Star Pattern Research Articles

An Electromagnetic-Driven Microshutter Array in a Field-of-View Gated Image System for All-Time Star Sensors

Aiming at the application requirements of a field of view (FOV) gated imaging system for all-time star sensors, a key device of a microshutter array with large unit size, high duty cycle, and fast response speed based on the electromagnetic actuation is designed. The proposed microshutter array adopts the principle that the current-carrying coil is subjected to the magnetic force in the magnetic field. The coil element is deflected by the loading current and acts as a light barrier in realizing the optical switch function. The effects of the coil element parameters on the magnetic force torque, torsion beam resistance torque, and switch response time are analyzed, and the structural parameters of the coil element are determined. A sample of the proposed microshutter array based on the electromagnetic actuation with a 4-mm period and a 2.8-mm aperture is fabricated and tested. The test results demonstrate the good switching function of the proposed microshutter array and show that the switch response time of the microshutter element is approximately 2.5 ms. This proposed microshutter array is used to gate an instantaneous small FOV to suppress the sky's background radiation and make a FOV-gated imaging system realize the multi-stars detection by switching the gated FOV rapidly. This will solve the problem that only one star can be detected within the FOV by a traditional all-time star tracker and promote the all-time star sensor to realize star pattern recognition and autonomous astronomical navigation in the daytime.

Pola Komunikasi antara Pengasuh dan Anak Asuh dalam Pembinaan Kedisiplinan Hafalan Al Qur’an di Pondok Zawiyatul Huffazh Kecamatan Air Joman

Children in the Air Joman sub-district attend school in Pondok Zawiyatul Huffazh, a non-formal education institution that teaches subjects based on the Qur'an. This pesantren emphasizes reading and memorizing the Qur'an more than anything else. Discipline in memorizing children's verses of the Qur'an is largely influenced by the communication style of caregivers and children they care for. This study focuses on communication patterns that foster discipline in memorizing the Qur'an between foster children and their caregivers, communication methods that foster discipline in memorizing the Qur'an between foster children and their caregivers, as well as supporting and inhibiting factors. patterns of communication between foster children and caregivers. Researchers used qualitative research methods in this study. where observation, interviews with various informants, and documentation were used to collect data Information collection was carried out through direct perception in the field, as well as direct inclusion with the guardians and principals of Zawiyatul Huffazh's life experiences. In addition, this study refers to Josep A. Devito's theory of communication patterns which states that there are five kinds of communication patterns: circle patterns, chain patterns, wheel patterns, and star patterns. The purpose of this study is to find out more about the communication patterns that exist between foster children in coaching in Air Joman District and their caregivers. Through this study, the findings from interviews and observations can also be examined to find out whether communication patterns have sufficient impact on the practice of memorizing the Qur'an.

Pointing correction technology of telescope of mobile tracking station based on star pattern matching deviation calibration

Pointing correction technology of telescope of mobile tracking station based on star pattern matching deviation calibration

TheGaia-ESO Survey: Probing the lithium abundances in old metal-rich dwarf stars in the solar vicinity

Context.Lithium (Li) is a fragile element that is produced in a variety of sites but can also be very easily depleted in stellar photospheres. Radial migration has been reported to explain the decrease in the upper envelope of Li measurements observed for relatively old metal-rich dwarf stars in some surveys.Aims.We test a scenario in which radial migration could affect the Li abundance pattern of dwarf stars in the solar neighbourhood. This may confirm that the Li abundances in these stars cannot serve as a probe for the Li abundance in the interstellar medium (ISM). In other words, to probe the evolution of the Li abundance in the local ISM, it is crucial that stellar intruders be identified and removed from the adopted sample.Methods.We used the high-quality data (including Li abundances) from the sixth internal Data Release of theGaia-ESO survey. In this sample we grouped stars by similarity in chemical abundances via hierarchical clustering. Our analysis treats both measured Li abundances and upper limits.Results.The Li envelope of the previously identified radially migrated stars is well below the benchmark meteoritic value (<3.26 dex); the star with the highest detected abundance has A(Li) = 2.76 dex. This confirms the previous trends observed for old dwarf stars (median ages ∼ 8 Gyr), where Li decreases for [Fe/H] ≳ 0.Conclusions.This result is supporting evidence that the abundance of Li measured in the upper envelope of old dwarf stars should not be considered a proxy for the ISM Li. Our scenario also indicates that the stellar yields for [M/H] >0 should not be decreased, as recently proposed in the literature. Our study backs recent studies that claim that old dwarfs on the hot side of the dip are efficient probes of the ISM abundance of Li, provided atomic diffusion does not significantly lower the initial Li abundance in the atmospheres of metal-rich objects.

