bluuebunny/crossref_metadata_2025 huggingface dataset:
Point Process Formulation of Long-Term Collision Risk Statistics from Orbital Fragmentation
Authors: Carpine Marie-Anne , Paul Yema , Delande Emmanuel , Ruch Vincent
Published: April 2024

This paper focuses on the estimation of statistics (mean and variance) on collision risks induced by on-orbit fragmentation, evaluated over a long horizon of time (several decades). Two major contributions are introduced and can be used independently from one another to address the estimation problem. First, a representation of the cloud of debris with point processes is proposed, focusing on the population statistics rather than individual pieces of debris. It allows for the limited propagation of the cloud statistics required for the computation of the risk statistics, and nothing more, reducing significantly the computational costs when compared to traditional methods propagating individual pieces of debris. Then, a novel risk function is proposed, exploiting the ergodicity of the encounter problem to estimate the number of collisions between a pieces of debris and a target, following a rigorous mathematical construction based on well-defined assumptions. These two methods are then combined and illustrated on a simulated scenario and compared with a traditional Monte Carlo approach. The results show that the point process-based estimate of the risk statistics is consistent with the Monte Carlo reference, while being faster to run by at least two orders of magnitude.
Safe and Scalable Real-Time Trajectory Planning Framework for Urban Air Mobility
Authors: Taye Abenezer G. , Valenti Roberto , Rajhans Akshay , Mavrommati Anastasia , Mosterman Pieter J. , Wei Peng
Published: April 2024

This paper presents a real-time trajectory planning framework for urban air mobility (UAM) that is both safe and scalable. The proposed framework employs a decentralized, free-flight concept of operation in which each aircraft independently performs separation assurance and conflict resolution, generating safe trajectories by accounting for the future states of nearby aircraft. The framework consists of two main components: a data-driven reachability analysis tool and an efficient Markov-decision-process-based decision maker. The reachability analysis overapproximates the reachable set of each aircraft through a discrepancy function learned online from simulated trajectories. The decision maker, on the other hand, uses a 6-degree-of-freedom guidance model of fixed-wing aircraft to ensure collision-free trajectory planning. Additionally, the proposed framework incorporates reward shaping and action shielding techniques to enhance safety performance. The proposed framework was evaluated through simulation experiments involving up to 32 aircraft in a generic city-scale area with a 15 km radius, with performance measured by the number of near-midair collisions (NMAC) and computational time. The results demonstrate the planner’s ability to generate safe trajectories for the aircraft in polynomial time, showing its scalability. Moreover, the action shielding and reward shaping strategies show up to a 78.71 and 85.14% reduction in NMAC compared to the baseline planner, respectively.
Modeling reactive flow dynamics of gelled acid in fracture-vuggy carbonates: a coupled thermal-hydrological-chemical simulation
Authors: Kong Xue , Liu Piyang , Zhang Kai , Yao Jun , Huang Zhaoqin
Published: April 2024

In engineering, gelled acids play a crucial role in facilitating reactive flow phenomena across diverse mediums. This study undertakes a comprehensive numerical investigation into the reactive flow dynamics within fracture-vuggy carbonates, employing gelled acid as the agent. The mathematical model intricately couples thermal, hydrological, and chemical aspects to provide a holistic understanding of the process. Fractures are meticulously modeled using a pseudo-fracture approach, while vugs are delineated as highly porous matrix clusters. The simulation meticulously examines the influence of vugs and fractures, in conjunction with the rheological behavior of gelled acid, on the dissolution process. Our findings reveal that compared to hydrochloric acid, gelled acid is more effective in treating high-temperature carbonate rocks. A lower power law index induces a more pronounced response in shear stress, resulting in a more uniform dissolution pattern. Moreover, the presence of vugs and fractures exerts a significant impact on both the trajectory of wormhole growth and its penetration depth. As the length of fractures increases and their number multiplies, their dominant influence on the growth of wormholes becomes more pronounced. Furthermore, an abundance of fractures may attenuate the influence of vugs. This study highlights the importance of controlling the power-law index and understanding the complex interactions between fractures and vugs for reactive flow.
A Novel Workflow for Predicting Seismic Reservoir Characterizations - OBN Case Study - Western Offshore, India
Authors: El Mawla Walid Abd , Goswami Saumya , Hassan Rania , Mishra Uday Shanker , Sengupta Souvik , Aly Omar , Mukherjee Anubrati , Basu S. , Mohapatra S. , Prakash Anand , Saluja Vikash
Published: April 2024

Objectives & Scope

To identify the extend and improve the hydrocarbon productivity of the reservoirs in the area, seismic inversion study was carried out with the latest seismic image data to characterize the lithology and identify the potential reservoir distribution in the area. Advantage of OBN multi-component seismic data is the capability of providing PP & PS datasets as it helped to conduct PP-PS joint inversion enhancing the inverted shear impedance and density followed by seismic stochastic inversion for better vertical resolution.

