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Due to the advantages of low electrical resistance and size miniaturization, Cu to Cu has become the important trends in microelectric interconnect fabrication. Robust Cu to Cu bonding with low temperature, ambient pressure (under N2 or air) and short processing time is strongly requested for advanced IC and substrate packaging, MEMS hermetic sealing, and flexible electronics assembly as well. Ultrasonic technique has recently be adopted in direct copper bonding, this study focuses on the influences of surface physical features on direct bonding between two copper electro-deposits. Experimental results show that joints consisting of hard bumps bonded with soft Cu surface exhibit improved bonding strength. They also indicate that the bonding temperature at 100°C with the protection of N2 and higher surface roughness both positively contribute to the joint strength.

In wireless sensor networks (WSNs), the sensor can be easily compromised by attacker. The traditional intrusion detection can’t detect the compromised nodes immediately. The undetected compromised sensors can utilize advanced resources to attract data stream, compromise and drop the data packets. In this paper, we propose a secure routing protocol (Secure Relay Grid Routing Protocol) based on probability prediction. In the protocol, the network is divided into different small grids. By utilizing the geographic information and intrusion detection information, the proposed protocol is designed with a routing metric which is based on a mathematics prediction model. The routing metric could guarantee the message detour those compromised grids that have not been detected by the intrusion detection. The theoretical analysis and OPNET simulation results show that the proposed protocol can provide high delivery ratio and decrease the number of the compromised packets.

Conditional Random Field is a discriminative model for time series data. In this paper, we propose an improved CRF and apply it to the task of air quality inference. Different from the classical CRF, our linear chain CRF is a supervised learning based on the deep convolution neural network, which has a strong learning ability and fast processing speed for the engineering big data. Specifically, we model the state feature function and the state transition feature function with deep convolutional neural network. The parameter space can store more feature expressions learned from a large number of data. For the state transition feature function of linear conditional random field, we add the influence of input sequence on this function. Through the modelling and learning both vertex features and edge features from data, we obtain a more powerful and more efficient CRF. Experiments on natural language and air quality data show our CRF can achieve higher accuracy.

This paper presents a cold-starting energy harvester in 65nm CMOS with source degradation tracking and automatic MPPT. A power-efficient architecture is proposed to keep the internal circuitry operating at 0.4V while regulating the output voltage at 1V using switched-capacitor DC-DC converters and a hysteresis controller. Peak efficiency of 86% is achieved at 0.39V input voltage and $1.34\mu\mathrm{W}$ of output power with 220nW of internal average power consumption. Integrated operation with lactate biofuel cells is demonstrated.

In view of the complex characteristics of sensitive words, this paper proposes a sensitive word detection method based on variants recognition. The paper proposes methods of word recognition and similarity calculation, include synonyms, substitutes, abbreviations and inflections, and then the method of sensitive word detection is carried out. Experiments show that the proposed method is more efficient in detecting sensitive words than other methods.

This paper describes the novel hybrid front-end beamforming architecture of a C-band mobile Polarimetric Atmospheric Imaging Radar (PAIR) system for weather applications. PAIR, a state-of-the-art radar on a mobile platform, will be shared with the scientific and radar communities to further research frontiers using its unprecedented high-temporal resolution and scanning flexibility. The system under development achieves dual polarization through novel polarimetric phased- array antenna design; improved detection capability through integrated solutions provided by solid state technology; faster update time through digital beamforming (DBF) in elevation; and a robust structure for fast deployment in severe weather. The concept and research applications and the development progress of PAIR will be reported in this paper.

The architecture of an ultra-wideband, supporting remote radio transceiver and designed using radio over fiber technique is proposed. This system works in the frequency range between 6GHz to 18GHz, and the remote distance reaches more than 200m. The gain values of the uplink and the downlink are 24.7±1dB and 4.8±1.2dB, respectively. The noise figures of both links are less than 20dB, and the phase linear jitters are no more than ±20°. Each module is fabricated using hybrid optoelectronic micro-assembly technology, whose volume is less than 85×40×15mm3.

This study aims to investigate microstructural effect on direct Cu bonding. Electro-deposited Cu samples with different grain sizes, preferred orientations as well as hardnesses were prepared. The influence of individual factors will be studied especially grain size. Experimental results show that through grain refinement the strength of directly-bonded electroplated copper joints can be effectively increased by 30%.

An innovative pre-treatment to enhance metallic bonding through the exposure of electromagnetic radiations including flash light and near infrared rays was proposed in this study. Short period of electromagnetic radiation exposures including near infrared radiation (NIR) and Xenon flash can significantly improve the bonding strength. It can be ascribed to the sudden heating/cooling and thus compressive residual stresses which enhance the diffusion of metallic atoms and direct bonding.

