scholarly journals Detecting Defects on Solid Wood Panels Based on an Improved SSD Algorithm

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5315 ◽  
Author(s):  
Fenglong Ding ◽  
Zilong Zhuang ◽  
Ying Liu ◽  
Dong Jiang ◽  
Xiaoan Yan ◽  
...  
Keyword(s):  
Detection Algorithm ◽  
Solid Wood ◽  
Single Shot ◽  
Labor Costs ◽  
Color Charge ◽  
Aesthetic Value ◽  
Charge Coupled Device ◽  
Different Types ◽  
The Mean ◽  
Low Efficiency

Wood is widely used in construction, the home, and art applications all over the world because of its good mechanical properties and aesthetic value. However, because the growth and preservation of wood are greatly affected by the environment, it often contains different types of defects that affect its performance and ornamental value. To solve the issues of high labor costs and low efficiency in the detection of wood defects, we used machine vision and deep learning methods in this work. A color charge-coupled device camera was used to collect the surface images of two types of wood from Akagi and Pinus sylvestris trees. A total of 500 images with a size of 200 × 200 pixels containing wood knots, dead knots, and checking defects were obtained. The transfer learning method was used to apply the single-shot multibox detector (SSD), a target detection algorithm and the DenseNet network was introduced to improve the algorithm. The mean average precision for detecting the three types of defects, live knots, dead knots and checking was 96.1%.

scholarly journals Water surface object detection using panoramic vision based on improved single-shot multibox detector

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Aofeng Li ◽  
Xufang Zhu ◽  
Shuo He ◽  
Jiawei Xia
Keyword(s):  
Object Detection ◽  
Water Surface ◽  
Detection Algorithm ◽  
Single Shot ◽  
Panoramic Vision ◽  
Feature Pyramid ◽  
The Mean ◽  
Detection Effect ◽  
Surface Object ◽  
Improved Algorithm

AbstractIn view of the deficiencies in traditional visual water surface object detection, such as the existence of non-detection zones, failure to acquire global information, and deficiencies in a single-shot multibox detector (SSD) object detection algorithm such as remote detection and low detection precision of small objects, this study proposes a water surface object detection algorithm from panoramic vision based on an improved SSD. We reconstruct the backbone network for the SSD algorithm, replace VVG16 with a ResNet-50 network, and add five layers of feature extraction. More abundant semantic information of the shallow feature graph is obtained through a feature pyramid network structure with deconvolution. An experiment is conducted by building a water surface object dataset. Results showed the mean Average Precision (mAP) of the improved algorithm are increased by 4.03%, compared with the existing SSD detecting Algorithm. Improved algorithm can effectively improve the overall detection precision of water surface objects and enhance the detection effect of remote objects.

A dual U-Net algorithm for automating feature extraction from satellite imagery

2021 ◽  
pp. 154851292098354
Author(s):  
Samuel Humphries ◽  
Trevor Parker ◽  
Bryan Jonas ◽  
Bryan Adams ◽  
Nicholas J Clark
Keyword(s):  
Neural Networks ◽  
Object Detection ◽  
Satellite Images ◽  
Detection Algorithm ◽  
Military Operations ◽  
Detection Algorithms ◽  
Us Military ◽  
Standard Product ◽  
Different Types ◽  
Road Intersections

Quick identification of building and roads is critical for execution of tactical US military operations in an urban environment. To this end, a gridded, referenced, satellite images of an objective, often referred to as a gridded reference graphic or GRG, has become a standard product developed during intelligence preparation of the environment. At present, operational units identify key infrastructure by hand through the work of individual intelligence officers. Recent advances in Convolutional Neural Networks, however, allows for this process to be streamlined through the use of object detection algorithms. In this paper, we describe an object detection algorithm designed to quickly identify and label both buildings and road intersections present in an image. Our work leverages both the U-Net architecture as well the SpaceNet data corpus to produce an algorithm that accurately identifies a large breadth of buildings and different types of roads. In addition to predicting buildings and roads, our model numerically labels each building by means of a contour finding algorithm. Most importantly, the dual U-Net model is capable of predicting buildings and roads on a diverse set of test images and using these predictions to produce clean GRGs.

scholarly journals Laser-induced damage thresholds of ultrathin targets and their constraint on laser contrast in laser-driven ion acceleration experiments

2020 ◽  
Vol 8 ◽  
Author(s):  
Dahui Wang ◽  
Yinren Shou ◽  
Pengjie Wang ◽  
Jianbo Liu ◽  
Zhusong Mei ◽  
...  
Keyword(s):  
Damage Threshold ◽  
Wide Band ◽  
Laser Pulses ◽  
Laser Damage Threshold ◽  
Single Shot ◽  
Bulk Materials ◽  
Free Standing ◽  
Wide Band Gap ◽  
Different Types ◽  
Laser Induced Damage

Abstract Single-shot laser-induced damage threshold (LIDT) measurements of multi-type free-standing ultrathin foils were performed in a vacuum environment for 800 nm laser pulses with durations τ ranging from 50 fs to 200 ps. The results show that the laser damage threshold fluences (DTFs) of the ultrathin foils are significantly lower than those of corresponding bulk materials. Wide band gap dielectric targets such as SiN and formvar have larger DTFs than semiconductive and conductive targets by 1–3 orders of magnitude depending on the pulse duration. The damage mechanisms for different types of targets are studied. Based on the measurement, the constrain of the LIDTs on the laser contrast is discussed.

