Human Visual Observation Research Articles

Effect of Disk Edge Profile on Scattering Characteristics of Liquid Droplets Splashed from Spinning Disk

Effects of disk edge profile on scattering characteristics of liquid droplets splashed from a rotating disk edge are experimentally investigated. In the present research, aluminum disks are utilized and purified water is employed for liquid. Scattering phenomena of the droplets are captured by the high-speed digital camera. Distribution of the droplet diameter is evaluated from these images and distributions of horizontal flying velocity component and angle of the droplets are measured by human visual observation of images. Liquid filaments are stretched outward from the stagnant liquid layer on lateral surface of disk edge by centrifugal force. Two main peaks appear in the distribution of the scattered droplet diameter and they are originated from large terminal droplets and small droplets generated from filamentwise breakup. Most of the scattered droplets fly slightly inside of the tangential direction of the disk edge. The water droplets splashed from the disk scatters with regularity compared with ethanol droplets.

Line-scan hyperspectral imaging system for real-time inspection of poultry carcasses with fecal material and ingesta

In poultry processing plants, fecal material and ingesta are the primary source of carcass contamination with microbial pathogens. The current practice of the poultry inspection in the United States is primarily human visual observations. Since the visual inspection is becoming more challenging in poultry processing plants adopting high-speed lines, a rapid sorting system could significantly improve the detection and monitoring of carcasses with surface fecal material and ingesta. As a result, we developed a prototype line-scan hyperspectral imaging system configured as a real-time multispectral imaging subsystem for online detection of surface fecal material and ingesta. Specifically, we integrated a commercially available off-the-shelf hyperspectral image camera into the system with two line lights and a custom software program for real-time multispectral imaging. The bottleneck of the imaging system was the data acquisition. For that reason, a multithreaded software architecture was designed and implemented not only to meet the application requirements such as speed and detection accuracy, but also to be customizable to different imaging applications such as systemic disease detection in the future. The image acquisition and processing speed tests confirmed the system could operate to scan poultry carcasses in commercial poultry processing plants. The fecal detection algorithm was based on the previous research using different hyperspectral imaging systems. A new carcass detection and image formation algorithm was developed to allow existing image processing and detection algorithms reusable without any modifications. Sixteen chicken carcasses and four different types of fecal and ingesta samples were used in a study to test the imaging system at two different speeds (140 birds per minute and 180 birds per minute) in a pilot-scale poultry processing facility. The study found that the system could grab and process three waveband images of carcasses moving up to 180 birds per minute (a line-scan rate 286 Hz) and detect fecal material and ingesta on their surfaces. The detection accuracy of the system varied between 89% and 98% with minimum false positive errors (less than 1%), depending on tested detection algorithms. Therefore, these findings provide the basis of not only a commercially viable imaging platform for fecal detection but also a single poultry inspection system for multiple tasks such as systemic disease detection and quality sorting.

Human Pose Regression Through Multiview Visual Fusion

We consider the problem of estimating 3-D human body pose from visual signals within a discriminative framework. It is challenging because there is a wide gap between complex 3-D human motion and planar visual observation, which makes this a severely ill-conditioned problem. In this paper, we focus on three critical factors to tackle human body pose estimation, namely, feature extraction, learning algorithm, and camera utilization. On the feature level, we describe images using the salient interest points represented by scale-invariant feature transform (SIFT)-like descriptors, in which the position, appearance, and local structural information are encoded simultaneously. On the learning algorithm level, we propose to use Gaussian processes and multiple linear (ML) regression to model the mapping between poses and features. Fusing image information from multiple cameras in different views is of great interest to us on the camera level. We make a comprehensive evaluation on the HumanEva database and get two meaningful insights into the three crucial aspects for human pose estimation: 1) although the choice of feature is very important to the problem, once the learning algorithm becomes efficient, the choice of feature is no longer critical, and 2) the impact of information combination from multiple cameras on pose estimation is closely related to not only the quantity of image information, but also its quality. In most cases, it is true that the more information is involved, the better results can be achieved. But when the information quantity is the same, the differences in quality will lead to totally different performance. Furthermore, dense evaluations demonstrate that our approach is an accurate and robust solution to the human body pose estimation problem.

