Parallel Light Research Articles

Ґендер у Країні сонця, що сходить (за дослідженнями російських японістів). Частина 1

The gender situation in the cosmogonic myths of the peoples of Japan is considered on the example of mythopoetry of the Ryukyu region, as well as the influence of these myths on the gender balance of the old Ryukyu societies both before Christ era and from its beginning up to the 19th century. The researcher E. Baksheev, based on the achievements of N. Nevsky – the founder of the Russian School of Japanese Studies, as well as his colleague A. Sadokova, reconstructed the role of a woman in the ancient Japanese society on the example of mythopoetry of the Ryukyu region. The chronicles «Records of Omorho Songs» (1532 – 1623), «Records about the path of the Ryukyu gods» (1603 – 1606) by the Japanese monk Taytyu: Rio: teya, «The Mirror of the Generations of Thu: Dzan – the Kingdom of the Ryukyu» (1650), «The Genealogy of Thu: Dzan» (1697 – 1701, 1874), «The Rite of the High Priestess» (1875) were the sources of the research. In the Japanese society, before the Meiji Revolution, at all social levels of its organization, along with a man who had socio-political and economic power – from the head of the house to the head of the rural community and, further, to the regional ruler and the king – there was a priestess (a relative and mainly a sister). Her functions were to rely on the authority of the leader spiritually and ritually, relying on the deities’ «will». The kings of Ryukyu were forced to rely on mediation of the priestesses so that siji (shōjo magic power) would come from the Other (parallel) light to protect the throne and the prosperity of the state in this light. In those old times, the status of such a priestess was even higher than that of a male ruler who ruled on her behalf. The Russian specialists on Japan define such a structure of power as diarchy («dual power»), and the system of government as theocratic. In the terminology of Japanese researchers, the theocratic system of government is called as the policy of «unity of worship and governance». In the XIII – XIV centuries the local and regional rulers were put under the control of the King Ryukyu. The priestesses also lost their independence and had to obey the High Priestess from the royal family. A single secular and religious power was divided into the highest (court) and lower (local) levels. A special feature of the Ryukyu mythology is the late records of the texts with preservation of many archaic motifs and their «applied», frankly social and political biased character. One of the main tasks of such myths was consecration of the status of the ruling elite and the magical assertion of its high status to support the current social hierarchy. «The Records of Omoro songs» (a poetic anthology in 22 volumes, which includes 1,553 old ritual priestly chants), as well as «The Records about the path of the Ryukyu gods» were not completed as in the early 17th century the Kingdom of Ryukyu became the target of aggression from the Japanese clan Satsuma and was under its indirect control. The following chronicles were created under different ideological supervision, which, however, did not change their essence. Also in the period of the 9th – 14th centuries, as an exception, the rare images of a female warrior appeared, and then disappeared in the 16th – 19th centuries before the Meiji Revolution, being replaced massively by the disenfranchised Japanese women – the wives of samurai, peasants, artisans and merchants. After the Meiji revolution in 1879, the government of Japan established the Okinawa prefecture.

Optimization design and realization of a keratometer

To realize a simplified keratometer, we proposed a design proposal based on corneal reflex imaging. Six pointolites which arranged in a regular hexagon were used to emit parallel light to the surface of a cornea and were reflected by the cornea. Then the image was captured by a telecentric optical system in the object space to a CMOS camera. In order to obtain the corneal curvature, the distance between two pointolites located on the regular hexagonal diagonal in the corneal reflection images were calculated by using the center of gravity algorithm. The imaging quality, measuring range and measuring precision of the system were theoretically analyzed, and the Ziess's model eye and human eyes were used to conduct experiments to verify the theoretical analysis results. The experiment results have shown that the precision of the measurement error is ±0.02 mm and the measurement range is from 5.5 mm to 11.6 mm (30 m-1 to 60 m-1 in diopter of cornea). The research will provide technical supports for the design and optimization of automatic keratometer.

Circadian pacemaker neurons of the Madeira cockroach are inhibited and activated by GABAA and GABAB receptors.