Lightweight detection algorithm for fine-grained surface defects of aerospace seal rings

2021 ◽  
pp. 1-18
Author(s):  
Hui Liu ◽  
Boxia He ◽  
Yong He ◽  
Xiaotian Tao
Keyword(s):  
Feature Extraction ◽  
Defect Detection ◽  
Surface Defect ◽  
Surface Defects ◽  
Detection Algorithm ◽  
Seal Ring ◽  
Fine Grained ◽  
Aerospace Applications ◽  
Surface Defect Detection ◽  
The Mean

The existing seal ring surface defect detection methods for aerospace applications have the problems of low detection efficiency, strong specificity, large fine-grained classification errors, and unstable detection results. Considering these problems, a fine-grained seal ring surface defect detection algorithm for aerospace applications is proposed. Based on analysis of the stacking process of standard convolution, heat maps of original pixels in the receptive field participating in the convolution operation are quantified and generated. According to the generated heat map, the feature extraction optimization method of convolution combinations with different dilation rates is proposed, and an efficient convolution feature extraction network containing three kinds of dilated convolutions is designed. Combined with the O-ring surface defect features, a multiscale defect detection network is designed. Before the head of multiscale classification and position regression, feature fusion tree modules are added to ensure the reuse and compression of the responsive features of different receptive fields on the same scale feature maps. Experimental results show that on the O-rings-3000 testing dataset, the mean condition accuracy of the proposed algorithm reaches 95.10% for 5 types of surface defects of aerospace O-rings. Compared with RefineDet, the mean condition accuracy of the proposed algorithm is only reduced by 1.79%, while the parameters and FLOPs are reduced by 35.29% and 64.90%, respectively. Moreover, the proposed algorithm has good adaptability to image blur and light changes caused by the cutting of imaging hardware, thus saving the cost.

scholarly journals Incidence and Characteristics of Retinoblastoma in Poland: The First Nationwide Study 2010–2017

2021 ◽  
Vol 18 (12) ◽  
pp. 6539
Author(s):  
Michał S. Nowak ◽  
Bożena Romanowska-Dixon ◽  
Iwona Grabska-Liberek ◽  
Michał Żurek
Keyword(s):  
Western Europe ◽  
External Beam Radiotherapy ◽  
Cohort Analysis ◽  
Developed Countries ◽  
Live Births ◽  
Focal Treatment ◽  
Different Types ◽  
The Mean ◽  
Birth Cohort Analysis

Background: The present study aimed to investigate the incidence and characteristics of retinoblastoma in the overall population of Poland. Methods: The retrospective survey of both National Health Fund (NHF) and National Cancer Registry (NCR) databases were performed to identify all retinoblastoma cases in Poland in the years 2010–2017. Results: During 2010–2017, the mean age-standardised incidence of retinoblastoma (the unit of incidence is per 1,000,000 person-years) was 10.15 (95% CI 7.23–13.08) among children aged 0 to 4 years and 5.39 (95% CI 4.18–6.60) in those aged 0 to 9 years. During 2010–2014 (to allow 5 years of follow-up), the mean incidence of retinoblastoma by birth cohort analysis in Poland was 4.89 (95% CI 4.04–5.74) per 100,000 live births, corresponding to an incidence of 1 per 20,561 (95% CI 15,855–25,267) live births. In Poland, 14.6% of children with retinoblastoma had enucleation of the eye globe, 76.8% received different types of chemotherapy combined with focal treatment, 5.9% were treated with external beam radiotherapy, and 2.7% were treated with focal treatments only. Conclusions: The incidence of retinoblastoma and the pattern of medical management of retinoblastoma in Poland was similar to that reported in developed countries in Western Europe, Asia, and North America.

scholarly journals Does Every Calculation Formula Fit for All Types of Intraocular Lenses? Optimization of Constants for Tecnis ZA9003 and ZCB00 Is Necessary