Reproducibility of Immunostaining Quantification and Description of a New Digital Image Processing Procedure for Quantitative Evaluation of Immunohistochemistry in Pathology

Quantification of immunostaining is a widely used technique in pathology. Nonetheless, techniques that rely on human vision are prone to inter- and intraobserver variability, and they are tedious and time consuming. Digital image analysis (DIA), now available in a variety of platforms, improves quantification performance: however, the stability of these different DIA systems is largely unknown. Here, we describe a method to measure the reproducibility of DIA systems. In addition, we describe a new image-processing strategy for quantitative evaluation of immunostained tissue sections using DAB/hematoxylin-stained slides. This approach is based on image subtraction, using a blue low pass filter in the optical train, followed by digital contrast and brightness enhancement. Results showed that our DIA system yields stable counts, and that this method can be used to evaluate the performance of DIA systems. The new image-processing approach creates an image that aids both human visual observation and DIA systems in assessing immunostained slides, delivers a quantitative performance similar to that of bright field imaging, gives thresholds with smaller ranges, and allows the segmentation of strongly immunostained areas, all resulting in a higher probability of representing specific staining. We believe that our approach offers important advantages to immunostaining quantification in pathology.

A New Evaluation Method for Surface Finish of Composite Automotive Panels Using Waveform Analysis

The surface finish of composite plates made using Resin Transfer Molding of glass/polyester is studied. A surface profilometer is used to measure the surface profile and to record raw data. The objective is to develop an objective method (rather than using human judgment) to differentiate the quality of one surface from another. Initially commonly used current techniques are utilized to assess the quality of the surface finish. These include subjective evaluation through a survey of observations from a group of people; the use of the average amplitude of the signals, frequency analysis, and filtering. For surfaces that have approximate quality, human visual observation can differentiate the quality between the surfaces, but the objective methods (average amplitude, frequency spectrum, and filtering) cannot. A new objective technique is found to be able to distinguish surfaces of approximate quality. This uses the comparison between the parameters of a reference good surface to those of the surface under consideration. A comparative index can be obtained to indicate the degree of similarity between the surface under study and the reference (good) surface.

Haze trends over the capital cities of 31 provinces in China, 1981–2005

This paper presents the patterns and trends of haze over 31 provincial capitals in China between 1980 and 2005. The haze measurements were based on human visual range observations at 31 synoptic meteorological stations operated by the China Meteorological Administration (CMA). The high haze regions were found in largely populated cities such as Chongqing, Beijing, and Shenyang, while the low haze regions were located in the cities with small populations such as Lhasa, Kunming, and Guiyang in southwestern China and Haikou in southern China. The haziness of the 12 cities shows a significantly (95%) decreasing trend, while that of the 13 cities shows a significantly increasing trend over the 25-year study period. The increases are evident in the eastern and southwestern cities in China. It has also been found that there is a decreasing haze trend in winter but an increasing trend in summer for many cities. Nonetheless, the causality for the reduction of aerosol emissions has not been established. This report is the first survey and preliminary analysis done on haze patterns and trends from 1980 to 2005 over the capital cities of 31 provinces in Mainland China.

Thermal Imaging Reveals Significantly Smaller Brazilian Free-Tailed Bat Colonies Than Previously Estimated

Using data collected with thermal imaging technology, we found a major reduction in population estimates of colony size in the Brazilian free-tailed bat (Tadarida brasiliensis) from 54 million, obtained in 1957 without this technology, to 4 million in 6 major cave colonies in the southwestern United States. The 1957 census was based on human visual observations of cave emergence flights that were subject to potentially high errors. The recent census was produced using an accurate, reproducible counting method and based on complete temporal records of colony emergences. Analysis of emergence flights from dusk through darkness also revealed patterns in group behavior that would be difficult to capture without thermal infrared technology. Flow patterns of bats during emergence flights exhibited characteristic single, double, or triple episodes, with the peak flow during the 1st episode. A consistent rhythmic pattern of flow episodes and pauses was revealed across colonies and was independent of emergence tempo.

