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Water visibility is a critical matter for underwater robots during operations, both for getting clear views of the environment, and as a calm and disturbance-free operating region for the manipulators to perform sampling or other operations. In reality, calm and clear water is not only restricted by the natural conditions, but also often hindered by the propeller operations from the robots themselves. Frequent gesture adjustments during manipulator operations are particularly stir-inducing from state-of-the-art underwater manipulative robots. In this work, tackling the flow disturbance issue, a novel underwater robotic platform was proposed with a jellyfish-inspired holonomic platform driven by propellers, a flow-deflection middle layer as an adjustable isolation, and a soft-robotic manipulator mounted below the bottom for operations. Compared with state-of-the-art works, the proposed platform achieved holonomic underwater locomotion with the vertical main direction having significantly reduced flow resistance; the flow-deflection layer could create a flow-calm region of 18.5 times larger underneath for the manipulator operations. A prototype robot was fabricated, and tested in closed- and open-water conditions. Results were compared to flow-simulation results with good agreements, verifying that the proposed jellyfish-inspired robotic concept was effective in both asymmetric underwater locomotion and reducing water disturbances for underwater manipulator operations.

Realization of Antenna-in-Package (AiP) needs to resolve several performance instability challenges at millimeterwave (mmW) frequencies. They are caused by the uncertainties of material properties and mechanical fabrication limitations. In particular, the material properties are highly dependent on frequencies and may exhibit properties of magnetization. Besides, the physical sizes of wavelength at mmW frequencies are very small, making the discrepancy by mechanical fabrications large to cause degradation to the AiP's radiation performance. The roughness of the metal surface may also cause performance degradation, which cannot be avoided due to adherence to the dielectric substrates. These potential performance degradation factors are examined in this paper by considering practical AiPs at 38 GHz bands. Comparisons between full-wave simulations and experimental measurements over AiP prototypes are performed to justify materials and fabrications' influencing factors.

Design of Antenna-in-Module (AiM) is presented to realize active and reconfigurable antenna arrays for potential 5G applications at millimeter-wave (mmW) frequencies. Due to the large array configuration, transmission line loss in the dielectric substrates is significant to cause gain degradation and heat issues. To overcome such drawbacks, unequal feeding lines in the beamforming circuits were employed, which were designed based on the available shortest paths. Active digital phase shifters (DPSs) are used to perform the beam steering while, in the meantime, compensate for the phase discrepancy arising from the unequal lengths of feeding lines. For broadband operation, the DPSs are realized by true-delay lines. A calibration technique was employed to perform the phase adjustment. Full-wave simulations by HFSS and experimental measurements on an AiM prototype are presented to validate the feasibility and demonstrate the radiation characteristics.

Recently, exploring the moon has attracted great interest. To monitor the lunar environment, wireless sensors can be scattered from the prober to the lunar surface to ensure uniform coverage of the target area. Network deployment is critical for wireless sensor networks (WSNs) because it determines the coverage and connectivity of WSNs. However, due to node damage, location deviations, and sink node failures, network deployment is challenging to achieve coverage and connectivity requirements. In this paper, we study the clusterbased WSN deployment scheme for lunar exploration, which consists of four phases, prober separation, cluster deployment, cluster landing, and networking. To meet the requirements of coverage and connectivity, a positive n-edge cross deployment method is proposed, and its connectivity and adaptability are analyzed. The simulation results show the effectiveness of the proposed method in terms of coverage and connectivity.

In this paper, an active antenna-in-package (AiP) design at millimeter wave frequencies (mmW) is presented for user equipment (UE) and customer-premises equipment (CPE) applications. In particular, the UE and CPE AiP implements 4 × 4 and 6 × 6 microstrip antenna elements on the stacked substrates of conventional system-in-package process to realize the desired gains for 5G applications. Within a 19 × 19 mm2 area, we are able to achieve -10 dB reflection coefficient bands of 24.25-29.5 and 37-43.5 GHz by simulations for the two most popular 5G frequency bands, where the simulated gains are 13.7 and 15.22 dBi, respectively. The beam scan range is up to ±40o. On the other hand, the CPE AiP is designed on a 33 × 33 mm2 area, where the maximum gains are 18.83 and 21.25dBi at 28 and 39 GHz, respectively.

Recently, wireless localization has attracted great interest. However, a type of localization problem has not received much attention and has not been well studied, in which all locations of nodes are predetermined, but when nodes are deployed to these positions, the relationship between identifiers and locations of nodes is unknown. Applications with such localization problems include smart lighting, structural health, smart roads and industrial monitoring, etc. In this paper, we investigate how to map node identifiers to known locations. Although the locations of nodes are given, it is still challenging to map the node identifier to known location because the combination of mapping possibilities is huge, and incorrect mapping may occur when several known locations are close to each other. To address this problem, we first propose a localization algorithm, called Q-Hop, in which the distance of two nodes is measured by a fine-grained hop count. Then, we propose a mapping method that maps the node positions estimated by Q-Hop to known locations. The simulation results demonstrate that our solution achieves satisfactory mapping accuracy, which will provide helpful insights for applications with such localization problems.

