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81.
Due to the limited improvement of single-image based super-resolution (SR) methods in recent years, the reference based image SR (RefSR) methods, which super-resolve the low-resolution (LR) input with the guidance of similar high-resolution (HR) reference images are emerging. There are two main challenges in RefSR, i.e. reference image warping and exploring the guidance information from the warped references. For reference warping, we propose an efficient dense warping method to deal with large displacements, which is much faster than traditional patch (or texture) matching strategy. For the SR process, since different reference images complement each other, and have different similarities with the LR image, we further propose a similarity based feature fusion strategy to take advantage of the most similar reference regions. The SR process is realized by an encoder–decoder network and trained with pixel-level reconstruction loss, degradation loss and feature-level perceptual loss. Extensive experiments on three benchmark datasets demonstrate that the proposed method outperforms state-of-the-art SR methods in both subjective and objective measurements. 相似文献
82.
Wireless Sensor Networks (WSN) are widely used in recent years due to the advancements in wireless and sensor technologies. Many of these applications require to know the location information of nodes. This information is useful to understand the collected data and to act on them. Existing localization algorithms make use of a few reference nodes for estimating the locations of sensor nodes. But, the positioning and utilization of reference nodes increase the cost and complexity of the network. To reduce the dependency on reference nodes, in this paper, we have developed a novel optimization based localization method using only two reference nodes for the localization of the entire network. This is achieved by reference nodes identifying a few more nodes as reference nodes by the analysis of the connectivity information. The sensor nodes then use the reference nodes to identify their locations in a distributive manner using Artificial Hummingbird Algorithm (AHA). We have observed that the localization performance of the reported algorithm at a lower reference node ratio is comparable with other algorithms at higher reference node ratios. 相似文献
83.
航管一次雷达维修测试平台是在国产航管一次雷达基础上,具有设备维修、维护、软件升级、雷达模拟、人员培训等功能,以满足技术保障人员对雷达设备维护、维修的要求。该测试平台按照功能可化分为维修参考系统、维修测试工装和维修测试软件等。本文叙述了航管一次雷达维修测试平台的设计原理和系统组成。 相似文献
84.
This paper presents a 5.7–6.0 GHz Phase-Locked Loop (PLL) design using a 130 nm 2P6M CMOS process. We propose to suppress reference spur through reducing the current mismatch in charge pump (CP), controlling the delay time in phase frequency detector (PFD), and using a smaller VCO gain (KVCO). With a reference frequency of 32.768 MHz, chip measurement results show that the frequency tuning range is 5.7–6.0 GHz, the reference spur is −68 dBc, the phase noise levels are −109 dBc/Hz and −135 dBc/Hz at 1 MHz and 10 MHz offset respectively for 5.835 GHz. Compared with existing designs in the literature, this work’s reference spur is improved by at least 17% and its phase noise is the lowest. Under a 1.5 V supply voltage, the power dissipation with an output buffer of the PLL is 12 mW. 相似文献
85.
Hetter KM Bellis DJ Geraghty C Todd AC Parsons PJ 《Analytical and bioanalytical chemistry》2008,391(6):2011-2021
The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production
procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of
laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation
ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate
powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure
levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle
fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of
2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized
and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis.
相似文献
Patrick J. ParsonsEmail: |
86.
A method is suggested for the calculation of a reference value and its uncertainty to be used in the frame of an interlaboratory
comparison (ILC). It is assumed that the reference value of the measurand is determined independently from the ILC round.
It is derived from a limited set of measurement results obtained from one or several expert laboratories. The procedure involves
three stages: (1) check of the experimental data and possible corrections; (2) check of the consistency of data, and possibly
increase of the uncertainties in order to attain internal consistency; (3) choice between fully, partially or un-weighted
mean. 相似文献
87.
