Point Placement Research Articles

A super-zoom algorithm for envelope peak position resolution using discrete Fourier transform with multiple-warped time-sampling point calculations

We propose a new method for super-zooming the position resolution of envelope peak signals using a discrete Fourier transform (DFT) with multiple-warped time-sampling point calculations. Position resolution of warped DFT (WDFT)-based envelope demodulation is nonlinear but can be externally controlled. Compared with previous studies of WDFT-based envelope demodulation, the proposed method further warps the placement of sampling points along the time axis, allowing us to evaluate the envelope with a denser collection of position sampling points. The proposed approach is introduced within the framework of optical frequency comb-based Michelson interferometry. Our experimental results demonstrated the superiority of the proposed algorithm over the conventional WDFT-based method for envelope position resolution. To the best of the authors’ knowledge, this is the first article to provide a definition of multiple-warped DFT and its application to envelope demodulation. The present technique is expected to be useful for high-precision distance measurements for scientific and industrial purposes.

Using existing infrastructure as ground control points to support citizen science coastal UAS monitoring programs

Recent publications have described the ability of citizen scientists to conduct unoccupied aerial system (UAS) flights to collect data for coastal management. Ground control points (GCPs) can be collected to georeference these data, however collecting ground control points require expensive surveying equipment not accessible to citizen scientists. Instead, existing infrastructure can be used as naturally occurring ground control points (NGCPs), although availably of naturally occurring ground control point placement on such infrastructure differs from published best practices of ground control point placement. This study therefore evaluates the achievable accuracy of sites georeferenced with naturally occurring ground control points through an analysis of 20 diverse coastal sites. At most sites naturally occurring ground control points produced horizontal and vertical root mean square errors (RMSE) less than 0.060 m which are similar to those obtained using traditional ground control points. To support future unoccupied aerial system citizen science coastal monitoring programs, an assessment to determine the optimal naturally occurring ground control point quantity and distribution was conducted for six coastal sites. Results revealed that generally at least seven naturally occurring ground control points collected in the broadest distribution across the site will result in a horizontal and vertical root mean square errors less than 0.030 m and 0.075 m respectively. However, the relationship between these placement characteristics and root mean square errors was poor, indicating that georeferencing accuracy using naturally occurring ground control points cannot be optimized solely through ideal quantity and distribution. The results of these studies highlight the value of naturally occurring ground control points to support unoccupied aerial system citizen science coastal monitoring programs, however they also indicate a need for an initial accuracy assessment of sites surveyed with naturally occurring ground control points at the onset of such programs.

Using Collocation to Solve the Schrödinger Equation.

We review the collocation approach to the solution of the Schrödinger equation and its uses in applications. Interrelations between collocation and other methods are highlighted. We also stress advantages and disadvantages of the rectangular collocation formulation. Using collocation makes it possible to use any, e.g. optimized, coordinates and basis functions, including nonintegrable basis functions, and provides a straightforward way of dealing with singularities in the potential. In addition, we stress that using collocation facilitates tuning the shape of basis functions and the placement of points, both of which can be done with machine-learning methods. Applications to electronic and vibrational problems are reviewed focusing on calculations for molecules on surfaces for which there are few variational calculations. Collocation has advantages when potential energy surfaces are unavailable, in particular, for molecule-surface systems, and for systems for which standard direct product quadrature grids, often used with variational methods, are costly.

Autocorrelation and Parameter Estimation in a Bayesian Change Point Model

A piecewise function can sometimes provide the best fit to a time series. The breaks in this function are called change points, which represent the point at which the statistical properties of the model change. Often, the exact placement of the change points is unknown, so an efficient algorithm is required to combat the combinatorial explosion in the number of potential solutions to the multiple change point problem. Bayesian solutions to the multiple change point problem can provide uncertainty estimates on both the number and location of change points in a dataset, but there has not yet been a systematic study to determine how the choice of hyperparameters or the presence of autocorrelation affects the inference made by the model. Here, we propose Bayesian model averaging as a way to address the uncertainty in the choice of hyperparameters and show how this approach highlights the most probable solution to the problem. Autocorrelation is addressed through a pre-whitening technique, which is shown to eliminate spurious change points that emerge due to a red noise process. However, pre-whitening a dataset tends to make true change points harder to detect. After an extensive simulation study, the model is applied to two climate applications: the Pacific Decadal Oscillation and a global surface temperature anomalies dataset.

