100 research outputs found
Improved Pattern Matching Algorithm
No full textPattern matching problem aims to search the most similar pattern or object by matching to an instance of that pattern in a scene image. In order to address the issue of finding an object in the target image efficiently, the most distinctive features are computed from the query pattern and need to be searched in the scene image. The scene image is logically divided into a number of candidate windows which are then to be matched with the query pattern. Due to repeated matching of the query pattern with local candidate windows, the pattern matching process requires a large amount of space in memory as well as it needs to be executed fast. Thus, pattern matching algorithms need to be memory efficient and as fast as possible. This paper makes an attempt to deal with these issues by presenting two effective pattern matching algorithms, namely, strip subtraction and strip division. The efficacy of the proposed pattern matching algorithms is tested on two databases, viz. a local database and MIT-CSAIL database containing random objects. The experimental results are proved to be computationally efficient ones while the proposed algorithms are compared with some existing algorithms possessing a uniform experimental setup
HPV guided object tracking: Theoretical advances on fast pattern matching technique
No full textSummaryPattern matching is a fundamental machine vision problem that deals with searching an object in a comparatively large scene. It can use to solve many vision problems ranging from typical human detection to searching defective parts in industrial automation. This paper reports a fast pattern matching technique which makes use of cumulative subtraction and cumulative division operations based on Image Integral model. The idea is to use both the cumulative subtraction and division operations to evaluate the image values on a very small rectangular region of the image scene as well as on the input pattern to be searched for. Image values are transformed to Haar Projection Values (HPVs) using Haar transform in order to achieve pattern matching on sliding window of the image scene. Computation of HPV needs seven arithmetic operations, including two addition and five subtraction operations, which are found to be same as that of Image Integral technique. Besides, the proposed pattern matching technique is identified as computationally effective in terms of both time and memory
Searching a pattern in token scene image via multi-variant symmetric pattern matching technique
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Early egg traits in Cancer setosus (Decapoda, Brachyura): effects of temperature and female size
No full textPrevious study on Cancer setosus (Molina, 1782) had shown that latitudinal changes in temperature control the number of annual egg masses. This study focused on the effects of pre-oviposition temperature and female size on egg-traits in C. setosus from Northern (Antofagasta 23ºS) and Central-Southern (Puerto Montt 41ºS) Chile. Blastula eggs produced in nature ranged in dry mass (DM) from 9.1 to 15.1 µg, in carbon (C) from 4.8 to 8.4 µg, in nitrogen (N) from 1.0 to 1.6 µg, in C:N ratio between 4.7 and 5.4, and in volume (V) between 152 and 276 mm3 x 10-4 per female. Blastula eggs from females caught early in the reproductive season in Puerto Montt (09/2006) were significantly higher in DM, C, N, and V than those of females caught two months later (11/2006), reflecting a seasonal increase in water temperature. In Puerto Montt “early” and “late” season blastula eggs were about 32% and 20% higher in DM, C, N, and V as eggs from Antofagasta, respectively. Subsequent egg masses produced in captivity in Puerto Montt followed this pattern of smaller eggs with lower DM, C, and N content at higher pre-oviposition temperatures. In Antofagasta no significant difference in DM, C, N and V between eggs produced in nature and subsequent eggs produced in captivity was found and all egg traits were significantly positively affected by maternal size. Reproductive plasticity in C. setosus helps explaining the species wide latitudinal distribution range
Photon-bunching in ground-based submillimeter-wave astronomy