A COMPUTER VISION METHOD FOR ON-LINE BEHAVIORAL QUANTIFICATION OF INDIVIDUALLY CAGED POULTRY

In addition to production, physiology, and health, behavior is an important issue with respect to animal welfarewhen evaluating novel housing systems. Behavioral characteristics are usually evaluated by audio-visual observation doneby a human observer present on the scene. This method is time consuming, expensive, subjective, and prone to human error.Automated objective surveillance, by means of inexpensive cameras and image-processing techniques, has the ability togenerate data that provide an objective measure of behavior, without disturbing the animals. The specific purpose of this studywas to develop a fully automatic on-line image-processing technique to quantify the behavior of a single laying hen as opposedto the current human visual observation. The image-processing system is based on the principle that the classification ofbehavior can be translated into classification of time series of different postures of the hen. The hens postures can berecognized in the camera image. The classification of the hens behavior is performed by dynamic analysis of a set ofmeasurable parameters, which are calculated from the images using image-processing techniques. The parameters werechosen based on their computational demands and analysis of their discriminative power regarding the different types of aspecific behavior. A first implementation of the system allowed us to identify three different types of individual behavior(standing, walking, and scratching). The objective of further investigation will be the classification of up to 15 different typesof behavior, such as pecking, eating, drinking, wing stretching, etc.

Automated analysis of foot-shock sensitivity and concurrent freezing behavior in mice

Foot-shock is used in a variety of behavioral tasks either as a motivational stimulus, a way to characterize different rodents, or to test various pharmacological agents for their antinociceptive or analgesic effects. All these procedures need to assess foot-shock sensitivity either to rule out possible differences (when the shock is used as a motivational stimulus) or to use the differences to compare animals or treatments. In addition, many of the procedures that utilize foot-shock as a motivational stimulus evaluate freezing as an index of anxiety or fear. In the present study, data obtained by an automated computer system was compared with data obtained by human observers to validate the automated system for examining foot-shock sensitivity in mice. The different computer measures obtained for foot-shock sensitivity exhibited high correlations with human scoring at shock levels as low as 0.2 mA. The computer controlled analysis provided a non-subjective, quantifiable measurement of the foot-shock-induced response as well as freezing behavior. Automated data collection is an improvement over the methods of human visual observation in that the data collection is more standardized, efficient and consistent.

Automatic On-Line Analysis Of Milk Constituents (Urea, Ketones, Enzymes And Hormones) Using Biosensors

Traditional methods of monitoring health changes in animals are based entirely on the human senses. However, in modern dairy production systems humans are rarely present, this is particularly the case with the introduction of robotic milking. In these systems all the functions of milking are automated and cows visit at times of their own choosing. Systems of automatic health monitoring are therefore a priority for research to ensure that the health and reproductive status of the animals can be assessed for management purposes. These systems must be automatic, work in field conditions without technical support and cost a few pence per analysis. The first task is to obtain representative biological samples automatically and non-invasively. As milk is flowing into the milking machine from the cow this can be achieved with ease, except that milk is non-homogeneous with a changing lipid fraction during milking. Lipid soluble components such as progesterone and vitamin A are affected by this change and a model has to be established to determine thresholds at different times during milking. Our main interests in dairy cows are in predicting ovulation, detecting metabolic imbalance and detecting preclinical mastitis inflammatory response. Our team is developing a fully automated ovulation prediction system based on the screen-printed carbon electrode biosensor for progesterone demonstrated by Pemberton et al. (1998). In recent experiments the automated system was able to detect concentrations of progesterone between 2 and 30 ng/ml in stored milk samples (r2= 0.96). The results of field tests are presented showing a good correlation between ELISA and the biosensor (r2= 0.91) on samples of fresh milk. The results of the recent field tests show the ability of the biosensor to characterise ovulation cycles of cows and to detect pregnancy. We have identified a major lack of other biological models to detect disease with on-line sensors. Our next objective is to create an integrated system for biological research with sensor systems for urea, ketones, lipids and enzymes in milk. This will allow the development of diagnostic models based on analysing numerical sensor-derived data rather than human visual observations for signs of ill health in dairy cows.