Design and analysis of an adjustable Stephenson-III closed-chain leg mechanism and its application in multi-legged robot

To improve the insufficient adaptability of single degree-of-freedom (DOF) closed-chain legs to unknown surroundings, this paper studies a novel adjustable closed-chain leg mechanism. Based on the traditional six-bar Stephenson-III leg mechanism, we add one degree-of-freedom to realize the adjustment of frame rod position, by which different shapes of foot trajectory curves are obtained. The height of the foot trajectory can be adjusted longitudinally to enhance the obstacle-surmounting ability, and the length of the walking stride can be changed in the transverse direction to achieve the landing point placement of the swing leg. The structure optimization, gait analysis and obstacle-surmounting simulation in different scenarios are carried out. The test results of walking ability and obstacle surmounting performance in specific surrounding show that the designed closed-chain leg mechanism can increase the maximum obstacle-crossing height and walking stability, which proves the promising characteristics of the proposed leg mechanism in the application of multi-legged robots.

Do additional target points speed up evolutionary algorithms?

Most runtime analyses of randomised search heuristics focus on the expected number of function evaluations to find a unique global optimum. We ask a fundamental question: if additional search points are declared optimal, or declared as desirable target points, do these additional optima speed up evolutionary algorithms? More formally, we analyse the expected hitting time of a target set OPT∪S where S is a set of non-optimal search points and OPT is the set of optima and compare it to the expected hitting time of OPT.We show that the answer to our question depends on the number and placement of search points in S. For all black-box algorithms and all fitness functions with polynomial expected optimisation times we show that, if additional optima are placed randomly, even an exponential number of optima has a negligible effect on the expected optimisation time. Considering Hamming balls around all global optima gives an easier target for some algorithms and functions and can shift the phase transition with respect to offspring population sizes in the (1,λ) EA on OneMax. However, for the one-dimensional Ising model the time to reach Hamming balls of radius (1/2−ε)n around optima does not reduce the asymptotic expected optimisation time in the worst case. Finally, on functions where search trajectories typically join in a single search point, turning one search point into an optimum drastically reduces the expected optimisation time.

Structural, electronic, optical, and mechanical properties of the all-inorganic lead-free metal halides double perovskites Cs2RbInX6 (X = Cl, Br, I): A first-principles based study

Lead-free metal halides double perovskite is an ideal alternative to lead-based perovskite and is poised to shine in the field of optoelectronics as a new and emerging photoelectric material. In this paper, we take as a starting point the halide double perovskite Cs2NaInCl6 which is a subject with well-established research results and determined the little-studied structure Cs2RbInCl6 by the replacement of the same-group element, and explore the effects of halogen substitution on the different properties, computational experiments and analyses of the Cs2RbInX6 (X = Cl, Br, I) have been carried out. Depending on the First-Principles studies, the band structure, density of states, optical and mechanical properties of this compound have all been systematically explored. The Materials Studio package's Castep code was used for all computational experiments. The tolerance factor (τ) reveal that Cs2RbInI6 is less stable than Cs2RbInCl6 and Cs2RbInBr6. The band gaps of all three compounds are direct. The light absorption is mainly attributed to the transition from the halogen X-p orbital to the In-s orbital. While Cs2RbInCl6 and Cs2RbInBr6 have no absorption occurring in the visible and infrared regions and possess a wide band gap, which considers them promising candidates for use in the ultraviolet detector. The replacement of halogen has noticeably enhanced the optical properties. The Cs2RbInX6 (X = Cl, Br, I) also meets the requirements for mechanical stability and is ductile, anisotropic, and toughness. Sequentially decreasing band gap values when the halogen from Cl to I, also obviously affects the placements of the threshold points and peaks in the various spectral figures and the macroscopic mechanical properties. The work presented in this paper sheds light on the electronic, optical, and mechanical characteristics of Cs2RbInX6 (X = Cl, Br, I), offering corresponding theoretical support for the related experimental research and promoting the possibility for the development of novel optoelectronic devices.

