Constraint-based stereo matching

The major difficulty in stereo vision is the correspondence problem that requires matching features in two stereo images. Researchers describe a constraint-based stereo matching technique using local geometric constraints among edge segments to limit the search space and to resolve matching ambiguity. Edge segments are used as image features for stereo matching. Epipolar constraint and individual edge properties are used to determine possible initial matches between edge segments in a stereo image pair. Local edge geometric attributes such as continuity, junction structure, and edge neighborhood relations are used as constraints to guide the stereo matching process. The result is a locally consistent set of edge segment correspondences between stereo images. These locally consistent matches are used to generate higher-level hypotheses on extended edge segments and junctions to form more global contexts to achieve global consistency

FUEL CONCENTRATION AND OPERATING TEMPERATURE EFFECTS ON CRITICAL AMOUNTS OF CATALYSTS ADDED TO THE FUEL CHANNELS OF DIRECT METHANOL FUEL CELL

[[abstract]]This study modifies the geometry of fuel channel corners in order to reduce the hydroresistance of the fuel within the channels, and investigates fuel concentration and operating temperature effects on the loading weight percentages of catalysts added to the fuel channels. The intent of the study is to further improve the output efficiency of DMFCs (direct methanol fuel cells). In this study, different proportions of catalysts, including active carbon and selenium (Se), were coated onto anode and cathode channels composed of PDMS (polydimethylsiloxane) to promote a fuel decomposition reaction in the fuel channels. The output of the DMFCs was measured under different operational temperatures and different supply fuel concentrations in order to find suitable catalyst loading values under different operational conditions. The experimental results indicate that under identical operating conditions, the performances of DMFCs can be greatly boosted using rounded channel turns rather than right angle turns. Furthermore, the results indicate that critical catalyst loading values exist for each catalyst under different operating temperatures. Suitable coating weight percentages for each catalyst are recommended for different operating temperatures. It was found that under lower operating temperatures and lower fuel supply concentrations, the effect of adding catalysts to fuel channels on the performance enhancement of DMFC is more apparent than for cases with higher operating temperatures and fuel supply concentrations. We also found that the fuel concentration effect on the performance of DMFCs was not apparent for a range of fuel concentrations investigated under the same operating temperature. In other words, while the fuel cells are under operation, even the supplied fuel concentrations vary, although not beyond operational concentration limitations. The effects of concentration variations on the performance of DMFCs with catalysts added to the channels can therefore be neglected.[[notice]]補正完

PERFORMANCE ANALYSIS OF DIRECT METHANOL FUEL CELLS BY COATING DIFFERENT PROPORTIONS OF CATALYSTS ONTO FUEL CHANNELS

[[abstract]]In this study, different proportions of catalysts, including Platinum (Pt), active carbon and Selenium (Se), were coated onto anode and cathode channels composed of PDMS (polydimethylsiloxane) to promote the fuel decomposition reaction in the fuel channels and to further enhance the output of the DMFCs under various operating temperatures. The experimental results indicated that under identical operating conditions, the performances of DMFCs with catalysts coated onto their channels are always superior to that of DMFCs without an added catalyst. The results indicate that a critical catalyst loading value exists for every catalyst. When the amount of catalyst added is less than this critical value, the output of the DMFCs can be greatly enhanced by increasing the proportion of the catalyst added to the fuel channels. However, when the amount of catalyst added exceeds the critical value, efficiency enhancements are no longer apparent. Suitable coating weight percentage for every catalyst was recommended. The corresponding recommendation values for catalysts of Pt, active carbon and Se are 0.06%, 0.29% and 0.29%, respectively, under the investigated operating conditions. The maximum power density increment of 182.3% can be attained in the case with 0.29% Se catalyst loading at an operating temperature of 30 degrees C.[[notice]]補正完

Reweighting for Nonequilibrium Markov Processes Using Sequential Importance Sampling Methods

We present a generic reweighting method for nonequilibrium Markov processes. With nonequilibrium Monte Carlo simulations at a single temperature, one calculates the time evolution of physical quantities at different temperatures, which greatly saves the computational time. Using the dynamical finite-size scaling analysis for the nonequilibrium relaxation, one can study the dynamical properties of phase transitions together with the equilibrium ones. We demonstrate the procedure for the Ising model with the Metropolis algorithm, but the present formalism is general and can be applied to a variety of systems as well as with different Monte Carlo update schemes.Comment: accepted for publication in Phys. Rev. E (Rapid Communications

Complete response of skull base inverted papilloma to chemotherapy: Case report.

BackgroundInverted papilloma (IP) is the most common benign sinonasal neoplasm. Endoscopic techniques, improved understanding of pathophysiology, and novel surgical approaches have allowed rhinologists to treat IPs more effectively, with surgery being the mainstay of therapy. Frontal sinus IP poses a challenge for surgical therapy due to complex anatomy and potentially difficult surgical access.ObjectivesWe reported a unique case of a massive frontal sinus IP that presented with intracranial and orbital extension, with near resolution after chemotherapy.MethodsA retrospective case review of a patient with a frontal sinus IP treated at a tertiary academic medical center.ResultsA 75-year-old male patient presented with nasal obstruction, purulent nasal discharge, and a growing left supraorbital mass. Endoscopy demonstrated a mass that filled both frontal and ethmoid sinuses, with orbital invasion. There also was substantial erosion of the posterior table, which measured 1.73 × 1.40 cm. A biopsy specimen demonstrated IP with carcinoma in situ. The patient was deemed unresectable on initial evaluation and, subsequently, underwent chemotherapy (carboplatin and paclitaxel). The tumor had a dramatic response to chemotherapy, and the patient elected for definitive surgery to remove any residual disease. During surgery, only a small focus of IP was found along the superior wall of the frontal sinus. No tumor was found elsewhere, including at the site of skull base erosion. The final pathology was IP without carcinoma in situ or dysplasia.ConclusionThis was the first reported case of chemotherapeutic "debulking" of IP, which facilitated surgical resection, despite substantial intracranial and orbital involvement. Although nearly all IPs can be treated surgically, rare cases, such as unresectable tumors, may benefit from systemic chemotherapy