Subject: Engineering, Control And Systems Engineering Keywords: unmanned air vehicles; mission planning; routing; weapon configuration; adaptive large neighborhood search
Online: 16 April 2019 (10:40:24 CEST)
There is an increasing trend that Unmanned Combat Air Vehicles (UCAVs) are employed to complete different combat missions in modern wars. This paper investigates a UCAV routing problem, which simultaneously considers the decisions for the configuration of weapons carried by the UCAV subject to its capacity and the allocation of weapons to the targets subject to their destroying requirements. An integer linear programming model is developed to formulate the problem. An adaptive large neighborhood search (ALNS) heuristic is proposed to solve the problem, in which seven neighborhood structures are designed and employed. Randomly generated instances covering the small, medium and large sizes are used to test the proposed ALNS algorithm. CPLEX is also utilized to solve the small-size instances, whose results are compared with that obtained by the ALNS algorithm. And the extensive experimental results confirm the effectiveness and superiority of the proposed ALNS algorithm.
ARTICLE | doi:10.20944/preprints201711.0141.v1
Subject: Social Sciences, Behavior Sciences Keywords: organizational culture; mission; consistency; involvement; adaptability
Online: 22 November 2017 (04:19:38 CET)
The main goal of this paper is to address how quickly and to what extent are international organizational cultures, brought by the world companies after the process of privatization, being implemented in a single monolithic culture. For this purpose was adopted and applied Denison model of organizational culture, which has been chosen because it emphasizes the need for balance between requirements for organization’s stability demands and its required flexibility. Considering that a different organizational culture reflects systematic change of an entire organization, this paper focuses on exploring the differences in culture dimensions among companies in domestic and foreign ownership in Serbia. A sample of 1000 employees was statistically processed. Changes in organizational culture tend to be relatively slow. The results confirm that organizational culture is a complex working environment, concerning organizational values, which represents a fundamental element of organizations. Given that the process of company ownership changes occurred fifteen years prior to the research implementation, obtained results show effects of interaction between national and organizational culture in this, relatively short, period of time. Obtained results can be generalized to countries that are passing or have recently passed a transition, and are similar in cultural characteristics.
ARTICLE | doi:10.20944/preprints202010.0389.v1
Online: 19 October 2020 (14:53:16 CEST)
The TanDEM-X mission is acquiring a new dataset to provide a temporally independent DEM, called "TanDEM-X Change DEM". This set of acquisitions taken between 2017 and 2020 has a clear temporal separation to the TanDEM-X global DEM data which were acquired between 2010 and 2015. Therefore, this new DEM aims to enable the characterization of terrain changes. Improvements in the acquisition planning and the data processing were necessary to generate this Change DEM with fewer acquisitions but still very high accuracy. For this, the use of an edited TanDEM-X DEM as a "starting point" for the interferometric processing is mandatory.
ARTICLE | doi:10.20944/preprints202307.0812.v1
Subject: Business, Economics And Management, Finance Keywords: Financial sustainability; Microfinance; Mission Drift; Welfarist; Institutionalist; Social Performance
Online: 12 July 2023 (11:08:33 CEST)
Microfinance banks and Institutions must simultaneously provide micro financial loans to unprivileged and poor people as well as self-sustaining, which means covering enough costs to eliminate the need for subsidies. To ascertain if Micro-finance Institutions can successfully navigate the double challenge of financial self-sustainability (FSS) as well as outreach to poor clientele and women borrowers i.e. outreach. There is no other alternative but to analyse the balance between FSS and outreach indicators of MFIs. The research goal is to see whether there was any compromise between the self-sustainability and outreach towards poor and female customers. The study used data of 100 MFIs driven from the database of microfinance information’s exchange (MIX) market with the objective to determine trade off between financial sustainability and outreach. The study found financial performance variables are positively and significantly related with average loans size which shows a mission drift, in which MFIs serve wealthy clientele. However, Indian MFIs have a extremely high outreach with their female clientele, confirming MFI's social commitment to objective of women’s empowerment. The research recommends to the Policy-makers that MFIs are compromising their financial services to underprivileged people and women in order to be financially sustainable. To guarantee that institutions are focused on outreach to underserved people in rural areas, the government should reform the policies regarding governing MFIs.
