We present two-dimensional measurements of the laser-induced plasma development and shock wave evolution in air. The breakdown is induced by a Q-switched Nd:YAG laser (
λ
=1064 nm) with a pulse ...duration of 4 ns. To study these fast laser-induced phenomena, we have developed a high-speed, two frame shadowgraph method. It enables 2D visualization of a laser-induced event in two time instances, which are delayed by an arbitrary time interval in the range from 300 ps to 30 ns. The established method is based on 30 ps, green (
λ
=532 nm), and linearly polarized laser pulse, which is split into two orthogonally polarized illumination pulses for direct and delayed illumination of the breakdown area. Exploiting polarization of the probe pulses, we capture two temporally and spatially separated frames with two CCD cameras. Special attention is given to the subsequent data processing, especially to the minimization of the systematic error due to alignment of both images, and to the determination of 2D velocity distribution from the captured image pairs.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This study investigates the effects of blockchain technology scalability limitations on the performance of Blockchain-Based Shared Manufacturing (BBSM), an innovative smart-manufacturing paradigm ...aimed at enhancing the utilization of global manufacturing resources via peer-to-peer (P2P) collaboration of self-organized manufacturing assets. Despite the prevalence of research highlighting blockchain technology’s scalability limitations as the main barrier for adoption, few studies have explored their effects on the operation of blockchain-based systems. The primary goal of the presented research work is to explore the implications of blockchain technology scalability limitations on the BBSM system’s performance and user behavior. To obtain realistic behavior, an experiment is conducted using an online game played by human participants. Analysis of the players’ strategy is used for implementation of a multi-agent simulation model, which is then employed to assess the influence of varying blockchain network configurations on the BBSM concept’s performance. Preliminary experimental findings reveal that a congested blockchain network leads to increased transaction costs and reduced service prices, consequently devaluing the manufacturing role in the BBSM system and causing underutilization of existing maximum production capacities. Moreover, allocating funds to financial activities rather than manufacturing activities yields superior outcomes for system users. Simulation results indicate that the BBSM system’s response to alterations in blockchain network throughput is contingent upon the production function. The findings of this study reveal that the scalability limitations of blockchain technology impair the performance of the BBSM system and affect user behavior in the system, underscoring the necessity for future research to concentrate on incorporating scalable solutions within blockchain-based manufacturing systems.
Shared Manufacturing is a new mode of social manufacturing based on the principles of a sharing economy. This paper presents a scalable framework for blockchain-based Shared Manufacturing that ...preserves the transparency and immutability characteristics of transaction records, which is critical to building trust between entities in blockchain-based systems. We define a blockchain-based protocol for the service execution according to the design principles of the sharing economy. We present a scalable integration of blockchain technology into the concept of Shared Manufacturing by employing cross-chain solutions. We discuss existing cross chain technologies regarding the requirements of Shared Manufacturing and propose hybrid approach. We compare implementations of the proposed framework on two different blockchain networks: Ethereum public network and Xdai sidechain network. We conduct user-oriented test to explore the performance (cost and time) of the implementations in realistic situations in order to justify the use of the sidechain technology. Results indicate that the implementation on the sidechains provides greater scalability than the implementation on the public blockchain network.
•Shared Manufacturing opens up manufacturing to unused local resources•Blockchain technology enables trusted environment between entities•Using cross-chain technology increases scalability of the blockchain-based Shared Manufacturing.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The paper presents a method and a system for assessing the kinematic parameters of distant noncooperative objects. An experimental measuring system was developed using a long distance laser ...rangefinder, a GPS receiver, an electronic inclinometer, and a CCD camera mounted on a motorized pan-tilt unit. During the measurement process, the system first establishes its position and orientation in a global coordinate system. Particle filtering approach based on adaptive template matching is used to track a moving object of interest in the acquired digital image sequence. The tracking and rangefinder data is employed to determine in real time the relative position of the object, thus obtaining its 3D trajectory and velocity. To enable repetitive range measurements, the tracking data is also used to actuate the pan-tilt unit directing the rangefinder towards the object. Experiments are presented which demonstrate the performance of the system for characterization of movement of vehicles and people at kilometer-range distances.
