Ontology-based semantic similarity: A new feature-based approach

Estimation of the semantic likeness between words is of great importance in many applications dealing with textual data such as natural language processing, knowledge acquisition and information retrieval. Semantic similarity measures exploit knowledge sources as the base to perform the estimations. In recent years, ontologies have grown in interest thanks to global initiatives such as the Semantic Web, offering an structured knowledge representation. Thanks to the possibilities that ontologies enable regarding semantic interpretation of terms many ontology-based similarity measures have been developed. According to the principle in which those measures base the similarity assessment and the way in which ontologies are exploited or complemented with other sources several families of measures can be identified. In this paper, we survey and classify most of the ontology-based approaches developed in order to evaluate their advantages and limitations and compare their expected performance both from theoretical and practical points of view. We also present a new ontology-based measure relying on the exploitation of taxonomical features. The evaluation and comparison of our approach’s results against those reported by related works under a common framework suggest that our measure provides a high accuracy without some of the limitations observed in other works.     

Iterative performance improvement of fuzzy control systems for three tank systems

This paper suggests the performance improvement of fuzzy control systems (FCSs) for three tank systems using iterative feedback tuning (IFT). The stable design of Takagi–Sugeno–Kang fuzzy controllers is guaranteed by means of a stability theorem based on LaSalle’s global invariant set theorem formulated for a class of multi input-multi output (MIMO) nonlinear processes. An IFT algorithm characterized by setting the step size to guarantee the FCS stability is proposed. The theoretical approaches are applied in a case study that deals with the IFT-based stable design of fuzzy controllers dedicated to the level control of a cylindrical three tank system as a representative MIMO system. A set of experimental results for a laboratory setup illustrates the performance improvement.     

Temporal Bayesian Knowledge Bases – Reasoning about uncertainty with temporal constraints

Time is ubiquitous. Accounting for time and its interaction with change is crucial to modeling the dynamic world, especially in domains whose study of data is sensitive to time such as in medical diagnosis, financial investment, and natural language processing, to name a few. We present a framework that incorporates both uncertainty and time in its reasoning scheme. It is based on an existing knowledge representation called Bayesian Knowledge Bases. It provides a graphical representation of knowledge, time and uncertainty, and enables probabilistic and temporal inferencing. The reasoning scheme is probabilistically sound and the fusion of temporal fragments is well defined. We will discuss some properties of this framework and introduce algorithms to ensure groundedness during the construction of the model. The framework has been applied to both artificial and real world scenarios.     

基于标号随机Petri网的GSM性能分析

GSM移动通讯网络系统是目前国内覆盖最广、可靠性最高、容量最大、保密性强的公共无线数字传输系统.GSM通信分系统在车载单元与监控中心之间进行数据传输,其性能优劣对车载定位系统起着十分重要的作用.结合实时UML状态机的直观、平台无关性特点和LSPN的理论分析能力,研究了GSM通信模块的工作模式,结合实例初步探索了该方法在移动通讯网络性能分析中的适用性.     

基于F410的分布式小电流接地系统故障选线装置

介绍了一种基于C8051F410单片机为核心构成的分布式小电流选线装置,并详细阐述了其硬件结构及选线原理。该装置硬件结构简单,安装方便,对提高城市配电网安全运行有很大的意义。     

Underground space needs an interdisciplinary approach

During a very long period of time, civil engineers have been the only ones to be designated as the experts for underground space, while the planners and architects were the ones of the development at the surface. This silo approach to work is now a thing for the past in most major cities, but solving this fragmentation of the disciplines does not happen overnight. It first took a few thinkers to promote and publish on the subject, such as Edouard Utudjian, founder of GECUS in 1937, and also that planners abandon their ambiguous position on this invisible space, become part of multi-disciplinary teams and participate in the dissemination of new knowledge, particularly through some international associations such as ACUUS. With biennial scientific conferences dating back to 1983, the organization actively promotes since partnerships amongst all actors in the field of planning, management, research and uses of urban underground space in all its forms. The originality of ACUUS comes from its success in attracting public, private and university levels into a cohesive network of mutual cooperation, which is not so common in international organizations.     

