Self-organizing nets for optimization

Given some optimization problem and a series of typically expensive trials of solution candidates sampled from a search space, how can we efficiently select the next candidate? We address this fundamental problem by embedding simple optimization strategies in learning algorithms inspired by Kohonen's self-organizing maps and neural gas networks. Our adaptive nets or grids are used to identify and exploit search space regions that maximize the probability of generating points closer to the optima. Net nodes are attracted by candidates that lead to improved evaluations, thus, quickly biasing the active data selection process toward promising regions, without loss of ability to escape from local optima. On standard benchmark functions, our techniques perform more reliably than the widely used covariance matrix adaptation evolution strategy. The proposed algorithm is also applied to the problem of drag reduction in a flow past an actively controlled circular cylinder, leading to unprecedented drag reduction.     

专访米兰市议会都市发展和计划章程负责人卡罗·马瑟洛利(Carlo Masseroli)先生的专访

约瑟夫:米兰作为2015年世博会主办城市,您认为世博会能为米兰提供什么机会?特别是城市管理方面,政府有什么预期目标? 卡罗:米兰世博会体现了正面的发展,我们应该遵循米兰精神:在接近城市的传统和渊源的同时与国际接轨.     

The Flying Brick: A Cautionary Note on Testing Flying Robots Using Guide Wires

A simple experiment demonstrates that an average vertical force can be produced by a small vibrator motor attached to a frame constrained to slide vertically on guide wires. The vertical force produced is sufficient to make the sliding element hover, similarly to a biologically inspired robotic insect. We show that this effect depends on the natural resonance frequency of the guide wires and the nature of the mechanical coupling between wires and sliding element. Based on the result of this experiment, we recommend that a control experiment should be performed in order to reach unambiguous conclusions concerning the actual flying capabilities of robotic insects tested using this kind of methodology.     

Three Gorges Dam stability monitoring with time-series InSAR image analysis

In this paper,we carried out a combination of permanent scatterer and quasi permanent scatterer time-series InSAR image analyses to extract geometric information over the area of the Three Gorges Dam.For the first time,we measured and analyzed the deformation of the Three Gorges Dam and its surrounding area using 40 SAR images acquired from 2003 to 2008.Our results indicate that the temporal deformation of the left part of the dam has ceased and that the deformation of the dam was influenced by the changing...     

The GaAlAsSb quaternary and GaAlSb ternary alloys and their application to infrared detectors

GaAlAsSb quaternary alloys and GaAlSb ternary alloys have been grown by liquid phase epitaxy (LPE) at 550°C and 450°C, respectively. The material compositions and epitaxial structures are suitable for fabricating photodiodes sensitive in the1.0-1.8 mum wavelength range. Various avalanche photodiode structures fabricated in these materials are discussed. The ion implanted GaAlAsSb APD's exhibit a high gain of 100, 82 percent quantum efficiency, and a FWHM of 400 ps. The heterojunction GaAlAsSb APD's have a gain of 40, 92 percent quantum efficiency, and a FWTM of 150 ps. The only remaining material problem which limits the performance of these devices is the high-surface leakage current.     

Clinical and pharmacokinetic observations on fluconazole in the management of cryptococcal meningitis

Natural killer (NK) cell activity, the autologous mixed lymphocyte reaction (AMLR) and proportions of T cell subpopulations (CD3+/CD4+ and CD3+/CD8+) and NK cells (CD16+) were studied in 21 patients with bilateral primary breast cancer (BBC), 10 patients with single-breast cancer (SBC) and 20 healthy controls. All patients studied had no evidence of disease and had been off radiotherapy and/or chemotherapy for at least 1 year. Ten patients with BBC were also treated with tamoxifen. Patients with SBC had NK cell activity, AMLR responses and T cell subpopulations that were comparable to those of normal controls. In patients with BBC, a significant (P < 0.01) increase in NK activity compared to that in normal controls (42 +/- 13% versus 21 +/- 10%, effector-to-target cell ratio, 25:1) and a significant (P < 0.05) decrease in CD4+ T cell proportions (30 +/- 15% versus 49 +/- 13%) and absolute numbers (472 +/- 82/mm3 versus 953 +/- 131/mm3) were found. However, the proliferative response of BBC patients' T lymphocytes in AMLR was in the range of the normal controls. Lymphocytes derived from 10 BBC patients treated with tamoxifen exhibited NK cell activity that was comparable to that of normal controls and patients with SBC, and was significantly (P < 0.01) reduced compared to the pretreatment period. BBC patients who received tamoxifen also show a reduction in the proportion of CD4+ T cells and in AMLR proliferative responses, which decreased compared to levels in normal controls. Taken together, these results indicate that long-term tamoxifen treatment modulates immune responses in BBC patients.     

Transmyocardial laser revascularization using a thoracoscopic approach

Transmyocardial revascularization is a new technique aimed to improve perfusion of the ischemic myocardium by creating transmyocardial channels with a laser. This report demonstrates that transmyocardial revascularization with a holmium laser can be performed through a thoracoscopic approach.     

Functional analysis of myocardial performance in murine hearts overexpressing the human beta 2-adrenergic receptor

Transgenic mice overexpressing the human beta 2-adrenergic receptor gene were compared with wild mice type in terms of cardiac function, using a modified work-performing isolated murine heart preparation and on-line computer analysis. A preload-dependent experiment was performed, in which venous return was gradually increased in 5 mmHg increments from 5 mmHg to 25 mmHg. At each preload, aortic flow, left atrial pressure and aortic pressure were measured in all hearts, and from these parameters stroke volume, contractility, and cardiac index (cardiac output divided by body weight in g) were calculated and compared between groups. At increasing preload levels, the heart rates ranged from 322 beats/min (+/-29) to 369 beats/min (+/-39) in control mice and from 469 beats/min (+/-36) to 540 beats/min (+/-39) in transgenic mice. Cardiac index increased from 138 microliters/min/g (+/-13) and 48 microliters/min/g (+/-5) for transgenic and control mice, respectively at 5 mmHg preload to 262 microliters/min/g (+/-51) and 167 microliters/min/g (+/-15), respectively at 20 mmHg preload. The contractility in the transgenic mice were significantly increased at lower preload levels compared to control mice (1420 mmHg/s +/- 204 v 1187 mmHg/s +/- 127). An increase in myocardial adrenergic receptor density (100-200 fold) leads to significantly higher indices of cardiac function in transgenic mice compared to control mice. The increased heart rate leading to a positive inotropic effect in the hearts of transgenic mice is, at least in part, due to the overexpression of adrenergic receptors. These findings suggest a possible alternative method of establishing a positive chronotropic and inotropic state without the use of pharmacological agents.