Spezifische OCT-Veränderungen bei einer neuen Mutation im RS1-Gen bei X-chromosomal-rezessiver Retinoschisis

X-linked retinoschisis (XLRS) is a rare vitreoretinal dystrophy caused by molecular genetic changes in the RS1 gene. It usually manifests itself at a young age with symmetrical splitting within different layers of the retina and leads to a significant reduction in visual acuity. Correct diagnosis at older ages is difficult due to nonspecific changes in OCT scans. We report the morphological changes in OCT scans at different stages of life in a family with XLRS and a novel mutation in the RS1 gene. Our 78-year-old index patient presented with visual disturbances that he had experienced since his childhood. After a detailed anamnesis, complete clinical examination and measurement with SD-OCT, we performed germline genetic testing using whole blood DNA on the index patient, his clinically unaffected daughter and her clinically affected son. The OCT examination of the index patient showed nonspecific atrophic macular changes on both sides. A fundoscopy of the 8-year-old grandson showed the typical macular star pattern. The OCT scan showed the typical retinoschisis of the macula. The genetic analysis revealed thepreviously undescribed pathogenic variant c.487T>G; p.Trp163Gly in the RS1 gene in all 3patients. The typical fundus image and OCT pattern, which are absent in the 78-year-old patient, are also present in childhood with the novel RS1 mutation. Our case shows that even with nonspecific changes in the OCT scans, a detailed family history can provide important information on X-linked recessive inheritance and thus for an appropriate molecular genetic diagnosis, so that rare retinal diseases can be diagnosed even at an advanced age.

Higher Concentration of Dietary Selenium, Zinc, and Copper Complex Reduces Heat Stress-Associated Oxidative Stress and Metabolic Alteration in the Blood of Holstein and Jersey Steers.

This study investigated the influence of high concentrations of dietary minerals on reducing heat stress (HS)-associated oxidative stress and metabolic alterations in the blood of Holstein and Jersey steers. Holstein steers and Jersey steers were separately maintained under a 3 × 3 Latin square design during the summer conditions. For each trial, the treatments included Control (Con; fed basal TMR without additional mineral supplementation), NM (NRC recommended mineral supplementation group; [basal TMR + (Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm) as DM basis]), and HM (higher than NRC recommended mineral supplementation group; [basal TMR + (Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm) as DM basis]). Blood samples were collected at the end of each 20-day feeding trial. In both breeds, a higher superoxide dismutase concentration (U/mL) along with lower HSP27 (μg/L) and HSP70 (μg/L) concentrations were observed in both mineral-supplemented groups compared to the Con group (p < 0.05). The HM group had significantly higher lactic acid levels in Jersey steers (p < 0.05), and tended to have higher alanine levels in Holstein steers (p = 0.051). Based on star pattern recognition analysis, the levels of succinic acid, malic acid, γ-linolenic acid, 13-methyltetradecanoic acid, and tyrosine decreased, whereas palmitoleic acid increased with increasing mineral concentrations in both breeds. Different treatment groups of both breeds were separated according to the VIP scores of the top 15 metabolites through PLS-DA analysis; however, their metabolic trend was mostly associated with the glucose homeostasis. Overall, the results suggested that supplementation with a higher-than-recommended concentration of dietary minerals rich in organic Se, as was the case in the HM group, would help to prevent HS-associated oxidative stress and metabolic alterations in Holstein and Jersey steers.

