با سلام خدمت کاربران در صورتی که با خطای سیستم پرداخت بانکی مواجه شدید از طریق کارت به کارت (6037997535328901 بانک ملی ناصر خنجری ) مقاله خود را دریافت کنید (تا مشکل رفع گردد).
ردیف | عنوان | نوع |
---|---|---|
1 |
A robust structural vibration recognition system based on computer vision
یک سیستم قوی تشخیص ارتعاش ساختاری بر اساس بینایی کامپیوتری-2022 Vibration-based structural health monitoring (SHM) systems are useful tools for assessing structural safety performance quantitatively. When employing traditional contact sensors, achieving high-resolution spatial measurements for large-scale structures is challenging, and fixed contact sensors may also lose dependability when the lifetime of the host structure is surpassed. Researchers have paid close attention to computer vision because it is noncontact, saves time and effort, is inexpensive, and has high efficiency in giving visual perception. In advanced noncontact measurements, digital cameras can capture the vibration information of structures remotely and swiftly. Thus, this work studies a system for recognizing structural vibration. The system ensures acquiring high-quality structural vibration signals by the following: 1) Establishing a novel image preprocessing, which includes visual partitioning measurement and image enhancement techniques; 2) initial recognition of structural vibration using phase-based optical flow estimation (POFE), which introduces 2-D Gabor wavelets to extract the independent phase information of the image to track the natural texture targets on the surface of the structure; 3) extracting the practical vibration information of the structure using mode decomposition to remove the complex environment of the camera vibration and other noises; 4) employing phase-based motion magnification (PMM) techniques to magnify small vibration signals, and then recognizing the complete information on the vibration time range of the structure. The research results of the laboratory experiments and field testing conducted under three different cases reveal that the system can recognize structural vibration in complicated environments.
keywords: Computer vision | Phase | Motion estimation | Motion magnification | Mode decomposition | Structural vibration |
مقاله انگلیسی |
2 |
A computer vision-based method for bridge model updating using displacement influence lines
یک روش مبتنی بر بینایی کامپیوتری برای بهروزرسانی مدل پل با استفاده از خطوط موثر جابجایی-2022 This paper presents a new computer vision-based method that simultaneously provides the moving vehicle’s
tire loads, the location of the loads on a bridge, and the bridge’s response displacements, based on which the
bridge’s influence lines can be constructed. The method employs computer vision techniques to measure the
displacement influence lines of the bridge at different target positions, which is then later used to perform
model updating of the finite element models of the monitored structural system.
The method is enabled by a novel computer vision-based vehicle weigh-in-motion method which the coauthors recently introduced. A correlation discriminating filter tracker is used to estimate the displacements at target points and the location of single or multiple moving loads, while a low-cost, non-contact weigh-in-motion technique evaluates the magnitude of the moving vehicle loads. The method described in this paper is tested and validated using a laboratory bridge model. The system was loaded with a vehicle with pressurized tires and equipped with a monitoring system consisting of laser displacement sensors, accelerometers, and cameras. Both artificial and natural targets were considered in the experimental tests to track the displacements with the cameras and yielded robust results consistent with the laser displacement measurements. The extracted normalized displacement influence lines were then successfully used to perform model updating of the structure. The laser displacement sensors were used to validate the accuracy of the proposed computer vision-based approach in deriving the displacement measurements, while the accelerometers were used to derive the system’s modal properties employed to validate the updated finite element model. As a result, the updated finite element model correctly predicted the bridge’s displacements measured during the tests. Furthermore, the modal parameters estimated by the updated finite element model agreed well with those extracted from the experimental modal analysis carried out on the bridge model. The method described in this paper offers a low-cost non-contact monitoring tool that can be efficiently used without disrupting traffic for bridges in model updating analysis or long-term structural health monitoring. keywords: Computer vision | Displacement influence line | Vehicle weigh-in-motion | Structural identification | Finite element method model | Model updating | Modal analysis | Bridge systems |
مقاله انگلیسی |
3 |
Computer vision-based illumination-robust and multi-point simultaneous structural displacement measuring method
روش اندازه گیری جابجایی ساختاری همزمان با روشنایی مبتنی بر بینایی کامپیوتری-2022 Computer vision-based techniques for structural displacement measurement are rapidly becoming
popular in civil structural engineering. However, most existing computer vision-based displace-
ment measurement methods require man-made targets for object matching or tracking, besides
usually the measurement accuracies are seriously sensitive to the ambient illumination variations.