Technological design of carbon fiber parts with a complex geometric shape for unmanned aerial vehicles

In this paper, the process of technological design of small-sized carbon fiber parts with complex geometry used in the design of unmanned aerial vehicles is considered. Approaches to the placement of splicing points in preform layers are presented. Regularities have been established that relate the number and location of splicing points in the reinforcing layers of carbon fiber reinforced composite and its mechanical characteristics.

Fluence-based QMRA model for bacterial photorepair and regrowth in drinking water after decentralized UV disinfection

Ultraviolet disinfection is a promising solution for decentralized drinking water systems such as communal water taps. A potential health risk is enzymatic photorepair of pathogens after UV disinfection, which can result in regrowth of pathogens. Even though photorepair is a known issue, no formal risk assessments have been conducted for photorepair after UV disinfection in drinking water. The main objective was to construct a quantitative microbial risk assessment (QMRA) of photorepair after UV disinfection of drinking water in a decentralized system. UV disinfection and photorepair kinetics for E. coli were modelled using reproducible fluence-based determinations. Impacts of water collection patterns, and wavelength-dependent water container material transmittance, sunlight intensity, and photorepair enzyme absorbance were quantified. After UV disinfection by 16 or 40 mJ/cm2 of < 5-log microorganisms per L, risk of infection did not exceed 1-in-10,000 under conditions permitting E. coli photorepair. Risk from photorepair was less than 1-in-10,000 for photorepair light exposure < 0.75 h throughout the day for UV fluence 16 mJ/cm2 or greater. UV disinfection followed by solar disinfection surpassing photoreactivation during storage reduced risk below 1-in-10,000 for photorepair light exposure > 2.5 h between modelled times of 9 AM – 3 PM. The model can be expanded to other pathogens as UV fluence and photorepair fluence response kinetics become available, and this QMRA can be used to inform the placement of community water access points to reduce risk of photorepair and ensure adequate shelf life of UV disinfected water under safe storage conditions.

Absolute IOP/EOP Estimation Models without Initial Information of Various Smart City Sensors

In smart cities, a large amount of optical camera equipment is deployed and used. Closed-circuit television (CCTV), unmanned aerial vehicles (UAVs), and smartphones are some examples of such equipment. However, additional information about these devices, such as 3D position, orientation information, and principal distance, is not provided. To solve this problem, the structured mobile mapping system point cloud was used in this study to investigate methods of estimating the principal point, position, and orientation of optical sensors without initial given values. The principal distance was calculated using two direct linear transformation (DLT) models and a perspective projection model. Methods for estimating position and orientation were discussed, and their stability was tested using real-world sensors. When the perspective projection model was used, the camera position and orientation were best estimated. The original DLT model had a significant error in the orientation estimation. The correlation between the DLT model parameters was thought to have influenced the estimation result. When the perspective projection model was used, the position and orientation errors were 0.80 m and 2.55°, respectively. However, when using a fixed-wing UAV, the estimated result was not properly produced owing to ground control point placement problems.

АНАЛИЗ УСЛОВИЙ РАЗМЕЩЕНИЯ ОСТАНОВОЧНЫХ ПУНКТОВ НА МАГИСТРАЛЬНОЙ СЕТИ КРУПНЕЙШЕГО СИМБИОТИЧЕСКОГО ГОРОДА

. A modern city is an extremely complex, self-developing organism trying to make its transport system more sustainable, in particular, by developing plans for sustainable urban mobility, improving transport and logistics, and many other aspects. The article deals with the placement of stopping points of route passenger transport and accidents, which allows us to assess the issues of transformation of approaches to transport planning of the route passenger transport network and the organization of urban traffic. The corresponding proposals on the choice of the location of stopping points, as well as their arrangement in the intersection zones are given.