Haze trends over the United States, 1980–1995

The patterns and trends of haze over the United States for the period of 1980–1995 are presented. Haze measurements are based on human visual range observations at 298 synoptic meteorological stations operated by the United States Weather Service. There was a significant (∼10%) decline in haziness over the 15-yr period. The reductions were evident throughout the eastern United States as well as over the hazy air basins of California. During the same period, in the eastern United States sulfur emissions also declined by about 10%. However, a causality for the reductions has not been established. This report is an update of an earlier survey of haze patterns and trends from 1950 to 1980.

Measuring Wheat Senescence with a Digital Camera

Documenting crop senescence rates is often difficult because of the need for frequent sampling during periods of rapid change and the subjective nature of human visual observations. The purpose of this study was to determine the feasibility of using images produced by a digital camera to measure the senescence rate of wheat and to compare the results with changes in greenness determined by two established methods. Measurements were made as part of an experiment to determine the effects of elevated CO 2 and limited soil nitrogen on spring wheat (Triticum aestivum L.) at the University of Arizona's Maricopa Agricultural Center, near Phoenix, AZ. Greenness' measurements were made during senescence of the crop with a color digital camera, a hand-held radiometer, and a SPAD chlorophyll meter. The green to red (G/R) for each pixel in an image was calculated and the average G/R computed for cropped images from a digital camera representing 1 m 2 for each treatment and sample date. The normalized difference vegetation index (NDVI) was calculated from the red and near-infrared canopy reflectances measured with a hand held radiometer. A SPAD reading was obtained from randomly selected flag leaves. All three methods of measuring plant greenness showed similar temporal trends. The relationships between G/R with NDVI and SPAD were linear over most of the range of G/R. However, NDVI was more sensitive at low values than G/R. G/R was more sensitive above G/R values of 1.2 than SPAD because the upper limits of SPAD measurements were constrained by the amount of chlorophyll in the leaf, while G/R responded to both chlorophyll concentration in the leaves as well as the number of leaves present. Color digital imaging appears useful for quantifying the senescence of crop canopies. The cost of color digital cameras is expected to decrease and the quality and convenience of use to improve.

First results from a pre-operational system for automatic detection and recognition of seismic signals associated with avalanches

AbstractA system for automatic, reliable, semi-instantaneous estimation of avalanche activity is presented in an attempt to check deterministic models and improve the surveillance of risk zones. The principle is the seismic detection of avalanches. Two experimental sites equipped with standard seismological equipment are described. Avalanche seismic signals are recorded, as well as many extraneous signals of natural or human origin. After several years of a posteriori identification of the signals, we are now able to set up criteria for the automatic recognition of non-avalanche signals. We have therefore developed an automatic analysis/decision system to discriminate between avalanche signals and others. This system worked satisfactorily in pre-operational conditions during the winter of 1995-96. The results are presented and compared with other data related to avalanche activity. Although there is still room for improvement, our system seems to be able to estimate avalanche activity better than human visual observations.

First results from a pre-operational system for automatic detection and recognition of seismic signals associated with avalanches

AbstractA system for automatic, reliable, semi-instantaneous estimation of avalanche activity is presented in an attempt to check deterministic models and improve the surveillance of risk zones. The principle is the seismic detection of avalanches. Two experimental sites equipped with standard seismological equipment are described. Avalanche seismic signals are recorded, as well as many extraneous signals of natural or human origin. After several years of a posteriori identification of the signals, we are now able to set up criteria for the automatic recognition of non-avalanche signals. We have therefore developed an automatic analysis/decision system to discriminate between avalanche signals and others. This system worked satisfactorily in pre-operational conditions during the winter of 1995-96. The results are presented and compared with other data related to avalanche activity. Although there is still room for improvement, our system seems to be able to estimate avalanche activity better than human visual observations.