GABA is the most abundant neurotransmitter in the circadian pacemaker circuits of mammals and insects. In the Madeira cockroach the accessory medulla (AME) in the brain's optic lobes is the circadian clock that orchestrates rest-activity rhythms in synchrony with light dark cycles. Three prominent GABAergic tracts connect the AME to termination sites of compound eye photoreceptors in the lamina and medulla. Parallel GABAergic light entrainment pathways were suggested to either advance or delay the clock for adjustment to changing photoperiods. In agreement with this hypothesis GABA activated or inhibited AME clock neurons, allowing for the distinction of three different GABA response types. Here, we examined which GABA receptors are responsible for these response types. We found that both ionotropic GABAA receptors and metabotropic GABAB receptors were expressed in AME clock cells. Via different signalling pathways, either one of them could account for all three GABA response types. The muscimol-dependently activated GABAA receptor formed a chloride channel, while the SKF 97541-dependently activated GABAB receptor signalled via G-proteins, apparently targeting potassium channels. Expression of chloride exporters or importers determined whether GABAA receptor activation hyper- or depolarized AME neurons. For GABAB receptor responses second messenger gated channels present in the clock cells appeared to decide about the polarity of the GABA response. In summary, circadian clock neurons co-expressed inhibitory and/or excitatory GABAA and GABAB receptors in various combinations, while cotransporter expression and the set of second messenger gated ion channels present allowed for distinct signalling in different clock neurons.

Global tool path optimization of high-resolution image reproduction in ultrasonic modulation cutting for structural coloration

Abstract Diffraction gratings are capable of splitting and diffracting parallel white light into a wide diffractive spectrum containing light with different wavelengths travelling in different directions. The apparent angle-dependent color effect is a form of structural coloration. In this paper, a rendering strategy for grating-induced high-resolution image reproduction has been demonstrated based on tool path optimization. The grating structures are generated by ultrasonic modulation cutting due to the cutting depth modulation. The high-resolution image rendering is accomplished by tailoring the interaction between visible light and grating structures through the design and optimization of the distribution of machined grating arrays. Fabricating the desired grating arrays requires a complex objective tool path with ever-changing discontinuous step velocity profiles, which is not achievable for any existing machine tools considering the limited acceleration capability. Unlike conventional toolpath optimization methods, the proposed research aims to relate the cutting process to high-resolution image rendering performance and optimize the quality of machined images through optimally approximating the objective tool velocity-location curve with a series of parametric splines in terms of minimum overall velocity error. A recursive optimization method has been developed to ensure the global optimum of the tool velocity profile considering the physical limitation of motion axes. The fitting performance of proposed method is quantitatively analyzed and evaluated through the simulation and experiment by comparing the real-time velocity-location profiles to the objective curves. In addition, the reproduction quality of machined images is evaluated by measuring the similarity between the reproduced and original images with both simulation and experimental results.

The Improved Canopy Shading Model Based on the Apple Intercropping System (Case Study: Loess Plateau, China)

The canopy shading model is widely used in agroforestry systems. However, the canopy shading model cannot be verified by the measured shading distribution of an apple tree due to the uneven ground and adjacent apple trees. This paper measures the spatial‒temporal distribution of the shading of apple trees based on the similarity principle of parallel solar light combined with 3D printing technology to improve the canopy shading model. The following results are drawn: (1) The current widely used canopy shading model does not consider the effect of the canopy penumbra, resulting in poor simulation accuracy in the shading distribution compared to the actual measurement; (2) The effect of canopy penumbra causes the deflection of sunlight. Hence, the paper presents the deflection equation of sunlight with statistically defined parameters derived using measured data of the shading distribution. The deflection equation of sunlight is added to the improved canopy shading model. The improved model can accurately simulate the shading distribution of an apple tree, and the simulation accuracy exceeds 94.12% when compared with the shading distribution of an apple tree; (3) The improved canopy shading model is applied to simulate the spatial‒temporal distribution of the shading of apple trees in a conventional arrangement (4 m × 5 m), and the simulation accuracy exceeds 89%. Thus, the improved canopy shading model can be applied to simulate the spatial‒temporal distribution of shading of apple trees.

Nonlinear mapping method for the generation of an elemental image array in a photorealistic pseudoscopic free 3D display.

