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A graph G = (V(G), E(G)) with p vertices and q edges is called (p, q)-graph. An injection f is said to be odd harmonious labeling of a (p, q)-graph G if there is an injective function f from a set of vertices V(G) to a set {0, 1, 2, …, 2q − 1} such that the induced function f∗ from a set of edges E(G) to a set of odd number {1, 3, 5, … 2q − 1} defined by f ∗ (uv)=f (u)+f (v) is a bijection. A graph G is said to be odd harmonious if there exists an odd harmonious labeling for G. In this paper we proved that several product graphs, such as m-shadow of cycle Dm (Cn), gear with pendant graphs and Shuriken graphs, are odd harmonious graphs.

The cause of moon phase is seem to be complicated for student, such that they almost performed misconception when tested. This study investigated the effective of using metacognitive strategies for improving grade 8 student’s understanding in moon phase. There are 30 student participated in this study. The framework of the study is interpretive paradigm. The data were obtained from 3 open-ended question about cause of moon phase and interview. Their responses has been categorized into groups by considering to scientific concept. And it could be grouped into 7 categories as following: 1) The moon rotate around the earth. Difference position of the moon cause of difference illuminated. 2) The earth obstruct the light fall on the moon 3) Clouds cover part of the moon 4) The shadow of the earth fall on the moon 5) The illuminated of the sun has difference 6) Earth rotation 7) The moon rotate around the earth and the angle between Sun, Earth and Moon. The post-test had done soon after finished the metacognitive strategy approach. The categories group was decrease from 7 to 4 groups, the remains group were 1), 2), 5) and 7). The number of student in group 7, student with correct scientific concept, increased. In-depth interview and document analysis show that many student has planning, implementing and checking concept during learning by themselves. They claim this steps can help them to understand learning and thinking process and understanding better related concept. It could be the students use the metacognitive strategies in learning.

We investigate the shadows of a certain class of rotating traversable wormhole. We consider the unstable spherical orbits and reveal their crucial role over the cusp formation in the shadows. For relatively small values of the wormhole angular momentum the cusps structure changes significantly. A set of critical values of the wormhole angular momentum exist for which the cusps are joined together or detached respectively from the shadow. Furthermore, we show that only some of the unstable spherical orbits possess specific impact parameters, which contribute to the shadow boundary.

We report on the investigation and comparison of two different processing approaches for interdigitated back contacted silicon heterojunction solar cells our photolithography based reference procedure and our newly developed shadow mask process. To this end, we analyse fill factor losses in different stages of the fabrication process. We find that although comparably high minority carrier lifetimes of about 4 ms can be observed for both concepts, the shadow masked solar cells suffer yet from poorly passivated emitter regions and significantly higher series resistance. Approaches for addressing the observed issues are outlined and first solar cell results with efficiencies of about 17 and 23 for shadow masked and photolithographically structured solar cells, respectively, are presented

Photovoltaic (PV) power generation has a particular problem for grid cooperation in that output can fluctuate due to the shadows created by clouds. If we can grasp the behavior of cloud shadows beforehand, then it may be possible to forecast output fluctuations. In this study, we want to prove if it is possible to calculate power output variation from the accumulated cloud shadow data. Cloud shadow behavior was measured from the ground by photodiodes (PDs) and the cloud shadow vector was calculated from the position and time difference. The time from the calculated cloud shadow vector to the arrival of the cloud shadow and the power generation output was calculated and compared with the actual solar power generation output. Thus, we confirmed that we can predict power generation output from a high correlation of two outputs. We found that prediction is possible, with high precision, at a short distance.

A set of optical methods for studying the dispersion and dynamics of liquids in high-speed gas jets was realized. Four optical methods were used: shadow imaging, PIV method, Laser Doppler Anemometer (LDA), a method for recording the dispersity of a spray by angular scattering of light. With the example of a supersonic coaxial jet with a central fluid supply, a technique is developed that makes it possible to obtain not only the sum of the data by four methods but new critical data on the structure of the two-phase flow, such as the concentration distributions of the spray.

