Computation Of Minimum Distance Research Articles

Minimum Distance Calculation Method for Collision Issues in Lifting Construction Scenarios

Minimum Distance Calculation Method for Collision Issues in Lifting Construction Scenarios

Collision-Free Trajectory Planning Optimization Algorithms for Two-Arm Cascade Combination System

As a kind of space robot, the two-arm cascade combination system (TACCS) has been applied to perform auxiliary operations at different locations outside space cabins. The motion coupling relation of two arms and complex surrounding obstacles make the collision-free trajectory planning optimization of TACCS more difficult, which has become an urgent problem to be solved. For the above problem, this paper proposed collision-free and time–energy–minimum trajectory planning optimization algorithms, considering the motion coupling of two arms. In this method, the screw-based inverse kinematics (IK) model of TACCS is established to provide the basis for the motion planning in joint space by decoupling the whole IK problem into two IK sub-problems of two arms; the minimum distance calculation model is established based on the hybrid geometric enveloping way and basic distance functions, which can provide the efficient and accurate data basis for the obstacle-avoidance constraint condition of the trajectory optimization. Moreover, the single and bi-layer optimization algorithms are presented by taking motion time and energy consumption as objectives and considering obstacle-avoidance and kinematics constraints. Finally, through example cases, the results indicate that the bi-layer optimization has higher convergence efficiency under the premise of ensuring the optimization effect by separating variables and constraint terms. This work can provide theoretical and methodological support for the efficient and intelligent applications of TACCS in the space arena.

Research on the method of air gap clearance selection for bushing at high-altitude areas

Abstract As an important component of the core equipment of the UHV substation, the operation reliability of the bushing is directly related to the safe operation of the main equipment. There are some technical problems in the development of casing in the Sichuan-Chongqing project, such as technical problems at high altitudes and a lack of relevant experience in the correction of air gap and equipment external insulation altitude. Therefore, there is an urgent need to research the selection of gap distance for UHV AC substation bushing electrical characteristics test in high altitude areas. In this paper, based on the standard meteorological conditions and the rod-plate gap switching impulse discharge test data at an altitude of 4300 m, the minimum gap distance of UHV AC substation bushing withstanding 1800 kV and 1950 kV under different methods is obtained. The results show that by comparing the two calculation methods, the minimum distance calculation method of the true test combined with the gap coefficient method avoids the error of altitude correction, and the minimum gap distance is reduced by 7.84%-14.17% compared with the former. The research content can provide a reference for selecting the dry arc distance of the casing. The next step should be to carry out the discharge characteristic test of the true-size electrode at a high altitude, so as to simulate the field situation more realistically and provide more powerful technical support for the project.

Human-robot collaborative task planning for assembly system productivity enhancement

PurposeIn the current era of Industry 4.0, the manufacturing industries are striving toward mass production with mass customization by considering human–robot collaboration. This study aims to propose the reconfiguration of assembly systems by incorporating multiple humans with robots using a human–robot task allocation (HRTA) to enhance productivity.Design/methodology/approachA human–robot task scheduling approach has been developed by considering task suitability, resource availability and resource selection through multicriteria optimization using the Linear Regression with Optimal Point and Minimum Distance Calculation algorithm. Using line-balancing techniques, the approach estimates the optimum number of resources required for assembly tasks operating by minimum idle time.FindingsThe task allocation schedule for a case study involving a punching press was solved using human–robot collaboration, and the approach incorporated the optimum number of appropriate resources to handle different types of proportion of resources.Originality/valueThis proposed work integrates the task allocation by human–robot collaboration and decrease the idle time of resource by integrating optimum number of resources.

Calculation of Minimum Plate Distance in Electrostatic Flocking Process Based on Dynamics Research

Calculation of Minimum Plate Distance in Electrostatic Flocking Process Based on Dynamics Research

1426. Integrating artificial intelligence and dynamic programming to identify microbial clusters through antimicrobial susceptibility sequence analysis