Challenges & Procedures

Challenge #1: The presence of un-delineated karst features within H3B reservoir unit causing lots of water break through, mud loss while drilling and losing the control on the newly drilling wells. Challenge #2: To locate new save optimized candidates for infill wells securing the production plateau and minimizing the risks behind the reservoir facies/quality. To meet the objectives a seismic reservoir characterization study was carried out by conditioning seismic dataset followed by angle stack generation of PP & PS datasets. Seismic velocity from imaging product was used to trend the low frequency model building after calibration with the well logs. All the information was then used to conduct pre-stack PP-PS joint inversion to generate several attributes such as P-Impedance, S-Impedance, VpVs ratio, density. This was followed by seismic stochastics inversion to enhance the vertical resolution beyond the seismic band-limit and to reduce the uncertainties, P10, P50 & P90 cases of elastic/Petro-elastic properties have been provided. Also, a full seismic attribute analysis has been performed to help locate the potential sweet spots for better well optimization processes. In addition to that the petro-elastic attributes have been used to trend the rock-models and compensate for the environmental model in 3D mode away from the well locations.
Does retensioning of adjustable-loop cortical suspension devices improve performance: A systematic review and meta-analysis
Authors: Campbell Seth Theodore , Liu Joseph , Gowd Anirudh K. , Amin Nirav , Sardelli Matthew , Morrison Martin
Published: April 2024

Objectives:

To date, there is conflicting evidence when comparing fixed-loop cortical suspension devices (FLDs) to adjustable-loop devices (ALDs). Some studies indicate that ALDs are inferior to FLD in regard to displacement and failure load while others show that they are biomechanically similar. The purpose of this study is to use a meta-analysis of biomechanical data to compare FLDs to ALDs with and without retensioning. It is hypothesized that retensioning the ALD will allow these devices to be biomechanically equivalent to the FLD in total unloaded displacement and failure load.

Materials and Methods:

This study sought to identify all biomechanical studies that compared fixed loops to ALD. A meta-analysis was performed to find the standardized mean difference with retensioning as a covariate.

Results:

The analysis of isolated tests showed that retensioning reduced the cyclic ALD displacement in comparison to non-retensioned ALD; however, both the ALD with and without retensioning had significantly higher cyclical displacement and significantly lower failure load compared to the FLD. In the meta-analysis of the animal model data, there was no significant difference between the ALD with retensioning and the FLD.

Conclusion:

This analysis suggests that retensioning reduces displacement of an ALD, with displacements measured in animal bone testing showing no significant difference as compared to FLD. However, in the device-only model, the ALD with retensioning and the ALD without retensioning had significantly higher cyclical displacement and significantly lower load to failure compared to the FLD. These data suggest that retensioning may be beneficial. However, there is significant heterogeneity in the pooled studies which limit the strength of this conclusion.
The Ego-Text of a Bibliophile: D.V. Ulyaninskyʼs Diary Entries in the “Catalog of New Library Acquisitions”
Authors: Samarin Alexander Yu.
Published: April 2024

The article analyzes the handwritten “Catalog of New Library Acquisitions” by the famous bibliographer and bibliophile D.V. Ulyaninsky (1861—1918), stored in the department of Rare books (the Book Museum) of the Russian State Library. It is considered as an ego-text that directly reflects the bibliophile life of the author and his experiences related to it. In the text, the bibliophile not only recorded all receipts to his personal library, but also left diary entries. From them, you can learn about the folding of the library structure, changes in the accounting system, and the exclusion of publications from its composition. In his diary entries, which became acts of self-communication and self-reflection, the bibliophile described his relationship with booksellers, difficulties in collecting, justified for himself the high costs of books, rejoiced at successful acquisitions, noted some events of public and personal life, etc. It is concluded that the “Catalog of New Library Acquisitions” acted as a draft, a pre-text for a detailed bibliographic description of the library of D.V. Ulyaninsky, which received a printed embodiment. Many of his notes remain only in manuscript. This fact makes them a unique source both for studying the biography of D.V. Ulyaninsky and for the history of the world of antique book trade and bibliophilia of the late 19th — early 20th century.
Forensic Panorama of Complex Suicide Case Study from India
Authors:   Department of Chemistry Division, Forensic Science Laboratory, India, D Saxena , S Sinha ,   Department of Chemistry Division, Forensic Science Laboratory, India, S Rai ,   Department of Chemistry Division, Forensic Science Laboratory, India, S Tripathy ,   Department of Chemistry Division, Forensic Science Laboratory, India
Published: April 2024

Complex suicides involve two separate method of self inflicted harm to take ones own life. Toxicological analysis of these medico-legal cases are encountered by the forensic analyst for chemical examination to ascertain cause of death. Statistical data for complex suicides is at present largely unrecorded though National Crime Records Bureau records suggest 53.6% by hanging followed by 25.8% deaths by poisoning in India. Compared to death by hanging, fatal cases due to pesticide intake with hanging are barely seen. Here in, we are reporting a rare case where the deceased had used this complex combination of suicide to terminate his life. A complete forensic investigation, including the scene of crime and autopsy examination, was observed wherein 44-year-old man had hung himself at his residence. Chemical examination to ascertain presence of any poison in visceral tissues to rule out intoxication was conducted. The chemical tests, Thin Layer Chromatography analysis, ATRFTIR and GC-MS instrumental analysis established the presence of pesticides (Organophosphorus and Pyrethroid) in his visceral organs. The cause of death as stated by the medical expert was anti-mortem hanging, but after detection of massive amount of pesticides in visceral tissues and post mortem blood, suggests ingestion of pesticides as well as asphyxia that led to the death of the deceased. Thus, the method of death was more toward planned complex definite suicide which is alarming and needs severe attention from various sections of society.
Evaluation of a Commercial TIMS-Q-TOF Platform for Native Mass Spectrometry
Authors: Panczyk Erin , Lin Yu-Fu , Harvey Sophie , Snyder Dalton , Liu Fanny , Ridgeway Mark , Park Mel , Bleiholder Christian , Wysocki Vicki
Published: April 2024

