Attitude Determination Research Articles

Developing an eyeball positioning method in the eye orbit for craniofacial identification in Korean population

We analysed the skulls and faces of Korean subjects using anthropometric methods to understand the anatomical characteristics of the eyeball and eye orbit region of Korean population and to determine the correlations between the hard and soft tissues around the eyeball and eye orbit region. In total, 82 sections in the region were measured to determine the correlations; among them, 34 showed significant differences by sex, and 6 showed significant differences by age. As the distance from the centre of the eye lens to the eye orbit is calculated as a ratio, we determined that the centre of the eye lens is located relatively on the lateral and superior position in each eye orbit in front view. Fourteen sections that could be used for craniofacial reconstruction/approximation in men and women were selected. Regression equations were derived according to the correlation of each section, and their reliabilities were verified by out of sample validation tests. Therefore, our results increase the accuracy of eyeball position determination, which would be useful for more efficient craniofacial reconstruction/approximation of the Korean population and should improve the efficiency of facial recognition.

3D-Oculography: New Method of Determination of Human Gaze Point Position in Space

INTRODUCTION: Oculography — a method of recording movement of eyeballs of a human or animal by analyzing changes in electrical potentials recorded by two electrodes fixed on skin near the eye socket is used to solve various problems. Among them are the determination of pronounced nystagmus, of characteristic changes of oculomotor reactions in different conditions of observing video images. Of interest is the determination of the position of gaze point (GP) and of the area of increased attention in three-dimensional space. This information is associated with the cognitive system of the observer and is of interest not only to physiologists, but also to specialists of related fields. . AIM: To experimentally prove the effectiveness of the developed method of 3D-oculography providing determination of the GP position in space. MATERIALS AND METHODS: The possibility of restoring GP position based on the analysis of recorded oculograms even in the presence of additive noise induced by the external electromagnetic fields, is proven by the numeric modeling method. Direct experimental studies were conducted with recording oculograms of a human observer on a previously verified equipment. A ZB-2 oculograph was used, the data obtained were verified by the method of average values. RESULTS: The obtained modeling results permitted to determine the maximal values of dispersion of additive noise and amplitude shifts of signals, which make possible satisfactory restoration of the coordinates of the GP and parameters of its movement trajectory. The qualitative correspondence of the experimental results to the results of numerical modeling was proven. The correspondence between trajectories of the observed object moving in space and trajectories of GP movement synthesized from counts of recorded oculograms was confirmed. CONCLUSION: Multichannel record of oculographic signals permits restoring parameters of the GP trajectory. Creating systems for recording these signals requires minimization of the noise level. An increase in dispersion of the noise component of the signal leads to most significant errors in calculating the coordinates of trajectory points.

Psychosocial determinants of adolescents' attitudes toward disclosing dating violence.

This study combined a person-oriented approach with a psychosocial framework of help-seeking to examine factors associated with the intent to disclose dating violence among developing adolescents. Data came from adolescents in middle and high school in a rural area in the southeastern United States, who were surveyed annually for 4 years (Nwave 1 = 580; Mage = 13 years, SD = 1.48; 52.7% female; 49% Black, 39% White, 11% Hispanic, or other minorities). Results confirm expectations that intraindividual (adolescent views on violence and safety); interindividual (peer and family dynamics); positional (gender, having a supportive adult); and ideological factors are all significant predictors of patterns in help-seeking attitudes. However, predictive relevance of some factors varied across help-seeking groups and data collection periods, supporting the differential effects hypothesis. For example, while greater friend social support increased the odds of belonging to "friend confidants," it simultaneously decreased the odds of being a member of "parent confidants" and "moderate help-seekers" groups. Additionally, the influence of family functioning tended to decrease over time, eventually losing its explanatory value at Wave 4. The article concludes by discussing how integration of a person-centered methodological approach with a robust theoretical foundation advances our understanding of variability in adolescents' responses to dating violence. Consideration of diversity in adolescent intentions to react to interpersonal violence is discussed further in the context of policy and practice to enhance protective options and prevent or minimize harm. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Multidimensional Position And Displacement Estimation Using Periodic Coded Optical Apertures In A Single Camera Imaging System

