Square Of Depth Research Articles

Binocular stereo vision based illuminance measurement used for intelligent lighting with LED

Intelligent lighting is responsible for providing an appropriate illuminance and balancing the environment and resources. An appropriate illuminance can improve visual effect of machine recognition, while it is always difficult to be measured and controlled. An illuminance measurement method by using depth measurement technology of binocular stereo vision is proposed in this study. Illuminance analysis models of single LED and combined LEDs are established, and theoretical calculation equations for analyzing the relationship between power, illuminance, and depth are proposed. The illuminance distribution of single LED and combined LEDs are measured. The difference between single LED and combined LEDs are obtained in terms of illuminance, power, energy efficiency, effective illuminance area, etc. The results show that the illuminance is proportional to power of LED consumed and inversely proportional to the square of depth of image. The higher the energy conversion efficiency under the high illuminance for both single LED and combined LEDs. The depth of image is measured by binocular stereo vision technology, which has a good measurement performance. The binocular stereo vision based illuminance measurement method proposed in this study is efficient, reliable and robust, which is in good agreement with the experimental results, and the relative error is less than 3.8 %. The illuminance measurement is realized without increasing the equipment and image acquisition workload, which lays the foundation for dynamic monitoring and controlling of illuminance. The research results can also be applied to related fields as well, such as the intelligent lighting of street lamp, high beam in automatic driving and supplement lamps in video monitoring.

Study on solid state steelmaking from thin cast iron sheets through decarburization in H2O–H2

ABSTRACT To study the decarburization behavior of cast iron sheets, a series of gas-solid experiments were carried out. The treatment was carried out under Ar-H2-H2O mixed gas atmosphere. Results show that P H2O/P H2 in the gas mixture determines the oxidation of iron at a given temperature and the critical value of P H2O/P H2 to produce ferric oxide rises with temperature. The oxidation of iron take place when the ratio of P H2O/P H2 > 0.62, 0.66, 0.7 at 1293 K, 1353 K, 1413 K, respectively. The gas-solid decarburization reaction of cast iron sheets follows first-order kinetics. Cross-sectional microstructure images indicate that graphitization of cast iron sheets occurs at 1353 and 1413 K. The depth of the decarburized layer increases gradually with temperature and time, the square of depth has a near linear relationship with time. The activation energies of the decarburization reaction calculated by two different ways are similar to that for internal carbon diffusion.

Energy dissipation contributed on the machined depth via dynamic plowing lithography of atomic force microscopy

In this study, the atomic force microscopy tip-based dynamic plowing lithography approach is employed to scratch on the poly(methyl methacrylate) thin-film surface. A theoretical model is established based on the relationship between the tip energy dissipation and material removal volume, and the corresponding experiments are also conducted. Both the theoretical and experimental results show that the drive amplitude is proportional to the square of the machined depth of the nanoscale grooves. The mean deviations between the predicted and experimental depths are less than 10%. It is also indicated that the scratching velocity in the range of 0.01–80 μm/s is proportional to the square of the depth (1/h2), and the mean deviations between the predicted and experimental depths are also less than 7%. In addition, based on the above conclusions, a uniform ripple with desired dimensions can be achieved successfully by overlapping the machined nanogrooves. The wavelength and amplitude of the ripples are determined by controlling the feature size of nanogrooves.

Third harmonic generation of a short pulse laser in a plasma density ripple created by a machining beam

An intense machining laser beam, impinged on a gas jet target, causes space periodic ionization of the gas and heats the electrons. The nonuniform plasma pressure leads to atomic density redistribution. When, after a suitable time delay, a second more intense laser pulse is launched along the periodicity wave vector q⃗, a plasma density ripple nq is instantly created, leading to resonant third harmonic generation when q=4ωp2∕(3ωcγ0), where ωp is the plasma frequency, ω is the laser frequency, and γ0 is the electron Lorentz factor. The third harmonic is produced through the beating of ponderomotive force induced second harmonic density oscillations and the quiver velocity of electrons at the fundamental. The relativistic mass nonlinearity plays no role in resonant coupling. The energy conversion efficiency scales as the square of plasma density and square of depth of density ripple, and is ∼0.2% for normalized laser amplitude ao∼1 in a plasma of 1% critical density with 20% density ripple. The theory explains several features of a recent experiment.