POLA KOMUNIKASI KELOMPOK FATAYAT NU TANGERANG DALAM PEMBENTUKAN KARAKTER HIDUP SEHAT PADA KEGIATAN “SHARING SEHAT BERSAMA FATAYAT”

The family is the foundation of the formation of a healthy living character, because it is from the family that the formation of a healthy living character actually begins. Good or bad a person's healthy way of life is clearly determined by the parenting pattern developed in the family. A mother becomes a good uswatun hasanah for her children, in realizing the child into a whole person who brings goodness to himself, his family, society, country, and the universe (maslahah). Approach The group communication pattern applied is an approach that can be better understood as a pattern of interaction than as a set of specific skills. This study aims to determine the pattern of communication in Healthy Sharing activities with Fatayat. This study was dissected based on the concept of group communication patterns, using a qualitative approach research method with a descriptive method. The results of the research are communication patterns, communication patterns, network communication schemes, all channels or star patterns and communication patterns, group interaction analysis, and character education by interacting and sharing education.

High-velocity Stars in SDSS/APOGEE DR17

We report 23 stars having Galactocentric velocities larger than 450 km s−1 in the final data release of the APOGEE survey. This sample was generated using space velocities derived by complementing the high-quality radial velocities from the APOGEE project in Sloan Digital Sky Survey’s Data Release 17 (DR17) with distances and proper motions from Gaia early Data Release 3 (eDR3). We analyze the observed kinematics and derived dynamics of these stars, considering different potential models for the Galaxy. We find that three stars could be unbound depending on the adopted potential, but in general all of the stars show typical kinematics of halo stars. The APOGEE DR17 spectroscopic results and Gaia eDR3 photometry are used to assess the stellar parameters and chemical properties of the stars. All of the stars belong to the red giant branch, and, in general, they follow the abundance pattern of typical halo stars. There are a few exceptions that would deserve further analysis through high-resolution spectroscopy. In particular, we identify a high-velocity Carbon-Enhanced Metal-Poor star, with a Galactocentric velocity of 482 km s−1. We do not confirm any hypervelocity star in the sample, but this result is very sensitive to the adopted distances and less sensitive to the Galactic potential.

IDVS: interactive 2D and 3D visualizations of proximal sensor data for rapid characterization of soil profiles

Knowledge of the soil’s physical and chemical properties in field-scale geographical areas is crucial for farmers and policymakers for agronomic productivity and environmental quality assessment. Proximal sensors can successfully model soil properties for these purposes and offer a way to rapidly acquire data from soil profiles. However, existing data analysis approaches are ill-suited to explore this type of multivariate proximal sensor data over large land areas and in a sizeable three-dimensional volume. Therefore, this work proposes a multifaceted approach with seamless integration of a star pattern for soil sample collection, data acquisition using proximal sensor devices, and an interactive data visualization solution for processing, analyzing, and reporting analysis results. This solution is the result of an interdis- ciplinary project in which data visualizers worked closely with soil scientists and agronomists to develop a tool called iDVS for rapid characterizations of soil profiles over larger geographical areas using proximal sensor technologies.

V1294 Aql = HD 184279: A bad boy among Be stars or an important clue to the Be phenomenon?

A reliable determination of the basic physical properties and variability patterns of hot emission-line stars is important for understanding the Be phenomenon and ultimately, the evolutionary stage of Be stars. This study is devoted to one of the most remarkable Be stars, V1294 Aql = HD 184279. We collected and analysed spectroscopic and photometric observations covering a time interval of about 25 000 d (68 yr). We present evidence that the object is a single-line 192.9 d spectroscopic binary and estimate that the secondary probably is a hot compact object with a mass of about 1.1–1.2 M⊙. We found and documented very complicated orbital and long-term spectral, light, and colour variations, which must arise from a combination of several distinct variability patterns. Attempts at modelling them are planned for a follow-up study. We place the time behaviour of V1294 Aql into context with variations known for some other systematically studied Be stars and discuss the current ideas about the nature of the Be phenomenon.