Accurately estimating multidimensional positions and displacements in fluid dynamic experiments is essential for understanding complex flow phenomena. This paper presents a novel optical measurement setup capable of determining velocity fields using periodic coded optical apertures in a single-camera imaging system. Our method involves placing a periodic transmission grating in front of the optical system and aligning a laser beam along the system’s optical axis. When particles intersect the laser beam, they scatter light, producing out-of-focus images on the imaging sensor resembling the periodic grating. The size and position of these images vary with the distance to the imaging system and the offset from the optical axis, allowing for accurate determination of particle positions. We derive mathematical formulas describing the imaging system and the relationship between image properties and particle positions and verify them through simulations. Additionally, we develop a calibration method enabling arbitrary optical imaging systems to be used with this technique. Finally, we demonstrate the effectiveness of our approach by measuring velocity fields near a ducted ship propeller, a practical application that underscores the real-world impact of our research in fluid dynamics.

Fourier light-field microscope for micro tomo-PTV in a cross-junction microfluidic channel

This paper presents a novel approach for comprehensive flow analysis within microfluidic systems by integrating particle tracking velocimetry (PTV) and shake-the-box (STB) techniques with plenoptic imaging. By combining the strengths of PTV and STB, which offer particle trajectory tracking and high-resolution particle position determination, respectively, our method enables accurate and detailed flow characterization. Leveraging Fourier light-field microscopy, a recent development of plenoptic imaging (or integral microscopy), we eliminate the need for multiple imagers and achieve high-resolution three-dimensional flow measurements using a single high-speed camera. The diffraction-limited resolution is on the order of 2 um in 3D, with the lateral and depth resolution within 25% of each other. This is an unprecedented depth resolution for a 3D velocimeter. Particle positions can in fact be resolved to less than the imaging wavelength. We demonstrate the effectiveness of this approach by capturing and analyzing a complex flow within a microfluidic device with a cross-junction channel. This measurement technique will provide valuable insights for optimizing microfluidic device design and performance as well as wall-bounded flows.

Proprioceptive swarms for celestial body exploration

The exploration of small celestial bodies has been a very active field ever since the dawn of space exploration. However, traditional approaches based on monolithic landers allow only the area in the immediate vicinity to the landing spot to be examined. Using mobile systems like rovers allow for better coverage, but at considerable cost and complexity. In this work, we propose an approach based on swarms of small nonmaneuverable agents, equipped with a sensor package, that are launched from a base station and made to land across the entire surface of the asteroid or comet. The methodology is based on multilateration using small range-finding radio frequency sensors aboard the agents; this enables position determination relative to the base station. Through dynamics simulation, we show that this approach is feasible even in highly irregular gravity fields where closed-form solutions for orbital mechanics are not available, such as the case of comet 67P/Churyumov–Gerasimenko. We show a sensitivity analysis of the absolute position error of the agents which originated from range-measurement error. The surface coverage is evaluated against the numerosity of the swarm. Finally, we show that allowing for a subset of agents to follow a long-period orbit around the object enables better localization of the landed agents, thus increasing the overall performance.

