Search

This paper presents a detailed study of turn-on uniformity under electrostatic discharge events in single-finger and multi-finger traditional DDSCR devices. Since the structure of the multi-finger DDSCR device is not completely symmetrical, the electric field strength of each finger breakdown junction is different, resulting in different impact ionization rates. Therefore, each finger of device cannot be turned on at the same time, and the turned-on finger enters the snap back region and pull down the voltage of the device. If the ESD failure voltage Vt2 of the multi-finger device is less than the trigger voltage Vt1, then other fingers will not turn on until the device fails, and the ESD current can be only discharged through the partial area. The transmission line pulse (TLP) test results show that the failure currents It2 of the single-finger, 2-finger and 4-finger DDSCR devices are 6.22A, 11.83A and 13.33A, respectively, and the 4-finger device cannot be uniformly turned on.

DDSCR devices with finger-type, snake-type and track-type layout are studied and fabricated in $0.5\mu \mathrm{m}$ 18V CMOS process. The finger-type DDSCR achieves the highest failure current about 13.06A, which is also the device that occupies the smallest chip area in three layout styles. In view of the efficient discharge capability (It/area), the finger-type structure provides more than 50% and 66% current handling capability per area higher than the snake-type and track-type, respectively. Due to its better area efficiency, the finger-type structure should be a promising layout of the DDSCR in the input and output ports ESD protection applications.

The odometer measurement model is introduced in this paper and a measurement model considering the lever arm error is established. The influence of the misalignment angle and the lever arm effect on the navigation accuracy in SINS/OD (Strapdown Inertial Navigation System/Odometer) integrated navigation is analyzed, and a high precision dead reckoning algorithm considering lever arm effect is proposed. Finally, the correctness and validity of the algorithm is verified by computer simulation.

As a significant step in artificial intelligence, robot aided object segmentation has drawn increasing attention in past decades. In this paper, a new object segmentation method is proposed based on 3-D information and robot manipulation. We use the Kinect to get the depth information of the object directly as well as the detected contours of it, with which both the primary object segmentation and the 3-D localization of the object can be formed. The usage of Kinect will not only simplify the segmentation process but also improve the performance. Next, the robot arm WAM (Whole Arm Manipulator) with a larger payload is chosen as the manipulator to make further judgment, making it possible to deal with a heavier object. After the manipulation, object segmentation can be accomplished according to the different occasions. Experiments are conducted to prove the effectiveness of this approach.

In robot perception system, distinguishing objects from complex environment is a difficult problem if without prior information. In this article, we study three cases that a robot may encounter in real-world application, no movable object, one object, or multiple objects, and then provide an object segmentation strategy through manipulation for each condition. The result shows that this method can provide sufficient prior information for accurate objects segmentation from robot's observation. Through this unsupervised algorithm, a robot can learn objects around reliably.

In order to reduce the hybrid decision system, a reduction algorithm is proposed based on the neighborhood rough set model and niche clone selection algorithm. In the model the indiscernibility relation is measured by neighborhood relation, and the universe spaces is approximated by neighborhood information granules, so the numerical attributes can be treated directly. The fitness function is designed, and the reduction algorithm is presented as well. The introduction of niche technology can avoid the early convergence of the antibody, and can avoid the sensitization and the local astringency of the parameter to the specific optimal objects. The validity and feasibility of the algorithm are demonstrated by the results of experiments on a classical data set and four UCI machine learning databases.

There are two semantic explanations including the lost and the unrelated for the missing values. To deal with the hybrid information systems which including the numerical attributes and the missing value attributes, a generalized incomplete rough set model is proposed based on neighborhood relations. The model approximates an arbitrary subset in the universe with neighborhood granules, and the generalized neighborhood relations are the generalization of the asymmetry similarity relations and the tolerance relations. It overcomes the shortcoming that the classical rough set can not deal with numerical attributes directly and can deal with the generalized incomplete system which has the missing values both include the lost and the unrelated. The discrimination methods of the missing value and a hybrid reduction algorithm are proposed also. The discrimination methods of the lost or the unrelated conditions are proposed based on the assumption of the consistency classification, and the influence of the noise samples and the neighborhood values to the classification accuracy is presented as well. The validity and feasibility of the reduction algorithm are demonstrated by the results of experiments on five UCI machine learning databases.

the memory management of the embedded operating system has its unique traits. And so SOS operating system should have its own suitable methods for the memory management because of its small memory and resource constraint. This paper analyses the memory management of SOS operating system, and proposes a new data structure with the combination of memory management methods about μ C / OSII, then deeply probes into the memory allocation and recovery mechanisms, which provides an effective solution for memory management of SOS operating system.