Mass-spectrometry based assays in structural biology studies measure either intact or digested proteins. Typically, different mass spectrometers are dedicated for such measurements: those optimized for rapid analysis of peptides or those designed for high molecular weight analysis. A commercial trapped ion mobility-quadrupole-time of flight (TIMS-Q-TOF) platform is widely utilized for proteomics and metabolomics, with ion mobility providing a separation dimension in addition to liquid chromatography. The ability to perform high-quality native mass spectrometry of protein complexes, however, remains largely uninvestigated. Here, we evaluate a commercial TIMS-Q-TOF platform for analyzing non-covalent protein complexes by utilizing the instrument’s full range of ion mobility, MS, and MS/MS (both in-source activation and collision cell CID) capabilities. The TIMS analyzer is able to be tuned gently to yield collision cross sections on native-like complexes comparable to those previously reported on various instrument platforms. In-source activation and collision cell CID were robust for both small and large complexes. TIMS-CID was performed on protein complexes streptavidin (53 kDa), avidin (68 kDa), and cholera toxin B (CTB, 58 kDa). Complexes pyruvate kinase (237 kDa) and GroEL (801 kDa) were beyond the trapping capabilities of the commercial TIMS analyzer, but mass spectra could be acquired. The presented results indicate that the commercial TIMS-Q-TOF platform can be used for both omics and native mass spectrometry applications; however, modifications to the commercial RF drivers for both the TIMS analyzer and quadrupole (currently limited to m/z 3,000) are necessary to mobility analyze protein complexes greater than about 60 kDa.
Operando Photoelectron Spectroscopy Analysis of Li6PS5Cl Electrochemical Decomposition Reactions in Solid-State Batteries
Authors: Aktekin Burak , Kataev Elmar , Riegger Luise M. , Garcia-Diez Raul , Chalkley Zora , Becker Juri , Wilks Regan G. , Henss Anja , Bär Marcus , Janek Jürgen
Published: April 2024

Most solid electrolytes (SEs) which are promising for all-solid-state battery (ASSB) applications are known to have a narrow electrochemical stability window. Consequently, parasitic electrolyte reactions are observed when high-energy-density electrode materials such as lithium and silicon are employed, hindering their utilization in commercial battery systems. Therefore, it is crucial to understand at which potentials such reactions start, and which chemical species are present in the subsequently formed solid electrolyte interphase (SEI). Herein, a new operando experimental approach is introduced to investigate such reactions by employing hard X-ray photoelectron spectroscopy (HAXPES). This approach enables the examination of the SEI formed below a thin metal film (e.g., 6 nm nickel) acting as the working electrode. The feasibility of this approach is demonstrated using a sulfide-based Li6PS5Cl solid electrolyte (lithium argyrodite). It is shown that electrolyte reduction reactions start upon polarization of the working electrode to voltages below 1.75 V (vs. Li+/Li) and result in considerable Li2S formation, particularly in the voltage range of 1.5 – 1.0 V. The overall intensity trends confirm the heterogeneous/layered microstructure of the SEI (e.g., preferential Li2O and Li2S deposition near the current collector). The reversibility of side reactions is also observed, as Li2O and Li2S decompose in the 2–4 V potential window, generating oxidized sulfur species, sulfites and sulfates. The introduced experimental approach is promising for the spectroscopic investigation of electrolyte side reactions under dynamic conditions for various solid electrolyte and current collector combinations.
Discovery of Crystallizable Organic Semiconductors with Machine Learning
Authors: Johnson Holly M. , Gusev Filipp , Dull Jordan T. , Seo Yejoon , Priestley Rodney D. , Isayev Olexandr , Rand Barry P.
Published: April 2024

Crystalline organic semiconductors are known to have improved charge carrier mobility and exciton diffusion length in comparison to their amorphous counterparts. Certain organic molecular thin films can be transitioned from initially prepared amorphous layers to large-scale crystalline films via abrupt thermal annealing. Ideally, these films crystallize as platelets with long-range-ordered domains on the scale of tens to hundreds of microns. However, other organic molecular thin films may instead crystallize as spherulites or resist crystallization entirely. Organic molecules that have the capability of transforming into a platelet morphology feature both high melting point (Tm) and crystallization driving force (ΔGc). In this work, we employed machine learning (ML) to identify candidate organic materials with the potential to crystallize into platelets by estimating the aforementioned thermal properties. Six organic molecules identified by the ML algorithm were experimentally evaluated; three crystallized as platelets, one crystallized as a spherulite, and two resisted thin film crystallization. These results demonstrate a successful application of ML in the scope of predicting thermal properties of organic molecules and reinforce the principles of Tm and ΔGc as metrics that govern the crystallization of organic thin films.
Subdomains of theHelicobacter pyloriCag T4SS outer membrane core complex exhibit structural independence
Authors: Roberts Jacquelyn R , Tran Sirena C , Frick-Cheng Arwen E , Bryant Kaeli N , Okoye Chiamaka D , McDonald W Hayes , Cover Timothy L , Ohi Melanie D
Published: April 2024

