In this paper,volume models are obtained from closed surface models by an accurate voxelization method which can handle the hidden cavities. This kind of 3D binary images is then converted to gray-level images by a fa...
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In this paper,volume models are obtained from closed surface models by an accurate voxelization method which can handle the hidden cavities. This kind of 3D binary images is then converted to gray-level images by a fast Euclidean distance transform (EDT).Moment invariants (MIs) which are invariant shape descriptors under similarity transformations,are then computed based on the gray images. Applications in shape analysis area such as principal axis determination,skeleton and medial axis extraction,and shape retrieval can be carried out base on EDT and MIs.
2-D projective moment invariants were firstly proposed by Suk and Flusser in [12]. We point out here that there is a useless projective moment invariant which is equivalent to zero in their paper. 3-D projective momen...
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2-D projective moment invariants were firstly proposed by Suk and Flusser in [12]. We point out here that there is a useless projective moment invariant which is equivalent to zero in their paper. 3-D projective moment invariants are generated theoretically by investigating the property of signed volume of a tetrahedron. The main part is the selection of permutation invariant cores for multiple integrals to generate independent and nonzero 3-D projective moment invariants. We give the conclusion that projective moment invariants don't exist strictly speaking because of their convergence problem.
作者:
Prof. Jian-Xin XuProf. Leonid FridmanDepartment of Electrical and Computer Eng. National University of Singapore 4 Engineering Drive 3 Singapore 117576 Tel +65 6874-2566
Fax +65 6779-1103 Dr Jian-Xin Xu received his Bachelor degree from Zhejiang University
China in 1982. He attended the University of Tokyo Japan where he received his Master's and Ph.D. degrees in 1986 and 1989 respectively. All his degrees are in Electrical Engineering. He worked for one year in the Hitachi research Laboratory Japan and for more than one year in Ohio State University U.S.A. as a Visiting Scholar. In 1991 he joined the National University of Singapore and is currently an associate professor in the Department of Electrical Engineering. His research interests lie in the fields of learning control variable structure control fuzzy logic control discontinuous signal processing and applications to motion control and process control problems. He is the associate editor of Asian Journal of Control member of TC on variable structure systems and sliding mode control of IEEE Control Systems Society and a senior member of IEEE. He has produced more than 90 peer-refereed journal papers near 160 technical papers in conference proceedings and authored/edited 4 books. Division de Estudios de Posgrado Facultad de Ingenieria National Autonomous University of Mexico DEP-FI
UNAM Edificio “A” Circuito Exterior Ciudad Universitaria A. P. 70–256 C.P.04510 Mexico D.F. Mexico Tel +52 55 56223014 Fax +52 55 56161719 Dr. Leonid M. Fridman received his M.S in mathematics from Kuibyshev (Samara) State University
Russia Ph.D. in Applied Mathematics from Institute of Control Science (Moscow) and Dr. of Science degrees in Control Science from Moscow State University of Mathematics and Electronics in 1976 1988 and 1998 respectively. In 1976–1999 Dr. Fridman was with the Department of Mathematics at the Samara State Architecture and Civil Engineering Academy Samara Russia. In 2000–2002 he was with the Department of Postgraduate Study and Investigations at the Chihuahu
Classical unequal erasure protection schemes split data to be protected into classes which are encoded independently. The unequal protection scheme presented in this paper is based on an erasure code which encodes all...
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Classical unequal erasure protection schemes split data to be protected into classes which are encoded independently. The unequal protection scheme presented in this paper is based on an erasure code which encodes all the data together according to the existing dependencies. A simple algorithm generates dynamically the generator matrix of the erasure code according to the packets streams structure, i.e., the dependencies between the packets, and the rate of the code. This proposed erasure code was applied to a packetized MPEG4 stream transmitted over a packet erasure channel and compared with other classical protection schemes in terms of PSNR and MOS. It is shown that the proposed code allows keeping a high video quality-level in a larger packet loss rate range than the other protection schemes.
In a cluster or a database server system, the performance of some data intensive applications will be degraded much because of the limited local memory and large amount of interactions with slow disk. In high speed ne...
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In a cluster or a database server system, the performance of some data intensive applications will be degraded much because of the limited local memory and large amount of interactions with slow disk. In high speed network, utilizing remote memory of other nodes or customized memory server to be as second level buffer can decrease access numbers to disks and benefit application performance. With second level buffer mode, this paper made some improvements for a recently proposed buffer cache replacement algorithm-LIRS, and brings forward an adaptive algorithm-LIRS-A. LIRS-A can adaptively adjust itself according to application characteristic, thus the problem of not suiting for time locality of LIRS is avoided. In TPC-H benchmarks, LIRS-A could improve hit rate over LIRS by 7.2% at most. In a Groupby query with network stream analyzing database, LIRS-A could improve hit rate over LIRS by 31.2% at most. When compared with other algorithms, LIRS-A also show similar or better performance.