Soft robotic devices have the potential to be widely used in daily lives for their inherent compliance and adaptability, which result in high safety under unexpected situations. System complexity and requirements are much lower, comparing with conventional rigid-bodied robotic devices, which also result in significantly lower costs. This paper presents a robotic glove by utilizing soft artificial muscles providing redundant degrees of freedom (DOFs) to generate both flexion and extension hand motions for daily grasping and manipulation tasks. Different with the existing devices, to minimize the weight applied to the user's hands, pneumatic soft actuators were located on the fore arm and drive each finger via cable-transmission mechanisms. This actuation mechanism brings extra adaptability, motion smoothness, and user safety to the system. This design makes wearable robotic gloves more light-weight and user-friendly. Both theoretical and experimental analyses were conducted to explore the mechanical properties of pneumatic soft actuators. In addition, the fingertip trajectories were analyzed using Finite Element Methods, and a series of experiments were conducted evaluating both the technical and practical performances of the proposed glove.

In this paper, a 2D axisymmetric model was built to observe the acoustic field and electric potential distributions during the energy transmission process from a piezoelectric layer to a metal plate. The effect of dimension of the piezoelectric transducer on the energy transmission is compared and analyzed by using the COMSOL multiphysics. Then, an experimental platform is instituted to verify the feasibility of the method of energy transmission by acoustic wave through a metal plate. Based on the finite element simulation and experimental test, it is found that the power conversion efficiency is related to the size of the transducer, the thickness of the metal plate, and other parameters. It is shown by experimental measurement that the conversion efficiency could be reached about 30%.

This paper proposes a general structure of ternary BiCMOS circuits, and analyzes the requirements of the driving signals of the output transistors. Then we derive the expressions of driving signals by means of Switch-signal theory. Based on it, the design technique of ternary BiCMOS circuits at switch level is presented. The design examples show that the designed ternary BiCMOS circuits not only have correct logic function but also have better performance.

Flip-flops are basic sequential elements in digital circuits and they have a deep impact on the performance of the circuits. In order to reduce the redundant transitions at internal nodes of the flip-flop, a conditional clock technique is proposed, and then a conditional clock pulse-triggered flip-flop (CCFF) based on this technique is designed. In CCFF, the clock is blocked when the input remains unchanged so that the internal nodes will not switch with the clock, which reduces the power consumption effectively. Based on the TSMC 0.18μm technology, the post-layout simulation results show that the proposed CCFF has an obvious advantage in power consumption when the data switching activity factor is below 50% as compared with other state-of-the-art pulse-triggered flip-flops, and the power saving is more than 50% when the activity factor is 10%.

In previous EEG preprocessing algorithms of brain-computer interface, there are problems such as huge amounts of processing EEG data and the ignorance of EEG's variance from person to person. This paper has proposed a novel method of preprocessing algorithm based on integration of multi-domain, using Fisher distance to select the sampling electrodes and spatial preprocessing is added to the traditional algorithm which is just based on time-frequency domain. It is proved to be effective and practical in overcoming the above drawbacks with experiments of EEG collection. The experiment results show that the proposed method can reduce more than 96.9% of the total processing EEG data and decrease 95.8% of the BCI system's total running time while remain almost equal classification accuracy, contributes to the online application.

According to Hydrophile-Lipophile Balance theory and emulsification principles, testing research was done on the emulsifying effects of α-series of regents which contained different function groups on diesel-ethanol systems. Diesel-ethanol systems were confected respectively while taking different ternary regents as emulsifier, and their stability was investigated, finally the CLZ compound emulsifier being developed. Comparison research was done on the stability of emulsified diesel-ethanol blends which were confected with different emulsifying processes. The results indicate that the α2 regent has strong emulsifying effects on diesel ethanol blends. The ternary regent having gradient HLB values can form the firm interface, making the emulsified diesel-ethanol blends have better stability. Compound interface forming method is a better emulsifying process for diesel-ethanol. The CLZ compound emulsifier has solved out the stability of E10 blend basically at a wide range of temperatures, also having strong emulsifying effects on E15 system.

Resonant tunneling diode (RTD) is nowadays considered the most mature type of quantum device which is used in high speed and low-power circuits. This paper presents a novel topology of RTD-based programmable logic gate (PLG) and takes three-variable PLG as an example. Then a realization algorithm is introduced to implement Boolean functions using PLG. They also can be used in nanopipelined architectures as a basic element for the design of complex functions.