ARTICLE | doi:10.20944/preprints202305.1423.v1
Subject: Environmental And Earth Sciences, Oceanography Keywords: Wind and current mission concept; Doppler scatterometer; wind work
Online: 19 May 2023 (10:05:19 CEST)
The kinetic energy transfer between the atmosphere and oceans, called wind work, affects ocean dynamics including near-inertial oscillations and internal gravity waves, mesoscale eddies, and large-scale zonal jets. For the most part, recent numerical estimates of global wind work amplitude are almost 5 times larger than those reported 10 years ago. This large increase is explained by the impact of the broad range of spatial and temporal scales covered by winds and currents, the smallest of which have only recently been uncovered by increasingly high resolution modeling efforts. However, existing satellite observations do not fully sample this broad range of scales. The present study assesses the capabilities of ODYSEA, a conceptual satellite mission to estimate the amplitude of wind work in the global ocean. To this end, we use an ODYSEA measurement simulator fed by the outputs of a km-scale coupled ocean-atmosphere model to estimate wind work globally. Results indicate that compared with numerical truth estimates, the ODYSEA instrument performs well globally, except for latitudes north of 40∘N during summer due to unresolved storm evolution. This performance is explained by the wide-swath properties of ODYSEA (a 1,700 km wide swath with 5 km posting for winds and surface currents), its twice-a-day (daily) coverage at mid-latitudes (low latitudes), and the insensitivity of the wind work to uncorrelated errors in estimated wind and current.
ARTICLE | doi:10.20944/preprints201907.0294.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: speckle; coherence; interference; differential absorption lidar; radiometry; space mission
Online: 26 July 2019 (00:47:56 CEST)
In the context of the French-German space lidar mission MERLIN dedicated to the determination of the atmospheric methane content, an end-to-end mission simulator is being developed. In order to check whether the instrument design meets the performance requirements, simulations have to count all the sources of noise on the measurements like the optical energy variability induced by speckle. Speckle is due to interference as the lidar beam are quasi monochromatic. Speckle contribution to the error budget has to be estimated but also simulated. In this paper, the speckle theory is revisited and applied to MERLIN double pulsed IPDA lidar and also to the DLR demonstrator CHARM-F. Results show: on the signal path, speckle noise depends mainly on the size of the illuminating area on ground; on the solar flux, speckle is fully negligible both because the pixel size and the optical filter spectral width; on energy monitoring path a decorrelation mechanism is needed to reduce speckle noise on averaged data. Speckle noises for MERLIN and CHARM-F can be simulated by Gaussian noises with only one random draw by shot separately for energy monitoring and signal paths.
ARTICLE | doi:10.20944/preprints202305.0005.v1
Subject: Physical Sciences, Space Science Keywords: Interstellar Mission; Hypatia Stellar Catalog; Stellar Abundance; Habitability; DNA-star
Online: 1 May 2023 (03:18:14 CEST)
The possibility of the life origin in the stellar systems, located at a distance of ~ 200 pc from the solar system, was investigated. The stars, in the spectrums of which C (carbon), O (oxygen), N (nitrogen), and P (phosphorus) are found, are called DNA–stars. Based on stellar abundances a new method for searching for habitable exoplanets has been developed and a list of 48 DNA–stars in the solar neighborhood, on which life is possible, has been defined. The quota of DNA–stars is equal 1.3% of the total amount of Hypatia Stellar Catalog. Only three DNA–stars out of selected 48 stars belong to the spectral class as our Sun (G2V). The closest to the solar system is the DNA-star with the number HIP 15510, which belongs to the G8V class and is 6 pc away from the solar system. Nine DNA--stars, which have the highest chemical similarity with solar spectrum, were identified. It is identified that one of these nine stars, HIP 24681, has six planets.