A Star Pattern Recognition Algorithm Based on the Radial Companion-Circumferential Feature

Attitude measurement is an important core technology of vehicle flight. It is of great significance to ensure the vehicle’s accurate orbit entry and orbit change, high-performance flight, reliable ground communication, high-precision ground observation, and successful completion of various space missions. Star sensor is the core component to realize an autonomous attitude measurement of the vehicle. Autonomous star map recognition is a key technology in star sensor technology, and it is also the focus and difficulty of research. When the star sensor enters the initial attitude acquisition mode, according to the algorithm, the star sensor can quickly obtain the initial attitude and enter the normal working mode. This paper proposes a star pattern recognition algorithm based on the radial companion-circumferential feature with a noise compensation code to address the low recognition rate caused by position noise in the process of constructing star patterns in the traditional star pattern recognition algorithm based on the radial feature. In order to solve the problem of slow matching search speed, a maximum matching number algorithm has been innovatively adopted, which can improve the search efficiency in the process of star pattern recognition. Thus, the capacity of the star pattern recognition feature library is effectively reduced, and the stability and recognition rate of the improved star pattern recognition algorithm are further improved. The improved star pattern recognition algorithm first establishes radial and circumferential feature vectors based on the bit vector, then adds the noise compensation code according to the companion star position error, then modifies the radial and circumferential feature vectors, and finally calculates the minimum similarity difference between the feature vector of the star pattern observed by the star sensor and the feature vector of the navigation star in the feature library to obtain the unique star pattern recognition result. The identification star database adopts the maximum matching number algorithm, which can improve the search efficiency, reduce the amount of redundant matching, and shorten the matching time. The simulation results show that even in the presence of star position and magnitude noise, the improved star pattern recognition algorithm with radial companion-circumferential feature maintains a high recognition rate of more than 97 percent, demonstrating that the algorithm’s robustness is superior to other algorithms. The revised method described in this work outperforms the classic triangle algorithm and the radial feature star pattern recognition algorithm without compensation code in terms of algorithm robustness, recognition success rate, and recognition time.

CSPM: Discovering compressing stars in attributed graphs

Graphs, also known as networks, are an expressive data representation used in many domains. Numerous algorithms have been designed to find interesting patterns in graphs. However, they have at least one of two major drawbacks. First, most algorithms focus on finding complex subgraphs but ignore relationships between attributes. But attributes play a major role in several real-life applications such as for profile completion in social networks. Second, the user must generally set multiple parameters that greatly influence results but are unintuitive to set. To provide a solution to these issues, this paper introduces a novel algorithm named CSPM (Compressing Star Pattern Miner) for discovering compressing patterns in an attributed graph. The algorithm is parameter-free and discovers star-shaped attribute patterns that reveal strong relationships between attribute values by utilizing the concept of conditional entropy and the minimum description length principle. Extensive experiments on real data show that CSPM is efficient and can find insightful patterns. In particular, it is observed that the discovered patterns can boost the accuracy of state-of-the-art graph attribute completion models on social network databy up to 15.39%. Moreover, it is found that CSPM can uncover many interesting patterns describing alarm correlations in data from a large-scale industrial telecommunication network.

The Role of Organizational Communication Patterns in Motivating Employees: A Study of a Small Manufacturing Company in Indonesia

This study examines the organizational communication patterns used by PT. Lezen Indonesia for motivating its employees, and the supporting and inhibiting factors thereof. A descriptive qualitative method was used. The authors used Joseph A. Devito’s theory of five communication patterns (the circle, chain, star, wheel, and Y patterns) and found that the PT. Lezen Indonesia used three of them – the chain, the star, and the circle pattern. They also noted that the communication pattern used by the leader to communicate with subordinates was not much different from the pattern used by the subordinates to communicate with the leader, namely the chain communication pattern and the star communication pattern. However, the communication patterns used by employees to communicate with each other were circular and star patterns, where the employees freely communicated with each other. Factors supporting communication patterns in motivating employee work were routine family gatherings and receiving rewards and remuneration on time. However, the inhibiting factor was a misunderstanding as the company leadership was not yet very fluent in delivering information in Indonesian. Another inhibiting factor for many employees who joined and instantly left the company was the low entry-level salary, lack of benefits, and the restriction on using cell phones while working.
 Keywords: communication, communication pattern, work motivation

Optical imaging system for an all-time star sensor based on field of view gated technology.