Limited available elemental image array resources may be the most severe bottleneck for the promotion and application of integral-imaging-based 3D display. We propose a nonlinear mapping method for the generation of an elemental image array to get a photorealistic pseudoscopic free 3D display based on the parallel light field reconstruction nature of the integral imaging system. All the light rays emitted from the display panel are classified into a corresponding parallel light field according to its direction, and all the parallel light fields are captured as orthogonal projections of the scene before synthesizing all the orthogonal projections using a nonlinear mapping method to form the final elemental image array. Preliminary optical experiments as well as ray optical analysis are conducted to prove the feasibility and validity of the proposed method. The proposed method can exploit most of the current 3D platform. It is an effective and efficient way to generate an elemental image array.

Large-area single photon compressive imaging based on multiple micro-mirrors combination imaging method

We demonstrate a single photon compressive imaging system with the image plane up to the entire digital micro-mirror device (DMD) work area. A parallel light source is designed to reduce the influence of light scattering on imaging resolution and a photon counting photomultiplier tube (PMT) with a large photosensitive area is used to effectively collect light reflected from the full screen of DMD. A control and counting circuit, based on Field-Programmable Gate Array (FPGA), is developed to load binary random matrix into the DMD controller for each measurement, and to count single-photon pulse output from PMT simultaneously. To reduce imaging time and huge memory occupation for image reconstruction, a multiple micro-mirrors combination imaging method is proposed. The signal-to-noise ratio and detection limit of the imaging system is theoretically deduced. Theoretical analysis and experimental results show that micro-mirrors combination imaging method is more suitable for faster imaging in a weaker-light-level environment. In order to achieve high imaging quality, the size of the combined pixels and the average time of each measurement should be moderate, so that the impact of Poisson shot noise is minimized.

Wine glass caustic and halo analogies.

This paper aims to develop an understanding of a peculiar hourglass-shaped caustic that can be observed if a partially filled wine glass is illuminated by parallel light. The light pattern is first described in terms of an idealized model of the liquid volume only: the sum of the parametric projection curves obtained by light refraction through liquid cones of varying wall inclinations in the framework of geometrical optics. Within this analysis, analogues to two specific refraction ice halos, the circumzenithal and the Parry arc, will prove to be helpful. The analysis is supplemented by ray tracing simulations that further elucidate the origin of the hourglass caustic when the glass is added to the refraction scenario.

Design of a high-precision and non-contact dynamic angular displacement measurement with dual-Laser Doppler Vibrometers

A wide dynamic range, high precision, non-contact and large bandwidth angular displacement measurement (ADM) is greatly necessary for the applications such as industrial control and military equipment. This paper proposes a simple and effective ADM method based on Doppler Effect, heterodyne detection and diffuse reflection, which can fulfill these requirements simultaneously. Two beams of parallel light generated by a pair of laser Doppler vibrometers are incident upon the surface of rotational target, then data processing unit acquires the velocity of dual laser incident points on the moving target, and resolves the rotational angular displacement and translation displacement of target through the relationship between dual laser beams dynamically. Several major measurement errors that may affect the ADM accuracy are analyzed. A high precision rotary table is used as an angular displacement standard to verify the measurement range and accuracy, the verification experiment shows that the measurement range is not less than ±10° and the measurement accuracy is 0.0362° based on the method. After using a polynomial error compensation, the measurement accuracy can be promoted to 0.0088°, and this compensation method can be applied to real time measurement.

Research on grating surface microstructure for the chromatic aberration compensation in infrared band