Abstract Background The spread of infectious diseases and antimicrobial resistance poses a significant threat, especially in developing countries where traditional DNA fingerprinting techniques are often not available. We propose a novel approach using dynamic programming algorithms to compare antimicrobial susceptibility sequences and identify clusters of related microbes. Methods We selected pathogens from specific infections and tested them with a range of antimicrobials, recording the test results as either sensitive (S), resistant (R), or unknown (U) to each drug. These results were combined into a sequence, or ATB string, for each pathogen (Fig. 1). To compare the sequences, we used dynamic programming (Fig. 2) to calculate the minimum edit distance between each pair of sequences. The edit distance reflects the number of atomic changes needed to transform one sequence into the other. In this case, atomic changes include insertion, deletion, substitution, and matching of individual test results (Fig. 3). We created a matrix of pairwise similarities by comparing all ATB strings. A cluster of similar strains was identified based on a cutoff in the edit distance matrix, such as a distance of less than 1. The method, which is available in the SACIH+ system (https://plus.sacihweb.com), was used to analyze the same strain of specific healthcare infections from a public hospital in Belo Horizonte, Brazil, diagnosed between Jan 2022 and Mar 2023.Figure 1.Antimicrobial testing and ATB string generation for selected pathogens. Antimicrobial testing and ATB string generation for selected pathogens.Figure 2.Sequence comparison using dynamic programming. Sequence comparison using dynamic programming. Results We analyzed S. aureus strains from surgical site infection - SSI (23 cases), pneumonia - PNEU (29 cases), and bloodstream infection - BSI (13 cases). Identified 4 SSI, 10 PNEU clusters (Fig. 4 and 5), and 4 BSI clusters using edit distance matrix. For K. pneumoniae strains from 21 BSI, 22 PNEU, and 34 urinary tract infection - UTI cases, found 5 clusters for PNEU and UTI, and 7 clusters for BSI (Fig. 6).Figure 3.Minimum edit distance calculation for sequence comparison. Minimum edit distance calculation for sequence comparison.Figure 4.Clustering of Staphylococcus aureus strains from 29 nosocomial pneumonia cases. Clustering of Staphylococcus aureus strains from 29 nosocomial pneumonia cases.Figure 5.Identification of a large cluster with 16 identical Staphylococcus aureus strains from 29 nosocomial pneumonia cases.Identification of a large cluster with 16 identical Staphylococcus aureus strains from 29 nosocomial pneumonia cases. Conclusion Our novel approach using dynamic programming to compare antimicrobial susceptibility sequences has shown promise in identifying clusters of related microorganisms, even without traditional DNA fingerprinting methods. The method represents a valuable tool for tracking the spread of infectious diseases, especially in settings where traditional methods are not available.Figure 6.Clustering of Klebsiella pneumoniae strains from 21 bloodstream infection cases.Clustering of Klebsiella pneumoniae strains from 21 bloodstream infection cases. Disclosures All Authors: No reported disclosures

An Online Distance Tracker for Verification of Robotic Systems’ Safety

This paper presents an efficient method for minimum distance calculation between a robot and its environment and the implementation framework as a tool for the verification of robotic systems' safety. Collision is the most fundamental safety problem in robotic systems. Therefore, robotic system software must be verified to ensure that there are no risks of collision during development and implementation. The online distance tracker (ODT) is intended to provide minimum distances between the robots and their environments for verification of system software to inspect whether it causes a collision risk. The proposed method employs the representations of the robot and its environment with cylinders and an occupancy map. Furthermore, the bounding box approach improves the performance of the minimum distance calculation regarding computational cost. Finally, the method is applied to a realistically simulated twin of the ROKOS, which is an automated robotic inspection cell for quality control of automotive body-in-white and is actively used in the bus manufacturing industry. The simulation results demonstrate the feasibility and effectiveness of the proposed method.

Contact-free release dynamics of tens of stacked satellites with multiaxial rotations

Stacked satellites have a promising application in aerospace engineering for the merits of high launch efficiency and networking capability. As one of the key technical points, releasing tens or even hundreds of satellites from the stacked state in a simple and contact-free manner is of importance. In this paper, the contact-free release dynamics of tens of stacked satellites is studied with only the initial multiaxial rotations of the system. First of all, a rigid multibody dynamic model of the stacked satellite system is established via the natural coordinate formulation (NCF). The NCF modeling scheme is able to describe the large overall motions of the satellites without any singularity and makes it possible to simplify the varying constraints between the satellites. Then, the orbital dynamics of the stacked satellite system is derived via coordinate transformation by taking the Coriolis forces, centrifugal forces, and gravity gradient into consideration. In order to rapidly and accurately detect the possible contact between satellites, a convex optimization model for minimum distance computation is proposed by using a hyperelliptic approximation for a cubic satellite. Finally, a benchmark example is given to validate the contact detection algorithm and three release dynamic cases for the stacked satellites are presented to demonstrate the effectiveness of the contact-free releasing approach with multiaxial rotations.

