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Biogenic nanoporous shells derived from marine diatoms Coscinodiscus wailesii were used for nanoparticle translocation experiments, and the observed ionic current was compared with results of analytical calculation and finite-element simulation. The lateral size ($250~\mu \text{m}$ ) of the shells enabled positioning and immobilization on micromachined silicon substrates. Since these shells have...
In order to improve spectrum utilization efficiency of Cognitive Radio (CR) systems, it is important for Secondary User (SU) to get knowledge about Primary User(PU)'s behavior when SU exploits opportunity to access spectrum. Radio Environment Database has recently been proposed to provide information about PU. Traditional advanced spectrum database constructed based on spectrum sensing method assumes...
Efficient coverage and energy conservation are two of the primary concerns for area coverage applications of randomly deployed wireless sensor networks. This paper developed a distributed algorithm using range adjustable sensors for maintaining the full coverage of such sensor networks. The algorithm contains two major parts: the first part aims at providing 100% coverage and the second part aims...
Efficient utilization of wireless bandwidth is a critical, if not the key, component of the wireless network architectures that balance availability and access. Cognitive Radio Networks (CRNs) are an important part of the solution to this problem. Common control channels (CCCs) for rendezvous in CRNs have limitations such as single point of failure, low scalability, and susceptibility to jamming attacks...
In cognitive radio networks where secondary users (SUs) access spectral white spaces left by primary users (PUs), there exists a trade-off between sensing and transmission. However, the white spaces depend on the PUs' traffic patterns, and this fact can be utilized to optimize SU transmissions after traffic identification. This paper studies the effective approaches to adapt SU transmissions to the...
Wireless Sensor Networks (WSN) which is capable in sensing, storing, processing and transmitting data has been widely applied in providing effective surveillance. Optimum sensor nodes placement in the surveillance area is needed to optimise the cost and efficiency of deployment. The positions of sensor nodes should be able to provide maximum coverage with longer lifetime. This paper proposed a sensor...
In this paper, we study the Cooperative Sensing Scheduling (CSS) problem for Cognitive Radio Network (CRN), from the perspective of balance between sensing performance and energy consumption. We place this problem in a practical scenario where both the primary users (PUs) and the secondary users (SUs) are heterogeneous: PU channels are different in terms of channel admission control, idle probability...
The time that micro mouse escape from the maze does not only depend on the length of its chosen path, but also on its acceleration or deceleration or turning characteristics. The Simply planning algorithm performance cannot accurately reflect the time performance that the micro mouse spend in escaping from the maze. By simulating the maze and micro mouse and modeling its moving features, this thesis...
The use of robotics in distributed monitoring applications requires wireless sensors that are deployed efficiently with an awareness of the information gain, communication constraints, resource allocation and coordination, and energy utilization. In this paper, we address the estimation of a parameterized spatial field distribution with a group of mobile robots sampling adaptively and using a statistically-aware...
This paper presents simulation programs for resonator gyros. Simulation programs are necessary to simulate dynamical behaviors of resonator and to develop control methods. The programs can be used to define the relationship between some non-uniformity of resonator and the performances of gyroscopes. For the purposes, the authors have developed simulation programs for resonator gyros coded by LabVIEW...
Momentum-Biased satellites are dual-spin satellites that do not consist of two parts (platform and rotor). Momentum-biased satellites are three-axis-stabilized. Most communications satellites, especially those operating in geostationary altitudes, are momentum-biased., The momentum bias is not sufficient to stabilize completely the momentum axis in space. Active control means are generally added to...
Prolonging lifetime of directional sensor networks is one of the hot topics these days because of vast application of these kinds of sensors. Since, the depletion of energy from one sensor indicates a lack of information being communicated from one part of the network. Hence, managing energy consumption of each sensor becomes critical. In this paper one approach for improving sensor network lifetime...
This paper addresses the consideration of navigation systems onboard the guided munitions based on tactical and technical specifications, such as choice of MEMS inertial sensors, navigation resolved algorithms. Based on the chosen sensors and environment scenarios, the simulation block diagram was performed under the MATLAB, simulation results, future key technologies and critical problems should...
When systemic rotation autocompensation technique is implemented in inertial navigation system (INS), inertial measurement unit (IMU) undergoes intentionally devised mechanical motions. This technique is one of the strategies of improving the system precision performance at the system level. A dual-axis continuous rotation scheme is introduced, and system error equation is derived. The behaviors of...
The K-connected deployment and power assignment problem (DPAP) in WSNs aims at deciding both the sensor locations and transmit power levels, for maximizing both the network coverage and lifetime under K-connectivity constraints, in a single run. It is shown that the multi-objective evolutionary algorithm based on decomposition (MOEA/D) is a strong enough tool for dealing with unconstraint real life...
Proportional-Integral-Derivative (PID) control is widely used to control mechanical systems. In PID control technique, however, there are limits to the accuracy of the resulting movement because of the influence of gravity, friction, and interaction of joints caused by modeling errors. Digital acceleration control has robustness for the modeling errors. But it requires position, velocity, and acceleration...
Energy efficiency is a critical consideration in the design of low cost sensor networks. This paper studies the problem of extending the lifetime of the sensor networks as far as possible while maintaining the quality of network coverage. A systematical analysis on the relationship between the network lifetime and cover sets alternation is given, and by introducing the concept of time weight factor,...
In this paper, we propose two novel data fusion schemes for cooperative spectrum sensing in the IEEE 802.22 WRAN system. The data fusion structure is proper for the WRAN system due to its centralized structure, and it can provide reliable sensing performance. The proposed data fusion schemes improve the sensing reliability by utilizing confidence vector of the sensing result. Moreover, application...
Optimal Opportunistic channel access of the unlicensed users has been a major problem in a cognitive radio system. In this paper, we consider an overlay cognitive radio system, where the secondary user senses the channel for an empty slot and transmits a constant power for a time period without sensing the channel again. We obtain the optimal transmission time of the secondary user to achieve the...
With technology scaling, vulnerability to soft errors in random logic is increasing. There is a need for on-line error detection and protection for logic gates even at sea level. The error checker is the key element for an on-line detection mechanism. We compare three different checkers for error detection from the point of view of area, power and false error detection rates. We find that the double...
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