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The purpose of this paper is to focus on alleviating the problems of both hidden and exposed terminal, which remain unsolved in many directional MAC protocols.

GPS is used to calibrate synchronization among the nodes, and directional antennas are used. In the protocol, different antenna mode and transmit power are used. The assertion signal and omni‐directional RTS are transmitted in omni‐directional mode, while directional CTS, directional RTS, DATA and ACK are transmitted in directional mode. With properly designed RTS‐CTS handshake, the protocol can make full use of spatial reuse of directional communication and enhance parallelism in data transmission.

The preliminary simulation results indicate that the protocol works well and achieves considerably high performance in both sparse and dense ad hoc networks.

The line of sight environment is the main limitation that the MAC protocol will be applied.

The protocol is a very useful solution for employing directional antennas for ad hoc networks.

The MAC protocol can effectively alleviate the directional hidden and exposed terminal problems as well as node deafness. It can greatly improve throughput and achieve low‐medium access delay, making it suitable for ad hoc networks.

The emphasis on inter-organizational systems gave rise to concerns about inter-organizational relationships as trading partners became aware of the socio-political factors and trust that affect their relationships. This paper examines the importance of inter-organizational-trust in business-to-business E-commerce organizations. It examines how inter-organizational relationships impact trading partner trust, perceived benefits, perceived risks, and technology trust mechanisms in E-commerce that can in turn influence outcomes of business-to-business E-commerce. This paper develops a conceptual model and tests the model using a case study research methodology. The aim is to solicit qualitative in depth understanding of inter-organizational-trust in business-to-business E-commerce. Eight organizations from a cross section of industries that formed four bi-directional dyads participated in the third stage of this study. The first two stages include exploratory case studies in three organizations in the automotive industry that applied EDI via Value-Added-Networks in 1997, and a nationwide survey of organizations that examined the extent of E-commerce adoption in Australia and New Zealand in 1998. The findings identify the need for trustworthy business relationships in an E-commerce environment.

Short columns can cause serious damage when subjected to an earthquake due to their high stiffness with low ductility. These columns can be exposed to multidirectional shear forces, which encouraged this study to investigate the behavior of structural short columns under bi-directional shear.

Finite element analysis (FEA) using ABAQUS is conducted and calibrated based on experimental data tested by previous researchers who studied the uni-directional behavior of short columns subjected to cyclic shear displacements. Then, the calibrated column models are further investigated to study the influence of bidirectional cyclic shear. Two scenarios are investigated, namely “simultaneous” and “sequential,” to compare the performance in terms of shear strength reduction.

The results show that the shear strength reduction significantly appears when 1:1 simultaneous bi-directional cyclic shear is applied. However, the shear reduction is more significant when the sequential scenario is applied. The seismic forces or deformations applied in orthogonal directions should be combined to achieve the maximum seismic response of structures as specified in Federal Emergency Management Agency (FEMA) 356 Standard. Finally, the combinations presented in literature to consider bi-directional shear are investigated. Based on FE results, the effect of applied 1:0.30 bi-directional cyclic shear simultaneously does not result in significant effect on the considered columns properly design for seismic forces.

To investigate the effect of multidirectional shear forces on the shear strength capacity of short columns, the presented effect of multidirectional shear forces in literature to consider bi-directional shear are investigated.

The purpose of this paper is to develop a directional and roll control system for unmanned combat air vehicle (UCAV) automatic takeoff roll, with the objective of keeping the UCAV along the runway centerline and keeping the wings level, especially when there is a crosswind.

The nonlinear model of the UCAV during takeoff roll is established. The model is linearized about the lateral‐directional equilibrium point at different forward speeds. The approximate directional model and roll model are extracted using time‐scale decomposition technique. Then the directional control law and roll control law are developed using gain scheduling approach. Nose wheel steering, differential brake and rudder are used as the primary directional control device at low, medium and high speeds, respectively, according to both the qualitative and quantitative analysis of their control effectiveness at different speeds. A priority matrix is developed to determine the secondary control device which is used if the primary control device fails, thus the directional control system can have a certain degree of fault tolerance.

This work developed the directional control law and roll control law by using gain scheduling approach. Experimental results verified that the developed directional and roll control system has high robustness and satisfactory fault tolerance: it can guarantee a safe takeoff under a 50 ft/sec crosswind, even if one directional control device fails, which satisfies the relevant criteria in MIL‐HDBK‐1797.

The directional and roll control system developed can be easily applied to practice and can steer the UCAV during takeoff roll safely, which will considerably increase the autonomy of the UCAV.

The paper shows how time‐scale decomposition technique is employed to extract the approximate directional model and roll model, which simplifies model analysis and control law design. A fault‐tolerant directional control system is designed to improve safety during takeoff.

The purposes of the study were (1) to examine whether directional dominance between co-existing athlete brands and sponsor brands exists; (2) to explore whether directional dominance influences consumers' memory interference; and (3) to test whether brand interference interacts with directional dominance among brands to influence consumer evaluation and behaviors under multiple endorsement and sponsorship portfolios.

The research is a 3 (directional dominance: symmetric dominance vs. asymmetric dominance with existing vs. asymmetric dominance with newly endorsed brand) x 2 (brand memory interference: interference vs. no interference) between-subjects factorial design.

The results indicate that (1) directional dominance influenced consumer brand interference, and directional dominance interacted with brand interference on (2) brand evaluation and (3) purchase intention in multiple brand portfolios.