TheHelicobacter pyloriCag type IV secretion system (Cag T4SS) has an important role in the pathogenesis of gastric cancer. The Cag T4SS outer membrane core complex (OMCC) is organized into three regions: a 14-fold symmetric outer membrane cap (OMC) composed of CagY, CagX, CagT, CagM, and Cag3; a 17-fold symmetric periplasmic ring (PR) composed of CagY and CagX; and a stalk with unknown composition. We investigated how CagT, CagM, and a conserved antenna projection (AP) region of CagY contribute to the structural organization of the OMCC. Single-particle cryo-EM analyses showed that complexes purified from ΔcagTor ΔcagMmutants no longer had organized OMCs, but the PRs remained structured. OMCCs purified from a CagY antenna projection mutant (CagY∆AP) were structurally similar to WT OMCCs, except for the absence of the α-helical antenna projection. These results indicate that CagY and CagX are sufficient for maintaining a stable PR, but the organization of the OMC requires CagY, CagX, CagM, and CagT. Our results highlight an unexpected structural independence of two major subdomains of the Cag T4SS OMCC.
Autocrine VEGF drives neural stem cell proximity to the adult hippocampus vascular niche
Authors: Dause Tyler J , Denninger Jiyeon K , Osap Robert , Walters Ashley E , Rieskamp Joshua D , Kirby Elizabeth D
Published: April 2024

The vasculature is a key component of adult brain neural stem cell (NSC) niches. In the adult mammalian hippocampus, NSCs reside in close contact with a dense capillary network. How this niche is maintained is unclear. We recently found that adult hippocampal NSCs express VEGF, a soluble factor with chemoattractive properties for vascular endothelia. Here, we show that global and NSC-specific VEGF loss led to dissociation of NSCs and their intermediate progenitor daughter cells from local vasculature. Surprisingly, though, we found no changes in local vascular density. Instead, we found that NSC-derived VEGF supports maintenance of gene expression programs in NSCs and their progeny related to cell migration and adhesion. In vitro assays revealed that blockade of VEGF receptor 2 impaired NSC motility and adhesion. Our findings suggest that NSCs maintain their own proximity to vasculature via self-stimulated VEGF signaling that supports their motility towards and/or adhesion to local blood vessels.
Reinterpretation of Friedmann-Robertson-Walker Universe with Variable Gravitational and Cosmological Term in Bouncing Cosmology
Authors: Meitei Asem Jotin , Singh Kangujam Priyokumar , Sabanam Syed , Chanu S. Kiranmala
Published: April 2024

This paper is devoted to investigate five dimensional homogeneous and isotropic FRW model with varying gravitational and cosmological constant with cosmic time. Exact solution of the Einstein field equations are obtained by using the equation of state p = (γ −1)ρ (gamma law), where γ which is an adiabatic parameter varies continuously as the universe expands. We obtained the solutions for different values of curvature K = 0, 1,−1 by using a(t) = R0(1 + α2t2)n, where α, n and R0 are positive constants. Behaviour of the cosmological parameters are presented for different cases of the models. Physical interpretation of the derived model are presented in details. Interestingly the proposed model justified the current cosmological observations with dark energy.
Effective Semiclassical Evolution of Bose Einstein Condensates
Authors: Hernandez Hernandez Hector
Published: April 2024

In this work we analyze the effective evolution of a one dimensional Bose-Einstein Condensate (BEC) within a semiclassical description of quantum systems based on expectation values of quantum dispersions and physical observables, known as momentous quantum mechanics. We show that the most prominent features and physical parameters of the system can be determined from the dynamics of the corresponding semiclassical system, consisting of an extended phase space including original classical observables and quantum dispersions, and we also show that particle trajectories for expectation values of observables are a particular characteristic in this framework. We also demonstrate that interactions with several potentials can be implemented in an intuitive way.
Importance of Reflected Solar Energy Loaded with SWCNTs-MWCNTs/EG Darcy Porous Stretched Surface: Midrich Scheme
Authors: Gunisetty Ramasekhar , Suneetha Sangapatnam , Ravikumar Vanipenta , Jakeer Shaik , Reddy Seethi Reddy Reddisekhar
Published: April 2024