Study of Cane Dimensional Characteristics to Justify Sprayer Parameters

Based on the study of dimensional characteristics of reeds, a sprayer is proposed for the treatment of panicles of reeds growing in the elements of the irrigation system of rice checks. The boom of the offered sprayer has an original shape, sprayers of which are located along the trajectory of a parabola, taking into account the placement of the upper points of the panicles across the width of the channel and equipped with a protective chamber device, made in the form of an Archimedes spiral with a spiral pitch equal to at least 20 cm, the offset of the spiral center from the axis of the spraying nozzle vertically is equal to the spiral pitch 20 cm, and from the location of the spraying nozzle to the bottom treatment zone of panicles 40 cm.

On the application of heuristic algorithms for solving the pseudogeometric version of the traveling salesman problem for the design of communication networks

The Mathematical models and algorithms developed to solve the traveling salesman problem are developed specifically for constructing optimal driving routes and choosing the optimal trajectory. At the same time, such models and algorithms are also used to solve several interconnected groups of applied problems; for example, it is the study of DNA chains, the calculation of the “similarity” of long strings, the construction of algorithms for checking special grammatical structures, etc. The resulting variants of the traveling salesman problem are close to the pseudogeometric version. We are most interested in issues related to communication networks (first of all, large ones). There are at least two different subject areas related to the application of the pseudogeometric version of the traveling salesman problem and heuristic algorithms for its solution. First, it is the location of the source points when generating the source data. Secondly, if we somehow organize the sequence of points well in advance, then the heuristic algorithms we use will work faster; at the same time, we can assume that such a “good location” is a pseudo-optimal solution to the traveling salesman problem. In the article, we also briefly describe our approach to classifying input data generation options designed primarily to test the operation and compare heuristic algorithms. In addition, an auxiliary algorithm for pseudo-optimal placement of points is described; it is desirable to use this algorithm specifically for a set of points generated as a variant of the pseudo-geometric version of the traveling salesman problem. The article also presents some results of computational experiments that allow comparing different algorithms for solving pseudogeometric variants of the problem.

ОЦЕНКА СОСТОЯНИЯ РАСТИТЕЛЬНОСТИ НА ОСНОВЕ МНОГОЛЕТНИХ ДАННЫХ СПУТНИКОВОГО МОНИТОРИНГА

In this study, MODIS satellite imagery data was processed for 2016 to identify areas with high fire danger, taking into account vegetation characteristics in 2016–2017. To assess the biodiversity of the territory and damage from vegetation fires, it is proposed an algorithm for the spatial and temporal analysis of vegetation fires distribution, taking into account their influence on vegetation transformation in the Russian Far East. The processing algorithm includes: the network imposition on the study area; obtaining satellite image fragments for the territory and converting the satellite image into operational-territorial units of a given size, with the transfer of attribute data over a multi-year period; forming vector layers of individual vegetation fires on the base of point placement or fires area, determining the nesting of individual fires in operational-territorial units and adding data on the condition of vegetation they arose on. The materials of the study contained both annual and daily vegetation data on the location of vegetation fires, based on MODIS satellite images, Terra spectroradiometer and Aqua Land Cover Modeling Grid Version 6. In the course of data analysis, 88 variants of vegetation condition transformation were found in the presence of from 1 to 11 fires. In 8604 cases, changes in the flora structure and quality were caused by an anthropogenic factor. In 40 variants, the transformation did not depend on fires. The maximum transformation is recorded in the following vegetation cover classes: small-leaved and broad-leaved forests, forest-steppes, steppes, meadows and arable land. Most cases of vegetation transformation in operational-territorial units (from 30 to 70%) are recorded when forest- steppe is turning to steppe.