Molecular interactions of trichoderma β-1,4-glucosidase (ThBglT12) with mycelial cell wall components of phytopathogenic Macrophomina phaseolina

Efficacy of a β-1,4-glucosidase from Trichoderma harzianum T12 (ThBglT12) in disrupting the cell wall of the phytopathogenic fungus M. phaseolina (Macrophomina phaseolina) was studied, as the underlying molecular mechanisms of cell wall recognition remains elusive. In this study, the binding location identified by a consensus of residues predicted by COACH tool, blind docking, and multiple sequence alignment revealed that molecular recognition by ThBglT12 occurred through interactions between the α-1,3-glucan, β-1,3-glucan, β-1,3/1,4-glucan, and chitin components of M. phaseolina, with corresponding binding energies of −7.4, −7.6, −7.5 and −7.8 kcal/mol. The residue consensus verified the participation of Glu172, Tyr304, Trp345, Glu373, Glu430, and Trp431 in the active site pocket of ThBglT12 to bind the ligands, of which Trp345 was the common interacting residue. Root mean square deviation (RMSD), root mean square fluctuation (RMSF), total energy, and minimum distance calculation from molecular dynamics (MD) simulation further confirmed the stability and the closeness of the binding ligands into the ThBglT12 active site pocket. The h-bond occupancy by Glu373 and Trp431 instated the role of the nucleophile for substrate recognition and specificity, crucial for cleaving the β-1,4 linkage. Further investigation showed that the proximity of Glu373 to the anomeric carbon of β-1,3/1,4-glucan (3.5 Å) and chitin (5.5 Å) indicates the nucleophiles’ readiness to form enzyme-substrate intermediates. Plus, the neighboring water molecule appeared to be correctly positioned and oriented towards the anomeric carbon to hydrolyze the β-1,3/1,4-glucan and chitin, in less than 4.0 Å. In a nutshell, the study verified that the ThBglT12 is a good alternative fungicide to inhibit the growth of M. phaseolina. Communicated by Ramaswamy H. Sarma

Elliptical torus cutter tool path generation based on minimum distance computation

In mould manufacture the elliptical torus cutters are used for their high cutting velocity, but the special geometry also brings issues in tool path generating and machining quality controlling. In this paper a guide curve tool path generating method for elliptical torus cutters is presented with the cutter location points computed by a minimum distance algorithm and the path spacing determined by an adaptive method. In the minimum distance algorithm, the calculation is resolved into an iterative process from point to freeform surface and an algebraic calculation process from point to elliptical torus surface considering the geometry of the cutter, which reduces the iterative process and improves the computing speed. In the adaptive path spacing method, the contacting geometry between the elliptical cutter and the workpiece surface is analysed and the relations among the scallop height, the tool tilt angle and the path spacing are deduced, based on which the guide curves are adjusted in advance to control the scallop height. Calculating examples and experiments are carried out, showing that the consuming time of cutter location (CL) points computation algorithm is reduced by 30% comparing to earlier method, and the adaptive path spacing method performs better than constant method in both scallop height controlling and tool path shortening. The results indicate that the presented tool path generating method can help to reduce both the machining and machine waiting time as well as ensuring the machining quality.

An empirical approach of modeling and assessment for the safe use of commercial electric detonators in radio frequency radiation hazards

In the modern era of communication technologies using amplitude modulation (AM) and frequency modulation (FM) the transmitting antenna of radio, television, radar, cellular phones, wireless data acquisition systems and global positioning systems (GPS) are the main sources of radio frequency radiation hazards. The transmitting antennas of these communication devices generate electromagnetic fields (EMFs). Electric detonator wires, under certain circumstances work as receiving antenna and pickup enough electrical energy from such fields to initiate unexpected explosion. There have been many cases of detonators being fired accidentally by radio frequency pick up. In this work an attempt has been made to minimize such explosions and to provide a basis for assessing and modeling the parameters of radio frequency radiation hazards associated with commercial electric detonators. This research examines the radiated powers of various frequency bands to determine the safe distance from transmitting antenna. Based on mathematical simulation, two empirical relations have been proposed for the calculation of minimum safe distance (MSD). Using these relations desired MSDs have been calculated for the relevant frequency bands. The obtained values have been compared with the available experimental values showing good agreement between them. The average percentage deviations of calculated MSDs from proposed relations are found between 0.096% and 10.718%, with regression coefficient 0.970 ≤ R ≤ 1. This reflects the soundness of the proposed empirical relations. The blasting engineers, detonator designers and researchers may use these relations as a handy tool to prevent undesired explosions by maintaining minimum safe distance in radio frequency prone hazardous areas.

