This paper deals with the design, optimization and development of a practical solution for application to the agro-food chain monitoring and control. The overall system was addressed in terms of the experienced platform, network issues related both to communication protocols between nodes and gateway operations up to the suitable remote user interface. Every constitutive element of the system chain was described in detail in order to point out the features and the remarkable advantages in terms of complexity reduction and usability.

关键词：光机电；传感器；农业监测；无线网络

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The United States and other nations are developing laser (i.e., 'light amplification by stimulated emission of radiation') applications, including high-energy lasers (HEL) and low-energy lasers (LEL). HELs will likely have military applications in ballistic missile defense (BMD), counter- air, counter-space, and counter-intelligence, surveillance, and reconnaissance (ISR). However, HEL applications will be slow to proliferate to many potential adversaries due to their high cost and technical complexity. LELs will be developed as technological byproducts of HELs and commercial applications and will rapidly proliferate, even to resource-constrained actors, due to their low cost and reduced technical complexity. By 2030 the Air Force will field air and space vehicles that will use focal plane arrays (FPA) as optical sensors. This paper argues that these sensitive FPAs will be vulnerable to LEL attack, and as LELs proliferate, they could render the Air Force's sensing technologies ineffective. Further, the paper makes the case that the Air Force must continue to investigate the effects of lasers on FPA sensors to better understand how to protect them, and then invest in the technologies to permit continued operation of all FPA sensors in future hostile environments. To explore this thesis, the paper introduces the basic theory of lasers and FPAs. It then discusses the regimes of future Air Force sensor operations, and analyzes the factors that could facilitate denial of optical sensors using LELs. The paper then looks at the basic methods of sensor protection against laser illumination, and makes recommendations for the Air Force to retain the use of optical sensors in a proliferated LEL environment.

关键词：光机电；传感器；激光；光学

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Robust communications are key to the success of naval operations such as area surveillance, control, and interdiction. Communications and sensor networks allow the flow of data and critical information that are necessary for conducting such operations from both tactical and strategic perspectives. In naval operations, platforms are hardly stationary, as the networking infrastructure operates from a variety of platforms in motion on the sea, above the sea, and from space. Sensor networks consist of nodes made up of small sensors that are able to monitor, process, and analyze phenomena over geographical regions of varying size and for significant periods. Some categories of these small sensors are able to collect and transmit sensor data about physical values (e.g., temperature, humidity, and sea state), or dynamic attributes of objects, such as speed, direction, and the existence of dangerous substances (e.g., radioactive materials and explosives). The objective of this thesis is to examine how unstructured sensor networks, known as ad-hoc sensor networks, can effectively support maritime interdiction operations and regional security by providing reliable communications and flow of information.

关键词：光机电；传感器；海上封锁；地区安全

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The complete list of nanostructured metal oxides and their response to different gaseous species and vapors is shown in Table A.24: The metal oxides include: aluminum, cadmium, cerium, cobalt, copper, gallium, indium, iridium, iron, molybdenum, niobium, nickel, tellurium, tin, titanium, tungsten, vanadium, zinc, zirconium, and mixed oxides. The gaseous species are: acetic acid, acetone, acetylene, ammonia, benzene, butane, carbon dioxide, carbon disulfide, carbon monoxide, chlorine, dimethyl methylphos-phonate, ethyl alcohol, ethylene, formaldehyde, helium, hexane, hydrogen, hydrogen sulfide, LPG, methane, methanol, methyl cyanide, nitrogen oxides, oxygen, ozone, petrol (gasoline), petroleum ether, propane, pro-pene, propanol, propylene, sulfur dioxide, sulfur hexafluoride, toluene, and xylene. Details of the nanostructures of various metal oxides are listed in Table A.2. As it is seen, the tin oxide nanostructures along with mixed oxides are dominating at present. Tungsten nanostructures very closely follow these two oxides. The intention of this table is to give a clear view of these nanostructures. Comparing Table A.2 with Table A.24, it is easy to draw and select the nanostructures for the desired application.

关键词：光机电；传感器；纳米结构；阵列

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In the first part of this chapter, some fundamental results of modern optimum experimental design theory were adopted to the framework of sensor networks with mobile nodes following the so-called 'direct approach' presented in the seminal paper [232]. The problem reduces to solving at each time instant a separate optimization task to which classical design algorithms can be applied. The drawbacks of this technique are the high demand for computational power due to the complexity of the resulting mathematical programming task, and the fact that only the measurability of the sensor trajectories can be guaranteed. It was shown that these difficulties can be reduced to some extent by suitable parametrization of the sensor paths. However, imposing additional control constraints (e.g., for collision avoidance or the sensor dynamics) complicates further the computational task and restricts the spectrum of potential applications.