Cyberaddiction to TikTok during the COVID-19 pandemic

Purpose The purpose of this study is to shed light on the determinants of TikTok cyberaddiction during the COVID-19 pandemic, as well as the resulting attitudinal and intentional reactions of users. Design/methodology/approach An online survey of 305 young TikTok users was conducted to test the research hypotheses. Data was analyzed through a partial least sqaures approach. Findings The results highlight the mediating role of cyberaddiction to TikTok in the relationship between psychological disorders (anxiety and loneliness) and attitude toward TikTok. Indeed, it was found that anxiety and loneliness contribute to TikTok cyberaddiction. The latter would have a positive effect on attitude toward TikTok, which decreases in the presence of fear of missing out (FOMO). It was also proven that attitude toward TikTok has a positive impact on attitude toward the brands promoted on this platform, resulting in an increase in purchasing intentions. Research limitations/implications This study was conducted during the COVID-19 pandemic. It is therefore interesting to replicate it to see if the research model can be still validated in the absence of an emergency situation. Testing the model on a larger target, including older TikTok users, could also lead to interesting findings. Practical implications Knowledge of the psychological factors behind cyberaddiction should not be seen as an opportunity to take advantage from addicted shoppers’ vulnerability. Managers should rather limit communication campaigns on TikTok during crisis periods, undertake retargeting actions by sparing vulnerable TikTok users and avoid stimulating anxiety and loneliness which can lead to cyberaddiction and compulsive purchases. Originality/value This study sheds light on the central role of cyberaddiction to TikTok in the relationship between psychological disorders and users’ reactions, during a pandemic. It focused on the moderating role of FOMO on the relationship between determinants of cyberaddiction and attitude toward TikTok. Escape theory and attachment theory were used and adapted to the context of social media.

Remote sensing of electron precipitation mechanisms enabled by ELFIN mission operations and ADCS

The Electron Loss and Fields INvestigation (ELFIN) mission comprising two 3U+ CubeSats was developed, built, and operated by several generations of undergraduate students at UCLA. The spin-stabilized CubeSats (spin-rate: 21 RPM) produced high-resolution measurements of precipitating, trapped, and backscattered fluxes of electrons and ions in the radiation belts. Launched in September 2018, ELFIN operated successfully until its deorbit just over four years later. Initially, however, mission operations was very challenging and only tapped the full mission potential after a thorough redesign of the operations paradigm. This mid-mission adjustment yielded the higher data downlink volume necessary to acquire a comprehensive data set, therefore enabling ensemble studies with sufficient statistical significance. The new operational framework also led to additional improvements across the mission. Most notably, the Attitude Determination and Control System (ADCS) benefited from more reliable collections of magnetometer data for attitude determination, enabling knowledge and control to <1°. This allowed high pitch-angle resolution (especially within the loss cone) and high energy resolution spectrograms, both powerful diagnostics of radiation belt electron and ion precipitation. This paper highlights the scientific advancements made possible by ELFIN’s efficient mission operations and ADCS design, unique for CubeSats, and emphasizes the role of electron precipitation measurements for future studies in magnetospheric, ionospheric, and atmospheric physics.

English as Additional Language (EAL) Status as a Determinant of Learning Environment, Attitudes and Achievement

English as Additional Language (EAL) Status as a Determinant of Learning Environment, Attitudes and Achievement

Design and simulation of sun position sensors for space applications: A comparative study.

Sun position sensors are used in space applications as part of the attitude determination and control system. The aim of this work is to describe the design process of single and dual axis sun position sensors based on a photodiode array detector and a window to limit and direct the light that reaches the detector. The design process involves choosing the sensor architecture, modeling its output, and then evaluating the model through simulation. Six architectures, with different configurations and geometries for both the detector and window, were modeled and compared. To evaluate the model and performance of the sensor, a program was developed, and simulations were made varying the window height and size as well as the photodiode size. From the simulations performed, we concluded that for each design, the key factors that influence the sensitivity and field of view performance are the window height and window or photodiode size, depending on the sensor configuration. From the comparison across architectures, the detector configuration, as well as the window geometry, influences the sensitivity and linearity of the response for similar conditions of operation. The two-quadrant detector configuration offers a better sensitivity than the triangular photodiode configuration. For a better linearity of the output, a square window is preferred. This comparative study is part of the development of new products for space applications by the National Atomic Energy Commission and contributes to the Argentinian National Space Plan.