Закономерности размещения цифрового предпринимательства в регионах России

Introduction: the implementation of the “Digital Economy” national program has an impact on business sector development both in Russia and in the regional aspect. The structural elements of regional entrepreneurial ecosystems are designed to promote the development of digital entrepreneurship. It has been hypothesized that the ecosystem substitutes influence on the increment of regional economic performance due to the digital sector differs in industrial and non-industrial types of regions. Objectives: to determine the growth points placement patterns for digital entrepreneurship in the regions as a whole, as well as by types (industrial and others), depending on the impact of factors in the regional environment. Methods: statistical groupings, comparison and matching, correlation and regression analysis, econometric modeling. Results: the data on 85 subjects of the Russian Federation for 2018–2021 have been examined, revealing a strong and noticeable correlation between the number of organizations in the information and communication technology (ICT) sector and the indicators of digital infrastructure, as well as strong correlation between financial security and the number of regional projects in the field of end-to–end technologies. Regression models have been built demonstrating the growth of the share and growth rates of production volumes in ICT sector and e-commerce companies in various types of regions. Conclusions: the above hypothesis has been confirmed stating that the region’s specialization has a significant impact on the features and pace of digital entrepreneurship development. Industrial regions do not demonstrate outpacing growth of digital businesses due to a significant time lag until the moment the production volumes increase resulting from the introduction and use of digital technologies manifests itself. Industrial regions show a high sensitivity to the development of scientific and technological infrastructure and have a more active demand and consumption of digital technologies. In other regions show a faster developing e-commerce and the service sector using digital platforms. Digital economy growth is boosted by the stimulation of IT projects and the state of the scientific and educational environment in these regions.

Vantage Point Placement Based on Inference of AS-level Connections

Internet topology data is useful for evaluating new protocols, services, and vulnerabilities in network infrastructures. To infer the AS-level topology, some projects deploy BGP routers worldwide, mainly on IXPs, collect and publish BGP routing information from other ASes called Vantage Points. Deploying more routers on various IXPs will make the topology data precise, but it is hard to deploy a lot of routers because of administrative costs. So, we carefully choose locations where we can obtain new topological information with a small number of new routers. In this study, we investigate which ASes and IXPs should be used as Vantage Points with a small number of additional routers. This work consists of two stages. First, we analyze current BGP routing information available to infer currently unobserved but possibly existing connections, and find that such connections tend to be between two ASes that have a high percentage not including 100% of common adjacent ASes. Second, we calculate which IXPs should be more suitable for installing BGP routers for the collection using the results on the first stage and data of ASes on IXPs. We also discuss IXPs recommended to deploy new routers are in different countries where many ASes are allocated.

DIRECTIONS IN RELATION TO IMPROVEMENT OF SYSTEM OF LOGISTIC PROVIDING OF SOLDIERY PARTS (SUBDIVISIONS) AT PLACING IN THE FIELD TERMS IN THE MODERN ARMED CONFLICTS

Ensuring the security and reliable defense of a military camp is necessary for any locality. However, due to the specificity and limitations of each region, they lead to the usage of appropriate measures that are adapted to the existing reality. Other issues related to the organization and maintenance of the field camp are determined primarily by security considerations. Therefore, the camp operates as a fully integrated system of deployed armed forces infrastructure which is designed to initially provide basic services and facilities for the location with the ability to improve over time by adapting to needs. The functional structure allows you to predict the spatial distribution of objects and improve the organization of the entire field camp. There are two main types of infrastructure within the camp: service and logistics (rear). In the conditions of operations as part of foreign missions, armed contingents of the NATO member states armies equip field camps of various types. According to the duration of usage, field camps are divided into: mobile (short term of placement), typical (up to a year) and foreign garrisons – large points of long-term placement of a military contingent (term of more than a year). The key task regarding the deployment of field camps is the placement of combat units (units) with all equipment, weapons, military and special equipment and other means in the deployment areas without long-term preparation of the infrastructure and material and technical base. The article presents the analysis, principles and approaches to the construction of the necessary infrastructure for the field deployment of armed contingents of the NATO armies member states when performing missions. The structure of a modern universal mobile complex of logistics support is determined and it consists of mobile modules (platforms) corresponding to their specific purpose. The ways of new global developments in the system of locating and ensuring the vital activity of personnel during the execution of combat tasks are presented. Views were considered ,recommendations were made and directions for improving the system of logistical support of military units (units) when deployed in the field in modern armed conflicts were discussed, as well as the expediency of equipping field camps according to the block-module system.