Firstly, the paper introduces the Wireless Sensor Networks (WSN) simply. It analyses the influence of lunar surface environment on the nodes of WSN and gives corresponding solutions. According to the characteristics of WSN and design requirements of the sensor node, we design a kind of sensor nodes which based on CC2431. Then the processor module, wireless communications module, location engine, power management module and temperature control module are described in detail. Finally, we conduct the localization experiment of blind nodes and robot navigation experiment.

GPS (Global Positioning System) have high position and velocity precision, star sensor is a high accuracy attitude measurement system, SINS (Strapdown Inertial Navigation System) can get all navigation information precisely at short period. In order to realize high-precision navigation, according to analyze the error model of above systems, both of the state equations and measurement equations were studied. Decentralized fusion method was used in navigation information processing in which Kalman Filter was used as Local-Estimator, and a new kind of Federated Filter based on partial information fusion was proposed. One of the filter configuration was been selected in the integrated navigation system. The results of the simulation validate that the navigation accuracy can be improved to a higher level in this method.

Wireless sensor network(WSN) is a new method of information acquisition and processing, and has great influence on more and more areas.Firstly, this paper presents a test-bed for WSN node and its appropriate characteristics for WSN node. And then, it specifies the analysis of the necessity of porting software to the exiting hardware platform and solutions to many problems during porting process.Finally, the experimental result is described in details, which well proves the feasibility of porting SOS to the chip CC2431.

An assistant robot with standing-up devices(ARSD) was developed according to the demands of paraplegic patients and elderly people. The robot can assist disabled persons during the sit-to-stand transfer and can also carrying them to move. In order to make the design and development of the robot more efficient and reliable, virtual prototype technology was employed. The model of the robot is built by Solid Works and is imported to ADAMS through Para Solid pipe. An algorithm based on neural network speed control was presented to implement path following for the robot. Furthermore, a co-simulation was performed using ADAMS and MATLAB to validate the control strategy.

Networking various tiny biosensors via wireless communication will help improve the performance of medical care system. One of the key components of the biosensor networks is communication platform. This paper investigates the radio characteristics of a body sensor platform named Medi for the wearable body sensor networks. The radiofrequency signal efficiency of proposed Medi platform is evaluated through experiments. In order to investigate possible adverse health effects of wireless radiation on the human body, we further look into the electric field distribution of Medi sensor node.

In this paper, a wireless sensor network based assistive system (WASN) is developed to help the deaf or the hearing-impaired people, particularly, help them to be aware of their environments. A brief review on the current assistive devices is also addressed first. The system architecture, components and specifications are presented for two typical application scenarios: smart home and smart school playground. A node platform is developed to implement the system. Finally, the system performance is evaluated by simulations, followed by the analysis of the feasibility and availability.

More and more wireless mobile sensor networks are employed by robotics to perform harsh tasks such as disaster rescue, emission sources localization or hazardous contaminants localization. There are a lot of network optimization problems to be solved in the protocol design of wireless mobile sensor networks (WMSN), such as rate control, flow control, congestion control, medium access control, queue management, power control and topology control etc. These issues involve several layers of the network protocol stack so that it's quite difficult to consider every single optimization problem of them in a holistic view. The majority of contemporary research works mainly deal with one or some of them in terms of certain applications or objectives. However, most of the proposed protocols are based on simulations or experiments which lack of sufficient mathematical or theoretical analysis to fully understand the convergence or stability. In order to study the theoretical basis of network algorithms, this paper briefly outlines the current methodologies exploited to design and optimize the performance of sensor networks. In addition, the paper investigates the theoretical aspects to make sense of the network optimization algorithms and give a survey mainly in terms of convex optimization, game theory and artificial intelligence.