Wireless sensor networks with co-processor refer to each node can measure and report data simultaneously. To minimize the execution time of a given task, a task scheduling algorithm based on divisible load theory(DTSWC) was proposed under clustering structure in wireless sensor networks with co-processor. Using this algorithm, the tasks can be reasonably allocated to each node in wireless sensor networks, such that the entire application can be finished in the shortest possible time. The optimal solution for the load allocation ratio on each node, and the closed-form solution for the shortest time required by finishing the application are obtained. Simulation results have shown the correctness of our theoretical analysis.

Mobility of nodes is considered as the potential solution for improving Ad Hoc network performance, such as maintaining a specified network topology, improving the power efficiency, and enhancing signal-to-noise ratio at the receivers, etc. However, node movement consumes certain amount of energy, which is limited at nodes, and should be counted when optimizing the system performance. In this paper, a distributed adaptive movement control algorithm to optimize the performance and overall power of Ad Hoc networks is proposed. In this algorithm, the decision of node movement is adaptively made accordance with the receiving signal strength. The results show that the mobility control algorithm can be effective to improve the network connectivity and also the performance.

It is well known that in general, feedback cannot increase the capacity of a discrete memoryless channel. However, it can help simplify the complexity of encoding and decoding. Schalkwijk and Kailath (1966) developed a class of block codes for Gaussian channels with ideal feedback. They showed that the probability of decoding error decreases as a second-order exponent in block length for rates below capacity. This paper proposes a coding scheme with ideal feedback and is applied to punctured convolutional codes and punctured Turbo codes. Our results seem to indicate that feedback largely equalizes the performance of classic (convolutional) codes and modern (turbo, LDPC) codes.

The main objective of middleware is to shield the details of network and operating systems while facilitate the rapid deployment of applications. In this paper, we discuss the middleware in wireless sensor network and analyze the strengths and weaknesses of mobile agent based middleware, then a new mobile agent based publish/subscribe middleware is proposed, which improves the efficiency of transmitting agent by using the publish/subscribe mechanism to build interest route. Finally, we evaluate its performance compared to the traditional working mechanisms from perspectives of energy consumption and execution time. The demonstrate results show that our proposal is more reliable and flexible as well as multifunctional than many other existed proposals.

In order to ensure the safety of dams of Fuhuashan reservoir operation, anti-slide stability of whole sections of the main dam and the secondary dam were analyzed by Swedish circle method and simplified Bishop method. The minimal safety factor of stability and the most dangerous slip circle were determined for cross sections not meeting stability requirements. The probable causation was analyzed, and conclusions and suggestions were provided.

Location estimation is an essential issue for wireless sensor networks (WSN). In this paper a new localization estimation algorithm for WSN is proposed which is based on the Grid-Scan method. In the proposed algorithm, the node collects its 1-hop and 2-hop anchors before the localization algorithm is waked up. Firstly, it obtains the intersection region of the 1-hop anchors' transmission area as the estimative region of its location. Then, the region is divided into grid array, and each grid is judged by examining the distance between any of the 1-hop and 2-hop anchors and the grid if it possibly is that grid the sensor located in. Finally, the estimated position is got by averaging locations of the possible grids. Simulation results show that the proposed algorithm achieves better accuracy than DLE.

To control wind turbine fatigue and optimize the fatigue distribution for offshore wind farm, a control network model is proposed based on Multi-Agent theory. A typical model of large-scale offshore wind farm is described. Power fatigue of individual wind turbine is defined. In offshore wind farm, a fatigue distribution estimation approach is studied. The Multi-Agent network is modeled based on the current communication network. All wind turbines act as independent agents, and can self-organize into wind power delivery groups adaptively according to the real wind direction. A solution for automatic agent controller synthesis using Uppaal Tiga and Simulink is presented. The fatigue distribution can be optimized to prolong the service time of a wind farm. This approach can also save some of the maintenance cost due to the expensive logistic visit by helicopters. Finally, a typical simulation result illustrates the feasibility of this multi-agent model.

In order to improve coverage of randomly deployed wireless sensor networks, a distributed deployment algorithm based on coverage addition factor (CAF) is proposed. In this algorithm, each node acquires the distribution of overlapped coverage arcs on the sensing circle based on its neighbors? positions and moves in the direction the coverage addition factor is the greatest. With the algorithm iterated, the coverage of every node and the total coverage of network are both increased obviously. As enhancements, a movement-adjustment scheme and three oscillation-control schemes are designed to avoid movement oscillation and reduce the deploying time. Simulation results show that CAF has advantages over other distributed algorithms such as VOR and VEC in terms of coverage, moving efficiency, moving distance and deploying time.

