Outer inner expansions are formulated on the basis of “Rational Strip Theory” for slender floating body motions due solely to the incident wave. More precisely, since the detail of a slender body is lost in a farfield, farfield potentials are assumedly represented by lines of pulsating source /or doublet, their densities are determined by matching with nearfield potentials. This scheme readily results in three dimensional diffraction as well as radiation potentials which are valid in a farfield. Unlike non-rational strip theories, wave pattern, force, drifting force, etc are all available in a three dimensional sense, since throughout the analysis all problems are discussed in terms of three dimensional velocity potentials. Measurements of wave heights forces manifest the respective validities of the farfield diffraction radiation potentials obtained here, substantiate that these potentials are dependable, at least, up to a wavelength as long as the body.

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The unified theory is enhanced to account for the wave diffraction in the direction of ship's logitudinal axis near the ship ends to solve the surge-mode radiation problem. Three-dimensional forward-speed effects are taken into account as in the original unified theory, by solving the integral equation for the outer source strength along the ship length. Numerical examples are shown for the surge added-mass damping coefficients, pressure distributions, wave- forces, added resistance in head waves; these are compared with experimental data corresponding results of other calculation methods. It is confirmed that the effects of wave diffraction near the ship ends are properly accounted for in the present method, which is pronounced in the prediction of the added resistance. The importance of the cross-coupling effects between surge pitch is also noted in the surge motion calculations.

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With their propensity to lead to sudden death, cardiac arrhythmias are a major clinical problem. They also represent an medical challenge which needs gene-to-bedside studies to unravel the underlying arrhythmogenic mechanisms. In this approach, animal models play a central role. This seminar presents an overview of current animal models of arrhythmias with a focus on genetically-modified mouse models which are promising tools for understanding the pathophysiological sequence of genetically-inherited arrhythmias (channelopathies). Although rare, cardiac channelopathies have broadened our understanding of proarhythmic mechanisms, largely thanks to animal models, as demonstrated with SCN5A-related arrhythmias. Mutations in this gene, which encodes the voltage-gated Na⁺ channel 1.5, underlie cardiac channelopathies such as the type 3 long QT syndrome, cardiac conduction diseases, Brugada syndrome, sick sinus syndrome, atrial standstill numerous overlap syndromes. Although patch-clamp studies in heterologous expression systems have provided key information to understand the genotype-phenotype relationships of these diseases, they could not clarify how mutations can be responsible for such a large spectrum of diseases, for the late age of onset or the progressiveness of some of them for the overlapping syndromes. Mouse models turned out to be powerful tools to elucidate the pathophysiological mechanisms of gene-related arrhythmic diseases offer the opportunity to investigate the cellular consequences of gene mutations such as the remodelling of other gene expression that might participate to the overall phenotype.

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It is investigated, through theoretical analysis, the positional accuracies of DME-based navigation systems. It is supposed that the short range navaids, i. e. DME VOR, are available. Four different types of navigation systems are examined, which utilize respectively; (1) single VOR/DME, (2) separate DME's, (3) one VOR/DME another DME, (4) 3 DME's. In all the cases, the barometric altitude information is also assumed to be involved, in determination of position. The LMS error criterion is applied to calculate the estimation of position. The horizontal dilution of precision (HDOP) is so chosen as the evaluation parameter in comparison among the above-mentioned -systems. Obtained results are shown in the form of equi-HDOP contours around the typical configuration of navaids. Favourite discussions are given to the 3 DME's method from the theoretical viewpoint. But in actual operation, it is recommended that selection should be made between the four -systems, owing to such conditions as propagation, flight attitude, configuration of navaids etc.

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Newman (1965) expressed the wave forces moments on a body in terms of the incident wave the far-field radiation potentials showed the numerical results for the submerged ellipsoids. In the present paper, we assume that the ship is represented by the singularity distributions on the central axis we derive the general expressions for the forces on a ship in waves. Some accounts of the forward-speed effect on the wave forces are considered in evaluating the strength of the singularity distributions. Comparisons among the calculated results by the present method, the usual strip theory, the experimental results have been made.

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A theoretical method is proposed for computing the wave forces on a ship running in the following oblique waves with very low encounter frequency. It incorporates, in addition to the Froude-Krylov forces, all the terms up to the lowest order of magnitude with respect to the disturbance of the incident waves. They include the interaction effect between the stationary waves generated when the ship running on a calm water the disturbed incident waves.
Several examples of numerical results by the method are presented to test its validity, for example, for predicting the wave yaw moment which was found by Motora et al. to bring about broaching-to phenomenon when it exceeds the course keeping ability of the ship given by the rudder action. The results show that the method proposed is better than the Froude-Krylov assumption for describing the relation between the wave force magnitude the location of the incident waves relative to the hull.