Saving energy, shortening processing times, maximizing thermal efficiency, and lengthening the life of industrial equipment are all possible outcomes of heating and cooling optimization. In recent years, there has been a rise in interest regarding the development of high-efficiency thermal systems for the purpose of enhancing heat and mass movement. This study presents an investigation on the non-linear flow of a hybrid nanofluid comprising of Multi Walled Carbon Nanotubes (MWCNTs) and Single Walled Carbon Nanotubes (SWCNTs) over an extended surface, considering the effects of Magnetohydrodynamics (MHD) and porosity, with engine oil serving as the base fluid. Also, radiation and Darcy-Forchheimer flow is considered.  The problem of regulating flow is transformed into ordinary differential equations (ODEs) by employing similarity variables. The Midrich Scheme is then used to implement a numerical solution to these equations in the program Maple. Through visual representations of fluid velocities and temperatures, the inquiry addresses several important factors, including magnetic parameters, porosity parameters, radiation parameters, Eckert numbers, inertia coefficients, and Biot numbers. The research has important implications in a number of real-world contexts. Due to its exceptional characteristics, such as reduced erosion, reduced compression drops difficulties, and greatly increased heat transfer rates, hybrid nanofluids are frequently used in heat exchangers. For instance, various cooling devices such as electromagnetic cooling systems, as well as heat exchangers including condensers, boilers, chillers, air conditioners, evaporators, coil preheaters, and radiators. Furthermore, it has the potential to be employed in pharmaceutical businesses and the field of biomedical nanoscience.
Heat And Mass Transfer on Flow Past an Accelerated Plate Through Porous Medium with Variable Temperature and Mass Diffusion in Presence of Heat Source/Sink
Authors: Rabha Rakesh , Deka Rudra Kanta
Published: April 2024

A study to look at how heat and mass transfer affect unsteady MHD flow across an accelerated plate with changing temperature and mass diffusion in the appearance of a heat source (or sink) through a porous medium is presented. Initially, the temperature and concentration of the fluid and plate are considered to be the same at t′ ≤ 0. At t′ > 0, an impulsive uniform acceleration A is applied to the plate in a vertical upward direction. The non-dimensionalised governing equations defining the flow problem are solved using Laplace transform approach. Effect of various physical quantities involved in the velocity, concentration, temperature, the rate of heat transfer and also the rate of mass transfer are investigated through graphs and tables and discussed.
A framework for event based modeling and analysis
Authors: Granat Janusz
Published: April 2024

In this paper we will present a framework for modeling and management of complex systems. There are various approaches for modeling of these systems. One of the approaches is events driven modeling and management of complex system. Such approach is needed in information systems that provide information in real-time. Most of the existing modeling approaches use only information about type of event and the time when an event occurs. However, in the databases we can store and then we can use much richer information about events. This information might be structured as well as unstructured. There are new challenges in algorithms development in case of description of event by various attributes.
Extensions of the minimum labelling spanning tree problem
Authors: Cerulli Raffaele , Fink Andreas , Gentili Monica
Published: April 2024

In this paper we propose some extensions of the minimum labelling spanning tree problem. The main focus is on the minimum labelling Steiner tree problem: given a graph G with a color (label) assigned to each edge, and a subset Q of the nodes of G (basic vertices), we look for a connected subgraph of G with the minimum number of different colors covering all the basic vertices. The problem has several applications in telecommunication networks, electric networks, multimodal transportation networks, among others, where one aims to ensure connectivity by means of homogeneous connections. Numerical results for several metaheuristics to solve the problem are presented.
Towards an Agent-Based Augmented Cloud
Authors: Dębski Roman , Byrski Aleksander , Kisiel-Dorohinicki Marek
Published: April 2024

In the paper an agent-based framework deployed in hybrid cluster and volunteer computing environment is presented. It utilizes two concepts proposed by the authors: Augmented Cloud and Agent Platform as a Service (AgPaaS). Both concepts are discussed in the context of Cloud Computing as defined by NIST. The key idea of the presented solution is to span the cloud (i.e., computing infrastructure) beyond the data center borders by utilizing web browsers as computational workers. The feasibility of the approach was demonstrated by two prototypes: the first one was based on Java Applets and Adobe Flash, whereas the second one on Microsoft Silverlight. The prototypes were next used to perform simple experiments, mainly related to scalability issues. Selected results from the experiments are discussed in the final part of the paper.
Component-Based Architecture for Systems, Services and Data Integration in Support for Criminal Analysis
Authors: Dajda Jacek
Published: April 2024

Criminal analysis processes is based on heterogeneous data processing. To support it, analysts utilize a large set of specialized tools, however they are usually designed to solve a particular problem are often incompatible with other existing tools and systems. Therefore, to fully leverage the existing supporting tools, their technological integration is required. In this paper we present original approach for integrating systems based on the component-driven paradigm. Firstly, a problem of supporting criminal analysis is described with a strong emphasis on the heterogeneity issues. Secondly, some theoretical information about integration is depicted followed by the details of the proposed architecture. Finally, the technological assumptions are discussed and prototype integration based on proposed concept is overviewed. om the experiments are discussed in the final part of the paper.
Recognizing Sets in Evolutionary Multiobjective Optimization
Authors: Gajda-Zagórska Ewa
Published: April 2024

