Contour Extraction of Flame for Fire Detection

2011 ◽  
Vol 383-390 ◽  
pp. 1106-1110
Author(s):  
Yun Yang Yan ◽  
Shang Bing Gao ◽  
Hong Yan Wang ◽  
Zhi Bo Guo

Fire detection based on sequences of images is more suitable for the need in big room or badly environment. Color and contour are both the important features of a flame image. The method to extract the contour feature of a flame image is developed based on threshold of flame area. The edges of the burning flames jitter continuously, but their contour are similar each other. The method to detect flames in video sequences is proposed here based on flame’s dynamic contour. Many experiments show that the system is able to work well and get high detection rate with a low false positive rate.

2011 ◽  
Vol 78 (3) ◽  
pp. 717-725 ◽  
Author(s):  
Erik S. Wright ◽  
L. Safak Yilmaz ◽  
Daniel R. Noguera

ABSTRACTDECIPHER is a new method for finding 16S rRNA chimeric sequences by the use of a search-based approach. The method is based upon detecting short fragments that are uncommon in the phylogenetic group where a query sequence is classified but frequently found in another phylogenetic group. The algorithm was calibrated for full sequences (fs_DECIPHER) and short sequences (ss_DECIPHER) and benchmarked against WigeoN (Pintail), ChimeraSlayer, and Uchime using artificially generated chimeras. Overall, ss_DECIPHER and Uchime provided the highest chimera detection for sequences 100 to 600 nucleotides long (79% and 81%, respectively), but Uchime's performance deteriorated for longer sequences, while ss_DECIPHER maintained a high detection rate (89%). Both methods had low false-positive rates (1.3% and 1.6%). The more conservative fs_DECIPHER, benchmarked only for sequences longer than 600 nucleotides, had an overall detection rate lower than that of ss_DECIPHER (75%) but higher than those of the other programs. In addition, fs_DECIPHER had the lowest false-positive rate among all the benchmarked programs (<0.20%). DECIPHER was outperformed only by ChimeraSlayer and Uchime when chimeras were formed from closely related parents (less than 10% divergence). Given the differences in the programs, it was possible to detect over 89% of all chimeras with just the combination of ss_DECIPHER and Uchime. Using fs_DECIPHER, we detected between 1% and 2% additional chimeras in the RDP, SILVA, and Greengenes databases from which chimeras had already been removed with Pintail or Bellerophon. DECIPHER was implemented in the R programming language and is directly accessible through a webpage or by downloading the program as an R package (http://DECIPHER.cee.wisc.edu).


Author(s):  
Narendra Malhotra ◽  
Jai Prakash Rao

ABSTRACT Ultrasound screening has advantages over maternal serum screening. These include confirmation of embryo viability, accurate assessment of gestational age, early diagnosis of multiple pregnancies and identification of chorionicity, the detection of major structural abnormalities, major defects of the heart and great arteries, skeletal dysplasias and genetic syndrome and measurement of NT thickness in assessing the risk for Down's syndrome. Nuchal translucency (NT) has emerged as the most sensitive ultrasound marker for detection of chromosomal anomalies in the first trimester. However, the use of ultrasound in routine screening still faces problems with reliability and quality control. Combination of maternal age, NT and first and biochemical second-trimester markers is known as the integrated test. A major goal of screening tests is to achieve high detection rate and low false-positive rate at a low cost. The integrated test best meets these criteria. It could achieve a detection rate of 85% for a false-positive rate of 1.2%. It has a much better positive predictive value and, therefore, fewer amniocentesis and fewer losses of normal fetuses. Only screen-positive cases could be taken for invasive testing.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Guangyong Gao ◽  
Zhao Feng ◽  
Tingting Han

Data authentication is an important part of wireless sensor networks (WSNs). Aiming at the problems of high false positive rate and poor robustness in group verification of existing reversible watermarking schemes in WSNs, this paper proposes a scheme using reversible watermarking technology to achieve data integrity authentication with high detection efficiency (DAHDE). The core of DAHDE is dynamic grouping and double verification algorithm. Under the condition of satisfying the requirement of the group length, the synchronization point is used for dynamic grouping, and the double verification ensures that the grouping will not be confused. According to the closely related characteristics of adjacent data in WSNs, a new data item prediction method is designed based on the prediction-error expansion formula, and a flag check bit is added to the data with embedded watermarking during data transmission to ensure the stability of grouping, by which the fake synchronization point can be accurately identified. Moreover, the embedded data can be recovered accurately through the reversible algorithm of digital watermarking. Analysis and experimental results show that compared with the previously known schemes, the proposed scheme can avoid false positive rate, reduce computation cost, and own stronger grouping robustness.