Assessment of user-interaction strategies for neurosurgical data navigation and annotation in virtual reality

While virtual-reality (VR) has shown great promise in radiological tasks, effective user-interaction strategies that can improve efficiency and ergonomics are still under-explored and systematic evaluations of VR interaction techniques in the context of complex anatomical models are rare. Therefore, our study aims to identify the most effective interaction techniques for two common neurosurgical planning tasks in VR (point annotation and note-taking) from the state-of-the-arts, and propose a novel technique for efficient sub-volume selection necessary in neuroanatomical navigation. We assessed seven user-interaction methods with multiple input modalities (gaze, head motion, controller, and voice) for point placement and note-taking in the context of annotating brain aneurysms for cerebrovascular surgery. Furthermore, we proposed and evaluated a novel technique, called magnified selection diorama (Maserama) for easy navigation and selection of complex 3D anatomies in VR. Both quantitative and semi-quantitative (i.e., NASA Task Load Index) metrics were employed through user studies to reveal the performance of each interaction scheme in terms of accuracy, efficiency, and usability. Our evaluations demonstrated that controller-based interaction is preferred over eye-tracking-based methods for point placement while voice recording and virtual keyboard typing are better than freehand writing for note-taking. Furthermore, our new Maserama sub-volume selection technique was proven to be highly efficient and easy-to-use. Our study is the first to provide a systematic assessment of existing and new VR interaction schemes for neurosurgical data navigation and annotation. It offers valuable insights and tools to guide the design of future VR systems for radiological and surgical applications.

OPTIMIZATION OF ACCESS POINT ARRANGEMENT AND PLACEMENT IN THE INDOOR ROOM OF SMP NEGERI 6 SALATIGA USING GENETIC ALGORITHM

Access points are generally only recommended to load up to 40 clients only. Thus, proper placement and arrangement of access points in a room or building can optimize the signal strength received by users. The purpose of this study is to optimize the arrangement and placement of access points built using the genetic algorithm method. In the system built, the user is required to input the number of populations, iterations and the number of nodes 1 and 2. In the program implementation, the population functions to load the genes resulting from the possible placement of the access point based on the iteration results. The access point placement optimization system using the genetic algorithm method has been successfully implemented, the system can perform calculations in processing the ideal access point placement. Access point placement using genetic algorithms can provide recommendations for network architecture design in terms of the coverage area that needs to be used so that designers can save time on node point design and estimate the ideal price in determining the number of access points for network installation and can assist in determining the required coverage area. ideal for schools.

PENGGUNAAN METODE SIMULATED ANNEALING DAN TRILATERATION UNTUK OPTIMASI PENEMPATAN POSISI TITIK AKSES STUDI KASUS: KANTOR KESYAHBANDARAN DAN OTORITAS PELABUHAN (KSOP) KELAS 1 TANJUNG EMAS

Computer network technology is developing rapidly, and wired networks are being replaced by WiFi technology.&#x0D; The limitation of the WiFi coverage area is the main problem with this technology. Therefore, it is necessary to design for optimal placement of access points.&#x0D; This study analyzes the need for access point placement at KSOP Tanjung Mas Port, Semarang, where the need for internet connection via WiFi is very high.&#x0D; Simulation Annealing and Trilateration method is used in this study to determine the position of the access point. With the point blankspot method can be reduced.