20,973 research outputs found
On the pollutant removal, dispersion, and entrainment over two-dimensional idealized street canyons
postprin
Overview of permanent-magnet brushless drives for electric and hybrid electric vehicles
With ever-increasing concerns on our environment, there is a fast growing interest in electric vehicles (EVs) and hybrid EVs (HEVs) from automakers, governments, and customers. As electric drives are the core of both EVs and HEVs, it is a pressing need for researchers to develop advanced electric-drive systems. In this paper, an overview of permanent-magnet (PM) brushless (BL) drives for EVs and HEVs is presented, with emphasis on machine topologies, drive operations, and control strategies. Then, three major research directions of the PM BL drive systems are elaborated, namely, the magnetic-geared outer-rotor PM BL drive system, the PM BL integrated starter-generator system, and the PM BL electric variable-transmission system. © 2008 IEEE.published_or_final_versio
Transperineal endoscopic drainage of a presacral and paraspinal abscess
published_or_final_versio
Constructing power system restoration strategies
System restoration is an integral part of the overall defense system against catastrophic outages. The nature of system restoration problem involves status assessment, optimization of generation capability and load pickup. The optimization problem needs to take into numerous practical considerations and, therefore, it cannot be formulated as one single optimization problem. The other critical consideration for the development of decision support tools is its generality, i.e., the tools should be portable from a system to another with minimal customization. This presentation will provide a comprehensive methodology for construction of system restoration strategies. The strategy adopted by each power system differs, depending on the system characteristics and policies. A new method based on the concept of "generic restoration milestones" and "generic restoration actions" has been developed. A specific restoration strategy can be synthesized by a combination of the milestones and actions based on the actual system conditions. The decision support tool is expected to reduce the restoration time, thereby improving the system reliability.published_or_final_versionThe 6th International Conference on Electrical and Electroincs Engineering (ELECO 2009), Bursa, Turkey, 5-8 November 2009. In Proceedings of the International Conference on Electrical and Electronics Engineering, 2009, p. I8-I1
Cancer gene therapy targeting angiogenesis: An updated review
Since the relationship between angiogenesis and tumor growth was established by Folkman in 1971, scientists have made efforts exploring the possibilities in treating cancer by targeting angiogenesis. Inhibition of angiogenesis growth factors and administration of angiogenesis inhibitors are the basics of anti-angiogenesis therapy. Transfer of anti-angiogenesis genes has received attention recently not only because of the advancement of recombinant vectors, but also because of the localized and sustained expression of therapeutic gene product inside the tumor after gene transfer. This review provides the up-to-date information about the strategies and the vectors studied in the field of anti-angiogenesis cancer gene therapy. © 2006 The WJG Press. All rights reserved.published_or_final_versio
Conformative Filtering for Implicit Feedback Data
Implicit feedback is the simplest form of user feedback that can be used for
item recommendation. It is easy to collect and is domain independent. However,
there is a lack of negative examples. Previous work tackles this problem by
assuming that users are not interested or not as much interested in the
unconsumed items. Those assumptions are often severely violated since
non-consumption can be due to factors like unawareness or lack of resources.
Therefore, non-consumption by a user does not always mean disinterest or
irrelevance. In this paper, we propose a novel method called Conformative
Filtering (CoF) to address the issue. The motivating observation is that if
there is a large group of users who share the same taste and none of them have
consumed an item before, then it is likely that the item is not of interest to
the group. We perform multidimensional clustering on implicit feedback data
using hierarchical latent tree analysis (HLTA) to identify user `tastes' groups
and make recommendations for a user based on her memberships in the groups and
on the past behavior of the groups. Experiments on two real-world datasets from
different domains show that CoF has superior performance compared to several
common baselines
Computation of milestones for decision support during system restoration
System restoration involves status assessment, optimization of generation capability, and load pickup. The optimization problem needs to take complex constraints into consideration, and therefore, it is not practical to formulate the problem as one single optimization problem. The other critical consideration for the development of decision support tools is its generality, i.e., the tools should be portable from a system to another with minimal customization. This paper reports a practical methodology for construction of system restoration strategies. The strategy adopted by each power system differs, depending on system characteristics and policies. A new method based on the concept of generic restoration milestones (GRMs) is proposed. A specific restoration strategy can be synthesized by a combination of GRMs based on the actual system conditions. The decision support tool is expected to reduce the restoration time, thereby improving system reliability. The proposed decision support tool has been validated with cases based on a simplified Western Electricity Coordinating Council (WECC) 200-Bus system and Hawaiian Electric Company system. © 2011 IEEE.published_or_final_versio
An integrated PM magnetic-geared machine for hybrid electric vehicles
Paper no. DS1-58The free-piston generators have the advantages of simple structure, high power density and high efficiency, so they are proposed for applying in the series hybrid electric vehicles (HEV). In this paper, a novel PM linear magnetic-geared machine serving as the free-piston generator is proposed. The machine consists of a linear permanent magnet synchronous machine (PMSM) and a linear magnetic gear (LMG), which are integrated together. The proposed machine adopts a structure that the high-speed mover of the LMG and the translator of the linear PMSM share the same moving part. There are four main parts in the machine topology, including the low-speed mover with PMs, the ferromagnetic pole pieces, the high-speed mover with PMs and the stator with three-phase windings. In order to improve the speed of the PMSM translator, the magnetic-geared topology is adopted, such that the designed machine can generate the high-voltage electricity and have the high power density. In the magnetic-geared machine, the tubular stator is designed as a 12-slot structure with concentrated windings. In order to integrate the machine and the magnetic gear magnetically and mechanically together, the high-speed mover of the magnetic gear is designed as the translator of the machine. The tubular machine translator consists of one row of PMs. And the low-speed mover of the magnetic gear consists of a tubular iron core and PMs mounted on the inner face of the core. The PMs of both low-speed mover and machine translator are radial magnetized. Between the low-speed mover and the high-speed mover of the magnetic gear, the ferromagnetic pole pieces are fixed there to modulate the magnetic fields. Since the LMG has the advantage of high force density inherently, the proposed novel PM linear magnetic-geared machine can obtain the high power density, high efficiency and weight reduction by comparing with the conventional linear machines. This work is performed and verified by using the finite element analysis (FEA) method.published_or_final_versio
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