Discovery and Follow-up of a Quasiperiodically Nulling and Subpulse Drifting Pulsar with the Murchison Widefield Array

The phenomenon of pulsar nulling, where pulsars temporarily and stochastically cease their radio emission, is thought to be indicative of a “dying” pulsar, where radio emission ceases entirely. Here we report the discovery of a long-period pulsar, PSR J0452−3418, from the ongoing Southern-sky MWA Rapid Two-meter pulsar survey. The pulsar has a rotation period of ∼1.67 s and a dispersion measure of 19.8 pc cm−3, and it exhibits both quasiperiodic nulling and subpulse drifting. Periodic nulling is uncommon, reported in only <1% of the pulsar population, with even a smaller fraction showing periodic nulling and subpulse drifting. We describe the discovery and follow-up of the pulsar, including a positional determination using high-resolution imaging with the upgraded Giant Metrewave Radio Telescope (uGMRT), initial timing analysis using the combination of Murchison Widefield Array (MWA) and uGMRT data, and detailed characterization of the nulling and drifting properties in the MWA’s frequency band (140–170 MHz). Our analysis suggests a nulling fraction of 34% ± 6% and a nulling periodicity of 42−1.3+1.5 pulses. We measure the phase (P 2) and time modulation (P 3) caused by the subpulse drifting, with an average P 2 of 7.1 −3.1+26.3 degrees and a P 3 of 4.8 −0.9+1.5 pulses. We compare and contrast the observed properties with those of other pulsars that exhibit subpulse drifting and quasiperiodic nulling phenomena, and find that the majority of these objects tend to be in the “death valley” in the period–period derivative (P– Ṗ ) diagram. We also discuss some broader implications for pulsar emission physics and the detectability of similar objects using next-generation pulsar surveys.

Direct position determination algorithm based on wideband array signal model in external illuminator system

Abstract Target location and tracking are among the most critical applications for external illuminator systems. Most traditional array signal direct position determination (DPD) techniques are based on narrowband signals. With the advancement of communication technology, various wideband signals are extensively utilized in communication systems, leading to the failure of some traditional DPD techniques. To address this issue, this article proposes a new DPD algorithm for wideband array signals. First, we suppress the direct wave (DW) interference in the received signal. Then, a cost function for the target coordinate is constructed based on the Maximum Likelihood (ML) criterion, and a phase matching matrix is created for the problem of unknown signal transmission time. Finally, the position estimation is obtained from the peak of the cost function. Simulation results demonstrate that the proposed algorithm outperforms traditional two-step localization methods based on the time difference of arrival of signals, particularly in cases where DW interference is present in the received signal.

The Photon-Counting CT Enters the Field of Cochlear Implantation: Comparison to Angiography DynaCT and Conventional Multislice CT.

Cochlear duct length (CDL) measurement plays a role in the context of individualized cochlear implant (CI) surgery regarding an individualized selection and implantation of the CI electrode carrier and an efficient postoperative anatomy-based fitting process. The level of detail of the preoperative temporal bone CT scan depends on the imaging modality with major impact on CDL measurements and CI electrode contact position determination. The aim of this study was to evaluate the accuracy of perioperative CDL measurements and electrode contact determination in photon-counting CT (PCCT). Ten human fresh-frozen petrous bone specimens were examined with a first-generation PCCT. A clinically applicable radiation dose of 27.1 mGy was used. Scans were acquired before and after CI insertion. Postoperative measurement of the CDL was conducted using an otological planning software and 3D-curved multiplanar reconstruction. Investigation of electrode contact position was performed by two respective observers. Measurements were compared with a conventional multislice CT and to a high-resolution flat-panel volume CT with secondary reconstructions. Pre- and postoperative CDL measurements in PCCT images showed no significant difference to high-resolution flat-panel volume CT. Postoperative CI electrode contact determination was also as precise as the flat-panel CT-based assessment. PCCT and flat-panel volume CT were equivalent concerning interobserver variability. CDL measurement with PCCT was equivalent to flat-panel volume CT with secondary reconstructions. PCCT enabled highly precise postoperative CI electrode contact determination with substantial advantages over conventional multislice CT scanners.