Medicina ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 319
Author(s):  
Ivajlo Popov ◽  
Veronika Popova ◽  
Juraj Sekac ◽  
Vladimir Krasnik
Keyword(s):  
Prediction Error ◽  
Poor Performance ◽  
Intraocular Lenses ◽  
Power Calculation ◽  
Universal Formula ◽  
Aspheric Iol ◽  
Different Types ◽  
The Mean ◽  
Clinically Significant ◽  
Mean Prediction Error

Background and Objectives: To evaluate the performance of intraocular lenses (IOLs) using power calculation formulas on different types of IOL. Materials and Methods: 120 eyes and four IOL types (BioLine Yellow Accurate Aspheric IOL (i-Medical), TECNIS ZCB00, TECNIS ZA9003 (Johnson & Johnson) (3-piece IOL) and Softec HD (Lenstec)) were analyzed. The performance of Haigis, Barret Universal II and SKR-II formulas were compared between IOL types. The mean prediction error (ME) and mean absolute prediction error (MAE) were analyzed. Results: The overall percentage of eyes predicted within ±0.25 diopters (D) was 40.8% for Barret; 39.2% Haigis and 31.7% for SRK-II. Barret and Haigis had a significantly lower MAE than SRK-II (p < 0.05). The results differed among IOL types. The largest portion of eyes predicted within ±0.25 D was with the Barret formula in ZCB00 (33.3%) and ZA9003 (43.3%). Haigis was the most accurate in Softec HD (50%) and SRK-II in Biolline Yellow IOL (50%). ZCB00 showed a clinically significant hypermetropic ME compared to other IOLs. Conclusions: In general, Barret formulas had the best performance as a universal formula. However, the formula should be chosen according to the type of IOL in order to obtain the best results. Constant optimizations are necessary for the Tecnis IOL ZCB00 and ZA9003, as all of the analyzed formulas achieved a clinically significant poor performance in this type of IOL. ZCB00 also showed a hypermetropic shift in ME in all the formulas.

scholarly journals Spectroscopic flat-fields can be used for precision CCD gain and noise tests

2021 ◽  
Vol 38 ◽  
Author(s):  
J. Gordon Robertson
Keyword(s):  
Ccd Camera ◽  
Matched Pair ◽  
Optical Fibres ◽  
Charge Coupled Device ◽  
Small Areas ◽  
Flat Field ◽  
Basic Parameters ◽  
The Mean ◽  
A Charge ◽  
Analogue To Digital

Abstract One of the basic parameters of a charge coupled device (CCD) camera is its gain, that is, the number of detected electrons per output Analogue to Digital Unit (ADU). This is normally determined by finding the statistical variances from a series of flat-field exposures with nearly constant levels over substantial areas, and making use of the fact that photon (Poisson) noise has variance equal to the mean. However, when a CCD has been installed in a spectroscopic instrument fed by numerous optical fibres, or with an echelle format, it is no longer possible to obtain illumination that is constant over large areas. Instead of making do with selected small areas, it is shown here that the wide variation of signal level in a spectroscopic ‘flat-field’ can be used to obtain accurate values of the CCD gain, needing only a matched pair of exposures (that differ in their realisation of the noise). Once the gain is known, the CCD readout noise (in electrons) is easily found from a pair of bias frames. Spatial stability of the image in the two flat-fields is important, although correction of minor shifts is shown to be possible, at the expense of further analysis.

Disability in Schizophrenic Disorders

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
J. Wancata ◽  
M. Freidl ◽  
F. Friedrich ◽  
T. Matschnig ◽  
A. Unger ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Social Consequences ◽  
Subjective Burden ◽  
Social Contacts ◽  
Mothers And Fathers ◽  
Duration Of Illness ◽  
The Family ◽  
Different Types ◽  
Icd 10 ◽  
The Mean

Aims:The purpose of this study was to investigate disability among patients suffering from schizophrenia and to identify predictors of disability.Methods:101 patients from different types of psychiatric services in Vienna and diagnosed with schizophrenia according to ICD-10 were included. They were investigates by means of 36-Item self-administered version of the WHO Disability Assessment Schedule II (WHO-DAS-II) and the PANSS-scale. Patients’ mothers and fathers were asked to fill in the Family Problem Questionnaire.Results:The mean total score of the WHO-DAS-II was 74.1 (SD 21.9). When using weighted sub-scores the highest disability scores were found for social contacts, participation in society and household (means 2.58, 2.57 and 2.51 respectively). Using logistic regression, overall disability was positively associated with patient's age, overall severity of symptoms (PANSS) and number of previous hospital admissions. Overall disability was not associated with duration of illness and or patient's gender. The subjective burden experienced by patients’ fathers and mothers were increased by reduced social contacts and impaired participation in society, while we could not find an association with other domains of patient's disability (understanding, mobility, self-care, household).Conclusions:This study shows that schizophrenia results in disability in several domains. Family caregivers’ burden was predominantly increased by social consequences of schizophrenia.