ARTICLE | doi:10.20944/preprints201902.0110.v1
Subject: Engineering, Control And Systems Engineering Keywords: two-echelon routing; vehicle routing; vehicle-mounted UAVs; ISR mission
Online: 13 February 2019 (10:33:55 CET)
In this paper, we present a novel Two-Echelon Ground Vehicle and Its Mounted Unmanned Aerial Vehicle Cooperated Routing Problem (2E-GUCRP). The 2E-GUCRP arises in the field of Unmanned Aerial Vehicle (UAV) Routing Problem such as those encountered in the context of city logistics. In a typical cooperated system, the UAV is launched from the Ground Vehicle (GV) and automatically flies to the designated target. Meanwhile, acting as a mobile base station, the GV can charge or change the UAV’s battery on the designated landing points to enable the UAV to continue its mission. The objective is to design efficient GV and UAV routes to minimize the total mission time while meeting the operational constraints. A Mixed Integer Programming (MIP) model, which could be solved by commercial software, is constructed to describe this problem. In order to quickly solve the medium-scale problems, two existing heuristics to solve 2E-VRP are improved. The computational experiments are set up to compare our model with the 2E-VRP. The results indicate that the 2E-GUCRP obtains a better efficiency. Further discussion of the practical instance points out that the increase in efficiency is related to the speed relationship between the GV and the UAV.
ARTICLE | doi:10.20944/preprints201709.0107.v2
Subject: Physical Sciences, Atomic And Molecular Physics Keywords: electron scattering; cross sections; Rosetta mission; atomic and molecular databases
Online: 21 October 2017 (15:30:59 CEST)
The emission of [O I] lines in the coma of Comet 67P/Churyumov-Gerasimenko during the Rosetta mission have been explained by electron impact dissociation of water rather than the process of photodissociation. This is the direct evidence for the role of electron induced processing has been seen on such a body. Analysis of other emission features is handicapped by a lack of detailed knowledge of electron impact cross sections which highlights the need for a broad range of electron scattering data from the molecular systems detected on the comet. In this paper we present an overview of the needs for electron scattering data relevant for the understanding of observations in coma, the tenuous atmosphere and on the surface of 67P/Churyumov-Gerasimenko during the Rosetta mission. The relevant observations for elucidating the role of electrons come from optical spectra, particle analysis using the ion and electron sensors and mass spectrometry measurements. To model these processes electron impact data should be collated and reviewed in an electron scattering database and an example is given in the BEAMD, which is a part of a larger consortium of Virtual Atomic and Molecular Data Centre – VAMDC.
ARTICLE | doi:10.20944/preprints202305.0202.v1
Subject: Physical Sciences, Space Science Keywords: Interstellar Mission; Habitability; DNA-star; Ensemble-Averaged Stellar Reactor; Stellar Abundance; Stellar Nucleogenesis
Online: 4 May 2023 (05:46:12 CEST)
Chemical elements in space can be synthesized by stellar nuclear reactors. Studying the dynamics of processes occurring in the stars introduces a concept of the ensemble-averaged stellar reactor. For future interstellar missions, the terrestrial and solar abundances were compared with considerable number of stars allocated in the ~ 200 pc solar neighborhood. According to the value of the effective temperature, four stellar classes are distinguished, for which the correlation coefficients and standard deviation are calculated. The statement about the possibility of transferring heavy elements synthesized by stars over long distances in space has been completely refuted. There is no immutability of the distribution of elements on neighboring stars and in the Solar System. It is shown that chemical elements are mainly synthesized inside each stellar reactor. The theory of the buoyancy of elements is generalized to stars. It has been suggested that stars overheat due to a shift in the parameters of nuclear processes occurring inside stars, which leads to the synthesis of heavy elements.