Wireless sensor networks (WSNs) have the potential to be widely used in many applications. Due to lack of a protected physical boundary, wireless communications are vulnerable to unauthorized interception and detection. While encryption can provide the integrality and confidentiality of the message, it is much more difficult to adequately address the source location privacy. For static deployed WSNs, adversary can easily perform trace-back attack to locate the source nodes by monitoring the traffic. The eavesdropped messages will leak the direction information of the source location by statistic analysis on traffic flow. In this paper, we propose a theoretical analysis measurement to address the quantitative amount of the information leakage from the eavesdropped message. Through this scheme, we analyze the conditions that satisfy the optimum protection for routing protocol design. Based on the proposed principle, we design a routing algorithm to minimize the information leakage by distributing the routing path uniformly in WSN. The theoretical analysis shows the proposed routing algorithm can provide approximate maximization of source location privacy. The simulation results show the proposed routing algorithm is very efficient and can be used for practical applications.

Authentication protocol is of great importance to ensure the security and privacy of users for RFID systems. In this paper, a lightweight authentication protocol for RFID systems was reviewed and a simple and effective attack was found. To launch the attack, an attacker only needs a rogue reader and sends a number of random values to a target tag. Then the tag will go on updating its state until it cannot be recognized by its server. Subsequently, the attacker repeats the attack to other tags, and he will paralyze the RFID system eventually. Finally, a countermeasure to fix the flaw was presented.

The University of Oklahoma's Advanced Radar Research Center has been developing several weather radar systems that leverage modern phased array technologies to provide advanced functionality as well as multi-function capability. This paper details the latest achievements during the development of these systems, as well as some notional plans for future research opportunities that these systems will enable.

This paper addresses the problem of steering Underactuated Surface Vessels (USVs) along given paths. Due to dynamical uncertainty and ocean disturbances induced by unknown wind, waves and ocean currents, there exist some imperfections in dealing with this non-linear systems with traditional control algorithms. A novel trajectory following controller based on Active Disturbance Rejection Control (ADRC) technique is proposed in the work. A desired heading angle is designed to ensure the USV will arrive at the trajectory. And the controller can treat all the dynamical uncertainty and ocean disturbances as external disturbances. The results of simulation are presented to show that the controller has better dynamic performance and the accurate straight line and curve trajectory tracking for USV is realized.

In the inter-regional grid environment, the coordination of the relay setting and the grid run-time operating mode has an important significance to grid security, relay protection settings verification has also been a lot of attention. This paper studies relay protection setting on-line verification system based on distributed data exchange platform in the inter-regional grid environment, introduces the structure of the distributed system, multidimensional grid data management, grid operation mode model expansion based on CIM model, and discusses the operation mode the relay setting verification.

In this paper, a general structure of type-III FIR filters with derivative constraints is proposed. It consists of a linear combinations of basic sub-filters, called cardinal filters, with weighting coefficients equal to derivatives of the target frequency response at ω = 0. Closed-form expressions for these cardinal filters are derived and their filter coefficients are shown to have a simple recursive relation. Numerical experiments confirm that the proposed design is much more numerically stable than the solution obtained by solving the derivative constraints.

In this paper, we propose a capacitor-less 1T-DRAM structure with the pass-way trench for improving the Retention Time (RT). We have improved the device fabrication process to form the pass-way trench of the structure which combines the Vertical Channel and the Gate-All-Around structure (PTVCT). The memory operation and its attractive performance in terms of programming window, retention time, and writing time are investigated. The pass-way trench improves programming window and retention time of the structure in comparison to conventional structure.

A vertical junctionless channel with T-shaped gate (VJCT) structure has been proposed as 1T DRAM. Designing in vertical channel topology can overcome scalability issues and reduce the area occupied. Also, the junctionless architecture of the channel can be easily fabricated. The T-shaped gate enhances the gate controllability over the channel and improves performance. Therefore, the proposed structure can enhance programming window and retention time. In addition, we use a new operating mechanism to achieve high writing speed and low power consumption for the device.

In this paper, we propose a novel structure of linear-phase type-I FIR filters. The structure consists of a linear combination of some basic filters, called the cardinal filters. The weighting coefficients are exactly the derivatives of the amplitude response at ω = 0. We solve a closed-form recurrence relationship between the filter coefficients. Implementation of the cardinal filters is discussed.

Rapid updates are a highly desired feature in the field of mobile weather radars. Various techniques have been utilized to improve volume update times, including the use of agile and multi-beam radars. Imaging radars, similar in some respects to phased arrays, steer the radar beam in software, thus requiring no physical motion. In contrast to phased arrays, imaging radars gather data for an entire volume simultaneously within the field-of-view (FOV) of the radar, which is defined by the broad transmit beam. As a result, imaging radars provide update rates exceeding those of existing mobile radars, including phased arrays. The Atmospheric Radar Research Center (ARRC) at the University of Oklahoma (OU) is currently engaged in evaluating a mobile X-band imaging radar system by through observations of severe weather events.

In this work, a transportable, dual-polarization X-band radar was developed at the Atmospheric Radar Research Center (ARRC) at the University of Oklahoma (OU). The system has been completed and used to produce some preliminary results using two in-housed developed solid-state amplifiers. The system uses a 1.2-m parabolic reflector dish, which provides a 1.8° beamwdith. Major components are housed on an azimuth-over-elevation pedestal. Long transmit pulse length is utilized to compensate for the relatively low-peak power output of the transmitter while pulse compression techniques is used to recover range resolution and sensitivity.