Assessment of Construction Practitioners’ Knowledge Sharing Attitude in Construction Projects in Nigeria

Individuals such as construction practitioners (CPs) are the focal point of knowledge sharing (KS). KS plays a cardinal role in knowledge management (KM). It is recognised as one of the most crucial aspect of KM which leads to better performance of organisations and construction projects. Literature has shown that KS success is largely driven by individual level variables such as attitude. Studies on KS largely neglect the individual level variables, e.g. perception, motivation and attitude. Hence, there is a lack of knowledge on the influence of the determinants of attitude on construction practitioners’ (CPs’) KS attitude. Therefore, this study aimed at assessing the influence of the determinants of attitude on CPs' KS attitude in construction projects with a view to improving knowledge sharing among CPs. The determinants of KS attitude and their components were identified from literature and were used to conduct a survey to assess the CPs' KS attitude. Quantitative method was adopted for this research and the data were collected using structured questionnaire administered to 174 Construction practitioners using Stratified Random Sampling. Data were analysed using Structural Equation Modelling. The study identified six determinants of KS attitude with four independent (perceiver, target, intensity and persistence) and two dependents (cognitive and affective). It was found out that the CPs perceiver, target, intensity and persistence as determinants of KS has influence on KS attitude. The study also found a high significant influence between measures of CPs’ motivation (intensity &amp; persistence) KS attitude compared to measures of their perception (perceiver &amp; target) and the strongest influence is between CPs intensity and their cognitive. The study concludes that CP’s as the perceivers and KS as what is been perceived (target) do not affect CPs knowledge sharing attitude, instead intensity and persistence (motivation) does. This study recommends that CPs should be educated about their perception of KS. The study recommends that construction practitioners level of motivation should be increased because motivation is what derives them to share knowledge rather than perception.

Determination of Football Academy Coaches' Attitudes and Thoughts Towards Match Analysis in Football

This study aimed to determine the attitudes and opinions of football academy coaches towards match analysis in football and assess if these vary based on demographic variables. Using a descriptive survey method, data were collected from 210 football academy coaches participating in training in Istanbul during the 2022-2023 season. The study included coaches from 21 clubs in the Spor Toto Super League and Spor Toto 1st League, within the Turkish Football Federation's Football Academies Project.No sampling was used; instead, the entire population was targeted with voluntary participation, resulting in 112 respondents. Data were collected using the Football Specific Match Analysis Scale by Gürkan et al. (2023). Due to non-normal distribution of data, Mann-Whitney U Test and Kruskal-Wallis Analysis of Variance were employed for statistical analysis, with significance set at 0.05.Findings revealed that technology use in football, specifically match analysis, is seen as highly beneficial by coaches. Match analysis was considered significantly important and contributive to their development. Coaches generally rated match analysis as "very high" in importance and contribution to player development. It was also found that:Younger coaches and those with less experience in the academy league rated match analysis more positively.Coaches with higher education levels and higher monthly incomes were more likely to value match analysis highly.Differences in attitudes and opinions were significant across age groups, tenure in the academy, education levels, and income brackets.These results indicate the growing importance of match analysis in football training and development, influenced by demographic factors.Keywords: Academy, Football, Football Academy Coach, Match Analysis.

“When Jobs Are Scarce”

Abstract This study examines the influence of Islam on attitudes toward female labor force participation as reflected in responses to the World Values Survey (WVS) question: “When jobs are scarce, should men have more right to a job than women?”. The authors expect that respondents in Islamic (Muslim-majority) countries will have more positive attitudes toward this statement than respondents in non-Islamic countries. They test the hypothesis that the higher the percentage of Muslims in a given country, the more likely respondents are to agree with this statement. The correlation is in the predicted direction, statistically significant and quite strong. Meanwhile, tests show that respondents in Arab countries show particularly strong support for this statement (significantly stronger than in non-Arab Muslim-majority countries). Based on this, the authors try to discuss possible determinants of such attitudes. Particular support is observed in Arab countries and those non-Arab countries that have experienced a strong Arab influence. These countries can be identified with the Umayyad Caliphate in the past and may have been particularly influenced by non-Islamic elements of Arab culture that are not directly related to Islam.

Single-Track Magnetic Tape Absolute Position Sensor with Self-Adaptivity.