At present, there are problems of large wavelength span and large system volume for the chromatic aberration correction in the infrared band, which is harmful to the miniaturization of the optical system, while, there are problems of low design freedom and low selectivity for the optical material. We designed a grating surface microstructure for infrared chromatic aberration correction. By analyzing the chromatic aberration correction of two common infrared wavebands of 4.8 μm and 10.6 μm, we focused on grating microstructure design. Taking the infrared chromatic aberration of the ZnSe lens as an example, the scattering surfaces of the two kinds of grating cell structures were simulated by FDTD method. The simulation results show that the single square cylinder grating microstructure performed a phase retardation of 1.4π at 4.8 μm and 0.7π at 10.6 μm, as a result the compensation effect was not good. While, the phase retardation of double square cylinders grating microstructure at 4.8 μm was 1.5π, and the all-phase modulation for range of 0–2π at 10.6 μm waveband had been achieved, which is suitable for infrared chromatic aberration compensation. The geometric parameters of the double square cylinders microstructure were designed to be L1 = 400 nm, L2 = 950 nm and K = 500 nm. Fabricate double square cylinders grating microstructure sample on the germanium substrate by the standard semiconductor fabrication technology. Profiler tested the structure parameters, and the results were shown as: L1 = 408 nm, L2 = 944 nm, and the height of the square cylinder is K = 495.32 nm, surface roughness is 16.32 nm; the peak transmissivities of two infrared bands for 4.7–4.9 μm and 10.5–10.7 μm were reached 65% and 62%; the test light path of longitudinal chromatic aberration was established by using the principle of parallel light measuring longitudinal chromatic aberration. After adding sample, the longitudinal chromatic aberration for the infrared waves were reduced by 55%, which proved the effect of the micro-nano structure device on the chromatic aberration correction in infrared band. Compared with traditional lens gluing and other technologies, this technology has the advantages of light weight, small size, high design freedom and good effect on chromatic aberration correction.

Nocte Is Required for Integrating Light and Temperature Inputs in Circadian Clock Neurons of Drosophila

Circadian clocks organize biological processes to occur at optimized times of day and thereby contribute to overall fitness. While the regular daily changes of environmental light and temperature synchronize circadian clocks, extreme external conditions can bypass the temporal constraints dictated by the clock. Despite advanced knowledge about how the daily light-dark changes synchronize the clock, relatively little is known with regard to how the daily temperature changes influence daily timing and how temperature and light signals are integrated. In Drosophila, a network of ∼150 brain clock neurons exhibit 24-hr oscillations of clock gene expression to regulate daily activity and sleep. We show here that a temperature input pathway from peripheral sensory organs, which depends on the gene nocte, targets specific subsets of these clock neurons to synchronize molecular and behavioral rhythms to temperature cycles. Strikingly, while nocte1 mutant flies synchronize normally to light-dark cycles at constant temperatures, the combined presence of light-dark and temperature cycles inhibits synchronization. nocte1 flies exhibit altered siesta sleep, suggesting that the sleep-regulating clock neurons are an important target for nocte-dependent temperature input, which dominates a parallel light input into these cells. In conclusion, we reveal a nocte-dependent temperature input pathway to central clock neurons and show that this pathway and its target neurons are important for the integration of sensory light and temperature information in order to temporally regulate activity and sleep during daily light and temperature cycles.

A least-squares method for the inverse reflector problem in arbitrary orthogonal coordinates

In this article we solve the inverse reflector problem for a light source emitting a parallel light bundle and a target in the far-field of the reflector by use of a least-squares method. We derive the Monge–Ampère equation, expressing conservation of energy, while assuming an arbitrary coordinate system. We generalize a Cartesian coordinate least-squares method presented earlier by Prins et al. [13] to arbitrary orthogonal coordinate systems. This generalized least-squares method provides us the freedom to choose a coordinate system suitable for the shape of the light source. This results in significantly increased numerical accuracy. Decrease of errors by factors up to 104 is reported. We present the generalized least-squares method and compare its numerical results with the Cartesian version for a disk-shaped light source.

Zebra textures in carbonate rocks: Fractures produced by the force of crystallization during mineral replacement