Among Evolutionary Multiobjective Optimization Algorithms (EMOA) there are many which find only Paretooptimal solutions. These may not be enough in case of multimodal problems and non-connected Pareto fronts, where more information about the shape of the landscape is required. We propose a Multiobjective Clustered Evolutionary Strategy (MCES) which combines a hierarchic genetic algorithm consisting of multiple populations with EMOA rank selection. In the next stage, the genetic sample is clustered to recognize regions with high density of individuals. These regions are occupied by solutions from the neighborhood of the Pareto set. We discuss genetic algorithms with heuristic and the concept of well-tuning which allows for theoretical verification of the presented strategy. Numerical results begin with one example of clustering in a single-objective benchmark problem. Afterwards, we give an illustration of the EMOA rank selection in a simple two-criteria minimization problem and provide results of the simulation of MCES for multimodal, multi-connected example. The strategy copes with multimodal problems without losing local solutions and gives better insight into the shape of the evolutionary landscape. What is more, the stability of solutions in MCES may be analyzed analytically.
Modeling and Simulation of a Vehicle Suspension with Variable Damping versus the Excitation Frequency
Authors: Suciu Claudiu Valentin , Tobiishi Tsubasa , Morii Ryouta
Published: April 2024

In this work, three types of vehicle suspensions were considered and modeled as follows: oil damper mounted in parallel with a compression helical spring, for which a Kelvin-Voigt model, consisted of a dashpot and an elastic element connected in parallel is considered; colloidal damper without attached compression helical spring, for which a Maxwell model, consisted of a dashpot and an elastic element connected in series is considered; and colloidal damper mounted in parallel with a compression helical spring, for which a standard linear model, consisted of a Maxwell unit connected in parallel with an elastic element is considered. Firstly, the vibration transmissibility from the rough road to the vehicle’s body for all these suspensions was determined under the constraint that damping varies versus the excitation frequency. Then, the optimal damping and stiffness ratios were decided in order to minimize the transmissibility of vibration from the rough pavement to the vehicle’s body.
Requirements of 4G-Based Mobile Broadband on Future Transport Networks
Authors: Fricke Matthias , Heckwolf Andrea , Herber Ralf , Ralf Nitsch  , Wevering Stefan
Published: April 2024

Long term evolution technologies provide new standards in mobile communications regarding available bandwidth. It is expected that users of one radio cell will share more than 100 Mbit/s in future. To take advantage of the full feature set of next generation mobile networks, transport network design has to face new requirements, caused by the architectural changes of LTE technologies. Especially the newly defined X2 interface impacts on the transport network requirements. X2 enables direct communication between evolved base stations (eNBs) and thus, enforces local solutions. At the same time a tendency of locating network elements at fewer, central sites to reduce operational expenditure can be observed, in particular concerning the transport layer. This leads tothe question of how the direct X2 connection of eNBs on the logical layer can be accommodated with a general centralization of transport networks. Our considerations show that for LTE, a centralized transport network is able to realize the local meshing between eNBs. However, for LTE Advanced, the standards currently discussed by the 3GPP initiative could lead to enhanced requirements on the X2 interface latency. Consequently, the implications for the network architecture have to be analyzed in more detail.
Secured Workstation to Process the Data of Different Classification Levels
Authors: Zieliński Zbigniew , Chudzikiewicz Jan , Furtak Janusz , Stasiak Andrzej , Brudka Marek
Published: April 2024

The paper presents some of the results obtained within the ongoing project related with functional requirements and design models of secure workstation for special applications (SWSA). SWSA project is directed toward the combination of the existing hardware and software virtualization with cryptography and identification technologies to ensure the security of multilevel classified data by means of some formal methods. In the paper the requirements for SWSA, its hardware and software architecture, selected security solution for data processing and utilized approach to designing secure software are presented. The novel method for secure software design employs dedicated tools to verify the confidentiality and the integrity of data using Unified Modeling Language (UML) models. In general, the UML security models are embedded in and simulated with the system architecture models, thus the security problems in SWSA can be detected early during the software design. The application of UML topology models enables also to verify the fundamental requirement for MLS systems, namely the hardware isolation of subjects from different security domains.
A Hybrid CPU/GPU Cluster for Encryption and Decryption of Large Amounts of Data
Authors: Niewiadomska-Szynkiewicz Ewa , Marks Michał , Jantura Jarosław , Podbielski Mikołaj
Published: April 2024

The main advantage of a distributed computing system over standalone computer is an ability to share the workload between cores, processors and computers. In our paper we present a hybrid cluster system – a novel computing architecture with multi-core CPUs working together with many-core GPUs. It integrates two types of CPU, i.e., Intel and AMD processor with advanced graphics processing units, adequately, Nvidia Tesla and AMD FirePro (formerly ATI). Our CPU/GPU cluster is dedicated to perform massive parallel computations which is a common approach in cryptanalysis and cryptography. The efficiency of parallel implementations of selected data encryption and decryption algorithms are presented to illustrate the performance of our system.
Optimal Pump Scheduling for Large Scale Water Transmission System by Linear Programming
Authors: Błaszczyk Jacek , Karbowski Andrzej , Krawczyk Kamil , Malinowski Krzysztof , Allidina Alnoor
Published: April 2024

Large scale potable water transmission system considered in this paper is the Toronto Water System, one of the largest potable water supply networks in North America. The main objective of the ongoing Transmission Operations Optimizer project consists in developing an advanced tool for providing such pumping schedules for 153 pumps, that all quantitative requirements with respect to the system operation are met, while the energy costs are minimized. We describe here a linear, so-called SimplifiedModel (SM), based on mass-balance equations, which is solved on week horizon and delivers boundary conditions for so-called Full Model (FM), which is nonlinear and takes into account hydraulic phenomena and water quality.
and Michał Dominik Stasiak	Recurrent Method for Blocking Probability Calculation in Switching Networks with Overflow Links
Authors: Głąbowski Mariusz , Stasiak Michał Dominik
Published: April 2024