As an essential and significant part of network security, the security of web applications has received more and more attentions at present. In this paper, we review the security of current web applications, and enumerate the most common attacks on them such as injection, cross site scripting, and insecure direct object references. Then by taking injection attack as an example, we explain the principles of injection attack and analyze the reasons for the vulnerability. Finally, to prevent these attacks, we provide several valuable suggestions.

Nowadays, as the technology and computer science highly developed, using computer at work, study, living and other aspects to offer assistance and support is not a new topic. No doubt, in the era of the highly developed utility software, the popularity of computers brings our life all aspects of convenience. It does favor to more convenient storage, provides accurate calculations, speeds up the information transmission, which let us more and more synchronized with the pace of the world. Similarly, in the university student's current management, computer's application helps the student affairs practitioners to effectively carry on the student data management and the information issue, obtain feeds back as well as analyze related student affairs. Student affairs practitioners, who become highly effective managers on using computers, benefit from the fruitful results of computer development, and offer more accurate services to university students. However, we cannot neglect the latent management risk and the efficiency loss on computer applications, such as moral hazard, information risk, communication efficiency loss, etc. In enhancing the work quality, it is necessary to take measures to dodge the above risk and the loss.

The first phased array radar dedicated to weather observation and analysis is now instrumented with eight, simultaneous digital receivers. The multi-channel receiver will collect signals from the sum, azimuth-difference, elevation-difference, and five broad-beamed auxiliary channels. The multi-channel receiver will allow the direct implementation of interferometry techniques to estimate crossbeam wind, shear and turbulence within a radar resolution volume. Access to the auxiliary channels will enable clutter mitigation and advanced array processing for high data quality with short dwell times. Potential benefits of high quality and high resolution data together with angular shear and turbulence include better understanding of storm dynamics and convective initiation, as well as better detection of small-scale phenomena including tornado and microbursts, ultimately leading to increased lead time for warnings, and improved weather prediction. This paper will describe the system concept, system installation and early results from fielded weather data returns.

The emerging technology of compressive sensing (CS) has been recently applied to many fields to effectively reconstruct high quality images using much fewer number of samples than those in conventional image reconstruction. In this work, the CS framework is applied for the first time to retrieve refractivity field from a network of weather radars. It has been shown that radar-derived refractivity field can be used as a proxy for near-surface moisture and has the potential to improve the prediction of convective initialization and understanding of other weather phenomena. The problem of refractivity retrieval is formulated for networked radars and is solved using CS with the goal of robust reconstruction. Moreover, the feasibility of compressing sensing for refractivity retrieval is demonstrated and verified using simulation. Preliminary results have shown qualitatively and quantitatively that CS technique performs better than the conventional constrained least square (CLS) approach and is less susceptible to noise contamination.

The ability to correctly perform associations of identified storms across time is important for compiling accurate storm histories and performing short-term hazardous weather forecasts. To help guide the design of adaptive sensing algorithms, an understanding of how often storms should be revisited by a radar system is needed. One of the many factors that contribute to determining revisit period for a storm is the minimum revisit frequency needed to maintain accurate tracks. In this paper, methods are developed to study this requisite revisit period. These methods depend on simulations of storm tracks that mimic real-world storm motions. Using these simulations, a tracking algorithm can be objectively evaluated to study how its results degrade with respect to update periods. A preliminary analysis to examine the performance degradation in a variety of meteorological setups is presented, focusing particularly on dense and sparse storm events and mixed storm motion behaviors.

Rapid updates are a highly desired feature in the field of mobile weather radars. Various techniques have been used to improve volume update times, including the use of agile and multi-beam radars. Imaging radars, similar in some respects to phased arrays, steer the radar beam in software, thus requiring no physical motion. In contrast to phased arrays, imaging radars gather data for an entire volume simultaneously within the field-of-view (FOV) of the radar, which is defined by the broad transmit beam. As a result, imaging radars provide update rates exceeding those of existing mobile radars, including phased arrays. The Atmospheric Radar Research Center (ARRC) at the University of Oklahoma (OU) is currently engaged in the design and fabrication of the world's first mobile imaging weather radar.

This paper analyzed the business application requirements of Three Gorges Reservoir area water environment risk assessment and early warning platform, referred to “Federal Enterprise Architecture”, based on the "SOA" and "modular" system architecture design, and then according to the needs of data resources “big focus”, established standard database exchange and procedure interactive interface based on web services, as well as water environment database based on GIS, explored the loosely coupled standard interface, the embedded water quality model and the display method with GIS integration.

The first phased array radar dedicated to weather observation and analysis is now instrumented with eight simultaneous digital receivers. The addition of these additional channels will enable the use of advanced signal processing to improve signal/clutter in an adaptive mode. Elimination of strone point and ground clutter returns from the low-level, volumetrically-distributed weather cell returns is a new application of adaptive processing. The NSF funded 8-channel receiver has been added to the National Weather Radar Testbed (NWRT) system in Norman, Oklahoma, to enable operation as a multi-function and/or adaptive processing system. Herein, we describe the system concept, system installation and early results from fielded weather data returns.