Earticle

Topology control in Wireless Sensor Network (WSN) has recently been an area of intense investigation, especially the cluster-based topology control algorithms. In this study, we propose Adaptive Clustering with Dynamic Cluster Radius (ACDCR), a cluster-based topology control algorithm. This protocol proves to have several salient features, such as higher energy efficiency, and better QoS (Quality of Service). The design is accomplished by employing the hop-adaptive cluster radius, cluster head selection criteria with left energy threshold, and several other mechanisms. In ACDCR, only nodes with higher residual energy level than their neighbors are identified as cluster head candidates. Each cluster is assigned with a hop related radius for load balancing. In addition, nodes are allowed to setup direct links with the base station, rather than only their cluster heads. Simulation study shows that ACDCR outperforms HEED (Hybrid Energy-Efficient Distributed Clustering) in terms of network lifetime and QoS with fairly reasonable tradeoffs.

In the wireless body sensor network system (WB-SNS), saving energy in sensor nodes is a high priority. As an energy-saving method for sensor nodes, the transmission power control (TPC) algorithm has been developed. The TPC technique is a method of saving energy by adjusting the transmission power of the radio chip inside a sensor node. Numerous TPC algorithms exist, but in this paper, the dynamic TPC algorithm was analyzed intensively. The existing dynamic TPC algorithm utilizes a linear equation to find the optimal transmission power level (TPL). However, the existing dynamic TPC algorithm may operate well when the channel condition is good but it could estimate the TPL inaccurately due to the generation of an incorrect linear equation when the channel conditions are bad. Therefore, to solve the problem described above, this paper proposes an extended dynamic TPC algorithm that can estimate errors earlier based on slope values, which can be extracted at the time of generation of the linear equation, and estimate transmission power better by reutilizing the existing transmission power to create a more accurate equation. Through an experiment, this paper also proves that the extended dynamic TPC algorithm showed better performance compared to the existing dynamic TPC algorithm.

The polymerase chain reaction (PCR) is a detection method used in almost all the experimental processes that involve manipulation of the current genetic materials to amplify the specific target genetic material to be preferably detected. The recent PCR thermal cycler has adopted a general-purpose computing platform in which specific operation systems run in a computing device to support the GUI. In this paper, PCR control software, including the GUI, which can be run on various platforms, is proposed. The GUI is implemented in Java, and the connection to the PCR device uses a standard interface USB to minimize the dependence on the platform. The proposed system has been verified to run in the commercial system using Windows OS and MAC OS.

Leading edge icing jeopardizes the aerodynamic performance of wing and the fly safety of airplane. Macro fiber composite(MFC) piezoelectric actuator possess favorable flexibility and large force output ability, which makes MFC quite suitable for the excitation of large curvature thin-walled structures such as wing leading edge. In this study, MFC is adopted for leading edge in flight deicing application. Key challenges of leading edge in flight deicing with MFC were investigated by finite element methodology and simulation approach, which include fundamental analysis of vibration deicing method, leading edge deicing excitation mode and MFC placement scheme determination. Base on thermal-elastic analogy modeling theory, asymmetric temperature load modeling method is proposed for the special actuation effect simulation of twist type MFC for deicing. Simulation results demonstrate the third natural vibration mode can be utilized for leading edge deicing with lowest energy consumption and twist type MFC has great potential for leading edge in flight deicing application.

Recently, there have been tremendous interests in the acceleration of general computing applications using a Graphics Processing Unit (GPU). Now the GPU provides the computing powers not only for fast processing of graphics applications, but also for general computationally complex data intensive applications. On the other hand, power and energy consumptions are also becoming important design criteria. Consequently, software designs have to consider the power/energy consumptions together with performance when they are developing software. In this paper, we explore a design space exploration with a commercial GPU: nVidia GTX 660 for investigating the best configuration of a kernel grid structure in a GPU for optimal power or energy consumption.

The gap metric is a successful metric in control theory, which can measure the uncertainty and describe the performance specifcations of the robust control system. In the framework of this metric, robust stability radius is proposed to characterize the stability robustness of the closed-loop system. When both the plant and the controller have uncertainties simultaneously, we introduce the structural robust stability, and prove the necessary and sufficient conditions of the robust stability of the feedback control system. In this paper, we proposed a multi-model robust control method, where the robust stability radius is used to generate the weights. Last, the simulation of a typical nonlinear process can prove the valid of the new strategy.

Neural networks are known as kinds of intelligent strategies since they have learning capability. There are various their applications from intelligent control fields, however, their applications have limits from the point that the stability of the intelligent control systems is not usually guaranteed. In this paper we propose an Adaptive Tracking Control of Nonlinear System the radial basis function network that is a kind of neural networks. The learning method involves structural adaptation and parameter adaptation. No prior knowledge of the plant is assumed, and the controller has to begin with exploration of the state space. The exploration versus exploitation dilemma of reinforcement learning is solved through smooth transitions between the two modes. The controller is capable of asymptotically approaching the desired reference trajectory, which is showed in simulation result.

The purpose of this paper is to more realistically predict the air gaps of the maglev vehicles under consideration. For doing so, the much more detailed dynamic modeling techniques, considering all the components are presented. In EMS-type maglev, air gap which is clearance between guideway surface and supporting magnet should be maintained within a limited value for preventing physical contact. The levitation control unit consists of electromagnets, gap sensors, choppers, and a controller. Thus, it would be desirable to include all the mechanical and electrical parts in the air gap simulation model. With the proposed model, air gaps are simulated to evaluate whether the mechanical contact would be occurred at maximum design speed.

In this paper, a calibration method for the ADC input impedance is presented for the buffer-less thermistor temperature measurement system. In the system the thermistors are interfaced without any buffer to ADC of a temperature measurement system. While a voltage follower or a buffer is usually required to minimize the influence of the ADC input impedance, a high performance operational amplifier is required to prevent the noise and distortion due to the additional circuit. Negative power is also necessary to prevent the distortion of the low voltage input signal. A buffer-less system and a calibration method are introduced to resolve such problems. The precision resistors with low temperature coefficients were employed to emulate the thermistors in the constant temperature water bath, yielding the calibration of the input resistance and the leakage current of ADC without any usage of the inconvenient water bath. The experimental results show that the mean of the calibration error decreased from 190mK to less than 50mK. The calibration error persists in less than 50mK for 8 months long, verifying the validity of the proposed calibration method.