Comet Shoemaker‐Levy 9 at Jupiter

From the 16th to the 22nd of July, 1994, the world was privileged to witness an event that probably recurs less often than once a century. Collision of the brightest nuclei of Periodic Comet Shoemaker‐Levy 9 produced enormous dark clouds that were the most dramatic and easily observed features on Jupiter recorded by human visual observation. They were seen by tens of thousands of people through hundreds or thousands of telescopes ranging in aperture from 5 to more than 100 cm. Tens of millions of people participated vicariously in the impact event through viewing on television the magnificent images from the Hubble Space Telescope (HST) and from numerous ground‐based telescopes.

Characterization of kraft pulp mill particulate emissions—A summary of existing measurements and observations

Particulate matter emission sources at a kraft pulp mill include kraft recovery furnaces, lime kilns, smelt dissolving tanks and power boilers. Chemical and physical characteristics of these paniculate emissions are reviewed. Measurements of particle size distributions for these sources made with cascade impactors and microscopic counting techniques both before and after paniculate control devices such as multiple cyclones, wet scrubbers, and electrostatic precipitalors are discussed. In general, particles with equivalent diameters less than 3 jim comprise the bulk of the controlled paniculate emissions from all sources. Sodium sulfate is the dominant paniculate emission from kraft recovery furnaces, smelt dissolving tanks and lime kilns. Results from a field investigation of the relationship between human observations of near-stack plume opacity and measured in-stack paniculate concentrations and opacities are summarized. Trained cenified panels of observers were used in the investigation to estimate plume opacities from two kraft recovery furnaces, a combination wood/coal-fired boiler, and a combination wood/oil-fired boiler at four different pulp mill locations. Plume opacities were varied from near-zero to 45 % by adjustment of the paniculate control equipment operation. The effects of different background viewing conditions, observer positions, observer experience levels, and plume characteristics are enumerated. It is concluded that there can be substantial variations between measured in-stack opacities and human perceptions of near-stack plume opacities. The degree of agreement between the human judgements and measured in-stack opacities is significantly affected by the background viewing conditions. It is further shown that even with a panel of six or seven trained observers with similar visual acuity, there can be significant departures of individual opacity readings from the panel mean opacity. Although this investigation deals with questions of human observations of near-stack opacity, it is likely that other studies concerned with human perceptions of visibility impairment at greater downwind distances will have to also address the inherently subjective nature of human visual observations and the effects of background viewing conditions. These factors will make it difficult to correlate human visual observations of plume characteristics to instrumental measures of opacity or opacity-related parameters made at the source.

Feeding Behavior and Host Preferences of Some Black Flies (Diptera:Simuliidae) in Wisconsin1

A rapid method for capturing simuliids attracted to and feeding on hosts is described. Engorged and nonengorged specimens readily entered the trap. The method was superior to human visual observation in detecting black fly feeding activity on avian hosts. The blood-sucking females were divided into two categories, those feeding on birds (ornithophilic) and those feeding on mammals (mammalophilic). Most avian feeders exhibited marked habitat and stratification preferences. Differences in the number of flies attracted to various sizes of simultaneously exposed birds were significant at the 5% level. Except for the ornithophilic species occurring in woodland habitats, preferences for mammals and birds were (within the habitats studied) generally related more closely to host size than to any other apparent factor. Engorgement rates were closely related to the attractiveness of the hosts. Simulium meridionale Riley and Eusimulium aureum (Fries) were vectors of Leucocytozoon parasites to turkeys, as was S. rugglesi N. & M. to ducks. Prosimulium magnum D. & S., S. decorum Walk., S. luggeri N. & M., S. jenningsi Mall., S. venustum Say, and S. vittatum Zett. were occasional livestock pests.