This study addresses the problem of low-cost microlens fabrication and outlines the development of a novel microforging apparatus for microlens mold fabrication. The apparatus consists of an ...electromagnetic impact tool which strikes a piston with a hardened steel ball into a workpiece. The impact creates a spherical indentation which serves as a lens cavity. The microforging apparatus is controlled by a microprocessor control unit communicating with a personal computer and enables on-the-fly variation of electromagnetic excitation to control the microforging process. We studied the effects of process parameters on the diameter of the fabricated lens cavities inspected by a custom automatic image processing algorithm. Different microforging regimes are analyzed and discussed. The surface quality of fabricated cavities has been inspected by confocal microscopy and the influence of fill factor on sphericity error has been studied. The proposed microforging method enables the fabrication of molds with 100% fill factor, surface roughness as low as Ra 0.15 µm and sphericity error lower than 0.5 µm. The fabricated microlens arrays exhibit nearly diffraction-limited performance, offering a wide range of possible applications. We believe this study provides access to microoptical technology for smaller optical and computer vision laboratories.
This study shows how unimorph deformable mirrors can be effectively fabricated out of commercially available piezo-buzzers without any high-tech equipment. Our design involves a quad-channel mirror ...with monolithically integrated flexures. The mirror is controlled by a custom quad-channel high-voltage driver unit, capable of 93 Vp-p and 75 kpps performance. The system exhibits 16-bit resolution over the angular working range of ±1.85 mrad, with 0.04 mrad V−1 angular sensitivity and 14% hysteresis. We demonstrate the mirror performance for focus control in microscopy and high-precision laser beam steering, opening a wide variety of applications in computational imaging, confocal microscopy, optical tweezing and laser lithography.
This paper presents an approach to integrating Blockchain and IoT technologies into modern supply chains. We propose the concept of a new logistics platform that is built as a distributed network of ...nodes and offers an alternative approach dealing with the complexity of modern supply chains by breaking them into smaller, functionally independent parts. The modular structure of the platform allows users to add their own nodes or extend the functionality of the existing ones. Nodes are communicating with the use of IoT technology, which serves as a bridge between the virtual and real worlds, making this platform truly digital. Blockchain technology is not only used for writing down agreements and for making transactions, but also as a trustworthy public listing of services and information. It connects the nodes into a public and secure system that provides reliable services of a supply chain. In this work, we describe the individual nodes and their implementation and present preliminary results of experiments using a laboratory model of a logistic chain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Researchers in the field of smart manufacturing have recognized the benefits of blockchain technology, which solves the trust problem in the open network without relying on any trusted third party. ...Blockchain technology enables interaction between otherwise competing manufacturing entities to satisfy increasing customer demands in a trustful way. However, existing blockchain networks are facing limitations, which are defined by the trade-off between scalability, decentralization, and security. The scalability of the blockchain network is defined as the ability of the network to support an increasing load of transactions and it is lower compared to the non-blockchain systems. In order to omit the effects of the limitations, scalability solutions are being presented. This research reviews the literature in the field of blockchain-supported manufacturing concerning scalability solutions. The selected literature has been reviewed and classified according to the type of scalability solution. For each type of scalability solution, the main features of the concepts and connection between blockchain technology and manufacturing system are highlighted and discussed. The main findings of the study are that Layer 1 scalability solutions are better represented in the literature and are predominating in the case of general smart manufacturing systems, whereas Layer 2 scalability solutions are better represented in the case of specific smart manufacturing systems. Based on insights obtained from the presented analysis, future directions and open issues regarding the scalability limitations and solutions in blockchain-supported manufacturing are presented.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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