ARTICLE | doi:10.20944/preprints202302.0203.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Hyperpectral; Deep learning; Neural networks; image processing; classification; segmentation; hardware accelerators; CHIME mission
Online: 13 February 2023 (07:32:31 CET)
Modern hyperspectral imaging technologies generate enormous datasets that could potentially transmit a wealth of information, but such a resource presents numerous difficulties for data analysis and interpretation. Deep learning techniques undoubtedly provide a wide range of potential for solving both traditional imaging tasks and exciting new problems in the spatial-spectral domain. This is true in the primary application area of remote sensing, where hyperspectral technology originated and has made the majority of its progress, but it may be even more true in the vast array of now existing and developing application areas that make use of these imaging technologies. The current review advances on two fronts: on the one hand, it is directed at domain experts who desire an updated overview of how deep learning architectures might work in conjunction with hyperspectral acquisition techniques to address specific tasks in various application sectors. On the other hand, by providing them with a picture of how deep learning technologies are applied to hyperspectral data from (near)real-time perspective. The contributions of this review include the existence of these two points of view and the inclusion of opportunities and important problems associated with the development of future CHIME mission to be launched by European Space Agency (ESA).
ARTICLE | doi:10.20944/preprints202001.0355.v1
Subject: Social Sciences, Education Keywords: Societal Challenges; mission-oriented; sustainability education; higher education institutions; partnership for the goals
Online: 29 January 2020 (12:10:02 CET)
Unlike other SDGs, the SDG4 about quality education is not a goal in itself, but rather a tool to achieve different goals. Universities in this respect play a crucial role in the short-term implementation of SDGs for education, including new approaches and contents. Current academic debates explore the best practices via deductive-theoretical or inductive-experiential methods, yet not always considering the geographical, and therefore cultural and infrastructural factors affecting the success and the failure of such practices. In this paper, we systematize the implementation of SDGs in Italian universities from 2016 to 2019. Eighteen experiences have been collected after a national call by the Italian Network of Sustainable Universities (RUS) aimed at mapping the current landscape of SDG related actions. Results have been analyzed according to two criteria: 1- the educational "container" where the SDGs implementation takes place (from random workshops to dedicated courses); 2- the different organizational scales (from the foundation of a new department to the campaigns by local green teams). With this paper, we do not propose a total refunding or "deus-ex-machina" solutions, disregarding the local factors and the local resources in Italian universities. On the contrary, we draw a map to propose the reuse of an existing structure with adjustments, retrofitting and renewal actions towards holistic and coordinated sustainability efforts. Results show that, within the Italian context, SDGs implementation is still primarily understood as a strategic element for branding and promoting the green image of the Athenaeum. Secondarily, it is seen whether as a separate discipline to be inserted into existing curricula and original teachings or as a conceptual tool for remedying specific societal challenges through random workshops or fieldworks. Conclusions highlight the value of this first Country-wide systematization of the Italian Higher Education Institutions toward SDGs implementation. This exercise avoids individual experiences remaining isolated and self-concluded, and, most importantly, provides comparability and transferability criteria to help similar cases. Further works envisage the recognition of same elements in the broader European traditions, as well as the enhancement of stimuli for a personal and societal transformation generated by the partnership of all those people and institutions engaged in the exciting yet urgent defy of today's societal challenges.
ARTICLE | doi:10.20944/preprints202302.0150.v1
Subject: Engineering, Marine Engineering Keywords: Synthetic Aperture Radar; Maritime Monitoring; Multi-frequency; Multi-mission; Ship Detection; CFAR; Sublook Analysis
Online: 8 February 2023 (16:04:16 CET)
In the framework of maritime surveillance, vessel detection techniques based on spaceborne Synthetic Aperture Radar (SAR) images have promoted extensive applications for the effective understanding of unlawful activities at sea. The paper deal with this topic presenting a novel approach exploiting a cascade application of a pre-screening, and discrimination phase. The latter leverage the SAR spectrum by means of sub-looks analysis. For the first time, the method has been validated with experiments on multi-frequency (C-, X-, and L-band) SAR images. For a future syngergic exploitation of more SAR missions, the developed dataset, composed of Sentinel-1, SAOCOM and COSMO-SkyMed images, is comprehensive of multiple images gathered over the same area with short time lag (below 15 minutes). Finally, the diversified processing chains and the results for each mission product and scenarios are discussed. Being the first dataset of SLC (Single Look Complex) SAR multi-frequency data, the present work intends to encourage additional research in this promising field of research.
