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151.
The polarization of light carries much useful information about the environment. Biological studies have shown that some animal species use polarization information for navigation and other purposes. It has been previously shown that a bioinspired polarization-difference imaging (PDI) technique can facilitate detection and feature extraction of targets in scattering media. It has also been established [J. Opt. Soc. Am. A 15, 359 (1998)] that polarization sum and polarization difference are the optimum pair of linear combinations of images taken through two orthogonally oriented linear polarizers of a scene having a uniform distribution of polarization directions. However, in many real environments the scene has a nonuniform distribution of polarization directions. Using principal component analysis of the polarization statistics of the scene, we develop a method to determine the two optimum information channels with unequal weighting coefficients that can be formed as linear combinations of the images of a scene taken through a pair of linear polarizers not constrained to the horizontal and vertical directions of the scene. We determine the optimal orientations of linear polarization filters that enhance separation of a target from the background, where the target is defined as an area with distinct polarization characteristics as compared to the background. Experimental results confirm that in most situations adaptive PDI outperforms conventional PDI with fixed channels. 相似文献
152.
Lin SS Yemelyanov KM Pugh EN Engheta N 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(9):2137-2153
In forensic science the finger marks left unintentionally by people at a crime scene are referred to as latent fingerprints. Most existing techniques to detect and lift latent fingerprints require application of a certain material directly onto the exhibit. The chemical and physical processing applied to the fingerprint potentially degrades or prevents further forensic testing on the same evidence sample. Many existing methods also have deleterious side effects. We introduce a method to detect and extract latent fingerprint images without applying any powder or chemicals on the object. Our method is based on the optical phenomena of polarization and specular reflection together with the physiology of fingerprint formation. The recovered image quality is comparable to existing methods. In some cases, such as the sticky side of tape, our method shows unique advantages. 相似文献
153.
Seyrafian S Pestehchian N Kerdegari M Yousefi HA Bastani B 《Hemodialysis international. International Symposium on Home Hemodialysis》2006,10(4):375-379
Cryptosporidium is one of the most common causes of diarrhea in the world, which can be severe and prolonged in immunocompromised patients. We compared the prevalence rate of Cryptosporidium infection in hemodialysis patients and 2 control groups (i.e., their healthy family members and normal population). Stool specimens of 104 adult outpatient chronic hemodialysis patients, their 91 healthy family members, and 140 healthy individuals were examined for the presence of Cryptosporidium oocysts by using a modified acid-fast staining method. Twelve (11.5%) dialysis patients were infected with Cryptosporidium. This was significantly higher than 4 (4.4%), and 5 (3.6%) cases in the 2 control groups, respectively (p < 0.05). There was no significant difference between the 2 control groups. The prevalence rate of Cryptosporidium infection did not correlate with patients' sex, age, duration of dialysis, history of kidney transplantation, or history of taking immunosuppressive drugs. However, it was significantly higher in diabetics vs. nondiabetics (19.4% vs. 8.3%, respectively, p < 0.05). Our results indicate that the prevalence rate of Cryptosporidium infection is considerably higher in dialysis patients than in the general population. Moreover, dialyzed diabetic patients had the highest rate of infection. As hemodialysis patients are candidates for renal transplantation, general preventive measures against acquiring Cryptosporidium infection must be considered. 相似文献
154.
Although the technology scaling has enabled designers to integrate a large number of processors onto a single chip realizing chip multi-processor (CMP), problems arising from technology scaling have made power reduction an important design issue. Since interconnection networks dissipate a significant portion of the total system power budget, it is desirable to consider interconnection network's power efficiency when designing CMP. In this paper, we present a variable frequency link for a power-aware interconnection network using the clock boosting mechanism, and apply a dynamic frequency scaling (DFS) policy, that judiciously adjusts link frequency based on link utilization parameter. Experimental result shows that history-based DFS successfully adjusts link frequency to track actual link utilization over time, demonstrating the feasibility of the proposed link as a power-aware interconnection network for system-on-chip (SoC). 相似文献
155.
Duan S. Golubovi Michiel J. van Duuren Nader Akil Antonio Arreghini Francesco Driussi 《Microelectronic Engineering》2009,86(10):1999-2004
Nitride storage non-volatile memories with hafnium silicate (HfSiOx) blocking dielectric and titanium nitride (TiN) metal gate aimed at low power embedded applications beyond the 45 nm node, have been fabricated and investigated. In addition to presenting the typical figures of merit of flash memories, the scalability of the devices has been assessed. We have also investigated the physical origin of the observed memory features. 相似文献
156.
The transformation kinetics and microstructural development of liquid phase sintered silicon carbide ceramics (LPS-SiC) are investigated. Complete densification is achieved by pressureless and gas pressure sintering in argon and nitrogen atmospheres with Y2O3 and AlN as sintering additives. Studies of the phase transformation from to -SiC reveals a dependency on the initial -content and the sintering atmosphere. The transformation rate decreases with an increasing -content in the starting powder and in presence of nitrogen. The transformation is completely supressed for pure -SiC starting powders when the additive system consists of 10.34 wt% Y2O3 and 2.95 wt% AlN. Materials without phase transformation showed a homogeneous microstructure with equiaxed grains, whereas microstructures with elongated grains were developed from SiC powders with a high initial /-ratio (>1:9) when phase transformation occurs. Since liquid phase sintered silicon carbide reveals predominantly an intergranular fracture mode, the grain size and shape has a significant influence on the mechanical properties. The toughness of materials with platelet-like grains is about twice as high as for materials with equiaxed grains. Materials exhibiting elongated microstructures show also a higher bending strength after post-HIPing. 相似文献
157.
