飞机结构修理部位的可检性与耐久性

论述了飞机结构损伤部位修理后的可检查性以及如何确定损伤结构修理后的首次检查期和检查周期；同时，也论述了改善修理部位耐久性的常用方法。

选取标准技术参数的原则和要求

制定标准时需要考虑在标准中规定哪些要求，将哪些参数纳入到标准中，取决以下原则和要求。

Enhancing Reliability via Checkpointing in Cloud Computing Systems

Cloud computing is becoming an important solution for providing scalable computing resources via Internet. Because there are tens of thousands of nodes in data center, the probability of server failures is nontrivial. Therefore, it is a critical challenge to guarantee the service reliability. Fault-tolerance strategies, such as checkpoint, are commonly employed. Because of the failure of the edge switches, the checkpoint image may become inaccessible. Therefore, current checkpoint-based fault tolerance method cannot achieve the best effect. In this paper, we propose an optimal checkpoint method with edge switch failure-aware. The edge switch failure-aware checkpoint method includes two algorithms. The first algorithm employs the data center topology and communication characteristic for checkpoint image storage server selection. The second algorithm employs the checkpoint image storage characteristic as well as the data center topology to select the recovery server. Simulation experiments are performed to demonstrate the effectiveness of the proposed method.

Heterogeneity and renal mass biopsy:a review of its role and reliability

Increased abdominal imaging has led to an increase in the detection of the incidental small renal mass(SRM). With increasing recognition that the malignant potential of SRMs is heterogeneous, ranging from benign(15%-20%) to aggressive(20%), enthusiasm for more conservative management strategies in the elderly and infirmed, such as active surveillance(AS), have grown considerably. As the management of the SRM evolves to incorporate ablative techniques and AS for low risk disease, the role of renal mass biopsy(RMB) to help guide individualized therapy is evolving. Historically, the role of RMB was limited to the evaluation of suspected metastatic disease, renal abscess, or lymphoma. However, in the contemporary era, the role of biopsy has grown, most notably to identify patients who harbor benign lesions and for whom treatment, particularly the elderly or frail, may be avoided. When performing a RMB to guide initial clinical decision making for small, localized tumors, the most relevant questions are often relegated to proof of malignancy and documentation(if possible) of grade. However, significant intratumoral heterogeneity has been identified in clear cell renal cell carcinoma(ccRCC) that may lead to an underestimation of the genetic complexity of a tumor when single-biopsy procedures are used. Heterogeneous genomic landscapes and branched parallel evolution of ccRCCs with spatially separated subclones creates an illusion of clonal dominance when assessed by single biopsies and raises important questions regarding how tumors can be optimally sampled and whether future evolutionary tumor branches might be predictable and ultimately targetable. This work raises profound questions concerning the genetic landscape of cancer and how tumor heterogeneity may affect, and possibly confound, targeted diagnostic and therapeutic interventions. In this review, we discuss the current role of RMB, the implications of tumor heterogeneity on diagnostic accuracy, and highlight promising future directions.

Inspection-replacement policy of system under predictive maintenance

In general, every system is in one of the three states： normal, abnormal, or failure state. When the system is diagnosed as abnormal state, it needs predictive maintenance, lfthe system fails, an identical new one will replace it. The predictive maintenance cannot make the system ＂as good as new＂. Under these assumptions, the reliability index and the inspection-replacement policy of a system were studied. The explicit expression of the reliability index and the average income rate （i.e., the long-run average income per unit time） are derived by using probability analysis and vector Markov process method. The criterion of feasibility for the optimal inspection-replacement policy under the maximum average income rate is obtained. The numerical example shows the optimal inspection-replacement policy can raise the average income rate when the optimal inspection-replacement policy is feasible.