ARTICLE | doi:10.20944/preprints202109.0276.v1
Subject: Social Sciences, Education Keywords: entrepreneurial university; entrepreneurship; faculties of education; self-perception; triple helix; third mission; teacher training.
Online: 16 September 2021 (11:03:53 CEST)
Universities have increasingly incorporated a third mission into their strategic planning. In addition to teaching and research, they have emphasised the training of entrepreneurs. However, there is still a lot of work to be done, as this process is facing resistance. The Entrepreneurial University covers all disciplines, including faculties of education. However, it has been shown that entrepreneurship tends to be more related to the faculties of economics and engineering, with a lesser presence in the faculties of education for various reasons: they consider entrepreneurship to be alien to their teaching role, there is a lack of entrepreneurial culture, and the objective of the Entrepreneurial University is unknown. The aim of this study is to analyse the level of entrepreneurship in Spanish faculties and schools of education. Forty deans and heads of education faculties in Spain took part in the survey. The results indicated a sufficient level of entrepreneurship; the dimensions related to active methodologies, and mission and strategy were the most developed, whereas entrepreneurship funding and entrepreneurship training for faculty employees were the least developed areas. Some deans noted that entrepreneurship was alien to their professional performance, although courses and good practices for the development of entrepreneurial initiative are gradually being implemented.
ARTICLE | doi:10.20944/preprints202309.0792.v1
Subject: Engineering, Mechanical Engineering Keywords: vibration qualification testing; random vibration; non-gaussian signals; kurtosis control; test tai-loring; mission synthesis
Online: 13 September 2023 (02:54:29 CEST)
In many industrial, automotive, and aerospace applications, electro-mechanical systems are subjected to random vibration excitations, and the most critical components are required to undergo qualification tests to verify their suitability. Measured field data are commonly considered as reference for the synthesis of random stationary signals used as shaker input excitations in laboratory tests. For the most popular procedures of random-control testing, the user sets the input profiles in terms of power spectral density (PSD) associated with randomized phases generated by the shaker controller to finally provide the physical motion. As a result, the overall probability distribution of the test signal tends toward Gaussian, whereas many real-life random excitations prove non-Gaussian due to distinctive bursts and peaks. The quantitative estimate of the number and amplitudes of peaks present in a certain signal is usually made through the statistical parameter known as kurtosis. The so-called kurtosis control methods presented in the literature are conceived to perform qualification tests with random and non-Gaussian vibration excitations. In this paper, two novel algorithms able to synthesize shaker input signals for random-control testing with prescribed PSD and kurtosis value are proposed, and the results of their application are comparatively discussed to assess their effectiveness and potentialities in different kinds of qualification testing, including accelerated fatigue-life tests.
ARTICLE | doi:10.20944/preprints202302.0216.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Nuclear; nuclear energy; nuclear reactors; nuclear waste management; iMAGINE; strategic development; vision development; mission development
Online: 13 February 2023 (11:26:53 CET)
Nuclear technologies have the potential to play a major role in the transition to a global net-zero society. Their primary advantage is the capability to deliver controllable 24/7 energy on demand. However, as a prerequisite for successful worldwide application, significant innovation will be required to create the nuclear systems of the 21st century, the need of the hour. The pros and cons of nuclear are discussed and analysed at different levels – the societal and public recognition as well as the scientific/engineering and economic level – to assure a demand driven development. Based on the analysis of the different challenges a vision for the nuclear system of the 21st century is synthesised consisting of three pillars – unlimited nuclear energy, zero waste nuclear, and accident free nuclear. These three combined visions are then transformed into dedicated and verifiable missions which are discussed in detail regarding challenges and opportunities. In the following a stepwise approach for the development of such a highly innovative nuclear system is described. Essential steps to assure active risk reduction and the delivery of quick progress are derived as answer to the critique on the currently observed extensive construction time and cost overruns on new nuclear plants. The 4-step process consisting of basic studies, experimental zero power reactor, small scale demonstrator, and industrial demonstrator is described. The 4 steps including sub-steps deliver the pathway to a successful implementation of such a ground breaking new nuclear system. The potential sub-steps are discussed with the view not only onto the scientific development challenges, but also as an approach to reduce the regulatory challenges of a novel nuclear technology.