Mobility, usability and security are major requirements for any Ad Hoc network systems, and there have been numerous papers in regards to them. However, often these requirements are addressed separately. For a valid s...
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ISBN:
(纸本)1595933069
Mobility, usability and security are major requirements for any Ad Hoc network systems, and there have been numerous papers in regards to them. However, often these requirements are addressed separately. For a valid solution, these requirements must be considered from an integrated view. In this paper, taking into account mobility and usability, we implement a framework which allows to securely share resources and services between devices in Ad-hoc networks, based on security policies defined by the owners of those devices. In addition, we extend our framework to support inter-domain sharing of services and resources. We detail our design, present the preliminary results of our prototype, and discuss the lessons learned, in particular how user experience led to several re-designs of the initial security solution. Copyright 2006 ACM.
Current and future NASA robotic missions to planetary surfaces are tending toward longer duration and are becoming more ambitious for rough terrain access. For a higher level of autonomy in such missions, the rovers w...
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Current and future NASA robotic missions to planetary surfaces are tending toward longer duration and are becoming more ambitious for rough terrain access. For a higher level of autonomy in such missions, the rovers will require behavior that must also adapt to declining health and unknown environmental conditions. The MER (Mars Exploration Rovers) called Spirit and Opportunity have both passed 600 days of life on the Martian surface, with extensions to 1000 days and beyond depending on rover health. Changes in navigational planning due to degradation of the drive motors as they reach their lifetime are currently done on Earth for the Spirit rover. The upcoming 2009 MSL (Mars Science laboratory) and 2013 AFL (Astrobiology Field laboratory) missions are planned to last 300-500 days, and will possibly involve traverses on the order of multiple kilometers over challenging terrain. This paper presents a unified coherent framework called SMART (System for Mobility and Access to Rough Terrain) that uses game theoretical algorithms running onboard a planetary surface rover to safeguard rover health during rough terrain access. SMART treats rover motion, task planning, and resource management as a Two Person Zero Sum Game (TPZSG), where the rover is one player opposed by the other player called "nature" representing uncertainty in sensing and prediction of the internal and external environments. We also present preliminary results of some field studies.
This paper describes a simple system that can be used for autonomous demand-side management in a load site such as a home or commercial facility. The system identifies the operation of individual loads using transient...
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During recent years, microprocessor energy consumption has been surging and efforts to reduce power and energy have received a lot of attention. At the same time, virtual execution environments (VEEs), such as Java vi...
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ISBN:
(纸本)9781595933324
During recent years, microprocessor energy consumption has been surging and efforts to reduce power and energy have received a lot of attention. At the same time, virtual execution environments (VEEs), such as Java virtual machines, have grown in popularity. Hence, it is important to evaluate the impact of virtual execution environments on microprocessor energy consumption. This paper characterizes the energy and power impact of two important components of VEEs, Just-in-time (JIT) optimization and garbage collection. We find that by reducing instruction counts, JIT optimization significantly reduces energy consumption, while garbage collection incurs runtime overhead that consumes more energy. Importantly, both JIT optimization and garbage collection decrease the average power dissipated by a program. Detailed analysis reveals that both JIT optimizer and JIT optimized code dissipate less power than un-optimized code. On the other hand, being memory bound and with low ILP, the garbage collector dissipates less power than the application code, but rarely affects the average power of the latter. Adaptive microarchitectures are another recent trend for energy reduction where microarchitectural resources can be dynamically tuned to match program runtime requirements. This research reveals that both JIT optimization and garbage collection alter a program's behavior and runtime requirements, which considerably affects the adaptation of configurable hardware units, and influences the overall energy consumption. This work also demonstrates that the adaptation preferences of the two VEE services differ substantially from those of the application code. Both VEE services prefer a simple core for high energy reduction. On the other hand, the JIT optimizer usually requires larger data caches, while the garbage collector rarely benefits from large data caches. The insights gained in this paper point to novel techniques that can further reduce microprocessor energy consumption. Cop
Memory bandwidth limitation is one of the major impediments to high-performance microprocessors. This paper investigates a class of store misses that can be eliminated to reduce data traffic. Those store misses fetch ...
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Memory bandwidth limitation is one of the major impediments to high-performance microprocessors. This paper investigates a class of store misses that can be eliminated to reduce data traffic. Those store misses fetch cache blocks whose original data is never used. If fully overwritten by subsequent stores, those blocks can be installed directly in the cache without accessing lower levels of the memory hierarchy, eliminating the corresponding data traffic. Our results indicate that for a 1 MB data cache, 28% of cache misses are avoidable across SPEC CPU INT 2000 benchmarks. We propose a simple hardware mechanism, the store fill buffer (SFB), which directly installs blocks for store misses, and substantially reduces the data traffic. A 16-entry SFB eliminates 16% of overall misses to a 64 KB data cache, resulting in 6% speedup. This mechanism enables other bandwidth-hungry techniques to further improve system performance
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