Why underground space should be included in urban planning policy – And how this will enhance an urban underground future

Cities worldwide tend to overlook an invaluable asset that lies beneath their surfaces. Most cities and urban regions are unaware of the benefits underground space use has to offer, both for climate inflicted and spatial constraints: In many cities, infrastructure development is being outpaced by population growth. Climate change effects are requiring radical new approaches in terms of coping with for example excessive rainfall. The available space at the surface is rapidly being used up and the biggest danger is that built-up spaces are taking over the public green spaces of cities thereby threatening livability and quality of life. Urban underground space forms a societal asset, which is often unappreciated and underestimated in terms of the role it can play within dynamic city environments and associated challenges.This paper will explore the ways in which urban underground space can be optimally integrated into the dynamic urban context. It also explores the often contradictory functions that make underground space use complicated from a planner’s perspective. The first-come-first-served strategy of underground space use has left many cities wondering how they are going to cope with the self-inflicted “chaos” under the surface. The often mono-functional uses of the underground lead to sub-optimal space use. Most cities and urban regions are unaware of the benefits underground space use has to offer. In guiding the future use of urban underground space, a comprehensive policy framework guiding its development is lacking on which decisions can be based. This often leads to the non-sustainable use of this important asset. It will be argued that both vision and planning are needed to be able to make the best use of this underrated underground real estate.The authors will also debate that just understanding the potential of underground space is not enough. Realising its actual potential and facilitating its development will require a spatial dialogue between many stakeholders, including planners, engineers, developers and public decision makers.     

Numerical simulation of air ventilation in super-large underground developments

Recent advancements in engineering technology have enabled the construction of super-large underground engineering projects in China. Currently, the ventilation requirements and standards of normal-size underground spaces are used for super-large underground excavating engineering projects in China. For example, the minimum air velocity of 0.15 m/s is the standard velocity for normal-size underground spaces; however, this value is also used as the required air velocity for diluting underground contaminants in super-large underground developments. This paper aims to examine the minimum ventilation requirements for super-large underground developments (S > 100 m²). A three-dimensional computational domain representing a full-scale underground space has been developed. The pertinent parameters such as dust concentration, smoke density, oxygen concentration and air temperature have been simulated. The results show that at some specific underground conditions, the ventilation air velocity of 0.15 m/s is sufficient to control the dust level, provide required oxygen concentration and maintain the air temperature at acceptable levels during development; however, it is not sufficient to bring the CO concentration below an acceptable safe limit. This must be considered by the ventilation system designers of super-large underground developments.     

Methanol electrooxidation at nickel-modified rhodanine self assembled monolayer films: A new class of multilayer electrocatalyst

Nickel modified rhodanine (Rh) self-assembled monolayer films (Rh-SAM/Ni) were fabricated on copper from 10.0 mM Rh containing methanol. The films were characterized with the help of scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDX) techniques. The methanol oxidation activity of the Rh-SAM/Ni electrode was tested in 1.0 M methanol containing 0.1 M KOH solution using many electrochemical techniques. The results indicated that well-ordered and very homogeneously distributed Rh-SAM films were assembled over the copper surface. The rate of methanol electrooxidation reaction can be enhanced by modifying copper surface with Rh-SAM/Ni multi-layer film. The enhanced activity was related to increasing active sites over the surface for adsorption and oxidation of methanol as well as facilitating oxidation or desorption of adsorpted intermediates of the process. It was suggested that the Rh-SAM layer could be a candidate supporting material for fabricating direct methanol fuel cell (DMFCs) anodes.     

A novel anions and cations co-doped strategy for developing high-performance cobalt-free cathode for intermediate-temperature proton-conducting solid oxide fuel cells

The sluggish activity of cathode at intermediate-temperature limits commercialization of proton-conducting solid oxide fuel cells (H-SOFCs). In this investigation, a novel cathode of Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_2.9−δF_0.1 was successfully developed by co-doping of anion F and cations Ca, Sn, Y. We studied the effect of F⁻-doping on phase structure, electrical conductivity and electrochemical properties of the cell. Compared with Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_3−δ, F⁻-doped Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_3−δ exhibited higher conductivity. Composite cathode consisting of Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_2.9−δF_0.1 and Sm_0.2Ce_0.8O_2−δ was applied in H-SOFCs with BaZr_0.1Ce_0.7Y_0.2O_3−δ electrolyte which achieves an encouraging performance with the maximum power density of 1050 mW cm⁻² and polarization resistance of 0.04 Ω cm² at 700 °C. The result of First-principles calculations based on spin-polarized Density Functional Theory shows that doping of F⁻ reduces the activation energy required for migration of oxygen ions. These results demonstrate that the anions and cations co-doped strategy can provide a new horizon for the cathode in H-SOFCs.