This article presents a new recurrent method for modelling multi-service switching networks with overflow links. In the proposed method, the blocking probability for a given stage of the switching network is determined on the basis of the characteristics of the preceding stage. A particular attention is given to a possibility of a considerable reduction of the internal blocking probability of the switching network that would result from an application of additional overflow links between neighbouring switches of the first stage of the network. The results of the analytical modelling of selected multi-service switching networks with overflow links in the first stage are compared with the results of the simulation experiments. The study confirms the accuracy of all the adopted theoretical assumptions in the proposed analytical model of the multi-service switching network.
Performance and Limitations of VDSL2-based Next Generation Access Networks
Authors: Heliotis George , Dimos Lowell-Panayotis , Kordoulis Ioannis , Agapiou George
Published: April 2024

In this paper, we first briefly review the main operational aspects of FTTC (xPON)/VDSL2 access networks. Then, we present performance measurements with respect to network sub loop operating length and VDSL2 operational profiles (8b, 12a, 17a), studying the rates that can be achieved at different scenarios. We then provide results of the effect of stationary crosstalk and non-stationary impulse noise on the provisioned service in an operating VDSL2 access network.
Dual-band Multi Slot Patch Antenna for Wireless Applications
Authors: Samsuzzaman Mohammad , Islam Mohammad Tariqul , Faruque Mohammad Rashed Iqbal
Published: April 2024

In this paper a novel configuration of broadband multi slot antenna for C/X bands is presented and analyzed. By cutting two diamond slots in the middle of the rectangular patch and three triangular slots in the right side of the patch, resonances can be created. Microstrip feed line is used in the down side region of the patch. Antenna characteristics were simulated using a finite element method (HFSS). According to simulations, the proposed multiple slot antennas can provide two separated impedance bandwidths of 970 MHz (about 11.96% centred at 8.11 GHz band) and 890 MHz (about 9.76% centred at 9.42 GHz band) and stable radiation patterns, promising for satellite systems.
ILP Modeling of Many-to-Many Replicated Multimedia Communication
Authors: Walkowiak Krzysztof , Bulira Damian , Careglio Davide
Published: April 2024

On-line communication services were evolving from a simple text-based chats towards sophisticated videopresence appliances. The bandwidth consumption of those services is constantly growing due to the technology development and high user and business needs. That fact leads us to implement optimization mechanisms into the multimedia communication scenarios. In this paper, the authors concentrate on many-to-many (m2m) communication, that is mainly driven by the growing popularity of on-line conferences and telepresence applications. An overlay model where m2m flows are optimally established on top of a given set of network routes is formulated and a joint model where the network routes and the m2m flows are jointly optimized. In the models, the traffic traverses through replica servers, that are responsible for stream aggregation and compression. Models for both predefined replica locations and optimized server settlement are presented. Each model is being followed by a comprehensive description and is based on real teleconference systems.
Statistical Analysis and Modeling of SIP Traffic for Parameter Estimation of Server Hysteretic Overload Control
Authors: Abaev Pavel , Razumchik Rostislav , Uglov Ivan
Published: April 2024

The problem of overload control in Session Initiation Protocol (SIP) signaling networks gives rise to many questions which attract researchers from theoretical and practical point of view. Any mechanism that is claimed to settle this problem down demands estimation of local (control) parameters on which its performance is greatly dependent. In hysteretic mechanism these parameters are those which define hysteretic loops. In order to find appropriate values for parameters one needs adequate model of SIP traffic flow circulating in the network under consideration. In this paper the attempt is made to address this issue. Analysis of SIP traffic collected from telecommunication operator’s network is presented. Traffic profile is built. It is shown that fitting with Markov Modulated Poisson Process with more than 2 phases is accurate. Estimated values of its parameters are given.
An Incentives Model Based on Reputation for P2P Systems
Authors: de Asıs López-Fuentes Francisco
Published: April 2024

In this paper an incentive model to improve the collaboration in peer-to-peer networks is introduced. The proposed solution uses an incentives model associated with reputation issues as a way to improve the performance of a P2P system. The reputation of the all peers in the system is based on their donated resources and on their behavior. Supplying peers use these rules as a way to assign its outgoing bandwidth to the requesting peers during a content distribution. Each peer can build its best paths by using a best-neighbor policy within its neighborhood. A peer can use its best paths to obtain best services related to content search or download. The obtained results show that proposed scheme insulates the misbehaving peers and reduces the free-riding so that the systems performance is maximized.
Quality of Variable Bitrate HD Video Transmission in New Generation Access Network
Authors: Makowski Piotr
Published: April 2024