关键词：光机电；传感器；路由；资源

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After the recent success in jamming wireless improvised explosive devices (IEDs), the threat nowadays has shifted towards the use of buried command wires. A capability to immediately detect the presence of a command wire would be of great value to the troops on the ground. The major challenge of a command wire sensor is to detect the wire in clutter and achieve a high probability of detection without large number of false alarms. The objective of this thesis is to investigate the wire scattering behavior and clutter characteristics through measurements performed in the NPS anechoic chamber. The research has successfully resolved the various multipath components within the anechoic chamber. The transmit-receive coupling between the antennas was reduced through the appropriate use of absorbers. Various wire scattering and clutter characteristics were established through the measurement results. In addition, the measurement results have also demonstrated close-in clutter rejection by utilizing time gating. Recommendations for future work were proposed to gather more data to support the ongoing NPS research on the Command Wire Sensor design.

关键词：光机电；传感器；控制导线；测量

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Sensing behavior is the most important and well-known property of metal-oxide materials. In addition to the sensitivity to light (photon) energy and external pressure, metal oxides demonstrate high sensitivity to their chemical environment. With the capacity to operate in harsh environment, they surpass other chemical sensors in their sensitivity, reliability, and durability. A sensor detects a change in the gas atmosphere due to a change in the electrical properties of sensing elements. It was found that a catalytic reaction and a gas-sensing process on a metal oxide are analogous to each other as both processes involve surface adsorption and chemical reaction with the surrounding gas environment.

关键词：光机电；传感器；氧化物；气体

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This study demonstrated the use of a unique prototype gas chromatograph with sensor array detection, the analytical components of which are microfabricated from Si (micro-GC), for analysis of indoor air concentrations of trichloroethylene (TCE) at low- and sub ppb levels, related to vapor intrusion (VI) applications. The objectives of this study were to demonstrate the performance of the prototype micro-GC in two operating modes: portable mode for forensic and spatial monitoring; and fixed location mode for longer term temporal monitoring (exposure estimation). Results from the micro GC and from TO -15 reference samples were compared. Above the mitigation action level (MAL; 2.3 ppb), the micro-GC accurately determined TCE under complex field matrix conditions. Below the MAL, TCE micro GC determinations were positively biased due to unresolved interferences. This study stands as the first of its kind, where micro-GC instrumentation was shown capable of sustained, reliable, automated measurements of a trace-level component (TCE) in a complex VOC mixture in real-world environments.

关键词：光机电；传感器；土壤蒸气入侵；应用

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Traumatic brain injuries (TBIs) result from exposure to high accelerations and are a serious threat to Soldiers in close contact with improvised explosive devices as well as sports players who are frequently involved in collisions. To improve TBI detection, the U.S. Army Research Laboratory (ARL) has developed a sensor small enough to be mounted in the ear. The sensor consists of an array of 3-axis microelectromechanical system (MEMS) acceleration threshold switches with different sensitivities that move to contacts under acceleration and complete a circuit. Previously, the outputs, which were voltage levels, required an analog-to-digital converter, but the implementation of the mechanism introduced a delay of 100 microsecs samples. This delay has caused the loss of data from switch closures that last less than 100 microsecs, so the sensor was redesigned with digital outputs, and a new program was developed. Clocked signals were used to simulate sensor data, and tests showed improved delays of 3 microsecs to 10 microsecs.

关键词：光机电；传感器；单片机；微机电系统

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We have produced a variety of superconducting transition edge sensor array designs for microcalorimetric detection of x-rays. Arrays are characterized with a time division SQUID multiplexer such that greater than 10 devices from an array can be measured in the same cooldown. Designs include kilo pixel scale arrays of relatively small sensors (-75 micron pitch) atop a thick metal heatsinking layer as well as arrays of membrane-isolated devices on 250 micron and up to 600 micron pitch. We discuss fabrication and performance of microstripline wiring at the small scales achieved to date. We also address fabrication issues with reduction of absorber contact area in small devices.

关键词：光机电；传感器；微热量计；性能测试

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