REST2: High-performance solar radiation model for cloudless-sky irradiance, illuminance, and photosynthetically active radiation – Validation with a benchmark dataset

REST2, a high-performance model to predict cloudless-sky broadband irradiance, illuminance and photosynthetically active radiation (PAR) from atmospheric data, is presented. Its derivation uses the same two-band scheme as in the previous CPCR2 model, but with numerous improvements. Great attention is devoted to precisely account for the effect of aerosols, in particular.Detailed research-class measurements from Billings, OK are used to assess the performance of the model for the prediction of direct, diffuse and global broadband irradiance. These measurements were made in May 2003 during a sophisticated radiative closure experiment, which involved the best radiometric instrumentation currently available and many ancillary instruments. As a whole, these exceptional measurements constitute the only known modern benchmark dataset made specifically to test the intrinsic performance of radiation models. Using this dataset as reference, it is shown that REST2 performs better than CPCR2 for irradiance, illuminance or PAR predictions. The availability of the turbidity data required by REST2 or other similar models is also discussed, as well as the effect that turbidity has on each component of broadband irradiance, PAR irradiance and illuminance, and on the diffuse/global PAR ratio.     

A Novel Environment Characterization Metric for Clustered MIMO Channels

In this work we introduce a novel metric for characterizing the double-directional propagation environment and use this metric to assess the performance of a SAGE parameter estimator for MIMO channels. Using the IlmProp, a geometry-based MIMO channel modeling tool, we construct synthetic channels for three different scenarios showing: (i) well separated clusters containing dense propagation paths, and single-bounce scattering; (ii) partly overlapping clusters containing widely spread propagation paths, and single-bounce scattering; (iii) unclustered multipath components (“rich scattering”), and double-bounce-only scattering. We model the scatterers and the receiver in the environment as fixed, but the transmitter as moving. The Initialization and Search-Improved SAGE (ISIS) estimation tool is used to extract the propagation paths from the constructed channels. Both true and estimated paths are fed to the new system-independent metric which genuinely reflects the structure of the channel and the compactness of the propagation paths. We use this metric to decide on the accuracy of the channel estimator. The results show a convincing agreement between true and estimated paths.     

Information Security Management: An Approach to Combine Process Certification And Product Evaluation

Information Security (IS) is the key to the effective management of any organisation in today’s commercial and industrial sectors. Line managers’ performance, for instance, is rated according to the extent to which their operations conform to the IS policies of their respective organizations. In the same way, senior management’s performance is judged by how well the organization performs in terms of internationally accepted codes of IS practice. IS management, however, is not always a quantifiable entity and its evaluation is complicated by the fact that it can be viewed either from an electronic perspective, in which case the focus will fall solely on product and/or systems evaluation, or from a procedural and management perspective, in which case the focus will, instead, fall on the certification of the IS management process. This article will, therefore, be devoted to providing a consolidated approach to the evaluation of IS management, in terms of which full cognisance will be taken of both these perspectives.     

高吸水性树脂在农业应用中的研究

高吸水性树脂是一种新型功能高分子材料，具有广泛的用途。针对其在农业应用方面的性能要求，分析了其作用机理，介绍了其在国内外的研究现状，指出了使用高吸水性树脂在农业应用中的发展前景。     

Optimization of a dual cycle cogeneration system based on a new exergetic performance criterion

An ecological performance analysis for an irreversible dual-cycle cogeneration system has been performed. The objective function is called as the exergetic-performance coefficient (EPC) and defined as the ratio of total exergy output to the loss rate of availability. The general and optimal performances of the irreversible dual-cycle cogeneration system, having a finite-rate of heat transfer, heat leak and internal irreversibilities based on the EPC objective function have been investigated. Comparisons with respect to the optimal total-exergy output are also provided in order to establish the utility of the new exergetic-performance coefficient. The analyzed results of the dual-cycle cogeneration system considered, working at maximum EPC conditions, have a significant advantage in terms of entropy-generation rate and can be used for the selection of optimal design parameters.     

Effects of Integrated Graphical Displays on Situation Awareness in Anaesthesiology

Anaesthetic information displays have been shown to influence anaesthesiologists’ situation awareness. In study 1 an object display was compared with the traditional display currently used. Twelve anaesthesiologists (residents and faculty members) participated in a simulator evaluation of the displays. Reaction times for detection of critical events and situation awareness were measured. The object display improved situation awareness for one of four test scenarios. Low-level situation awareness was higher with the traditional display, and medium-level situation awareness was higher with the new display. In study 2, an integrated 3D display was compared to the traditional display. Twelve students participated in the evaluation. The new 3D display helped the observers to see changes more rapidly. In one scenario, situation awareness was higher with the new display than with the traditional display. In summary, during 63% of the simulated scenarios, reliable differences were found in favour of the new displays. Thus, by introducing integrated graphical displays in the operating room, anaesthesiologists’ performance may be improved.     

水泥砼桥面防水粘结材料性能研究

铺装结构中防水粘结层的设置对于混凝土桥面至关重要。对三种防水粘结材料的原材料性能进行检验，室内模拟了三者的实际路用性能并进行对比分析，现场检测了防水粘结层的拉拔强度和剪切强度，为合理选择防水粘结材料提供了依据。     

向心分离采样器级常数的估算

在设计向心分离采样器时,需估算其各收集级的级常数D_(ae)(50)值,但目前尚无现成的计算公式可用。本文对多种型号的向心分离采样器的结构参数与实验刻度结果进行了对比分析,在撞击器计算公式的基础上,给出了一个修正公式,用于估算向心分离采样器的级常数,结果与实验值基本一致,可供设计向心分离器时作参考。     

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在城市内建设CNG汽车加气站成本高，合理布局CNG汽车加气站至关重要。结合技术经济学和交通系统分析的观点，探讨了公交车和出租车不同的加气行为，提出了CNG汽车加气选站时应遵循的5项原则或假设，并根据最短路径理论建立了加气站和车站车源分配模型。通过对加气站车辆来源及售气情况的计算，得到加气站负荷率、投资回收期、加气行驶里程等3类评价指标，对加气站布点选址与整体经济性进行了评价分析。编制了城市CNG汽车加气站布点计算机辅助选址评价软件，对城市新增加气站布点的合理性进行了预测检验，能满足用户对加气站的时空分布要求，为拟建城市加气站布点规划提供了参考。     

Discussion on the determination of sail residue in silk fibroin solution with a water quality testing pen北大核心CSCD

the salt residue is one of the quality indexes of silk fibroin products.The products with low salt residue are not only healthier for human body, hut also more stable in exterior qualities, such as color and smell.Instrumental analysis and chemical analysis are currently methods to accurately determine salt residues in silk fibroin products, but they still need to be supplemented by real-time and quick detection methods in practical production.This paper discusses the determination method with a water quality testing pen and investigates the response of the water quality pen to the changes in the concentration of a variety of solutions, and associates with application examples.The results show that the TDS measured by the water quality pen is highly linearly correlated with the changes in the concentrations of CaCU , NaCl, and fibroin-CaCU solutions.The principle and method of the TDS water quality testing pen have an application prospect in the field of real-time and rapid approximate evaluation of salt residue in silk fibroin solution. © 2021 China Silk Association. All rights reserved.