The effect of oxidation of anoxic sediment upon the extraction of 13 elements (Cd, Sn, Sb, Pb, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As) using the optimised Community Bureau of Reference of the European Commission (BCR) sequential extraction procedure and a dilute acid partial extraction procedure (4 h, 1 mol L−1 HCl) was investigated. Elements commonly associated with the sulfidic phase, Cd, Cu, Pb, Zn and Fe exhibited the most significant changes under the BCR sequential extraction procedure. Cd, Cu, Zn, and to a lesser extent Pb, were redistributed into the weak acid extractable fraction upon oxidation of the anoxic sediment and Fe was redistributed into the reducible fraction as expected, but an increase was also observed in the residual Fe. For the HCl partial extraction, sediments with moderate acid volatile sulfide (AVS) levels (1-100 μmol g−1) showed no significant difference in element partitioning following oxidation, whilst sediments containing high AVS levels (>100 μmol g−1) were significantly different with elevated concentrations of Cu and Sn noted in the partial extract following oxidation of the sediment. Comparison of the labile metals released using the BCR sequential extraction procedure (ΣSteps 1-3) to labile metals extracted using the dilute HCl partial extraction showed that no method was consistently more aggressive than the other, with the HCl partial extraction extracting more Sn and Sb from the anoxic sediment than the BCR procedure, whilst the BCR procedure extracted more Cr, Co, Cu and As than the HCl extraction. 相似文献
88.
High Efficiency Video Coding (HEVC) improved the coding efficiency significantly. Compared to its predecessor H.264/AVC, it can provide equivalent subjective quality with more than 57% bit rate reduction. However, the improvement on coding efficiency is obtained at the expense of much more intensive computation complexity. In this paper, based on an overall analysis of computation complexity at the HEVC encoder, a low complexity encoder optimization scheme is proposed by reducing the number of available candidates for evaluation in terms of the intra prediction mode decision, early termination of coding unit (CU) splitting and adaptive reference frame selection. With the proposed scheme, the rate distortion optimization (RDO) technique of HEVC can be implemented in a low-complexity way for complexity-constrained encoders. Experimental results demonstrate that, compared with the original HEVC reference encoder implementation, the proposed optimization scheme can achieve more than 40% complexity reduction on average with coding performance degradation as only 0.43% which can be ignorable. 相似文献
89.
云计算是全新的互联网应用商业模式,它在提高资源利用率的同时,也给信息安全带来了很大的安全隐患和挑战,安全性成为用户选择云计算应用时的首要考虑因素。本文在介绍云计算的关键特征及安全问题基础上,对云计算的安全参考模型和安全应对策略进行了分析,并分别从云计算服务提供商和云计算用户的角度提出不同对象的云计算安全应对策略与建议。 相似文献
90.
Chavagnac V Milton JA Green DR Breuer J Bruguier O Jacob DE Jong T Kamenov GD Le Huray J Liu Y Palmer MR Pourtalès S Roduhskin I Soldati A Trueman CN Yuan H 《Analytica chimica acta》2007,599(2):177-190
Ten international laboratories participated in an inter-laboratory comparison of a fossil bone composite with the objective of producing a matrix and structure-matched reference material for studies of the bio-mineralization of ancient fossil bone. We report the major and trace element compositions of the fossil bone composite, using in-situ method as well as various wet chemical digestion techniques.For major element concentrations, the intra-laboratory analytical precision (%RSDr) ranges from 7 to 18%, with higher percentages for Ti and K. The %RSDr are smaller than the inter-laboratory analytical precision (%RSDR; <15-30%). Trace element concentrations vary by ∼5 orders of magnitude (0.1 mg kg−1 for Th to 10,000 mg kg−1 for Ba). The intra-laboratory analytical precision %RSDr varies between 8 and 45%. The reproducibility values (%RSDR) range from 13 to <50%, although extreme value >100% was found for the high field strength elements (Hf, Th, Zr, Nb). The rare earth element (REE) concentrations, which vary over 3 orders of magnitude, have %RSDr and %RSDR values at 8-15% and 20-32%, respectively. However, the REE patterns (which are very important for paleo-environmental, taphonomic and paleo-oceanographic analyses) are much more consistent.These data suggest that the complex and unpredictable nature of the mineralogical and chemical composition of fossil bone makes it difficult to set-up and calibrate analytical instruments using conventional standards, and may result in non-spectral matrix effects. We propose an analytical protocol that can be employed in future inter-laboratory studies to produce a certified fossil bone geochemical standard. 相似文献