Article presents influence of multiplying variable bitrate high definition (HD) video streams in an access network link on Quality of Service (QoS). The aim of a conducted study is to define key parameters influencing Quality of Experience (QoE). Numerous simulations were performed and indicators like packet loss, delay, jitter, frame loss and bandwidth utilization were observed. Moreover, two independent algorithms were used to indicate QoE values of video streams. These are SwissQual VQuadHD and Telchemy VQMon applications which provided credible full reference and no reference algorithms, respectively. In the article evaluation of accuracy of no reference algorithm is performed. In future work it is planned to build analytic model of VBR video transmission and to undertake more thorough research of transmitting multiplied HD video streams in an access network using various QoS policies and optimizing size of buffers.
New Tool for Examining QoS in the VToIP Service
Authors: Uhl Tadeus , Nowicki Krzysztof , Paulsen Stefan
Published: April 2024

This paper is dedicated to the subject of measuring QoS in the Video Telephony over IP (VToIP) service. QoS measurement models in general and then models designed specifically for measuring QoS in the VToIP service are presented. A new numerical tool for examining the quality of VToIP video streams VToIP is described. The tool’s functionality is then put to the test in a number of analysis scenarios. The results and insights gained from the analyses are then presented in several diagrams, and interpreted. The paper concludes with a summary and an outlook on further areas of work.
The Influence of Self-Efficacy of College Students in Privacy Protection and Behavior in Social Networking Context
Authors: Cui Mingwu , Ding Fangfang , Cai Kun
Published: April 2024

In the era of mobile social media, users who show themselves on social platforms will face the risk of privacy breaches. Frequent data leaks and increasingly complex social media privacy protection terms intensify users’ privacy concerns, along with mandatory privacy exposure, contributing to privacy fatigue among users. This study examines the changes in privacy protection behavior among college students under the influences of privacy concerns and privacy fatigue from the perspective of self-efficacy in privacy protection. Data is collected through a questionnaire survey, and a structural equation model is established to provide insights into protecting user privacy. The results of this research indicate that college students’ internal self-efficacy in privacy protection has a negative impact on privacy fatigue. College students’ privacy concerns are significantly negatively correlated with their willingness to disclose information, while privacy fatigue is significantly positively correlated with their willingness to disclose information. Privacy fatigue among college students has a significant positive influence on both their disclosure intention and the behavior of disengaging from privacy protection.
Mengenalkan Edukasi Robot untuk Mengembangkan Kreativitas dan Imajinasi Anak Usia Dini di TK Aisyah Kauman Kecamatan Ponorogo
Authors: Munirah Munirah , Vidyasari Rhesma Intan , Triyanto Andy
Published: April 2024

Peran gadget saat ini sudah sangat mengubah perilaku, kebiasaan dan pola hidup kita terutama untuk anak-anak yang masih usia dini. Namun demikian, dampak positif dengan adanya gadget pun tidak bisa kita pungkiri. Banyak hal yang bisa kita manfaatkan dengan adanya perkembangan teknologi yang ada saat ini terutama untuk membangun dan menumbuhkan semangat dan kreativitas bagi para anak-anak sejak usia dini. Salah satunya adalah memperkenalkan dan mengedukasikan kepada mereka, teknologi robot yang bukan hanya sekedar teknologi semata namun dapat dijadikan sebagai bahan atau objek permainan yang seru, apalagi robot yang tidak langsung pakai, yang harus dirakit dulu untuk bisa digunakan. Hal ini cenderung dapat melatih imajinasi anak-anak dan menambah skill serta kreativitas pada anak. Dalam kegiatan ini, kami akan mengenalkan robot pada anak-anak di TK Aisyiyah Kauman Ponorogo selaku mitra kegiatan kami dengan menggunakan metode demonstrasi dan eksperimen kepada anak-anak di TK. Diharapkan dengan kedua metode itu dapat memberikan pengalaman bagi anak-anak serta menumbuh kembangkan imajinasi kepada anak bahwa belajar robot itu juga menyenangkan.
Peranan Customer Service dalam Meningkatkan Kepuasan Konsumen Bandara Internasional I Gusti Ngurah Rai
Authors: Purwandari Delina Putri , Wijaya Gede Crisna
Published: April 2024

Sebagai bentuk perwujudan atas pertumbuhan ekonomi Indonesia, diperlukan sebuah bandar udara guna untuk mempermudah segala proses kegiatan pariwisata dan perekonomian di Indonesia. Bandar Udara Internasional I Gusti Ngurah Rai merupakan salah satu bandara terbesar di Bali dengan rata-rata penerbangan sebanyak 165.000 per tahun dan 20-25 juta penumpang pertahun. Namun, pada tahun 2021 saat pandemic Covid-19 mencuat Bandara Internasional I Gusti Ngurah Rai menghentikan sementara penerbangan internasional. Dengan adanya hal ini, tentu akan mempengaruhi peran customer service sebagai wajah utama bandara dalam memenuhi kepuasan konsumen melalui kualitas pelayanan yang diberikan. Tujuan laporan ini dibuat adalah untuk mengetahui bagaimana peran dan kualitas layanan customer service dalam mempengaruhi dan meningkatkan adanya kepuasan konsumen pada Bandar Udara Internasional I Gusti Ngurah Rai. Customer service menjalankan perannya dengan melayani cases, problem dan laporan dari penumpang dengan tingkatan cases ringan, sedang hingga berat. Memberikan good customer experience dapat menunjukkan bahwa kualitas layanan customer service memuaskan.