Investigation of loading and force sensing properties of a probe-type microforce sensor with force-distance curves

In this paper,the force-distance curves have been employed to investigate the force sensing properties of the probe-type microforce sensors.In the preliminary studies,two kinds of probe-type microforce sensors have been used to load the objects with dry and wetted surfaces.One is a developed piezoresistive cantilever force sensor with sensitivity of 35 μN/V and the other an atomic force microscope(AFM) cantilever beam probe with sensitivity of 10.4 nN/V.The force outputs corresponding to the regimes of appr...     

基于贪婪-改进果蝇算法的无线传感器网络路由协议

针对无线传感器网络(WSNs)中簇首选择和传输问题,基于贪婪和改进果蝇算法提出一种新型网络路由协议CRP-FOAGA.该协议结合节点位置和剩余能量建立适值函数,通过改进果蝇算法实现适值函数的最优求解,利用贪婪算法实现簇头节点的多跳传输.仿真结果表明:该算法合理规划了簇头节点分布,降低了网络能耗,提升了网络的寿命,具有更好的性能.     

Flexible humidity sensor in a sandwich configuration with a hydrophilic porous membrane

We constructed a wearable and flexible humidity sensor (thickness: 80 μm) in a sandwich configuration, with a hydrophilic poly-tetrafluoroethylene membrane placed between two gold deposited layers, using soft-MEMS techniques. The device was used to measure humidity level, via its electrical conductivity, using a multi-frequency LCR-meter at frequencies ranging from 100 Hz to 100 kHz. The device was calibrated at 100 Hz against moist air over the range of 30–85% RH, which includes normal humidity levels in the atmosphere and physiological air such as breath and evaporating sweat. The response sensitivity of the humidity device was extremely high, even for recovery to dry air; for example response time was less than 1 s for a conductivity shift between humid air of 80% RH and dry air of −60 °C dew point. The sensor performance was reproducible over multiple measurements, with a coefficient of variation of 1.77% (n = 5). The sensor was appropriate for physiological applications, and was successfully used in two non-invasive approaches: to monitor breath air at the mouth, and to measure sweat moisture from the nostrils.     

Kinetic behavior of resistive oxygen sensor using cerium oxide

In order to decrease exhaust gas emissions, oxygen gas sensors with fast response are required. We evaluated two kinds of fast response time (<1 s) for two oxygen sensors with different cerium oxide particle sizes and crystallite sizes, using two methods: the commonly used jump method and the so-called dynamic method. The dynamic method consists of comparing the amplitude of oxygen partial pressure with that of the sensor output, following the changes in oxygen partial pressure produced by periodic modulation of the hydrostatic pressure with the composition of the atmosphere kept constant. The response times obtained with the jump method and dynamic method are defined as t₉₀ and t_b, respectively. Further, we evaluated the relationship between the amplitude magnitude of the oxygen sensor output (A_n) and the frequency of the oxygen partial pressure (f), using the dynamic method. The results obtained were as follows. The value of t_b for the oxygen sensor with a crystallite size and grain size of about 100 nm was 134 ms or less at 1173 K. The value of t₉₀ was 20 and 1 ms when the oxygen partial pressure changed from high to low and from low to high, respectively. From a plot of log A_n versus log f, it was concluded that the kinetics of a sensor using cerium oxide with crystallite and grain sizes from 100 to 300 nm were controlled by diffusion when the oxygen partial pressure was periodically changed in the shape of a sine wave. It was found that the newly developed equipment was able to evaluate two kinds of response times less than 50 ms.     

Modified semi-supervised affinity propagation clustering with fuzzy density fruit fly optimization

Neural Computing and Applications - Affinity propagation (AP) is a clustering method that takes as input measures of similarity between pairs of data points. As the oscillations and preference...     

A new type humidity sensor using micro-air-bridge heaters

A new type absolute-humidity sensor with very quick response, very small power consumption and high sensitivity, which is based on the detection of the thermal conductivity change in humid air at heated temperature above 400°C, has been developed and demonstrated. Since this new type absolute-humidity sensor is able to be easily heated up above 400°C within 30–40 msec because of a micro-air-bridge heater structure, the surface of its sensing area is refreshed by burning out adsorbed dusts, oil, etc. Thermal conductivity _mix of mixed gas expressed by Sutherland-Wassiljewa equation is applied to the humid air to study this absolute humidity sensor. Only a single micro-air-bridge heater operation driven by double pulse-currents for this humidity sensor is also proposed.     