Analysis of Indentation Creep

AbstractIncreasingly, indentation creep experiments are being used to characterize rate-sensitive deformation in specimens that, due to small size or high hardness, are difficult to characterize by more conventional methods like uniaxial loading. In the present work we use finite element analysis to simulate indentation creep in a collection of materials whose properties vary across a wide range of hardness, strain rate sensitivities, and work hardening exponents. Our studies reveal that the commonly held assumption that the strain rate sensitivity of the hardness equals that of the flow stress is violated except for materials with low hardness/modulus ratios like soft metals. Another commonly held assumption is that the area of the indent increases with the square of depth during constant load creep. This latter assumption is used in an analysis where the experimenter estimates the increase in indent area (decrease in hardness) during creep based on the change in depth. This assumption is also strongly violated. Fortunately, both violations are easily explained by noting that the “constants” of proportionality relating 1) hardness to flow stress and 2) area to (depth)2 are actually functions of the hardness/modulus ratio. Based upon knowledge of these functions it is possible to accurately calculate 1) the strain rate sensitivity of the flow stress from a measurement of the strain rate sensitivity of the hardness and 2) the power law exponent relating area to depth during constant load creep.

ROENTGENOLOGICAL DETERMINATION OF THE HEART VOLUME OF RATS

AbstractA method for X‐ray determination of the heart volume of rats is described. Using general anesthesia the heart was X‐rayed in the frontal and sagittal planes. The relative volume of the heart, calculated from the length, breadth and depth was multiplied by the correction factor of 0.44 to obtain the absolute volume. The correction factor has been estimated by empirical analysis in heart models. The relationship between length (a), breadth (b) and the square of depth (c). i.e c2/a×b; does not change during growth. The standard error of estimate for a single determination calculated from 168 duplicated determinations was 7.3 %.

壓延工場に於ける加熱爐の熱能率と鋼片の大小に據る損得比較其他に就て

As an example of reheating furnace of billets, a furnace for wire rod mill was taken as the subject for the present investigation. The writer measured the temperature of billets heated in the furnace and of the waste gas passing through the flue. He theoretically calculated the beat efficiency, the size of billet and the ra'e of heating, which he compared with the results of the present experiment in order to find out the difference in heat efficiency & etc. due to the size of billets.Summary of Conclusions.1. The temperature in the furnace gradually decreases from the fire-grate to the flue; being on average 1, 230°C at the fire-grate and 474°C at the flue (Figs. 1-3).2. The fall of temperature due to bad combustion practice is sensibly large at the part of higher temperature near the fire-grate, but does not affect so much at the other parts of the furnace (Fig. 2).3. The average surface temperature of the heated billets taken out of the furnace was 1, 226°C, every billet having been kept heating in the furnace for about 56 minutes and a half (Tab. 1-2).4. The heat capacity of the heating furnace to be contained at its stationary state is equivalent to 2.32 Kgr. tons of coal, which being equal to about 53 per cent of the fuel fired in the furnace to obtain the same state.5. The loss of heat due to radiation and conduction & etc. is about 13.1 per cent of the total amount of fuel fired.6. The heat which was carried out by billet is about 22.68 per cent of the total fuel.7. The heat to be carried away by ashes is about 1.13 per cent of the total fuel used.8. The heat which was carried away by the waste gas through the flue amounts to about 56.5 per cent of the total heat evolved by the fuel fired.9. From the equation of heat conduction, the relation between the thickness of the billet and the heating time was calculated; the results shows that the increase of the heating time was proportional to the square of depth (Figs. 8-9).10. Of two kinds of billets of sizes respectively 9.6×9.6×102.0cm. and (9.6×2)×(9.6×2) ×102.0cm., when heated in the furnace under the same condition, the former required 0.127 tons of coal per ton of billet and the latter 0238 tons of coal, the heat efficiencies of both being respectively 22.68 per cent and 12.20 per cent. It was found by calculation that the increase in depth caused the increase of coal used, but on the contrary, the heat efficiency diminished (Figs. 10-11).11. In billets of the above sizes, it was found that when they were charged in the furhace kept at 1, 240°C, the former required 22 minutes to reach 1, 000°C at the centre, while the latter, an hour and 32 minutes to reach the same temperature at the same point.12. Six kinds of specimens of cube and four kinds of billets were charged in the furnace kept at 900°C in order to observe the time taken by the temperature of the surface and that at the centre of the specimen to feach 900°C (Figs. 12-15).13. The fact that the increase in thickness of a billet caused the increase of heating time in proportion to the square of it was experimentally ascertained. If x be the thickness of plate, or a side of cube or the cross section of billet, and t be the time taken by the temperatures of the respective specimens to reach the same height at their centres, then. x2=at (Fig. 16).