No full textDESHIMA (the Deep Spectroscopic High-Redshift Mapper) is a 347 channel superconducting spectrometer with spectral resolution R =500 that operates in the range of 220GHz to 440GHz and can therefore accurately measure the frequency of spectral lines in order to calculate redshift z.This report investigates the sensitivity of DESHIMA-like spectrometers by investigating photon noise due to Poisson and bunching effects. It gives a broad overview of photon statistics and explains, through an analogous model, that photon bunching occurs due to an underlying change in the probabilistics, rather than the act of detecting itself. After that I investigate photon and quasiparticle recombination noise for a DESHIMA-like spectrometer with Lorentzian filters and find a closed form equation for NEP per channel for a constant power spectral density arriving at the filters.Previously the bandwidth of the filters was assumed to be negligible, resulting in an overestimation of the bunching. Because the photons that are impinging on the detector span a bigger bandwidth, the bunching is a factor of π/2 smaller than previously approximated.This NEPτ is defined at an integration time of τ=0.5s. For other integration times this is scalable, however this will only hold while the integration time is much bigger than the coherence time τ≫tcoh. Because of the correlation between photons arriving shorter than a coherence time apart, the scaling of the NEPτ drops in cases when τ≫̸tcoh.Finally I propose and describe modifications to the sensitivity model DESHIMA uses. The following features have been be improved and added:- Integrate over the entire power spectrum when calculating photon noise- Use arbritatry filter designs loaded from a file- Improve estimations of the quantities that express sensitivityI compare the proposed modifications to the old model, which has previously been compared with measurement results, and use it to validate the changes. Other than the previously mentioned factor of π/2 for the bunching term and the smoothing out in local extrema, the modified simulation results are similar to the old model. This is because the Lorentzian filters have a small bandwidth ν≫Δν, such that the previous narrowband approximation held for most non-extreme cases.https://joristiebosch.github.io/thesis/ Interactive version available https://github.com/deshima-dev/deshima-sensitivity Python model described in ThesisDESHIMAApplied Physic
RETRACTED: Nuclear Translocation of LIM Kinase Mediates Rho-Rho Kinase Regulation of Cyclin D1 Expression
No full textAbstractThis article has been retracted at the request of the authors.Reason: We have recently reviewed the primary source data for our paper entitled “Nuclear Translocation of LIM Kinase Mediates Rho-Rho Kinase Regulation of Cyclin D1 Expression” [Dev. Cell, 5: 273–284 (2003)]. We have found that portions of the figures assembled by the lead author are not fully supported by the primary data. We are therefore retracting this paper. We express our deep regret to the scientific community
Scalable Network I/O in Linux
No full textRecent highly publicized benchmarks have suggested that Linux systems do not scale as well as other systems, such as Windows NT, when used as network servers. Windows NT contains features such as I/O completion ports that help boost network server performance and scalability. In this paper we focus on improving the Linux implementation of poll() to reduce the expense of managing large numbers of network connections. We also explore the newer POSIX RT signal API that will help network servers scale into the next decade. A comparison between the two interfaces shows that a server using our /dev/poll interface scales better than a server using RT signals.http://deepblue.lib.umich.edu/bitstream/2027.42/107905/1/citi-tr-00-4.pd
Functional diversification of Argonautes in nematodes:an expanding universe
No full textIn the last decade, many diverse RNAi (RNA interference) pathways have been discovered that mediate gene silencing at epigenetic, transcriptional and post-transcriptional levels. The diversity of RNAi pathways is inherently linked to the evolution of Ago (Argonaute) proteins, the central protein component of RISCs (RNA-induced silencing complexes). An increasing number of diverse Agos have been identified in different species. The functions of most of these proteins are not yet known, but they are generally assumed to play roles in development, genome stability and/or protection against viruses. Recent research in the nematode Caenorhabditis elegans has expanded the breadth of RNAi functions to include transgenerational epigenetic memory and, possibly, environmental sensing. These functions are inherently linked to the production of secondary siRNAs (small interfering RNAs) that bind to members of a clade of WAGOs (worm-specific Agos). In the present article, we review briefly what is known about the evolution and function of Ago proteins in eukaryotes, including the expansion of WAGOs in nematodes. We postulate that the rapid evolution of WAGOs enables the exceptional functional plasticity of nematodes, including their capacity for parasitism
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