Radha Guha Author Vitae Nader Bagherzadeh Author Vitae Author Vitae 《Computers & Electrical Engineering》2009,35(2):258-285
There are many design challenges in the hardware-software co-design approach for performance improvement of data-intensive streaming applications with a general-purpose microprocessor and a hardware accelerator. These design challenges are mainly to prevent hardware area fragmentation to increase resource utilization, to reduce hardware reconfiguration cost and to partition and schedule the tasks between the microprocessor and the hardware accelerator efficiently for performance improvement and power savings of the applications.In this paper a modular and block based hardware configuration architecture named memory-aware run-time reconfigurable embedded system (MARTRES) is proposed for efficient resource management and performance improvement of streaming applications. Subsequently we design a task placement algorithm named hierarchical best fit ascending (HBFA) algorithm to prove that MARTRES configuration architecture is very efficient in increased resource utilization and flexible in task mapping and power savings. The time complexity of HBFA algorithm is reduced to O(n) compared to traditional Best Fit (BF) algorithm’s time complexity of O(n2), when the quality of the placement solution by HBFA is better than that of BF algorithm. Finally we design an efficient task partitioning and scheduling algorithm named balanced partitioned and placement-aware partitioning and scheduling algorithm (BPASA). In BPASA we exploit the temporal parallelism in streaming applications to reduce reconfiguration cost of the hardware, while keeping in mind the required throughput of the output data. We balance the exploitation of spatial parallelism and temporal parallelism in streaming applications by considering the reconfiguration cost vs. the data transfer cost. The scheduler refers to the HBFA placement algorithm to check whether contiguous area on FPGA is available before scheduling the task for HW or for SW. 相似文献
158.
Wireless sensor networks (WSN) are used for many applications such as environmental monitoring, infrastructure security, healthcare
applications, and traffic control. The design and development of such applications must address many challenges dictated by
WSN characteristics on one hand and the targeted applications on the other. One of the emerging approaches used for relaxing
these challenges is using service-oriented middleware (SOM). Service-oriented computing, in general, aims to make services
available and easily accessible through standardized models and protocols without having to worry about the underlying infrastructures,
development models, or implementation details. SOM could play an important role in facilitating the design, development, and
implementation of service-oriented systems. This will help achieve interoperability, loose coupling, and heterogeneity support.
Furthermore, SOM approaches will provision non-functional requirements like scalability, reliability, flexibility, and Quality
of Service (QoS) assurance. This paper surveys the current work in SOM and the trends and challenges to be addressed when
designing and developing these solutions for WSN. 相似文献
159.
Ahmadian M Yousefi N Van Ginkel SW Zare MR Rahimi S Fatehizadeh A 《Water science and technology》2012,66(4):754-760
In this study, treatment of slaughterhouse wastewater by electrocoagulation was investigated in batch system using Fe electrodes. The effect of various variables such as electrode number, current density and operating time was tested. Pollutant removal efficiency increased with increasing electrode number and operating time. The biochemical oxygen demand (BOD(5))(,) chemical oxygen demand (COD), total suspended solid (TSS), and total nitrogen (TN) removal efficiencies using eight electrodes at a contact time of 50 min and a current density of 10 A/m(2) were 66, 62, 60, and 56%, respectively. Higher electrode numbers will allow shorter operating times to achieve certain removal efficiencies. Also, removal efficiencies increased by increasing the current density; the highest removal efficiencies of BOD(5,) COD, TSS, and TN at a contact time of 50 min and a current density of 25 A/m(2) were 97, 93, 81, and 84%, respectively. The results also show that the reactor pH varies directly with the current density; at 25 A/m(2), the reactor pH increased from an initial value of 7.1 to 7.7 after 50 min. The experimental results showed that the kinetics of BOD(5), COD, TSS and TN removal could be fitted adequately using a first order kinetic model (higher R(2)). 相似文献
160.
Acute Cycling Exercise Induces Changes in Red Blood Cell Deformability and Membrane Lipid Remodeling
Travis Nemkov Sarah C. Skinner Elie Nader Davide Stefanoni Mlanie Robert Francesca Cendali Emeric Stauffer Agnes Cibiel Camille Boisson Philippe Connes Angelo DAlessandro 《International journal of molecular sciences》2021,22(2)
Here we describe the effects of a controlled, 30 min, high-intensity cycling test on blood rheology and the metabolic profiles of red blood cells (RBCs) and plasma from well-trained males. RBCs demonstrated decreased deformability and trended toward increased generation of microparticles after the test. Meanwhile, metabolomics and lipidomics highlighted oxidative stress and activation of membrane lipid remodeling mechanisms in order to cope with altered properties of circulation resulting from physical exertion during the cycling test. Of note, intermediates from coenzyme A (CoA) synthesis for conjugation to fatty acyl chains, in parallel with reversible conversion of carnitine and acylcarnitines, emerged as metabolites that significantly correlate with RBC deformability and the generation of microparticles during exercise. Taken together, we propose that RBC membrane remodeling and repair plays an active role in the physiologic response to exercise by altering RBC properties. 相似文献