Considering that conventional single-sponsor sponsorship or single-endorser endorsement portfolios are increasingly rare, research on concurrent circumstances of multiple endorsers and multiple endorsed brands in multiple brand portfolios was necessary. By expanding and reconceptualizing the context of brand networks, this study provides empirical evidence on how the dominance and directionality between endorser and (existing and newly) endorsed brands—an athlete endorser's strong pre-existing association with an existing endorsed brand in particular—influenced consumer brand interference and the brand evaluation in multiple brand portfolios.

The aim of this study was to understand the stick-slip properties of single and multiple yarn pull-out in dry and treated polyester satin woven fabric in boundary regions.

Polyester satin pattern woven fabric was used to conduct the pull-out tests in order to examining the kinetic region of the force-displacement curve. Data generated from this research help the authors to obtain stick-slip force and accumulative retraction force.

It was found that stick-slip force and accumulative retraction force depend on the number of pulled ends in the fabric, fabric sample dimensions and softening treatments. Stick-slip forces of polyester satin fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test. Stick-slip force in single and multiple yarn pull-out tests in the dry polyester satin fabric was generally higher than those of the softening treated polyester satin fabric. In addition, the warp directional single and multiple yarn stick-slip and accumulative retraction forces in the dry and softening treated polyester fabrics were generally higher than those in the weft direction in the fabric edges due to fabric density. On the other hand, the amount of stick-slip force was related to the number of interlacement points in the fabric, whereas the amount of accumulative retraction force was related to fabric structural response.

The mechanism of stick-slip and accumulative retraction force of dry-treated polyester satin pattern woven fabrics were explained. This research could be valuable for development of multifunctional fabrics in technical textiles and ballistic.

The purpose of this study is to analyze influence of airfoil profile on lateral-directional flying quality of flying wing aircraft. The lateral-directional stability is always insufficient for aircraft with the layout due to the absence of vertical stabilizer. A flying wing aircraft with double-swept wing is used as research object in the paper.

The 3D model is established for the aircraft with flying wing layout, and parametric modeling is carried out for airfoil mean camber line of the aircraft to analyze lateral-directional stability of the aircraft with different camber line parameters. To increase computational efficiency, vortex lattice method is adopted to calculate aerodynamic coefficients and aerodynamic derivatives of the aircraft.

It is found from the research results that roll mode and spiral mode have a little effect on lateral-directional stability of the aircraft but Dutch roll mode is the critical factor affecting flying quality level of such aircraft. Even though changes of airfoil mean line parameters can greatly change assessment parameters of aircraft lateral-directional flying quality, that is kind of change cannot have a fundamental impact on level of flying quality of the aircraft. In case flat shape parameters are determined, the airfoil profile has a limited impact on Dutch roll mode.

Influences of airfoil profile on lateral-directional flying quality of aircraft with double-swept flying wing layout are revealed in the thesis and some important rules and characteristics are also summarized to lay a theoretical basis for design of airfoil and flight control system of aircraft with the layout.

To focus on grid generation which is an essential part of any analytical tool for effective discretization.

This paper explores the application of the possibility of unstructured triangular grid generation that deals with derivationally continuous, smooth, and fair triangular elements using piecewise polynomial parametric surfaces which interpolate prescribed R³ scattered data using spaces of parametric splines defined on R² triangulations in the case of surfaces in engineering sciences. The method is based upon minimizing a physics‐based certain natural energy expression over the parametric surface. The geometry is defined as a set of stitched triangles prior to the grid generation. As for derivational continuities between the two triangular patches C⁰ and C¹ continuity or both, as per the requirements, has been imposed. With the addition of a penalty term, C² (approximate) continuity can also be achieved. Since, in this work physics‐based approach has been used, the grid is analyzed using intersection curves with three‐dimensional planes, and intrinsic geometric properties (i.e. directional derivatives), for derivational continuity and smoothness.

The triangular grid generation that deals with derivationally continuous, smooth, and fair triangular elements has been implemented in this paper for surfaces in engineering sciences.

This paper deals with the important problem of grid generation which is an essential part of any analytical tool for effective discretization. And, the examples to demonstrate the theoretical model of this paper have been chosen from different branches of engineering sciences. Hence, the results of this paper are of practical importance for grid generation in engineering sciences.

The paper is theoretical with worked examples chosen from engineering sciences.

Argues that the unidirectional measurement and evaluation of service quality in any specific service encounter is not enough in itself to understand the existing service quality between two actors in a dyadic service encounter. Therefore, a method is introduced for the express purpose of analysing the perceptual bi‐directionality of service quality in order to measure and evaluate the dynamics of service quality in dyadic service encounters.

The snail moves by propagating traveling waves from tail to head. If it is possible to propagate a traveling wave in many directions, an omni‐directional mobile robot could be realized. The purpose of this paper is to develop an omni‐directional mobile robot using the locomotion mechanism of the snail and to study the basic properties of the robot.

A unit for mobile robot was developed to generate the traveling wave based on the snail. The omni‐directional mobile robot is composed of eight units arranged in a circular shape and each abutting unit is connected by a spring. The robot generates a traveling wave by elongation and contraction of the units and realizes an omni‐directional locomotion.

It was confirmed that the robot moves using the traveling wave locomotion. Furthermore, the locomotion experiment confirmed that the robot moved in the expected direction with reasonable accuracy.

This paper proposes a new omni‐directional mobile mechanism using traveling wave based on a snail locomotion. Since the locomotion mechanism of the snail involves moving a larger area than is the case with other creatures, it is able to move not only on irregular ground such as swamps, but also on walls and ceilings. Hence, it is thought that this robot could be applied to the inspection of walls.