Assessment of traffic safety at median openings using surrogate safety measures: a case study in India

Traffic safety is an integral part of transportation engineering. In developing countries, its importance is even more. Additionally, at uncontrolled median openings, the severity of road crashes increase many fold. Conventionally, road crash data were used to analyse safety. However, in developing countries, the accuracy of this data is highly questionable. Therefore, in this study, a new technique in addition to post encroachment time (PET), which is a surrogate safety measure is used to predict the severity of probable road crashes at median openings. After the extraction of PET values from field data, they have been compared with the minimum braking times obtained from calculation of minimum stopping sight distance. The comparison shows that while the number of road crashes may be less at lower traffic volume levels, however the severity of those crashes is much higher as compared to the road crashes occurring at high traffic volumes.

Exact Separation of Forbidden-Set Cuts Associated With Redundant Parity Checks of Binary Linear Codes

In recent years, several integer programming (IP) approaches were developed for maximum-likelihood decoding and minimum distance computation for binary linear codes. Two aspects in particular have been demonstrated to improve the performance of IP solvers as well as adaptive linear programming decoders: the dynamic generation of forbidden-set (FS) inequalities, a family of valid cutting planes, and the utilization of so-called redundant parity-checks (RPCs). However, to date, it had remained unclear how to determine whether or not there exists any violated FS inequality w.r.t. any known or unknown parity-check. In this note, we prove NP -hardness of this RPC separation problem. Moreover, we formulate an IP model that combines the search for most violated FS cuts with the generation of RPCs, and report on computational experiments. Empirically, for various instances of the minimum distance problem, it turns out that while utilizing the exact separation IP does not appear to provide a computational advantage, it can apparently be avoided altogether by combining heuristics to generate RPC-based cuts.

Calculating the Support Function of Complex Continuous Surfaces With Applications to Minimum Distance Computation and Optimal Grasp Planning

The support function of a surface is a fundamental concept in mathematics and a crucial operation for algorithms in robotics, such as those for collision detection and grasp planning. It is possible to calculate the support function of a convex body in a closed form. For complex continuous, especially nonconvex, surfaces, however, this calculation can be far more difficult and no general solution is available so far, which limits the applicability of those related algorithms. This article first presents a branch-and-bound (B&B) algorithm to calculate the support function of complex continuous surfaces. An upper bound of the support function over a surface domain is derived. While a surface domain is divided into subdomains, the upper bound of the support function over any subdomain is proved to be not greater than the one over the original domain. Then, as the B&B algorithm sequentially divides the surface domain by dividing its subdomain having a greater upper bound than the others, the maximum upper bound over all subdomains is monotonically decreasing and converges to the exact value of the desired support function. Furthermore, with the aid of the B&B algorithm, this article derives new algorithms for the minimum distance between complex continuous surfaces and for globally optimal grasps on objects with continuous surfaces. A number of numerical examples are provided to demonstrate the effectiveness of the proposed algorithms.

Efficient Minimum Distance Computation for Solids of Revolution

AbstractWe present a highly efficient algorithm for computing the minimum distance between two solids of revolution, each of which is defined by a planar cross‐section region and a rotation axis. The boundary profile curve for the cross‐section is first approximated by a bounding volume hierarchy (BVH) of fat arcs. By rotating the fat arcs around the axis, we generate the BVH of fat tori that bounds the surface of revolution. The minimum distance between two solids of revolution is then computed very efficiently using the distance between fat tori, which can be boiled down to the minimum distance computation for circles in the three‐dimensional space. Our circle‐based approach to the solids of revolution has distinctive features of geometric simplification. The main advantage is in the effectiveness of our approach in handling the complex cases where the minimum distance is obtained in non‐convex regions of the solids under consideration. Though we are dealing with a geometric problem for solids, the algorithm actually works in a computational style similar to that of handling planar curves. Compared with conventional BVH‐based methods, our algorithm demonstrates outperformance in computing speed, often 10–100 times faster. Moreover, the minimum distance can be computed very efficiently for the solids of revolution under deformation, where the dynamic reconstruction of fat arcs dominates the overall computation time and takes a few milliseconds.