The wide field of view (FOV) of traditional star sensor optical systems restricts the ability to suppress atmospheric background. An optical imaging system for an all-time star sensor based on FOV gated technology is proposed. In this system, a wide FOV telescope is used to observe a large sky area containing multiple stars. A microlens and microshutter array is employed to subdivide the wide FOV and gate a narrow FOV to suppress atmospheric background radiation. Assisted by a common imaging lens, each set of microlens and microshutter elements corresponds to a FOV gated imaging channel. With the rapid switching of gated FOV, multiple stellar images are obtained on a common detection during daytime. As an example, a FOV gated optical imaging system with 0.4° gated FOV and 61 imaging channels is designed. In addition, a simplified prototype is developed, and a preliminary experiment of FOV gated imaging is performed near the ground. The results verify the capability of multiple stellar detections during daytime. The proposed optical imaging system has a strong capability of suppressing atmospheric background radiation and provides sufficient FOV gated imaging channels to enhance the probability of detecting multiple stars. It provides an effective technical way to develop all-time star sensors based on star pattern recognition and enables a completely autonomous attitude determination possible for platforms inside the atmosphere during daytime.

Contrast based method for the automated analysis of transfer functions and spatial resolution limits of micro- and nano-focus computed tomography systems: Evaluation with simulated data

Micro- and nano-focus X-ray sources are extensively used in X-ray computed tomography systems to achieve high spatial resolution. This is essential, when scanning small objects, where resolution limitations are mainly connected to the size of the focal spot. Therefore, much effort has been put into reducing the size of the focal spot, where the measurement of the focal spot size is challenging. In this paper, the implementation of a new evaluation method for the quantitative determination of the system’s transfer function and the source’ spot size and shape are presented. The spatial resolution is calculated at different evaluation points to assess which particular threshold should be used to obtain the resolution limit and the focal spot size and shape. The implementation is explained and evaluated with the aid of simulated and real radiographs of the test chart, featuring line and star patterns designed to bridge the gap between existing resolution standards.

Polyhedra and Honeycombs in a Coffered Ceiling in the Picasso Museum in Malaga.

This paper reflects upon the remarkable ceiling of the Picasso Museum in Malaga, an example of the wooden coffered ceilings built during the early Renaissance in Spain. The unusual design of the ceiling is based on octagons surrounded by four-pointed stars. This is used as the point of departure for a mathematical investigation of polyhedral forms. Two different polyhedra are constructed, conceived in such a way that the honeycombs generated by them, can be considered a polyhedral generalization of the planar pattern of regular octagons and four-pointed stars. Both are constructed by means of special truncations of a cube. The truncation procedure is extended to construct a polyhedral generalization of the planar pattern of four-pointed stars and 45° rhombuses; in this case, the polyhedron obtained is a variation of one of the star polyhedra drawn by Jamnitzer. The geometric honeycombs thus defined could be used as models for new designs.

Coefficients for Assessing the Visibility of Materials Used in Anti-Smog Face Masks

Abstract The application of phosphorescence for the modification of face mask materials is motivated by the need to appreciably increase their visibility while using graphical elements with a relatively small area. Phosphorescent dyes absorb part of the visible spectrum while emitting radiation at wavelengths that are longer than the absorbed ones. Thus, a phosphorescent substance can emit light even if it is not being illuminated at a given time (but was before). This paper describes studies of the optical properties based on parameters such as the reflectance coefficient, chromaticity coordinates, as well as luminance measured from digital images for two models of smog-protective face half-masks differing in terms of their inner layer with filtration properties and outer printed layer. The external surface of one mask type is printed with a phosphorescent solid star pattern, while the other with a phosphorescent open star pattern. The influence of the inner filter layer was assessed in correlation with the colour of the outer layer and the type of printing. Moreover, the phenomenon of phosphorescence was identified. The study resulted in developing a material with properties providing better visibility under defined use conditions.