ARTICLE | doi:10.20944/preprints201808.0340.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: precipitation; tropical rainfall measurement mission (TRMM); multi-satellite precipitation analysis (TMPA); upper indus basin (UIB).
Online: 19 August 2018 (03:53:47 CEST)
The present study aims to evaluate the capability of the TRMM-3B42-(V7) precipitation product to estimate appropriate precipitation rates in the Upper Indus basin (UIB) and the analysis of the dependency of the estimates’ accuracies on the time scale. To that avail statistical analyses and comparison of the TMPA- products with gauge measurements in the UIB are carried out. The dependency of the TMPA estimates’ quality on the time scale is analysed by comparisons of daily, monthly, seasonal and annual sums for the UIB. The results show considerable biases in the TMPA- (TRMM) precipitation estimates for the UIB, as well as high false alarms and miss ratios. The correlation of the TMPA- estimates with ground-based gauge data increases considerably and almost in a linear fashion with increasing temporal aggregation, i.e. time scale. The BIAS is mostly positive for the summer season, while for the winter season it is predominantly negative, thereby showing a slight over-estimation of the precipitation in summer and under-estimation in winter. The results of the study suggest that, in spite of these discrepancies between TMPA- estimates and gauge data, the use of the former in hydrological watershed modelling, endeavoured presently by the authors, may be a valuable alternative in data- scarce regions, like the UIB, but still must be taken with a grain of salt.
ARTICLE | doi:10.20944/preprints202305.1485.v1
Subject: Engineering, Aerospace Engineering Keywords: Unmanned Aerial Vehicle; Reconfigurable; Multi-mission; Computational Fluid Dynam- 16 ics; Additive Manufacturing; Finite Element Analysis
Online: 22 May 2023 (09:35:00 CEST)
The performance of a small reconfigurable unmanned aerial vehicle (UAV) is evaluated, 1 combining a multidisciplinary approach in computational analysis of additive manufactured struc- 2 tures, fluid dynamics, and experiments. Reconfigurable UAVs promise cost savings and efficiency 3 without sacrificing performance, while demonstrating versatility to fulfill different military mission 4 profiles. The use of computational fluid dynamics (CFD) in UAV design produces higher accuracy 5 aerodynamic data, which is particularly important for complex aircraft concepts such as blended 6 wing bodies. To address challenges relating to anisotropic materials, the Tsai-Wu failure criterion is 7 applied to structural analysis, using CFD solutions as load inputs. Aerodynamic performance results 8 show the low-speed variant attains an endurance of 1 hour, 48 minutes, whereas for its high-speed 9 counterpart, it is 29 minutes at 66.7% higher cruise speed. Each variant serves different aspects of 10 small UAS deployment in combat, with low-speed envisioned for close surveillance, and high-speed 11 for incursions. Experimental and simulation results suggest room for design iteration, in wing area 12 and geometry adjustments. Structural simulations demonstrated the need for airframe improvements 13 in the low-speed configuration. This paper highlights the potential of reconfigurable UAVs to disrupt 14 the industry, advocating for further research and design improvements.