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海洋波集波レンズは波浪制御技術の一つであり，波の向きを変えることによって波をある一点に集めることができ，静穏海域の確保，波浪エネルギー有効利用のための要素技術として期待できる。本論文では，無限水深中にレンズを入射波の波頂線に対して平行に設置することにより波を集め，レンズの形状を細長体として， レンズの幅を波長と同程度であると仮定して， レンズを表現する特異点分布をmatched asymptotic expansion 法により求めた。すなわち，入射波がレンズを通過した後に焦点に集まる流場の解析解を与えた。得られた特異点分布により，集波を実現するレンズの断面形状は，入射波を反射せず透過波が入射波に対してある位相差をもつ効果を与えることが明らかになった。その位相差は，焦点とレンズ上の点との間の距離と波数により決まり，幾何光学における光路差で決まる。得られた特異点分布を利用して自由表面変位を計算した結果によると，波長iとレンズの長さLと焦点距離Qの関係が， L/2=Q23えであれば適当な集波効果が得られ，焦点では，入射波の約5倍の波高が得られることがわかった。

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The present study investigates a Medium Access Control (MAC) protocol for reliable inter-vehicle communications (IVC) to support safe driving with the goal of reducing road traffic accidents. A number of studies have evaluated the performance of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. However, the communication quality provided by the CSMA/CA protocol is seriously degraded by the hidden terminal problem in IVC. Therefore, we propose a new MAC protocol, referred to as Periodic Broadcast-Timing Reservation Multiple Access (PB-TRMA), which can autonomously control transmission timing avoid packet collisions by enhancing the Network Allocation Vector () for periodic broadcast communications. The simulation results show that the proposed protocol can resolve the hidden terminal problem mitigate data packet collisions. Moreover, the behavior of PB-TRMA is similar to that of Time-Division Multiple Access (TDMA). In addition, we show that two procedures, namely, packet collision retrieval hidden terminal detection, are essential ingredients in PB-TRMA in order to achieve high quality performance.

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The present study investigates a Medium Access Control (MAC) protocol for reliable inter-vehicle communications (IVC) to support safe driving with the goal of reducing road traffic accidents. A number of studies have evaluated the performance of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. However, the communication quality provided by the CSMA/CA protocol is seriously degraded by the hidden terminal problem in IVC. Therefore, we propose a new MAC protocol, referred to as Periodic Broadcast-Timing Reservation Multiple Access (PB-TRMA), which can autonomously control transmission timing avoid packet collisions by enhancing the Network Allocation Vector () for periodic broadcast communications. The simulation results show that the proposed protocol can resolve the hidden terminal problem mitigate data packet collisions. Moreover, the behavior of PB-TRMA is similar to that of Time-Division Multiple Access (TDMA). In addition, we show that two procedures, namely, packet collision retrieval hidden terminal detection, are essential ingredients in PB-TRMA in order to achieve high quality performance.

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In this paper, coupled vibration analyses between longitudinal-vertical vibration of main hull girder longitudinal vibration of superstructure for two container ships are carried out using two-dimensional finite element method beam models. On the other hand, vibration tests were carried out during construction trial trip, the results of which are compared with calculated frequencies responses. The major conclusions obtained from these calculations measurements are as follows: (1) The natural frequency of superstructure is fairly affected by the funnel interaction when the difference between both uncoupled frequencies is small. (2) There is possibility which coupling effect with vertical vibration of main hull girder may be more than 10% on the natural frequency of superstructure. (3) To predict the responses in operating condition with due accuracy, further investigation for some vibration factors, such as estimation method for propeller forces, damping factors in main hull girder local structure so on, are necessary.

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Wave induced vibration (springing) has been studied both theoretically experimentally. The excellent researches have been reported in each field. But only theoretical experimental studies are not enough to investigate springing. It is necessary to carry out the measurement of springing on board. Especially the measurement on board is very important to get the relation between springing sea condition. The new type of ship cultivated in Mitsubishi Heavy Industries, Ltd. which is the shallow draft tanker (L/B=5) is a suitable ship to measure springing. Then the long-term measurement from October in 1974 to February in 1975 was carried out. According to the result of measurement, the sea condition which the ship encountered was Beaufault Scale 8 at the most. The upper limit of springing stress (RMS) was about 0.6 kg/mm^2. The average frequency of the hull nodal vibration for the ballast condition was about 36.O cpm. Through the long-term measurement of springing this time, the basic data to investigate springing in relation to sea condition were gained to a certain extent.

