Single-Mode Operation and Frequency Doubling of Fiber-Coupled Diode Butt-Coupling-Pumped Nd:YVO(4) Lasers

We present a simple way to achieve single-frequency operation by using a fiber-coupled diode butt-coupling-pumped Nd:YVO(4) laser in a flat-flat cavity. Single-mode outputs of 620 and 260 mW for fundamental and second-harmonic wavelengths were obtained when the laser was pumped by an 1100-mW fiber-coupled laser diode. Experimental results show that thermal effects provide not only a stable resonator with a good overlap of laser mode and pump size but also enhance single-frequency performance.     

Patients' trust in their physicians: effects of choice, continuity, and payment method

OBJECTIVE: To evaluate the extent to which physician choice, length of patient-physician relationship, and perceived physician payment method predict patients' trust in their physician. DESIGN: Survey of patients of physicians in Atlanta, Georgia. PATIENTS: Subjects were 292 patients aged 18 years and older. MEASUREMENTS AND MAIN RESULTS: Scale of patients' trust in their physician was the main outcome measure. Most patients completely trusted their physicians "to put their needs above all other considerations" (69%). Patients who reported having enough choice of physician (p < .05), a longer relationship with the physician (p < .001), and who trusted their managed care organization (p < .001) were more likely to trust their physician. Approximately two thirds of all respondents did not know the method by which their physician was paid. The majority of patients believed paying a physician each time a test is done rather than a fixed monthly amount would not affect their care (72.4%). However, 40.5% of all respondents believed paying a physician more for ordering fewer than the average number of tests would make their care worse. Of these patients, 53.3% would accept higher copayments to obtain necessary medical tests. CONCLUSIONS: Patients' trust in their physician is related to having a choice of physicians, having a longer relationship with their physician, and trusting their managed care organization. Most patients are unaware of their physician's payment method, but many are concerned about payment methods that might discourage medical use.     

Costimulatory approaches to adoptive immunotherapy

Costimulation is critical for induction of full T-cell effector function, and thus represents an attractive immunotherapeutic approach for the treatment of cancer. This review examines these approaches, including ex vivo T-cell expansion, systemic "delivery" of constimulation, tumors transduced or transfected with costimulatory ligands, and vaccine strategies using coimmunization with the genes for costimulatory ligands. Impressive results in animal models have been demonstrated and a wide range of human clinical trials are underway.     

一种解偏微分方程逆问题的并行算法

论述一种偏微分方程逆问题的数值解法和阵列机与 PVM平台上实现的并行算法。     

Is Sampling Useful in Data Mining? A Case in the Maintenance of Discovered Association Rules

By nature, sampling is an appealing technique for data mining, because approximate solutions in most cases may already be of great satisfaction to the need of the users. We attempt to use sampling techniques to address the problem of maintaining discovered association rules. Some studies have been done on the problem of maintaining the discovered association rules when updates are made to the database. All proposed methods must examine not only the changed part but also the unchanged part in the original database, which is very large, and hence take much time. Worse yet, if the updates on the rules are performed frequently on the database but the underlying rule set has not changed much, then the effort could be mostly wasted. In this paper, we devise an algorithm which employs sampling techniques to estimate the difference between the association rules in a database before and after the database is updated. The estimated difference can be used to determine whether we should update the mined association rules or not. If the estimated difference is small, then the rules in the original database is still a good approximation to those in the updated database. Hence, we do not have to spend the resources to update the rules. We can accumulate more updates before actually updating the rules, thereby avoiding the overheads of updating the rules too frequently. Experimental results show that our algorithm is very efficient and highly accurate.     

用于车辆导航仪中的自动快速寻北系统

本文是陆地车辆导航仪中快速自动寻北系统研制结果的一个总结报告，包括系统的组成原理、硬件设计、软件设计．本文最后还给出了系统的误差分析．     

Procedure guidance for Internet forensics coping with copyright arguments of client-server-based P2P models

Digital technology for transferring and controlling data has made substantial advances in recent years. It is important to protect innovations and to curb the copyright infringements in computer-based systems. Copyright is a legal framework of basic rights, allowing the owner to control or permit someone else to reproduce copyrighted works with commercial value. In recent decades, copyright violations have been moving into the criminal realm. This paper focuses on the procedure guidance of a fictitious P2P model, and discusses whether it contributes to the crime of copyright infringement in dealing with the distribution of digital content. From the perspective of internet forensics, the action research and the whole control mechanism, it is shown that a commercial server has full control over the P2P model.     

Detecting rogue access points using client-side bottleneck bandwidth analysis

A rogue access point (AP) is an unauthorized AP plugged into a network. This poses a serious security threat. To detect an AP, a network manager traditionally takes the electric wave sensor across an entire protected place. This task is very labor-intensive and inefficient. This study presents a new AP detection method without extra hardware or hard work. This new method determines whether the network packets of an IP address are routed from APs, according to client-side bottleneck bandwidth. The network manager can perform his job from his office by monitoring the packets passing through the core switch. The accuracies remain above 99% when the parameter, sliding window size, of the proposed algorithm is larger than 20, according to experimental results. The proposed method effectively reduces the network manager's workload, and increases network security.     

Ocean remotely sensed image analysis using two-dimensional continuous wavelet transforms

Ocean remote sensing is a useful way to obtain ocean wave information. Due to possible inhomogeneities from remotely sensed images, the current work proposes issues concerning ocean wave image analysis using the two-dimensional continuous wavelet transforms (2-D CWTs) to calculate local wave image spectra from inhomogeneous images. To optimize the algorithm of the 2-D CWT for wave image analysis, this work explores ideal parameter values for the wavelet function. The current study also analyses the limits of spatial image resolution and wave image size. After implementing the 2-D CWT on satellite and X-band radar images, this study presents local image spectra and ocean wave information from all the ocean images. These local image spectra reveal the phenomenon of wave refraction and wave nonlinearity nearshore. Compared to real wave spectra, the wavelet spectra present accurate results to describe local wave features in the spatial frequency domain.     

Data aggregation in wireless sensor networks using ant colony algorithm

Data aggregation is important in energy constraint wireless sensor networks which exploits correlated sensing data and aggregates at the intermediate nodes to reduce the number of messages exchanged network. This paper considers the problem of constructing data aggregation tree in a wireless sensor network for a group of source nodes to send sensory data to a single sink node. The ant colony system provides a natural and intrinsic way of exploring search space in determining data aggregation. Moreover, we propose an ant colony algorithm for data aggregation in wireless sensor networks. Every ant will explore all possible paths from the source node to the sink node. The data aggregation tree is constructed by the accumulated pheromone. Simulations have shown that our algorithm can reduce significant energy costs.