male catches showed a characteristic diel attraction rhythm from 4. pm to midnight. The diel rhythm of the male response to the sex pheromone started earlier in the evening in the spring season compared to mid and late seasons. This study provides a novel sex pheromone trap for G. molesta to monitor its population in field conditions in real-time without visiting or counting. The field monitoring data can be accessed any time through a designated internet website. © 2011 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Source

Mori H.,Tokushima University | Horiuchi S.,Tokushima University | Nishimura S.,Digital Solution Inc. | Nikawa H.,Hiroshima University | And 9 more authors.
Archives of Oral Biology | Year: 2010

Objective: Bruxism, the parafunctional habit of nocturnal grinding of the teeth and clenching, is associated with the onset of joint degeneration. Especially prolonged clenching is suggested to cause functional overloading in the temporomandibular joint (TMJ). In this study, the distributions of stresses in the cartilaginous TMJ disc and articular cartilage, were analysed during prolonged clenching. The purpose of this study was to examine if joint degradation due to prolonged clenching can be attributed to changes in stress concentration in the cartilaginous tissues. Design: Finite element model was developed on the basis of magnetic resonance images from a healthy volunteer. Condylar movements recorded during prolonged clenching were used as the loading condition for stress analysis. Results: At the onset of clenching (time = 0 s), the highest von Mises stresses were located in the middle and posterior areas (6.18 MPa) of the inferior disc surface facing the condylar cartilage. The largest magnitude of the minimum principal stress (-6.72 MPa) was found in the condylar cartilage. The stress concentrations were relieved towards the superior disc surface facing the temporal cartilage. On the surfaces of the temporal cartilage, relatively lower stresses were found. After 5-min clenching, both stress values induced in the TMJ components were reduced to 50-80% of the stress values at the onset of clenching, although the concomitant strains increased slightly during this period. Conclusions: It is suggested that both the condylar and temporal cartilage layers along with the TMJ disc, play an important role in stress distribution and transmission during prolonged clenching due to tissue expansion. Furthermore, our study suggests that a development of stress concentrations in the TMJ during prolonged clenching and risk factors for the initiation of TMJ degeneration could not be confirmed. © 2010 Elsevier Ltd. All rights reserved. Source

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