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 Making up approximately eleven per cent of Malaysia's multiethnic population is an Indian community that made massive migrations to the Southeast Asian peninsula during the latter nineteenth century. They came looking for work found it as indentured laborers on the rubber estates. They were, for the most part, Tamil speaking, although there were pockets using Punjabi, Malayalam, Telugu Kanarese. In their new land, they were exploited by the British colonialists; their rebellion against their masters is the commencement of the history of Malaysian Indian mass media.

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A 3-D integral-equation method is developed for predicting the hydrodynamic forces acting on resulting motions of a ship, with the effects of tank-wall interference included. The proposed calculation method is restricted to the zero-speed problem, but provides in principle an exact solution for a body of arbitrary geometry. The integral equations for the radiation diffraction velocity potentials on the body surface are derived by applying Green's theorem, solved numerically with a discretization of the body in panels, with the velocity potential assumed constant on each panel. The Green function satisfying the tank-wall boundary condition is provided by first considering an infinite number of mirror images then obtaining a closed-form expression for the resultant infinite series. Computed added mass, damping coefficient, wave- force for a hemisphere for a ship with two planes of symmetry are compared with corresponding experiments which are also carried out in the present study. Virtually perfect agreement exists between experiments numerical predictions, suggesting the validity of the present integral-equation method. Based on these reliable numerical computations, the characteristics of ship motions in a resticted waterway are studied

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The sporadic E (Es) layer is a layer in the ionospheric E region with a dense electron density thin altitudinal thickness at altitudes around 100 km. It has been pointed out by International Civil Aviation Organization (ICAO) that the Es layer has a potential to introduce anomalous long-range propagation in the frequency band of aeronautical navigation communication (EsAP: Es Anomalous Propagation). In order to reveal the detailed characteristics of EsAP, we have constructed a network of instruments for continuously monitoring the intensities of waves of various VOR ILS LOC stations in Japan. In this paper, we introduce the following latest results obtained using data from this monitoring observation: 1) derivation of statistical characteristics (seasonal/local time dependence) of EsAP occurrence probability, 2) mapping of the spatial structure of Es in 2D by combining EsAP observations with GPS-TEC ROTI data, 3) detailed investigation of the long-range propagation of ILS-LOC signal from Taiwan. We also discuss the possibility for using the anomalous propagation of VHF signal for studies of equatorial plasma bubbles, a different phenomenon in the ionospheric F region.

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The MAC protocol of IEEE 802.11 reduces hidden terminal problem using the RTS/CTS handshaking mechanism. However, it lacks the ability to release or reallocate a channel that was reserved but not used. For Mobile Ad hoc NETworks (MANET), this often keeps the channel unnecessarily inaccessible, resulting in inefficient channel utilization. In this paper, we propose schemes for releasing reallocating unused channels in MANET deployed over IEEE 802.11. We introduce a Network Allocation Vector () updating method that can improve the performance of the existing RTS Validation scheme our proposed Extra Frame Transmission scheme. We then combine these schemes as a further improvement. Through simulations, done in different scenarios with varying networking load node density, we were able to show that combining these schemes leads to a throughput improvement of up to 40%. In addition, our proposed mechanisms have no compatibility problems.

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The experimental results of the X-ray emission spectroscopic investigation of thin Au_1-xSi_x (x≤0.3 x=1.5×10^-3) films layered Au/Si/Au structures with intermediate Si layer are presented. The thin films have been deposited on different substrates at 80 300K. Three chemical states of Si atoms have been observed: 1) the state corresponding to the Si state in pure single crystal silicon, 2) the state bonded chemically with Au atoms, 3) the peculiar state that corresponds to the dilute solid solution of Si atoms in gold. It have been shown that chemical states of Si had different influence to the oxidation process. The most active system with respect to the oxidation have been found Si state, bonded chemically.

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Measurements of the propeller-induced oscillating pressures induced on the hull surface were made on a destroyer in her sea trial the results were compared with those of the model tests previously made by one of the authors. Both results agreed well. Further the authors present an empirical formula for estimating the total surface force induced by a propeller on a flat bottom near propeller.

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The present paper proposes a numerical method for calculating the coupled ship motions sloshing in time-domain. In the present method, strip theory is used to solve the ship motion problem a finite difference method is used for the sloshing problem; both problems are calculated in time domain. To verify the computational results, first the calculated force due to sloshing was compared to experimental data good agreement was found. Next, the authors compared the numerical experimental results for ship motions, the accuracy of numerical computation was confirmed. Finally, the wave height at certain position in the tank was compared. Even near the natural frequency of the tank, the numerical results based on the present method showed good agreement with the experimental ones. Moreover, a special case when tank is fully filled with liquid was discussed, both experimental computational results showed that the influence of liquid cargo is different from the solid one although the tank is completely filled.

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