2021 ◽  
Author(s):  
Xiang Shen ◽  
Ying Chen ◽  
Chaowen Li ◽  
Fucheng Yang ◽  
Zhanbo Wen ◽  
...  

Abstract In terms of radiation biological dose estimation, the cytokinesis block micronucleus (CBMN) assay is the internationally recognized dose estimation method. Due to the subjectivity and the time-consuming of manual detection, it cannot meet the needs of rapid standard assay of CBMN. Therefore, in this research work, we combined the convolutional neural network to design a software that can be used for rapid standard automatic detection of micronuclei in Giemsa stained binucleated lymphocytes image. The software analysis workflow is divided into four stages: cell acquisition, adhesive cell masses segmentation, cell type identification, micronucleus counting. After verification, our algorithm can quickly and effectively detect binucleated cells and micronucleus even when the cytoplasm is blurred, multiple micronucleus are attached to each other, or micronucleus is attached to the nucleus. In the test of a large number of random images, the software reached 99.4% of the manual detection in terms of the detection rate of binucleated cell, and the false positive rate of binucleated cell was 14.7%. In terms of micronucleus detection rate, the software reached 115.1% of manual detection, and its false positive rate was 26.2%. The analysis time of each picture is about 0.3s, an order of magnitude faster than conventional method.


Algorithms ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 368
Author(s):  
Yajing Zhang ◽  
Kai Wang ◽  
Jinghui Zhang

Considering the contradiction between limited node resources and high detection costs in mobile multimedia networks, an adaptive and lightweight abnormal node detection algorithm based on artificial immunity and game theory is proposed in order to balance the trade-off between network security and detection overhead. The algorithm can adapt to the highly dynamic mobile multimedia networking environment with a large number of heterogeneous nodes and multi-source big data. Specifically, the heterogeneous problem of nodes is solved based on the non-specificity of an immune algorithm. A niche strategy is used to identify dangerous areas, and antibody division generates an antibody library that can be updated online, so as to realize the dynamic detection of the abnormal behavior of nodes. Moreover, the priority of node recovery for abnormal nodes is decided through a game between nodes without causing excessive resource consumption for security detection. The results of comparative experiments show that the proposed algorithm has a relatively high detection rate and a low false-positive rate, can effectively reduce consumption time, and has good level of adaptability under the condition of dynamic nodes.


2020 ◽  
Vol 48 (6) ◽  
pp. 030006052091182
Author(s):  
Huixian Li ◽  
Shuang Qin ◽  
Fanfan Xiao ◽  
Yuhong Li ◽  
Yunhe Gao ◽  
...  

Objective This study was performed to evaluate the capability of routine clinical indicators to predict the early outcome of embryos with cardiac activity in women with recurrent spontaneous abortion (RSA). Methods A retrospective cohort study of pregnant women with a history of RSA in a Chinese tertiary hospital was performed using unadjusted and multivariable logistic regression. Results Of 789 pregnant women with RSA, 625 (79.21%) had ongoing pregnancy, whereas 164 (20.79%) developed abortion before 20 full weeks of gestational age even after embryonic heart motion was detected. The final model had an area under the curve of 0.81 (95% confidence interval, 0.78–0.84) with a sensitivity of 74.39%, a specificity of 76.00%, and a false-positive rate of 52.32% at a fixed detection rate of 90%. Conclusions The combination of multiple routine clinical indicators was valuable in predicting the early outcome of embryos with cardiac activity in viable pregnancies with RSA. However, this model might result in a high false-positive rate with a fixed detection rate of 90%; other markers must be investigated to identify first-trimester RSA once positive embryonic heart motion is established.