One of the key elements in short-term solar forecasting is the detection of clouds and their movement. This paper discusses a new method for extracting cloud cover and cloud movement information from ground based camera images using neural networks and the Lucas-Kanade method. Two novel features of the algorithm are that it performs well both inside and outside of the circumsolar region, i.e. the vicinity of the sun, and is capable of deciding a threefold sun state. More precisely, the sun state can be detected to be either clear, partly covered by clouds or overcast. This is possible due to the absence of a shadow band in the imaging system. Visual validation showed that the new algorithm performed well in detecting clouds of varying color and contrast in situations referred to as difficult for commonly used thresholding methods. Cloud motion field results were computed from two consecutive sky images by solving the optical flow problem with the fast to compute Lucas-Kanade method. A local filtering sche...

In this paper, a novel lost packets recovery scheme which encrypts the effective parts of an original packet into two shadow packets based on (2, 2)-threshold XOR-based visual Secret Sharing (VSS) is proposed. The two shadow packets used as watermarks would be embedded into two normal data packets with digital watermarking embedding technology and then sent from one sensor node to another. Each shadow packet would reveal no information of the original packet, which can improve the security of original packet delivery greatly. The two shadow packets which can be extracted from the received two normal data packets delivered from a sensor node can recover the original packet lossless based on XOR-based VSS. The Performance analysis present that the proposed scheme provides essential services as long as possible in the presence of selective forwarding attack. The proposed scheme would not increase the amount of additional traffic, namely, lower energy consumption, which is suitable for Wireless Sensor Network...

Experimental and numerical investigation of the interaction of supersonic jets is performed. The localization of jets is restricted by the walls of the semi-open channel. The jets intersect at a single point. The values of pressures on the surface of the channel as well as the total pressure at the exit of the channel were obtained. The shadow photography is applied for registering the flow structure. The strong influence of the prechamber pressure as well as the ratio of area of the inlet holes to the area of the channel output section on the formation of the flow structure is shown.

There is nowadays a high demand for research on using renewable sources of energy including solar energy. The availability of stable and efficient solar energy is of paramount importance. Therefore, it is vital to install solar panels in locations which are most of the time not in shadow. To illustrate this idea we have developed a shadow identification method for digital elevation models (DEMs) using the computational means of MATLAB whose environment and tools allow fast and easy image processing. As a source of DEMs we use the Shuttle Radar Topography Mission (SRTM) database since it covers most of the terrain of our planet.

With the increase of installations on the land, the impact to the optical environment result from shading by PV panels is needed to be concerned. This paper describes how to calculate illumination level on the land around the isolated CPV panel. The land under the flat-plate PV is often dark but the shading influence from the tracking CPV is not very significant in most of the cases. This is because the shadow by the tracking panels moves by the movement of the sun. The integrated illumination level is averaged after integration in a day or a year. This effect is enhanced in the high latitude area. The shading influence by CPV is further decreased by the design of a higher pedestal. With this advantage, CPV can be combined with agriculture as a double use of the land.

Fiber bundles for imaging internal organs with minimum physical damage have been increasingly developed for both basic life sciences and clinical applications. Reflectance imaging is possible using fiber bundles for detecting the intrinsic optical contrast of blood vessels and tissue structure. The placement of an illumination source adjacent to imaging optics causes scattered light from deeper tissue layers to illuminate superficial tissues and results in a reflectance image. However, it does not have focal capacity and lacks depth resolution. In this study, we performed spatial analysis for the vertical reconstruction of in vivo tissues using a multipositional illumination scheme. The observed image corresponded to the “shadow” of a target object. When we manipulated the location of illumination, the shadow moved horizontally depending on the depth of the target. We used this horizontal displacement as a cue and successfully performed the vertical reconstruction of mouse brain blood vessels.

The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. Chapter 4 covers general procedures of defect search, which is based on vector analysis principles. In conclusion, the main applications of X-ray tomography are presented.

A new pattern of space coordinate system based on sun-tracking surface has been introduced in this paper. The calculation of shadow area between HCPV trackers has been simplified within this kind of coordinate system. The spaces between rows and columns of HCPV arrays can be calculated accurately. Therefore, an appropriate layout of trackers arrangement for a HCPV power plant can be determined and designed by use of this method.

This paper describes the results of a self-shading loss analysis of a high concentration photovoltaic (HCPV) plant based on pedestal and carousel solar tacking systems. To determine the best possible tracker array configuration to minimize self-shading loss, a multiobjective genetic algorithm (MOGA) was used with a theoretical shadow model and cloudless solar spectrum model. As a result of MOGA optimization, the trade-off between land-use efficiency and the capacity factor in the optimized tracker arrays was characterized and compared.