ARTICLE | doi:10.20944/preprints202211.0064.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Burnt severity index; bird responses; generalized linear models; fire recurrency; time since last fire; Sentinel 2, Landsat satellite mission
Online: 3 November 2022 (02:27:45 CET)
Fire regimes in mountain landscapes of southern Europe have been shifting from their baselines due to the accumulation of fuel fostered by long-standing rural abandonment and fire exclusion policies. Understanding the role of fire on biodiversity is paramount to implement adequate management to mitigate the impacts of altered fire regimes and land abandonment on biodiversity. Here, we explored to what extent the spatiotemporal variation in burn severity has affected bird abundance of a mountain abandoned landscape located in the Atlantic-Mediterranean transition (NW Iberia). We took advantage of: (1) satellite images of Sentinel 2 and Landsat missions to compute burn severity indicators from 2010 to 2020, and (2) standardized bird surveys carried out over 206 point-counts along the breeding season of 2021. Bird abundance models were built from burn severity metrics together with well-known fire regime attributes (% of burnt area and time since fire). Our results showed that the spatiotemporal variation of burn severity significantly correlated with the abundance of the 39% of the modeled species, supporting the role of pyro-diversity in driving bird populations in our region. The burnt area also explained abundance patterns for 28% of species. Time since fire only correlated with the abundance of 3 species. Our findings confirm the importance of incorporating burn severity indicators into the toolkit of decision makers to anticipate the response of birds to fire management.
ARTICLE | doi:10.20944/preprints202011.0462.v1
Subject: Physical Sciences, Acoustics Keywords: Eclipsing binary minima timing method; Transit timing variation method; Eclipsing binary stars; CM Draconis; TESS space mission; Computational Methods
Online: 18 November 2020 (09:51:19 CET)
The Kwee van Woerden (KvW) method for the determination of eclipse minimum times has been a staple in eclipsing binary research for decades, due its simplicity and independence of external input parameters. However, its estimates of the timing error have been known to be of low reliability. During the analysis of very precise photometry of CM Draconis eclipses from TESS space mission data, KvW’s original equation for the timing error estimate produced numerical errors, which evidenced a fundamental problem in this equation. This contribution introduces an improved way to calculate the timing error with the KvW method. A code that implements this improved method, together with several further updates over the original method is presented as well. An example application on the CM Draconis light curves from TESS is given, where we show that its timing error estimates of about 1 second are in excellent agreement with error estimates obtained by other means.
ARTICLE | doi:10.20944/preprints202302.0310.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: Unmanned Aerial Vehicle; Facility Location Problem; Mission Planning; Restricted Airspace; UAS Geographical Zone; Water Search & Rescue; Open Source Georeferenced Data
Online: 17 February 2023 (11:46:40 CET)
With Unmanned Aerial Vehicles (UAV), a swift response to urgent needs like search \& rescue missions or medical deliveries can be realized. Simultaneously, the legislator is establishing so-called geographical zones, which restrict UAV operations to mitigate the air and ground risk to third parties. These geographical zones serve a particular safety interest, but they may also hinder the efficient usage of UAVs on time-critical missions with a range-limiting battery capacity. In this study, we address a facility location problem for up to two UAV hangars with a robust optimization model considering demand hotspots, geographical zones as restricted areas, a standard mission to satisfy battery capacity constraints, and the impact of wind scenarios. To this end, water rescue missions are used exemplary, for which positive and negative location factors for UAV hangars and areas of increased drowning risk as demand points are derived from open-source georeferenced data. Optimal UAV mission trajectories are computed with an A* algorithm considering five different restriction scenarios. As this pathfinding is very time-consuming, binary occupancy grids and image processing algorithms accelerate the computation by identifying either entirely inaccessible or restriction-free connections beforehand. For the optimal UAV hangar locations, we maximize accessibility while minimizing the service time to the hotspots, resulting in a decrease from the average service time of 570.4 s for all facility candidates to 351.1 s for one and 287.2 s for two optimal UAV hangar locations.