In this study, we demonstrate a single-track magnetic code tape-based absolute position sensor system. Unlike traditional dual-track systems, our method simplifies manufacturing and avoids crosstalk between tracks, offering higher tolerance to alignment errors. The sensing system employs an array of magnetic field sensing elements that recognize the bit sequence encoded on the tape. This approach allows for accurate position determination even when the number of sensing elements is fewer than the number of bits covered, and without the need for specific spacing between sensing elements and bit length. We demonstrate the system's ability to learn and adapt to various magnetic code patterns, including those that are irregular or have been altered. Our method can identify and localize the sensed magnetic field pattern directly within a self-learned magnetic field map, providing robust performance in diverse conditions. This self-adaptive capability enhances operational safety and reliability, as the system can continue functioning even when the magnetic tape is misaligned or has undergone changes.

The Effects of Pointing Error Sources on Energy Delivery from Orbiting Solar Reflectors

Many proposals are being made for cleaner, more sustainable forms of energy production. Terrestrial solar photovoltaic farms (SPFs) could potentially deliver large quantities of energy to the grid, although these are limited to daytime use. The output from these SPFs could be enhanced, particularly around dawn and dusk, by the use of orbiting solar reflectors (OSRs) in near-polar orbit. These would reflect an image of the solar disk, or solar image (SI), onto the SPFs to augment their energy output. Pointing requirements are therefore to ensure that reflected sunlight is delivered to the terrestrial SPF, avoiding the losses incurred by an offset of the SI and the SPF itself. The SI would typically be of order 10 km for a reflector in a 1000 km orbit. Given the potentially large size of the reflectors, this presents a challenge for the attitude determination and control system (ADCS) to ensure that the maximum quantity of energy can be delivered to a SPF, typically requiring large control moment gyro actuators. In addition, there exist numerous sources of error in the ADCS which can cause further degradation in the quantity of energy delivered to the SPF. These errors can manifest in the resolution of the various sensors, flexible structural modes, manufacturing inaccuracies, and misalignments due to vibration during launch. This paper will investigate the effects of pointing error sources (PES) on the reflector ADCS and so on the quantity of energy delivered to the SPF. With the application of a PD controller with feedforward compensation, and the set of noise characteristics defined in this paper, numerical simulations will show the typical losses in energy delivered to SPFs of 0.015% when the model accounts for PES in onboard sensors, actuator uncertainty and flexible structural modes.

A trend of "geomagnetic jerks" in the inhibition of the earth's south magnetic pole?

The possibility of a reversal in the displacement of the Earth's South Magnetic Pole (SMP), the speed of which has decreased threefold over the past 60 years, is being discussed, which does not contradict the theory of “geomagnetic jerks.” The results of the experiment on measurements of magnetic declination on 6-9.04.2020 in the Southern Ocean are presented. Remote measurements are caused by the fact that during the day the SMP moves along a quasi-closed perimeter with semi-axis sizes up to 50 km. The discrepancies between the magnetic declination measurements and the model isogons of the International Geomagnetic Reference Field (IGRF13) model allow us to estimate the daily average position of the SMP. An example with the estimation of magnetic deviation of ship magnetic declination observations affecting the SMP position determinations is analyzed.

Stochastic analysis of drift error of gyroscope in the single-axis attitude determination

Understanding and mitigating the various stochastic errors in gyroscope measurements is crucial for accurate attitude determination. White noise and bias instability can introduce drift errors, reducing the system’s accuracy. Efficient sensor selection and algorithm design necessitate a thorough understanding of these influences and how they propagate throughout the system. This paper addresses the propagation of significant stochastic errors in the attitude determination system, including white noise (angle random walk), bias instability, rate random walk, and correlated noise. The paper discusses the modeling strategy and statistical characteristics of these error contributors. It then evaluates the variance propagation of these errors within the output of a single-axis attitude determination system. The presented analysis calculates and compares the impact of each source of error on the system’s precision over time. Experiments with the MPU6050 and L3G4200D sensors are conducted to validate the analytical results.