A hybrid approach using genetic and fruit fly optimization algorithms for QoS-aware cloud service composition

This paper addresses the QoS-aware cloud service composition problem, which is known as a NP-hard problem, and proposes a hybrid genetic algorithm (HGA) to solve it. The proposed algorithm combines two phases to perform the evolutionary process search, including genetic algorithm phase and fruit fly optimization phase. In genetic algorithm phase, a novel roulette wheel selection operator is proposed to enhance the efficiency and the exploration search. To reduce the computation time and to maintain a balance between the exploration and exploitation abilities of the proposed HGA, the fruit fly optimization phase is incorporated as a local search strategy. In order to speed-up the convergence of the proposed algorithm, the initial population of HGA is created on the basis of a heuristic local selection method, and the elitism strategy is applied in each generation to prevent the loss of the best solutions during the evolutionary process. The parameter settings of our HGA were tuned and calibrated using the taguchi method of design of experiment, and we suggested the optimal values of these parameters. The experimental results show that the proposed algorithm outperforms the simple genetic algorithm, simple fruit fly optimization algorithm, and another recently proposed algorithm (DGABC) in terms of optimality, computation time, convergence speed and feasibility rate.     

The design of a new remote manipulator for space operation using a 4-cable-driven thrusters-embedded configuration

A new remote manipulator based on cable-driven parallel mechanism (CDPM) is designed for space long-distance operations (e.g. space capture/docking and other long-distance space activities) in this paper. By controlling the cables and thrusters which are equipped on the manipulator simultaneously, the new remote manipulator can achieve expected position, linear velocity, and angular velocity. The new manipulator has a larger controllable workspace compared with usual CDPMs. The structure and characteristics of this manipulator are discussed in this paper. The volume and characteristics of the workspace are also discussed. The influence of the distance on the static equilibrium is studied. The simulation results show that the workspace of this new manipulator is larger than usual CDPM’s. The results also indicate that the cable forces and thruster vectors can completely constrain the manipulator and meet the requirements of space activities. The results of the simulation also show that the controllable workspace of the manipulator is not continuous at some regions. Hence, trajectory planning is necessary.     

A new displacement sensor using pseudoelastic titanium-nickel alloy wire

The authors have developed a new displacement sensor using a wire of pseudoelastic titaniumnickel (Ti-Ni) alloy wire. In the measurement, it was found that this alloy exhibited good linearity between the strain and electric resistance. This linearity has been generally applicable up to several percent strain. In addition, a repeat test and dynamic characteristics have been examined. From these results, it is concluded that this Ti-Ni alloy wire has a possible application as a displacement sensor. Its features include compactness, reduction in weight, and environment attack.     

Characterizing free-living light exposure using a wrist-worn light monitor

It was the purpose of this study to pilot the use of a new wrist-worn light monitoring device to document that indoor lighting for a particular day-shift work environment could serve as the primary light exposure dosage in healthy free-living humans. Twelve employees of a local hospital volunteered to wear a wrist-worn light monitor during all waking hours for an entire workweek (Monday-Friday). Light data were analyzed (3-Factor RM ANOVA) for the dose of light exposure (minutes of exposure x light intensity) within six light intensity categories (< 1, 1-100, 101-200, 201-500, 501-1000, > 1000 1x) relative to time spent within their work environment and all other time of the day. The greatest dose of exposure occurred within the 201-500 1x range during the subjects' work shift. These data support the premise of others that long term exposure to dim indoor light intensities commonly experienced within a variety of work environments may serve as the primary entrainment factor for physiological and behavioral processes following a circadian rhythm.     

捷联惯性传感器多余度配置的误差标定技术研究

对捷联惯性传感器多余度配置系统的标定技术进行了研究。详细分析了多余度惯性传感器各参数的测量原理及计算公式,针对典型的非正交配置(六传感器正十二面体)的多余度惯性测量单元(IMU),提出了一种简易的且具有较高精度的误差模型参数静态标定方法,给出了计算误差模型参数的数学推导过程和解析表达式。仿真结果表明:该计算方法精度较高,可以有效估计出多余度IMU的误差模型参数,提高了惯导精度。     

Wearable sensor activity analysis using semi-Markov models with a grammar

Detailed monitoring of training sessions of elite athletes is an important component of their training. In this paper we describe an application that performs a precise segmentation and labeling of swimming sessions. This allows a comprehensive breakdown of the training session, including lap times, detailed statistics of strokes, and turns. To this end we use semi-Markov models (SMM), a formalism for labeling and segmenting sequential data, trained in a max-margin setting. To reduce the computational complexity of the task and at the same time enforce sensible output, we introduce a grammar into the SMM framework. Using the trained model on test swimming sessions of different swimmers provides highly accurate segmentation as well as perfect labeling of individual segments. The results are significantly better than those achieved by discriminative hidden Markov models.     