The monitoring and acquisition of patients' physiological information are quite crucial for the further treatment. Wireless network of biomedical sensors shows great potential to significantly enhance the biometrics performance. Meanwhile, it poses prominent characteristics and challenges to medicos and engineers for its particular medical application compare to other application of wireless sensor networks (WSN). This paper first investigates the exciting conceivable application of WSN in medical area. Then the unique challenges and requirements are analyzed in detail. Along with the further study of the logical architecture and network protocols, preliminary solutions are proposed for the WBSN in a hospital environment.

Method of identifying the dynamic model of accelerometer on precision centrifuge is studied in this paper. Through the method of improved Levy's identification, using only the accelerometer magnitude frequency response data, the accelerometer's dynamic mathematical model can be identified expressed in transfer function. The practicability and effectiveness of the method is illustrated by means of experiment.

Wireless Biosensor Networks will enhance the medical performances due to its many advantages such as long term monitoring, fast network establishment, untethered connectivity and ambulatory diagnosis. The network protocol plays a paramount role in performing the medical tasks. Due to many unique challenges imposed on the network design in wireless biosensor networks, especially when it is related to healthcare, there are a lot of network optimization problems to be solved in the network design such as congestion control, medium access control, power control and bioeffects control etc. These issues involve several layers of the network protocol stack so that it is not practical to consider every single optimization problem independently. It is better to consider the whole network stack as adaptive cross layer optimization problem in a holistic view. The main contribution of this paper is the employment of cross layer optimization methods to combat the unique challenges posed to the WBSN. Two preliminary optimization schemes are proposed: one is for joint congestion control and medium access control, and the other for joint power and bioeffects control. In the later scheme, we introduce the biological effects into the utility model for two purposes, one is to evaluate and control the bioeffects caused by higher power radiofrequency, and the other is to use it as the cost of non-cooperative game for each node. This position paper also briefly outlines the current methodologies exploited for wireless network cross layer design and investigates the theoretical problems.

The adverse biological effects may be caused by wireless biosensor networks in long term monitoring. This is the first paper that specifically derives a bioeffect metric to evaluate the performance of wireless biosensor networks in terms of health effect consideration. This paper investigates the bioeffects caused by radiofrequency transmission of sensor node, including thermal effects and athermal effects. The bioeffects model is studied in both near-field and far-field, in relation to Specific Absorption Rate (SAR). The main contribution of this work is that a normalized bioeffect metric, equivalent Coefficient-of-Absorption-and-Bioeffects (CAB), is derived to evaluate and design the communication protocols for wireless biosensor networks. After analyzing the simulation results, we identify the factors that can reduce the adverse health effects when designing the communication system. Finally we suggest that a bioeffect aware power scheduling algorithm is paramount for the system.

An assistant robot with standing-up devices (ARSD) is developed to provide the functions of standing-up from chair and moving for elderly people and paraplegic patients. Virtual prototype technology is employed to make the design and development of the robot more efficient and reliable. And, the co-simulation design method is presented. In order to run a 3D simulation, the model of the robot is built by Solid Works and is imported to ADAMS through Para Solid pipe. A multi-objective genetic algorithm based on neural network response surface is used to find the Pareto-optimal solutions in the optimum design of ARSD. In order to find the required answer in the Pareto set, a multi-objective fuzzy decision method is presented also. Finally, the mode of human-robot interactive control is discussed.

Mobile wireless telemedicine is the latest area that exploits novel advance in telecommunication technology which provides health care delivery to the inaccessible areas that are hampered by the limitation of the conventional telecommunication technologies. To provide intelligent and high quality monitoring services to patients, best-practice decision support to the professionals and cost-effective maintenance for the management, a third generation (3G) wireless based solution to the telemedicine system is proposed in this paper to support regular and ad-hoc monitoring for the high-frequency interactive contacts between patients and professionals. This paper presents some of the relevant design issues for integration telehealthcare applications with current 3G mobile telecommunication technologies.