Zebra textures are enigmatic banded fabrics that occur in many carbonate-hosted ore deposits, dolomite hydrocarbon reservoirs and carbonate successions globally. They consist of a variety of minerals and are characterised by parallel light and dark bands that occur at a millimetre- to centimetre-scale. Based on petrological evidence, there is general consensus that the dark bands formed by replacement of the carbonate host rock. Historically, more contention surrounds the origin of the light bands, but the dominant view is that these are mineral-filled cavities, which is supported by overwhelming textural evidence. Overall, the feature common to all versions of zebra textures is mineral replacement of the original carbonate host.We suggest that mineral replacement (and the force of crystallization) in association with open space generation is a viable mechanism for the development of zebra cavity systems. Dissolution and open space generation in either evaporites or carbonates adjacent to the site of replacement reactions is necessary to remove the confining pressure from the rock and to allow the development of fractures. The pressure of the growing replacement crystals within the carbonate pervasively splits the carbonate apart, producing thin strips of carbonate surrounded by open space. The fractures may then be subject to dissolution and are later filled by cements. Very regular stratabound zebra textures (as found in ore deposits like Cadjebut, Australia and San Vicente, Peru) may be related to stratabound dissolution (of evaporites or carbonates), whereas irregularly distributed zebra textures are more likely to be associated with irregular carbonate dissolution.

High-performance parallel hexapod-robotic light abrasive grinding using real-time tool deflection compensation and constant resultant force control

In robotic grinding, significant tool deflection occurs due to the lower stiffness of the manipulator and tool, compared with operation by universal grinding machines. Tool deflection during robotic grinding operation causes geometrical errors in the workpiece cross section. Also, it makes difficult to control the grinding cutting depth. In this study, a method is proposed for calculation of the tool deflection in normal and tangential directions based on grinding force feedback in these directions. Based on calculated values, a real-time tool deflection compensation (TDC) algorithm is developed and implemented. Force interaction between the tool and workpiece is significant for grinding operation. Implementing grinding with constant normal force is a well-known approach for improving surface quality. Tool deflection in the robotic grinding causes orientation between the force sensor reference frame and tool reference frame. This means that the measured normal and tangential forces by the sensor are not actual normal and tangential interaction forces between the tool and workpiece. In order to eliminate this problem, a resultant grinding force control strategy is designed and implemented for a parallel hexapod-robotic light abrasive surface grinding operation. Due to the nonlinear nature of the grinding operation, a supervised fuzzy controller is designed where the reference input is identified by the developed grinding force model. This grinding model is optimized for the robotic grinding operation considering setup stiffness. Evaluation of the experimental results demonstrates significant improvement in grinding operation accuracy using the proposed resultant force control strategy in parallel with a real-time TDC algorithm.

Variable aperture-based ptychographical iterative engine method.

A variable aperture-based ptychographical iterative engine (vaPIE) is demonstrated both numerically and experimentally to reconstruct the sample phase and amplitude rapidly. By adjusting the size of a tiny aperture under the illumination of a parallel light beam to change the illumination on the sample step by step and recording the corresponding diffraction patterns sequentially, both the sample phase and amplitude can be faithfully reconstructed with a modified ptychographical iterative engine (PIE) algorithm. Since many fewer diffraction patterns are required than in common PIE and the shape, the size, and the position of the aperture need not to be known exactly, this proposed vaPIE method remarkably reduces the data acquisition time and makes PIE less dependent on the mechanical accuracy of the translation stage; therefore, the proposed technique can be potentially applied for various scientific researches.

Methodology of filter-type multi-dithering phase control for quasi parallel light interference

The quasi parallel light interference is one kind of basic ways to use the energy of interference light to interact with matter. Because the phase of each parallel light beam needs to meet the coherent condition, it is required that the phase of each light beam be controlled timely. There are some kinds of phase control methods, such as the heterodyne phase-locking method, the stochastic parallel gradient descent algorithm, the self-referred and self-synchronous phase-locking method the multi-dithering phase-locking method, etc. Among them, the multi-dithering method needs not the referenc light, it is to load multi-frequency sinusoid signals to the phase modulator, and realize the recognition of phase difference and the output of feedback voltage by multiplying circuit and integrating circuit. In view of the shortcomings of the existing methods, a scheme of filter-type multi-dithering phase control for quasi parallel light interference is proposed, in which the phase differences are identified and corrected by the modulation signals and filtering signals of different frequencies. Theoretical analysis of coherent light intensity for the scheme is made. The principle of filter-type multi-dithering phase control method is put forward, and the numerical analysis and simulation experiment for filter-type multi-dithering phase control method are carried out. In the simulation experiment, the fiber interference light path is used to simulate the light intensity of quasi parallel light interference at one point in space, and the change of photoelectric signal indicates the change of interference light intensity. The phase control feedback loop is composed of photoelectric signal amplifying circuit, bandpass filtering circuit, amplitude measuring circuit, direct current amplifying circuit and adder circuit. The results have shown that the phase difference among light beams can be recognized by the method, and the direct current voltage signal that is proportional to the phase difference of signal can be fed to control the phase modulator. The phase difference can be corrected. The control bandwidth is 2.5 kHz, and the output voltage range of phase control is 0.034.45 V. Compared with the classical multi-dithering method, the method of filter-type multi-dithering phase control has some advantages. Each multiplying circuit in the classical method needs a very small amplitude reference signal, which causes the reference signal to have a very small range of values, and the relationship between integral time and modulation period needs considering. The integral time is usually ten times longer than the modulation period, which causes the control bandwidth of the system to decrease. However, the feedback loop of the filter-type multi-dithering phase control method does not require any reference signal, so each signal does not affect each other, and the increase in the number of beams does not have a significant influence on the control bandwidth either. Therefore the filter-type multi-dithering phase control method is a useful phase-control method.