Allocating kanbans for a production system in a general configuration with a new control strategy

We consider a production system in a general configuration with a new control strategy: the push policy for the part sending and the kanban mechanism for the work-in-process (WIP). The production system is composed of many stations (or workshops) such as an entry station, a set of workstations, a central station, and an exit station. This type of system is modeled as an open queueing network (OQN) in a general configuration with a Markov-type part sending policy and a machine no blocking (MNB) mechanism. The most important performance measures of the production system are the total throughput of the workstations and the total blocking flow of blocked parts sent from the workstations to the central station. This paper discusses an optimization problem with multiple objectives: allocate kanbans to the workstations so as to simultaneously maximize the total throughput and minimize the total blocking flow. Based on a semi-open decomposition approach, several useful properties of the system are characterized. These properties are used to develop a marginal algorithm for the optimization problem. Moreover, a dynamic simulation approach is devised as a tool for evaluating the quality of the solutions obtained by the algorithm. Numerical experiments are provided to demonstrate the efficiency of the algorithm through the simulation approach.     

一种新型电客式蓝宝石压力传感器

介绍一种高精密、高稳定、线性度佳、结构简单的新型电容式蓝宝石压力传感器.以圆形c面(0001)取向蓝宝石片作为压力传感器的膜片和基片,并且采用两种方案改善普通电容式蓝宝石压力传感器的非线性特性.第一种方法是在一个基片中央区电极内制作一个圆形无金属电极区(圆形无电极区的直径与中央区电极的直径具有特定比率),提高线性度,改...     

一种新型扭矩传感器的研制

介绍了一种以微小弹性扭臂的电桥法为基础的新型微小扭矩传感器。它利用4片等厚的弹性臂测量微小扭矩作用下的形变,通过计算机串口通信,实现了数据的记录与读出。经实验,该传感器能够在0～40mN·m的测量范围内,达到0.01mN·m的测量准确度。     

Selection and navigation of mobile sensor nodes using a sensor network

Hybrid sensor networks comprise of mobile and static sensor nodes set up for the purpose of collaboratively performing tasks like sensing a phenomenon or monitoring a region. In this paper, we present a novel approach for navigating a mobile sensor node (MSN) through such a hybrid sensor network. The static sensor nodes in the sensor network guide the MSN to the phenomenon. One or more MSNs are selected based on their proximity to the detected phenomenon. Navigation is accomplished using the concepts of credit based field setup and navigation force from static sensor nodes. Our approach does not require any prior maps of the environment, thus cutting down the cost of the overall system. The simulation results have verified the effectiveness of the proposed approach. In each of the simulation runs, the static sensor nodes were able to successfully guide the MSN towards the phenomenon.     

Inductive proximity sensor with a flat coil and a new differential relaxation oscillator

A high-sensitivity flat-coil inductive proximity sensor microsystem has been realized and successfully tested. The flat coil, made with CMOS-compatible post processes, is connected to a versatile differential relaxation oscillator electronic interface. In this new and simple interface, the excitation, the signal extraction and amplification are assured by only one operational amplifier. Experimental results on the microsystem confirm that large output frequency variations occur when a metallic target approaches the sensor.     

A multichannel surface plasmon resonance sensor using a new spectral readout system without moving optics

Surface plasmon resonance (SPR) sensors with spectral interrogation provide a high refractive index resolution, a large dynamic range and a fixed optical detection module. In this work, we propose a new multichannel spectral detection unit that uses only one spectrometer to measure the reflection spectrum from multiple sensing spots serially without any mechanical movement. This spectral detection unit is designed based on a spatial light modulator (SLM) configured as a programmable optical aperture for the spectrometer. To demonstrate this concept, a five-channel laboratory SPR prototype was built based on the proposed multichannel detection unit, and we evaluated the device's sensitivity and resolution using a refractive index test. Refractive index resolution of 1.4 × 10⁻⁶ refractive index units (RIU) can be reached using the five-channel prototype. This sensor is suitable for low-cost multichannel biosensing applications that do not contain fast kinetics.     

Design of a flight control architecture using a non-convex bundle method

We design a feedback control architecture for longitudinal flight of an aircraft. The multi-level architecture includes the flight control loop to govern the short-term dynamics of the aircraft, and the autopilot to control the long-term modes. Using $H_\infty $ performance and robustness criteria, the problem is cast as a non-convex and non-smooth optimization program. We present a non-convex bundle method, prove its convergence, and show that it is apt to solve the longitudinal flight control problem.