1983 ◽  
Vol 37 (2) ◽  
pp. 221-227 ◽  
Author(s):  
M. J. Ducker ◽  
Rosemary A. Haggett ◽  
W. J. Fisher ◽  
Glenys A. Bloomfield ◽  
S. V. Morant

ABSTRACTOne hundred Friesian heifers were tail-painted between 14 and 21 days after calving. Once a week the paint strip was renewed if any paint had been removed. Over the whole period of observation the ovulation detection rate by definite signs of oestrus was high (0·79), whilst the proportion of silent ovulations detected by tail paint removal was low (0·10). In addition, tail paint was not removed on 0·28 of the occasions when definite oestrus with ovulation occurred and on 0·26 of the occasions when all the paint was removed it was not associated with any reproductive event. In practice, the critical time for tail paint to be effective is during the service period. Again, tail paint identified fewer (P < 0·001) ovulations than definite signs of oestrus (0·66) and had a significantly higher false positive rate (P < 0·001). Month of calving did not affect these results but the accuracy of tail paint declined as the season progressed (P < 0·001). False positive indications were not associated with individual animal characteristics. In a second trial 43 cows were tail-painted and 43 were not. There was no significant difference in the mean number of days from calving to first insemination or successful pregnancy between the two groups. It is concluded that in these trials tail paint was not an effective or reliable aid or alternative to oestrus detection.


1993 ◽  
Vol 163 (6) ◽  
pp. 809-812 ◽  
Author(s):  
Michael Philpot ◽  
Alistair Burns

‘The medial temporal lobe of the brain is important for normal cognitive function, notably for memory, and is the region with the most extensive pathological change in Alzheimer's disease (AD). We wanted to find out if atrophy of the medial temporal lobe could be detected in life in patients in whom a diagnosis of AD was subsequently established histopathologically. The minimum width of the medial temporal lobe, measured by temporal-lobe-oriented computed tomography (CT) about one year before death, in 44 patients with a histopathological diagnosis of AD (cases) was nearly half (0.56 of the median) that in 75 controls of the same age with no clinical evidence of dementia (95% confidence interval 0.51–0.61). There was little overlap between the distributions of measurements in cases and controls. A cut-off (< 0.79 MoM) selected to yield a 5% false-positive rate gave an expected detection rate of 92%. A cut-off selected to yield a false-positive rate of 1 % (< 0.70 MoM) yielded a 79% detection rate. 20 of the 44 patients with histopathologically diagnosed AD had been scanned more than once before death, and the test (cut-off < 0.79 MoM) was positive in all 20 more than a year before and in 9/10 more than 2 years before death. In 10 subjects with dementia but with histopathology excluding AD, the mean minimum width of the medial temporal lobe was significantly greater than that in the cases with AD, but was not significantly different from that in controls. Medial temporal lobe CT is a non-invasive, rapid, simple and effective test for AD which could have immediate application firstly in improving the accuracy of prevalence and incidence studies and, secondly, for the identification of groups of high-risk patients in the evaluation of novel treatments for AD. In the future, it could be applied as a screening test.”


2005 ◽  
Vol 12 (4) ◽  
pp. 197-201 ◽  
Author(s):  
Nicholas J Wald ◽  
Joan K Morris ◽  
Simon Rish

Objective: To determine the quantitative effect on overall screening performance (detection rate for a given false-positive rate) of using several moderately strong, independent risk factors in combination as screening markers. Setting: Theoretical statistical analysis. Methods: For the purposes of this analysis, it was assumed that all risk factors were independent, had Gaussian distributions with the same standard deviation in affected and unaffected individuals and had the same screening performance. We determined the overall screening performance associated with using an increasing number of risk factors together, with each risk factor having a detection rate of 10%, 15% or 20% for a 5% false-positive rate. The overall screening performance was estimated as the detection rate for a 5% false-positive rate. Results: Combining the risk factors increased the screening performance, but the gain in detection at a constant false-positive rate was relatively modest and diminished with the addition of each risk factor. Combining three risk factors, each with a 15% detection rate for a 5% false-positive rate, yields a 28% detection rate. Combining five risk factors increases the detection rate to 39%. If the individual risk factors have a detection rate of 10% for a 5% false-positive rate, it would require combining about 15 such risk factors to achieve a comparable overall detection rate (41%). Conclusion: It is intuitively thought that combining moderately strong risk factors can substantially improve screening performance. For example, most cardiovascular risk factors that may be used in screening for ischaemic heart disease events, such as serum cholesterol and blood pressure, have a relatively modest screening performance (about 15% detection rate for a 5% false-positive rate). It would require the combination of about 15 or 20 such risk factors to achieve detection rates of about 80% for a 5% false-positive rate. This is impractical, given the risk factors so far discovered, because there are too few risk factors and their associations with disease are too weak.


Sign in / Sign up

Export Citation Format

Share Document