In wireless ad hoc networks, in order to prolong network life time and improve network capacity, it is necessary to reduce large transmission power of nodes. Due to the random distribution of nodes, traditional topology control algorithms fail to solve this problem completely. So we propose a distributed movement control algorithm to solve this problem. Target locations and redundant nodes are identified first based on localized minimum spanning trees(LMST) and localized uncut-vertex nodes (LUV) respectively. After moving nodes candidates are found out from redundant nodes, they finally move to target locations directly. Simulation results show that the LMST-LUV movement control algorithm can reduce the maximum communication radius and improve the performance of topology control dramatically.

The topology of a wireless sensor network has a significant effect on the network performance. Although topology control algorithms can optimize the network topology, the resultant topology is usually changeable. In this paper, we focus on how to maintain the network connectivity while reducing the maintenance overhead as some nodes fail. A distributed topology maintenance algorithm based on the shortest path tree is proposed. In this algorithm, nodes in immediate surroundings of a faulty node are first triggered to respond, and if they couldn’t ensure that the network is connected, the other related nodes are further triggered. Simulation results show that the proposed scheme can efficiently maintain the network connectivity with significant reduction in the overhead for topology maintenance.

This paper introduces a multiple signal mapped LDPC-BICM that enhances performance by combining coding and modulation similar to trellis coded modulations. Furthermore, a symbol decoding of LDPC-BICM is introduced, which directly uses the symbol metric. With the symbol decoding, an LDPC-BICM system can take the advantage of non-Gray constellation mappings. Simulation results are presented to show that the mixed non-Gray and Gray mapped LDPC-BICM with symbol decoding outperforms the conventional single Gray mapped LDPC-BICM with bit decoding by at least 0.2 dB.

A simple method based on Newton's identities and their extensions is presented for determining the actual minimum distance of cyclic codes. More significantly, it is shown that this method also provides a mechanism for generating the type of syndrome matrices needed by Feng and Tzeng's (see ibid., vol.40, p.1364-1374, Sept. 1994) new procedure for decoding cyclic and BCH codes up to their actual minimum distance. Two procedures for generating such matrices are given. With these procedures, we have generated syndrome matrices having only one class of conjugate syndromes on the minor diagonal for all binary cyclic codes of length n

Using a location set contained in an m-dimensional affine or projective space over F/sub q/, m-dimensional q-ary extended Reed-Solomon codes of any given length are constructed. An algorithm for decoding these codes is also developed.

Systematic m-bit symbol codes are constructed by modifying (m+/spl tau/)-bit symbol Reed-Solomon (RS) codes. These new codes are called systematic modified Reed-Solomon (SMRS) codes and have code length that far exceeds 2/sup m/, the length of m-bit RS codes. Although the systematic encoding of an SMRS code is slightly more complicated then that of the conventional RS codes, the decoding of the new code is exactly the same as that of the conventional RS codes. With one single 8-bit symbol SMRS code, it is now possible to protect entire 512-byte data sector of a data storage system, such as disk drive. It is also shown that 2/sup /spl tau// SMRS codes with distinct and fixed most significant /spl tau/-bits in all symbols of a code can be modified from a single RS code. Using these distinct SMRS codes for adjacent tracks in a disk drive, the probability that the correct track to be read at all time can be significantly enhanced.

A new class of linear codes is constructed from generalized Hermitian curves. The codes are distinct from algebraic-geometric codes. It is shown that these new codes are better than some of the AG codes on Garcia and Stichtenoth (see Inventions Mathematics, vol.121, p.211-22, 1995) curves.

A new construction of linear codes from algebraic curves is introduced. In essence, the construction is of the BCH type, namely, it is to extend the method of constructing BCH codes to the construction of codes from algebraic curves. As a consequence, a new class of codes is constructed without relying much on algebraic geometry. A comparison to algebraic-geometric codes from Hermitian curves showed that our codes typically have much larger minimum distance at a higher code rate. In particular, compared to Hermitian codes on H(2/sup /spl alpha//), which have length 2/sup 3/spl alpha//, then, at a higher code rate, our codes have a minimum distance of at least 2/sup [/spl alpha//4]/ times greater than that of the Hermitian codes. Examples have also shown that, for the same code length and designed minimum distance, our codes can have higher dimension compared to codes constructed from the approach given by Feng and Rao (see IEEE Trans. Inform. Theory, vol.40, pp.981-1002, July 1994).

Low complexity soft decision decoding algorithms for Reed-Muller codes and Barnes-Wall lattices are presented. These algorithms are constructed based on the usage of generalised minimum distance (GMD) decoding recursively. Evaluation of the algorithms on AWGN channel through computer simulation indicates a slight degradation in performance, compared to maximum likelihood decoding, but with considerable reduction in complexity.