TECHNICAL NOTE | doi:10.20944/preprints202112.0250.v1
Subject: Environmental And Earth Sciences, Oceanography Keywords: regional sea level; satellite altimetry; tide gauge; validation; mission bias; North Sea; Sentinel-3A; Jason-1; Jason-2; Jason-3; Envisat; Saral
Online: 15 December 2021 (09:25:54 CET)
Consistent calibration and monitoring is a basic prerequisite for providing reliable time series of global and regional sea level variations from altimetry. The precision of sea level measurements and regional biases for six altimeter missions (Jason-1/2/3, Envisat, Saral, Sentinel-3A) is assessed at eleven GNSS-controlled tide gauge stations in the German Bight (SE North Sea) for the period 2002 to 2019. The gauges are partly located at the open water, partly at the coast close to mudflats. The altimetry is extracted at virtual stations with distances from 2 to 24 km from the gauges. The processing is optimized for the region and adjusted for the comparison with instantaneous tide gauges readings. An empirical correction is developed to account for mean height gradients and slight differences of the tidal dynamics between gauge and altimetry which improves the agreement between the two data sets by 15-75%. The precision of the altimeters is depending on location and mission and is shown to be at least 1.8 to 3.7 cm based on an assumed precision of 2 cm for the gauges. The accuracy of the regional mission biases is strongly dependent on the mean sea surface heights near the stations. The most consistent biases are obtained based on the CLS2011 model with mission dependent accuracies from 1.3 to 3.4 cm. Hence, the GNSS-controlled tide gauges operated operationally by WSV might complement the calibration and monitoring activities at dedicated CalVal stations.
ARTICLE | doi:10.20944/preprints202305.2109.v1
Subject: Physical Sciences, Particle And Field Physics Keywords: Universe mass ratio golden rule; dark energy; dark matters; Planck mission; WMAP missions; Black holes; Cosmic background neutrinos; Universe evolution; Flat photon space
Online: 30 May 2023 (10:19:25 CEST)
Our matter universe is made up of four components of dark energy (DE), dark matters (DMs), leptons and quarks which are created from the decay of the primary black hole through the inflation after big bang. In the three-dimensional quantized space model, the sum (DER) of the dark energy (DE) and radiations (R) is the flat photon space and there are 39 particles of 3 dark matters, 9 leptons and 27 quarks. Generally speaking, the mass ratio of the quarks with the 27 particles is smallest and the mass ratio of the DER photon space with the 1 massless photon is largest. Therefore, the mass ratios of DER, DMs, leptons and quarks are inversely proportional to the particle numbers of DER, DMs, leptons and quarks as the first assumption. This simple rule is called as the universe mass ratio golden rule in Fig. 12. This simple rule is successfully applied to the observed mass ratios of the Planck and WMAP missions. The best particle number combination (1, 3, 9, 27) of the four components (DER, DMs, Leptons, Quarks) to explain the Planck 2018 and WMAP results is the same as the particle number combination (1, 3, 9, 27) of the 3-dimensional quantized space model. The calculated mass ratios of DER, DMs, leptons and quarks are 67.5 %, 22.5 %, 7.5 % and 2.5 %, respectively. And the calculated mass ratios of neutrinos and ordinary matters are 5.0 % and 5.0 %, respectively. The mass ratios of the dark energy (68.47(23) %) and matters (31.53(23) %) obtained from the Planck 2018 results are consistent with the calculated mass ratios of the DER (67.5 %) and matters (32.5 %). The mass ratio of the dark energy (72.1(15) %) obtained from the WMAP 9 year results is explained as the summed mass ratio (72.5 %) of DER (67.5 %) and neutrinos (5.0 %). The universe evolution including the super-massive black holes (SMBHs) is shown in Fig. 4. The accelerated space expansion of our universe requires the addition of the new dark energy. If this new dark energy is added, the mass ratio of the dark energy is a little bit increased. The difference (0.97 %) between the observed value (68.47(23) %) and calculated value (67.5 %) is explained by adding the new dark energy in Figs. 2, 4, 7, 8, 9, 10 and 11. The corrected mass ratios of DER, DMs, leptons and quarks are 68.47 %, 21.8286 %, 7.2762 % and 2.4254 %, respectively. The corrected mass ratios of the neutrinos (called as cosmic background neutrinos) and ordinary matters (OMs) are 4.8508 % and 4.8508 %, respectively. These corrected mass ratios can explain the mass ratios obtained from the WMAP and Planck missions. In other words, the mass ratios calculated from the best particle number combination support the elementary particles, dark matters and dark energy (photon space) proposed by the three-dimensional quantized space model based on the 10-D Euclidean space.