Design and Implementation of Security Solution for Computer Network

This article analyzes the problem of computer network security, and design scheme of the network security system. The scheme uses advanced network security technologies, includes a complete set of physical isolation, desktop system security, virus protection, identity authentication, access control, information encryption, message integrity check, non-repudiation, security audit, intrusion detection, vulnerability scanning, electromagnetic leakage emission protection, security management and other security technology and management measures, the purpose is to establish a complete, multi-level three-dimensional, network security defense system.

Chronic methadone use,poor bowel visualization and failed colonoscopy:A preliminary study

AIM:To examine effects of chronic methadone usage on bowel visualization,preparation,and repeat colonoscopy.METHODS:In-patient colonoscopy reports from October,2004 to May,2009 for methadone dependent(MD) patients were retrospectively evaluated and compared to matched opioid naive controls(C).Strict criteria were applied to exclude patients with risk factors known to cause constipation or gastric dysmotility.Colonoscopy reports of all eligible patients were analyzed for degree of bowel visualization,assessment of bowel preparation(good,fair,or poor),and whether a repeat colonoscopy was required.Bowel visualization was scored on a 4 point scale based on multiple prior studies:excellent = 1,good = 2,fair = 3,or poor = 4.Analysis of variance(ANOVA) and Pearson χ 2 test were used for data analyses.Subgroup analysis included correlation between methadone dose and colonoscopy outcomes.All variables significantly differing between MD and C groups were included in both univariate and multivariate logistic regression analyses.P values were two sided,and < 0.05 were considered statistically significant.RESULTS:After applying exclusionary criteria,a total of 178 MD patients and 115 C patients underwent a colonoscopy during the designated study period.A total of 67 colonoscopy reports for MD patients and 72 for C were included for data analysis.Age and gender matched controls were randomly selected from this population to serve as controls in a numerically comparable group.The average age for MD patients was 52.2 ± 9.2 years(range:32-72 years) years compared to 54.6 ± 15.5 years(range:20-81 years) for C(P = 0.27).Sixty nine percent of patients in MD and 65% in C group were males(P = 0.67).When evaluating colonoscopy reports for bowel visualization,MD patients had significantly greater percentage of solid stool(i.e.,poor visualization) compared to C(40.3% vs 6.9%,P < 0.001).Poor bowel preparation(35.8% vs 9.7%,P < 0.001) and need for repeat colonoscopy(32.8% vs 12.5%,P = 0.004) were significantly higher in MD group compared to C,respectively.Under univariate analysis,factors significantly associated with MD group were presence of fecal particulate [odds ratio(OR),3.89,95% CI:1.33-11.36,P = 0.01] and solid stool(OR,13.5,95% CI:4.21-43.31,P < 0.001).Fair(OR,3.82,95% CI:1.63-8.96,P = 0.002) and poor(OR,8.10,95% CI:3.05-21.56,P < 0.001) assessment of bowel preparation were more likely to be associated with MD patients.Requirement for repeat colonoscopy was also significant higher in MD group(OR,3.42,95% CI:1.44-8.13,P = 0.01).In the multivariate analyses,the only variable independently associated with MD group was presence of solid stool(OR,7.77,95% CI:1.66-36.47,P = 0.01).Subgroup analysis demonstrated a general trend towards poorer bowel visualization with higher methadone dosage.ANOVA analysis demonstrated that mean methadone dose associated with presence of solid stool(poor visualization) was significantly higher compared to mean dosage for clean colon(excellent visualization,P = 0.02) or for those with liquid stool only(good visualization,P = 0.01).CONCLUSION:Methadone dependence is a risk factor for poor bowel visualization and leads to more repeat colonoscopies.More aggressive bowel preparation may be needed in MD patients.

AN ALGORITHM FOR MAXIMUM LIKELIHOOD ESTIMATES TO SEMI-PARAMETRIC REGRESSION MODEL WITH INTERVAL CENSORED DATA

In this paper we study the practical procedure for getting the maximumlikelihood estimates in a semi-parametric regression model with interval censored data.On the basis of the on previous theoretical results, we give the detailed algorithms when there are one or two covariates in the model.