大面积高均匀度平行光曝光机用自由曲面复眼透镜设计

大面积高均匀度平行光曝光机用自由曲面复眼透镜设计

Mechanism of Sunlight Damage on Drip Tape by Pendant Droplets in Mulched Drip Irrigation

Abstract. Drip irrigation under mulch has been applied in China for nearly 20 years, but sunlight damage from the lens effect through droplets beneath clear plastic mulch is always a problem that cannot be ignored. Droplet volume and mulch wettability affect the geometric parameters of the pendant droplets. Changes in geometric parameters were experimentally investigated by analyzing side-view images of droplets. Models were built to predict droplet focal length and light-gathering power based on the geometric parameters. A comparison between numerical and optical experimental results suggested that the focal length model was accurate and reliable. The effective incident area of the parallel light proposed in this study could also be used to represent the light-gathering power, which had a relationship with the drip tape burning rate. The increase in wettability of the clear mulch considerably increased the focal length of the pendant droplets, expanded the focal length range, enhanced the light-gathering power, and thus increased the risk of drip tape burning. In practice, pendant droplets with a wetting radius of 3 to 5 mm, with corresponding focal lengths of 5 to 12 mm, have a high probability of emergence. Therefore, the distance between the mulch and drip tape should be beyond this focal length range to reduce the risk of drip tape burning by pendant droplets. In addition, filming the mulch surface with hydrophobic materials to increase the contact angles of droplets can also protect the drip tape from sunlight damage. Keywords: Drip irrigation under mulch, Drip tape burning, Effective incident area of parallel light, Focal length, Pendant droplet.

Shock waves generated by sudden expansions of a water jet

Direct shadowgraph with parallel light combined with high-speed recording has been used to analyze the water jet of a cutting machine. The use of image processing allowed observing sudden expansions in the jet diameter as well as estimating the jet velocity by means of the Mach angle, obtaining velocities of about $$500\,\hbox {m}\,\hbox {s}^{-1}$$ . The technique used here revealed the development of hydrodynamic instabilities in the jet. Additionally, this is the first reporting of the onset of shock waves generated by small fluctuations of a continuous flow of water at high velocity surrounded by air, a result confirmed by a transient computational fluid dynamics simulation.

Parallel light configuration that increases the radiation tolerance of integrated circuits

Total ionizing dose tolerances of current integrated circuits are limited to 3–10 kGy because semiconductor devices are fundamentally vulnerable to radiation. However, using programmable architecture, the total ionizing dose tolerances of integrated circuits can be increased if the integrated circuits can be repaired each time a permanent failure occurs. Nevertheless, current programmable devices cannot allow such repairable use because their serial programming functions fail immediately, even if only a few transistors on the devices are damaged. To increase the radiation tolerance of integrated circuits, this paper presents a proposal of a new optoelectronic programmable device with a parallel light configuration architecture instead of current field programmable gate arrays which have a serial configuration architecture. This demonstration confirms 1.9 MGy radiation tolerance on an optoelectronic programmable device using a non-radiation-hardened standard complementary metal oxide semiconductor process.