OBSERVATIONS INDICATING A SEX CYCLE IN THE MALE RABBIT

1964 ◽  
Vol 46 (4) ◽  
pp. 597-607 ◽  
Author(s):  
Jan Erik Kihlström ◽  
Otto Hornstein
Keyword(s):  
Body Temperature ◽  
Mucous Membrane ◽  
Immature Stage ◽  
Male Urethra ◽  
Male Rabbit ◽  
Exfoliated Cells ◽  
Different Types ◽  
The Mean ◽  
Male Sex ◽  
Sex Cycle

ABSTRACT Recently some physiological characteristics of a sex cycle in male animals have been demonstrated. However, nothing is known at present about any morphological expressions of this cycle, and particularly about any rhythmical variation in exfoliation of cells comparable with that of the vaginal mucous membrane. On the assumption that such a rhythm may occur in the male urethra, the exfoliation of cells in this organ has been studied by taking daily smears. Cyclically varying frequencies of four different types of exfoliated cells, mainly in an immature stage, were demonstrated. Only a fifth type of cells, characterized by cornification and nuclear degeneration, is not subjected to such rhythmical variation. The mean duration of these cycles is about four days. Simultaneous investigations on the seminal volume and body temperature showed some relation to the cycle of cell desquamation. The results give additional evidence for the existence of a male sex cycle, probably with a hormonal background.

Properties of Unitary IPSCs in Hippocampal Pyramidal Cells Originating From Different Types of Interneurons in Young Rats

1997 ◽  
Vol 77 (4) ◽  
pp. 1939-1949 ◽  
Author(s):  
Mohamed Ouardouz ◽  
Jean-Claude Lacaille
Keyword(s):  
Reversal Potential ◽  
Pyramidal Cells ◽  
Mean Amplitude ◽  
Paired Pulse ◽  
Young Rats ◽  
Different Types ◽  
The Mean ◽  
Paired Pulse Depression ◽  
Types Of Interneurons ◽  
Stimulation Of

Ouardouz, Mohamed and Jean-Claude Lacaille. Properties of unitary IPSCs in hippocampal pyramidal cells originating from different types of interneurons in young rats. J. Neurophysiol. 77: 1939–1949, 1997. Whole cell recordings were used in hippocampal slices of young rats to examine unitary inhibitory postsynaptic currents (uIPSCs) evoked in CA1 pyramidal cells at room temperature. Loose cell-attached stimulation was applied to activate single interneurons of different subtypes located in stratum oriens (OR), near stratum pyramidale (PYR), and at the border of stratum radiatum and lacunosum-moleculare (LM). uIPSCs evoked by stimulation of PYR and OR interneurons had similar onset latency, rise time, peak amplitude, and decay. In contrast, uIPSCs elicited by activation of LM interneurons were significantly smaller in amplitude and had a slower time course. The mean reversal potential of uIPSCs was −53.1 ± 2.1 (SE) mV during recordings with intracellular solution containing potassium gluconate. With the use of recording solution containing the potassium channel blocker cesium, the reversal potential of uIPSCs was not significantly different (−58.5 ± 2.6 mV), suggesting that these synaptic currents were not mediated by potassium conductances. Bath application of the γ-aminobutyric acid-A (GABAA) receptor antagonist bicuculline (25 μM) reversibly blocked uIPSCs evoked by stimulation of all interneuron subtypes. In bicuculline, the mean peak amplitude of uIPSCs recorded with potassium gluconate was reduced to 3.5 ± 4.4% of control ( n = 7). Similarly, with cesium methanesulfonate, the mean amplitude in bicuculline was 2.9 ± 3.1% of control ( n = 13). Application of the GABAB receptor antagonist CGP 55845A (5 μM) resulted in a significant and reversible increase in the mean amplitude of uIPSCs recorded with cesium-containing intracellular solution. Thus uIPSCs from all cell types appeared under tonic presynaptic inhibition by GABAB receptors. Paired stimulation of individual interneurons at 100- to 200-ms intervals did not result in paired pulse depression of uIPSCs. For individual responses, a significant negative correlation was observed between the amplitude of the first and second uIPSCs. A significant paired pulse facilitation (154.0 ± 8.0%) was observed when the first uIPSC was smaller than the mean of all first uIPSCs. A small, but not significant, paired pulse depression (90.8 ± 4.0%) was found when the first uIPSC was larger than the mean of all first uIPSCs. Our results indicate that these different subtypes of hippocampal interneurons generate Cl−-mediated GABAA uIPSCs. uIPSCs originating from different types of interneurons may have heterogeneous properties and may be subject to tonic presynaptic inhibition via heterosynaptic GABAB receptors. These results suggest a specialization of function for inhibitory interneurons and point to complex presynaptic modulation of interneuron function.

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