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1.
In this paper we describe the application of data mining methods for predicting the evolution of patients in an intensive care unit. We discuss the importance of such methods for health care and other application domains of engineering. We argue that this problem is an important but challenging one for the current state of the art data mining methods and explain what improvements on current methods would be useful. We present a promising study on a preliminary data set that demonstrates some of the possibilities in this area.  相似文献   
2.
Population balance models have been used in chemical engineering since the 1960s and have evolved to become the most important tools for design and control of particulate processes. In this paper we show that the intrinsic particle parameter that determines changes in the process and should thus be included in the population balance is the particle volume. The basic population that is modeled should be the mass distribution, or the volume distribution if the density is constant. The population balance thus describes the change of the volume distribution of volume with time. Furthermore, we suggest that the “birth” and “death” terms that are often used to describe discrete events in particulate processes can almost always be replaced by a rate of change term.To design and control existing and future processes, a multi-dimensional population balance model is required. We propose a volume-based model in which the particle properties that are modeled are the volumes of solid, liquid, and air, respectively. In the most general case the model will consist of a properties vector and a distribution tensor. Depending on the complexity of the process, one or more of the properties may be omitted from the model. This is shown in three examples of increasing complexity: comminution, sintering, and granulation.  相似文献   
3.
页岩储层大规模体积压裂对储层实施改造,是实现非常规油气资源工业化开发的核心技术,但目前该技术的机理研究和应用都处于起步发展阶段。大规模体积压裂可能带来潜在的地质灾害风险,主要包括淡水资源的消耗、浅水层的污染、断层活化诱发地质灾害和地表侵蚀、甲烷泄露致空气污染、植被破坏等问题。从体积压裂机理入手,研究了上述存在的地质灾变风险及灾害发生机制,并从勘探调研合理的页岩气开采区块、设计科学的钻井完井方式、压裂液注入速率方案、实时监测断层破裂带应力及滑移状态以及废水废气回收处理等角度提出对应的科学指导和防范措施,对国内页岩气顺利开展工业化开采、避免潜在的地质环境灾变对人类产生危害具有重要的指导意义。  相似文献   
4.
在军事领域中,随着军事斗争的复杂性的不断增加,人们一直在寻求一种能在实验条件下“预先实践战争”的方法,来深入地研究未来战争的规律。现代科学技术的飞速发展,使得人们这一愿望得以实现。在虚拟现实技术基础上发展起来的“虚拟战争”方法,正是研究增强军队战斗力的有效途径。本文对这一课题作了概要的阐述。  相似文献   
5.
棉纺织印染前处理废水成分复杂、水质较差、处理难度较大。采用膜生物反应器(MBR)处理经过简单预处理的印染前处理废水,可使废水水质大为改善、后续处理压力大大减轻。在近100 d的现场试验中,得出了MBR的最佳操作参数为:温度25℃,HRT 18 h,MLSS 8 g/L,DO 2.8 mg/L,pH 7.5~8.5。在最佳工艺条件下,SS、色度、NH_3—N和COD_(Cr)去除率分别约为90%、30%、72%、72%。该工艺运行成本约为1.643元/m~3。  相似文献   
6.
Recently, there has been an increasing interest in directed probabilistic logical models and a variety of formalisms for describing such models has been proposed. Although many authors provide high-level arguments to show that in principle models in their formalism can be learned from data, most of the proposed learning algorithms have not yet been studied in detail. We introduce an algorithm, generalized ordering-search, to learn both structure and conditional probability distributions (CPDs) of directed probabilistic logical models. The algorithm is based on the ordering-search algorithm for Bayesian networks. We use relational probability trees as a representation for the CPDs. We present experiments on a genetics domain, blocks world domains and the Cora dataset. Editors: Stephen Muggleton, Ramon Otero, Simon Colton.  相似文献   
7.
Despite the constant improvement of therapeutical options, heart failure (HF) remains associated with high mortality and morbidity. While new developments in guideline-recommended therapies can prolong survival and postpone HF hospitalizations, impaired exercise capacity remains one of the most debilitating symptoms of HF. Exercise intolerance in HF is multifactorial in origin, as the underlying cardiovascular pathology and reactive changes in skeletal muscle composition and metabolism both contribute. Recently, sodium-related glucose transporter 2 (SGLT2) inhibitors were found to improve cardiovascular outcomes significantly. Whilst much effort has been devoted to untangling the mechanisms responsible for these cardiovascular benefits of SGLT2 inhibitors, little is known about the effect of SGLT2 inhibitors on exercise performance in HF. This review provides an overview of the pathophysiological mechanisms that are responsible for exercise intolerance in HF, elaborates on the potential SGLT2-inhibitor-mediated effects on these phenomena, and provides an up-to-date overview of existing studies on the effect of SGLT2 inhibitors on clinical outcome parameters that are relevant to the assessment of exercise capacity. Finally, current gaps in the evidence and potential future perspectives on the effects of SGLT2 inhibitors on exercise intolerance in chronic HF are discussed.  相似文献   
8.
几种烟草薄片的性能及热裂解产物分析   总被引:1,自引:0,他引:1       下载免费PDF全文
本研究对10种烟草薄片样品(9种国产,1种进口)的化学组分首次进行全面系统的分析和对比.结果 表明,烟草薄片的化学组分(热水抽出物含量、总糖含量、还原糖含量、总植物碱含量、总氮含量和灰分含量)存在不同程度的差异,因此其相应的热失重特性和热裂解成分存在差异.利用热重/差示扫描量热法对烟草薄片样品在空气氛围下的质量损失特性...  相似文献   
9.
Quantum Key Recycling (QKR) is a quantum cryptographic primitive that allows one to reuse keys in an unconditionally secure way. By removing the need to repeatedly generate new keys, it improves communication efficiency. ?kori? and de Vries recently proposed a QKR scheme based on 8-state encoding (four bases). It does not require quantum computers for encryption/decryption but only single-qubit operations. We provide a missing ingredient in the security analysis of this scheme in the case of noisy channels: accurate upper bounds on the required amount of privacy amplification. We determine optimal attacks against the message and against the key, for 8-state encoding as well as 4-state and 6-state conjugate coding. We provide results in terms of min-entropy loss as well as accessible (Shannon) information. We show that the Shannon entropy analysis for 8-state encoding reduces to the analysis of quantum key distribution, whereas 4-state and 6-state suffer from additional leaks that make them less effective. From the optimal attacks we compute the required amount of privacy amplification and hence the achievable communication rate (useful information per qubit) of qubit-based QKR. Overall, 8-state encoding yields the highest communication rates.  相似文献   
10.
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