This paper presents a tool for designing new photovoltaic power plants based on a collective optimization of the tracking trajectory of the sun‐tracking systems. The presented tool can also be used to improve production in existing tracking power plants.By analyzing an array of Sun‐tracking systems as a collective system, an optimization model was developed to determine the individual positions for each tracker along the day, which render the maximum global output for the array. This improvement in global output, relative to the same array without optimized positions, is achieved by minimizing the amount of shadow, cast on some systems by others, due to their relative position and location.Based on the premise that, by using collectively optimized movements for the sun trackers, the same global output can be obtained in a smaller installation area, a design tool was created to compute a production performance parameter for different inter system distances, which can then be crossed with installation cost ...

In this paper, we propose a fast and stable human detection based on subtraction stereo for generic environments. Scanning an input image by detection windows, the numbers and size is controlled by distance obtained from subtraction stereo. A preprocessing phase reduces the effect of noise and shadow, for a better segmentation. This control decrease the computation time, important in real‐time applications, skipping a large number of detection windows. Experimental results show that the proposal is faster and less false detection.

Skyline Solar has developed a novel medium concentration PV product. The system is a linear concentrator that tracks the sun with a 1‐axis horizontal tracker. Reflectors are used to concentrate sunlight 7–50x using non‐imaging optics. The receivers use Silicon cells and passive cooling. The product's design has been guided by a detailed Performance Prediction Tool (PPT) that relates component characteristics and climate data to the overall energy production. In contrast with other tools, the PPT captures the non‐linearity of conditions such as weather, system architecture (stringing, shadow management) and the value of energy as a function of time of day and season. This paper describes the key elements of the PPT and compares its predictions to real‐world results from different locations with significantly different DNI. Moderate DNI sites are San Jose, California and Kona, Hawaii. The higher DNI site is Nipton, California (DNI ∼7.2). Skyline's PPT accurately predicts the energy harvest for two Skyline S...

This chapter presents a vision‐based lane‐vehicle detection and tracking system comprising of (i) enhanced lane boundary detection, (ii) linear‐parabolic lane region tracking, and (iii) vehicle detection with a proposed possible vehicle region verification. First, a road image is partitioned into sky and road region. Lane boundaries are then extracted from the road region using line model estimation without applying Hough Transform. These detected boundaries are tracked in consecutive video frames with possible edges scanning and linear‐parabolic modeling. An approximate lane region is subsequently constructed with the predicted model parameters. By integrating the knowledge of lane region with vehicle detection, vehicle searching region is restricted to the road area so as to detect the shadow underneath a vehicle continuously with less interference to the road environment and non‐vehicle structures. A self‐adjusting bounding box is used to extract likely vehicle region for further verification. Besides horizontal symmetry detection, a vertical asymmetry measurement is presented to validate the extracted region and to obtain the center of frontal vehicle. Simulation results have revealed good performance of lane‐vehicle detection and tracking system.

In this work is developed a three‐dimensional reconstruction system using the Shades3D tool of the Matlab® Programming Language and materials of low cost, such as webcam camera, a stick, a weak structured lighting system composed by a desk lamp, and observation plane in which the object is located. The reconstruction is obtained through a triangulation process that is executed after acquiring a sequence of images of the scene with a shadow projected on the object; additionally an image filtering process is done for obtaining only the part of the scene that will be reconstructed. Previously, it is necessary to develop a calibration process for determining the internal camera geometric and optical characteristics (intrinsic parameters), and the 3D position and orientation of the camera frame relative to a certain world coordinate system (extrinsic parameters). The lamp and the stick are used to produce a shadow which scans the object; in this technique, it is not necessary to know the position of the light ...

In a previous system we showed how the three‐dimensionality of an object can be projected and preserved on a diffractive screen, which is just a simple diffractive holographic lens. A transmission object is illuminated with an extended filament of a white light lamp and no additional element is necessary. The system forms three‐dimensional (3D) images with normal depth (orthoscopic) of the shadow type. The continuous parallax, perfect sharpness and additional characteristics of the image depend on the width and extension of the luminous filament and the properties of the diffractive lens. This new imaging system is shown to inspire an interesting extension to non‐perfect reflective or refractive imaging elements because the sharpness of the image depends only on the width of the source. As new light sources are being developed that may result in very thin linear white light sources, for example, light emitting diodes, it may be useful to further develop this technique. We describe an imaging process in which a rough Fresnel metallic mirror can give a sharp image of an object due to the reduced width of a long filament lamp. We will discuss how the process could be extended to Fresnel lenses or to any aberrating imaging element.

