Few views image reconstruction using alternating direction method via ‐norm minimization

In the medical computer tomography field, total variation (TV), which is the ‐norm of the gradient‐magnitude images, is widely used as the regularization based on the compressive sensing theory. To overcome the TV model's disadvantageous tendency of uniformly penalize the image gradient and over smooth the low‐contrast structures, an iterative algorithm based on the ‐norm optimization of the finite difference is proposed. To rise to the challenges introduced by the ‐norm minimization, the algorithm uses the alternating direction method to solve the unconstrained augmented Lagrangian function, which involves a hard thresholding method, a linearization and proximal points technique for each subproblem. The simulation demonstrates the conclusions and indicates that the algorithm proposed in this article can obviously improve the reconstruction quality. © 2014 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 24, 215–223, 2014     

Optimized Projection Matrix for Compressed Sensing

Sparse signals can be reconstructed from far fewer samples than those that were required by the Shannon sampling theorem, if compressed sensing (CS) is employed. Traditionally, a random Gaussian (rGauss) matrix is used as a projection matrix in CS. Alternatively, optimization of the projection matrix is considered in this paper to enhance the quality of the reconstruction in CS. Bringing the multiplication of the projection matrix and the sparsifying basis to be near an equiangular tight frame (ETF) is a good idea proposed by some previous works. Here, a low-rank Gram matrix model is introduced to realize this idea. Also, an algorithm is presented via a computational method of the low-rank matrix nearness problem. Simulations show that the proposed method is better than some other methods in optimizing the projection matrix in terms of image denoising via sparse representation.     

内蒙古英雄山铜金多金属矿成矿特征

内蒙古英雄山铜金多金属矿矿区地处内蒙古自治区阿拉善盟额济纳旗,位于北山成矿带,矿区具多种成矿类型,其中铜铁多金属矿床产于矿区中部隐伏花岗闪长斑岩与围岩的接触带中,受断裂构造和褶皱鞍部控制,属矽卡岩型矿床;金银多金属矿为次生氧化矿,受次级断裂构造控制,为氧化—淋滤型矿床。     

一种检测和防御TearDrop攻击的新算法

TearDrop是网络入侵者利用TCP/IP协议栈的漏洞对目标进行的一种恶性攻击,危害大且不断出现新的变形。通过对TearDrop及其变形攻击原理的研究,利用网络分片、重组知识,提出了一种对TearDrop及其变形进行检测和防御的新算法——FRD算法。该算法用高效的双链表实现,计算复杂度低、检测速度快。最后对算法进行了试验验证,结果表明,其对TearDrop及其变形的检测非常有效。     

Contribution of dynamic charging effects into dopant contrast mechanisms in silicon

In this work, SEM capability for imaging of both p- and n-doped regions in Si was demonstrated. The best dopant contrast was found when the primary electron range (R) is comparable or larger than the maximum escape depth of secondary electrons (∼5λ) (λ stands for mean free path). Beyond this scale (R < 5λ, R > > 5λ) the contrast between p-, n-doped and intrinsic regions gradually disappears. The dopant profiles obtained by SEM were judged using scanning capacitance microscopy (SCM), dopant selective etch (DSE) and secondary ion mass spectrometry (SIMS) measurements, and excellent matching was demonstrated. A novel dopant contrast mechanism incorporating dynamic charging effects that take place during e-beam/specimen interaction is suggested. Under threshold steady-state imaging conditions, an E _bi field in Si near the surface region is formed. This field, governed by secondary electron (SE) emission and trapping of some incident and generated SE, accelerates electrons towards the surface in p-type regions and decelerates them in n-type regions, compared with the intrinsic material. This results in the observed dopant contrast: C(n) < C(i) < C(p). Use of the SEM for 2D-dopant imaging provides many advantages; giving fast results, covering a wide range of dopant concentrations, applicable to real devices, and does not require sample preparation needed by SCM and DSE. In addition, SEM-dopant contrast data quantification is possible using SIMS standards which needs to be defined with more details.     

电机轴的可靠性计算

可靠性设计是一种新的设计方法.这种方法在许多方面得到应用,如结构设计、强度分析、寿命估算和断裂安全分析等。本文论述了转轴可靠性理论,并以实际算例对电机轴的疲劳强度进行了可靠性计算。希望这一方法在工程实践中得到进一步的推广和应用.     

Isotype-specific immune responses in murine experimental anisakiasis

A murine experimental model of anisakiasis has been developed in BALB/c and C57BL/10 mice orally inoculated with an Anisakis simplex living third stage larva (L3) in order to investigate isotype-specific immune responses against excretory-secretory (ES) products and crude extracts (CE) from L3. Specific antibody production showed similar patterns against both ES and CE antigens with higher levels against the latter. The dynamics of the production showed the earliest responses in BALB/c, in which antibodies were principally of the immunoglobulin (Ig)M isotype. Responses to the IgG1 subclass were mainly produced in the C57BL/10 strain. Levels of IgG2a were practically undetectable. With sera from C57BL/10 mice high levels of the IgG2b isotype were detected. A slight IgG3 response was only detected against the CE antigen in the C57BL/10 strain by the end of the experiment and IgA responses were very low. Humoral responses against A. simplex antigens are different depending on individual characteristics and thymus-independent epitopes might be represented into A. simplex antigens and their stimuli could be different regarding the murine strain used.     

Problems found in the isolation of mycelial fungi (Fusarium solani) from blood culture (Bacter NR-860)

BACKGROUND: F. solani fungemia is unusual. Patients at risk are immunosuppressed, have underlying malignancy or severe debilitating diseases. METHODS: We report two cases of F. solani fungemia in two non neutropenic patients who had been treated with wide-spectrum antibiotics an/or systemic corticosteroids, parenteral nutrition and intravenous lines. Bactec NR-860 (Becton-Dickinson) system was used, and growth was detected in aerobic conditions (between 3-7 days of incubation). RESULTS: Removal of the catheters with or without i.v. amphotericin B were used successfully. CONCLUSION: The spectrum of Fusarium sp. fungemia is discussed. Current available antifungal therapy is also reviewed.     

本质安全自动控制技术在火炸药药柱压制生产线中的应用

弹药压装药是生产各种弹药和战斗部的重要组成部分,现代化局部战争要求弹药生产在短时间内实现大批量、变批量多品种快速生产,因此要求弹药生产必须改变传统落后的生产方式,实现高效本质安全自动化和柔性化生产。本文介绍采用自动化控制技术、防静电技术、在线检测技术、上位机监控技术、在危险场所采用隔离栅的本质安全技术的控制系统如何应用在火炸药药柱压制生产线上,实现火炸药药柱压制生产过程实时监控、安全可靠、大批量柔性化生产。