PERANCANGAN SISTEM PENDETEKSI BERITA HOAX MENGGUNAKAN ALGORITMA LEVENSHTEIN DISTANCE BERBASIS PHP

In the 4.0 era where the Internet is an important part of life today, information can be easily accessed anytime, anywhere. But not all information distributed through the internet is in the form of facts. Data presented by the Ministry of Communication and Information based on a survey conducted in 2018 said that as many as 800,000 sites in Indonesia indicated that non-fact or hoax news spreaders were indicated. As a result of hoax news generated is very dangerous because it attacks the minds of the human subconscious, so it is needed a system that can detect hoax news. In this study used a database containing hoax news documents. The algorithm applied is the TF-IDF algorithm to measure the weight of a word in a hoax document and combined with the Levenshtein Distance (LD) algorithm to measure the distance between words in a document. The application of the Levenshtein Distance Method in the Hoax Detection System has several stages that begin with the pre-processing of the word (prepocessing text) followed by the TF-IDF calculation phase and then the minimum distance calculation between words using the Levenshtein Distance algorithm. The result of a limit of 0.1 on 40 documents that have been classified as test data has high Precision, Recall and Accuracy values, namely Precision 1; Recall 0.71; and Accuracy 80%.

AUTOMATIC DETECTION OF FOREST-ROAD DISTANCES TO IMPROVE CLEARING OPERATIONS IN ROAD MANAGEMENT

Abstract. There is a complex relation between roads and fires. Several major wildfires were ignited near to roads (Morrison 2007) and how they progressed is an important role to understand the importance to forest management in this environment. Nowadays, a sustainable forest management is necessary both for environment and politics. One of the reasons of road management is that these infrastructures provide an effective firewall in case of forest fires and an escape route for the population. Forest management optimization in road surroundings would improve wildfires prevention and mitigate their effects. One of the main indicators of road safety is the distance between road and vegetation.The aim of this work is to develop a methodology to determine what areas do not obey current laws about safety distances between forest and roads. The acquisition of LiDAR data is done by Lynx Mobile Mapper System from University of Vigo. The methodology is automated using LiDAR data processing. The developed algorithms are based in height and length segmentation of the road. The objective is classifying vegetation groups by height and calculate the distance to the edges of road. The vegetation is divided in groups of height of 5, 10, 15 and 30 m. The minimum distance calculation is 2 m, for the vegetation of 5 m height and a maximum of 60 m for vegetation 30 m height. The height of vegetation has a directly relation with the distance separation with the road.

Minimum distance computation of linear codes via genetic algorithms with permutation encoding

We design a heuristic method, a genetic algorithm, for the computation of an upper bound of the minimum distance of a linear code over a finite field. By the use of the row reduced echelon form, we obtain a permutation encoding of the problem, so that its space of solutions does not depend on the size of the base field or the dimension of the code. Actually, the efficiency of our method only grows non-polynomially with respect to the length of the code.

Minimum distance calculation using laser scanner and IMUs for safe human-robot interaction

Abstract In this study we investigate the use of a laser scanner/range-finder and inertial measurement units (IMUs) for the application of human-robot interaction in a dynamic environment with moving obstacles/humans. Humans and robots are represented by capsules, allowing to calculate the human-robot minimum distance on-the-fly. A major challenge is to capture the capsules pose. Data from a laser scanner and IMUs attached to the human body are fused to define the torso relative position and the upper body (arms and chest) configuration, respectively. Collision avoidance is achieved with a customized potential field’s method that allows to adjust the pre-defined robot paths established off-line while keeping the task target. The proposed framework is validated in real environment using a SICK laser scanner, IMUs and a KUKA iiwa robot. Experiments demonstrated the robustness of the proposed approach in capturing human motion, calculating the human-robot minimum distance and the robot behavior that smoothly avoids collisions with the human.

Efficient Calculation of Minimum Distance Between Capsules and Its Use in Robotics

The problem of minimum distance calculation between line-segments/capsules, in 3D space, is an important subject in many engineering applications, spanning CAD design, computer graphics, simulation, and robotics. In the latter, the human–robot minimum distance is the main input for collision avoidance/detection algorithms to measure collision imminence. Capsules can be used to represent humans and objects, including robots, in a given dynamic environment. In this scenario, it is important to calculate the minimum distance between capsules efficiently, especially for scenes (situations) that include a high number of capsules. This paper investigates the utilization of QR factorization for performing efficient minimum distance calculation between capsules. The problem is reformulated as a bounded variable optimization in which an affine transformation, deduced from QR factorization, is applied on the region of feasible solutions. A geometrical approach is proposed to calculate the solution, which is achieved by computing the point closest to the origin from the transferred region of feasible solutions. This paper is concluded with numerical tests, showing that the proposed method compares favorably with the most efficient method reported in the literature.