The theme of solar diameter variability is presented with the data of solar astrolabes, the four data points of the Solar Disk Sextant and the central eclipses observed near the shadow’s limbs. All data are from the last 3 decades. The results obtained with solar astrolabes are different from Northern (Calern) and Southern hemisphere (Rio de Janeiro, Santiago), this is possibly due to atmospheric effect. Eclipses measurements are not affected by atmospheric turbulence because the event’s geometry is determined outside the atmosphere, they give systematically larger diameter values than astrolabes. Videos of eclipses are discussed in term of projection on a screen versus direct imaging at the focal plane with filtered telescope. Relations between filters densities, telescope diameters, frame rate of video cameras, and portion of the outer solar limb lost during eclipse imaging are presented. Loss of 0.02” are typical for 10 cm ND5 filtered telescope. A commercial 60 fps camcorder for Baily beads timing is discussed in terms of signal‐to‐noise ratio.

Rainfall and flow prediction, adapting the Venkataraman single time series approach and Wiener multiple time series approach were conducted for Aralikottai tank system, and Kothamangalam tank system, Tamilnadu, India. The results indicated that the raw prediction of daily values is closer to actual values than trend identified predictions. The sister seasonal time series were more amenable for prediction than whole parent time series. Venkataraman single time approach was more suited for rainfall prediction. Wiener approach proved better for daily prediction of flow based on rainfall. The major conclusion is that the sister seasonal time series of rain and flow have their own identities even though they form part of the whole parent time series. Further studies with other tropical small watersheds are necessary to establish this unique characteristic of independent but not exclusive behavior of seasonal stationary stochastic processes as compared to parent non stationary stochastic processes.

UW Cen is unique among the cool R Coronae Borealis (RCB) stars in having a visible circumstellar shell. The central star acts like a “lighthouse,” shining through gaps between the near‐star dust clouds, and lighting up different portions of the outer nebula. We have obtained HST/ACS images of the UW Cen nebula taken at 5 epochs in 2004. We are using the light echo to calculate an accurate distance to UW Cen and to map out the pattern of dust clouds forming near the star.

We report on the optical properties of a quantum dot (QD) structure grown by shadow mask‐controlled epitaxy. In this method the dots are grown in a number of very small islands spaced by 1 micron from each other and connected through a uniform 800 nm‐wide wire‐like barrier. We find that if carriers are photo‐excited into the wire‐like barrier, they diffuse for microns before being trapped into the shadow mask‐defined islands of self‐assembled QDs.

Sonar performance in shallow water is severely degraded by multipath which reduces image contrast and degrades the performance of interferometric processing. This is an important limitation for high resolution applications such as minehunting, where target recognition exploits chiefly the shape and size of the target shadow. Experimental data showing the nature and importance of the multipath is presented together with a new sonar design, optimized to achieve a high level of multipath rejection at large range to water depth ratio.

We have developed a set of software tools that allow to monitor the performance of the flight X‐ray CCD cameras as soon as data arrive at MIT. An emission line at 5.9 keV from the on‐board Fe‐55 radioactive calibration source is clearly visible in the spectra and provides the means to measure the gain and the noise for each observation in each of the 4 CCD chips in operation. Both parameters can change with time, depending on the phase of the moon and the amount of light leaking into the system. Time vs. position scatter plots were found to be an extremely powerful tool in understanding of the device performance. They illustrate the evolution of the light leaks produced by the dark Earth at the beginning and the end of each orbit. With a bright X‐ray source in the field of view the shadow of the mask projected on the surface of the CCD clearly shows the motions of the spacecraft.

We use two optical and one ultraviolet spectrophotometric datasets of Her X-1/HZ Her, from the Isaac Newton Telescope and Hubble Space Telescope respectively, to construct Doppler maps (maps in velocity space) and light curves, which are then used as diagnostics with which to test the validity of two warped disk models published in the literature. We find that whilst the light curves may be explained with these models, the maps are not. The maps may be explained if the accretion stream is thick enough to cast a significant shadow over the heated face of the donor star, but in this case the modelled light curves do not match observations.