LAMOST J045019.27 + 394758.7, with peculiar abundances of N, Na, V, Zn, is possibly a Sculptor dwarf galaxy escapee

ABSTRACT We present the results of the high-resolution (R ∼ 60 000) spectroscopic analysis of the star LAMOSTJ045019.27 + 394758.7 (hereafter J045) from the list of carbon stars of LAMOST DR2. From our analysis, we find that J045 does not exhibit the spectral characteristics of carbon stars. It is found to be a metal-poor ([Fe/H] = −1.05) giant that shows very unusual elemental abundances, particularly for N, Na, V, and Zn. J045 shows α-elements (Mg, Si, Ca) with near-solar values (<[α/Fe]> = 0.09) in contrast to Galactic stars that show [α/Fe] in the range 0.2–0.3 dex. In J045, Sc and Ti are under abundant with [X/Fe] ≤ −0.25. Vanadium gives [V/Fe] = 0.51 and zinc is under-abundant with [Zn/Fe] = −0.62. The object exhibits near-solar abundances for Sr, Y, Ba, Pr, and Sm. The La is marginally enhanced, and Ce and Nd are marginally under-abundant in J045. With [Ba/Eu] = −0.38, the object falls into the category of neutron-capture rich r-I stars. The estimated abundances of various elements show that the observed abundance pattern is not compatible with the abundances characteristic of Galactic metal-poor stars but matches quite closely with the abundance pattern of Sculptor Dwarf galaxy stars of similar metallicity. Based on the above observational evidences, we suggest that the object is a possible Sculptor Dwarf Galaxy escapee.

On the Spectral Evolution of Hot White Dwarf Stars. III. The PG 1159–DO–DB–DQ Evolutionary Channel Revisited

We continue our comprehensive theoretical investigation of the spectral evolution of white dwarfs based on sophisticated simulations of element transport. In this paper, we focus on the transformation of PG 1159 stars into DO/DB white dwarfs due to the gravitational settling of heavy elements and then into DQ white dwarfs through the convective dredge-up of carbon. We study the impact of several physical parameters on the evolution of the surface carbon abundance over a wide range of effective temperatures. In the hot PG 1159 and DO phases, our calculations confirm that the temperature of the PG 1159-to-DO transition depends sensitively on the stellar mass and the wind mass-loss rate. We show that measured carbon abundances of DOZ white dwarfs are mostly accounted for by our models, with the notable exception of the coolest DOZ stars. In the cooler DB and DQ phases, the predicted atmospheric composition is strongly influenced by the stellar mass, the thickness of the envelope, the initial carbon content, the efficiency of convective overshoot, and the presence of residual hydrogen. We demonstrate that, under reasonable assumptions, our simulations reproduce very well the observed carbon abundance pattern of DQ stars, which thus allows us to constrain the extent of the overshoot region in cool helium-rich white dwarfs. We also argue that our calculations naturally explain a number of recent empirical results, such as the relative excess of low-mass DQ stars and the presence of trace hydrogen and/or carbon at the surface of most DC and DZ stars.

A Star Identification Algorithm Based on Recommended Radial Pattern

Star identification is a key technology in the research of star sensors. As a classical star pattern for identification, the radial pattern of a chosen star represents the geometric distribution of neighboring stars. Previous researches usually combine the rotation-invariant radial pattern with other less reliable patterns like cyclic pattern to identify the chosen star. Seldom studies use the radial pattern for direct identification as it is sensitive to noise and inefficient to eliminate spurious matches. To solve the problem, a novel star identification algorithm based on the recommended radial pattern was developed. The algorithm introduced the Apriori algorithm to mine the association rules between a star and neighboring stars, recommend the companion stars, and generate the recommended radial pattern. Based on the association rules, the algorithm integrated the matching results of a star and recommended companion stars to identify the chosen star. The simulation test and night sky image test both show that the proposed algorithm is robust to position noise, brightness noise, and false stars. The novel matching strategy is not limited to the radial pattern algorithms, it provides a new idea for all the star pattern algorithms.