A computer vision-based illumination robust and multi-point simultaneous measuring method is
proposed for structural displacement measurements. The method consists of two part, one is for
segmenting the beam body from its background, the segmentation is perfectly carried out by fully
convolutional network (FCN) and conditional random field (CRF); another is digital image cor-
relation (DIC)-based displacement measurement. A simply supported beam is built in laboratory.
The accuracy and illumination robustness are verified through three groups of elaborately
designed experiments. Due to the exploitation of FCN and CRF for pixel-wise segmentation,
numbers of locations along with the segmented beam body can be chosen and measured simul-
taneously. It is verified that the method is illumination robust since the displacement measure-
ments are with the smallest fluctuations to the illumination variations. The proposed method does
not require any man-made targets attached on the structure, but because of the exploitation of
DIC in displacement measurement, the regions centered on the measuring points need to have
texture feature. keywords: پایش سلامت سازه | اندازه گیری جابجایی | بینایی کامپیوتر | یادگیری عمیق | تقسیم بندی شی | همبستگی تصویر دیجیتال | Structural health monitoring | Displacement measurement | Computer vision | Deep learning | Object segmentation | Digital image correlation |
مقاله انگلیسی |
4 |
A Survey on Post-Quantum Public-Key Signature Schemes for Secure Vehicular Communications
مرور طرحهای امضای کلید عمومی پسا کوانتومی برای ارتباطات امن خودرو-2022 Basic security requirements such as confidentiality,
user authentication and data integrity, are assured by using
public-key cryptography (PKC). In particular, public-key signature schemes provide non-repudiation, integrity of transmitted
messages and authentication. The presence of a large scale
quantum computer would be a real threat to break the most
widely used public-key cryptographic algorithms in practice,
RSA, DSA, ECDSA signature schemes and Diffie-Hellman key
exchange. Thus, all security protocols and applications where
these public-key cryptographic algorithms are used are vulnerable to quantum-computer attacks. There are five directions of
cryptographic primitives secure against a quantum computer:
multivariate quadratic equation-based, hash-based, lattice-based,
code-based and supersingular isogeny-based cryptography. These
primitives could serve as replacements for current public-key
cryptographic algorithms to prepare for post-quantum era. It is
important to prioritize the fields to be replaced by post-quantum
cryptography (PQC) since it is hard to replace the currently
deployed PKC with PQC at the same time. The fields directly
connected to human life such as vehicular communications should
be the primary targets of PQC applications. This survey is
dedicated to providing guidelines for adapting the most suitable
post-quantum candidates to the requirements of various devices
and suggesting efficient and physically secure implementations
that can be built into existing embedded applications as easily
as traditional PKC. It focuses on the five types of post-quantum
signature schemes and investigates their theoretical backgrounds,
structures, state-of-the-art constructions and implementation
aspects on various platforms raging from resource constrained
IoT devices to powerful servers connected to the devices for
secure communications in post-quantum era. It offers appropriate solutions to find tradeoffs between key sizes, signature
lengths, performance, and security for practical applications.
Index Terms— Implementation attack | post-quantum cryptography | public-key signature scheme | quantum algorithm | Shor algorithm | side-channel attack. |
مقاله انگلیسی |
5 |
Pathophysiology of Advanced Heart Failure
پاتوفیزیولوژی نارسایی پیشرفته قلب-2021 The pathophysiologyof advanced heart failure (HF) can be characterized asa complex interplay ofdysregulated mechanisms comprising impaired hemodynamics, neurohormonal and proinflammatory
activation, dysfunctional cardiorespiratory reflex control, and inadequate energy handling, all of which
ultimately lead to multiorgan dysfunction; at the later stage of HF, numerous comorbidities, whose underlying pathophysiologiesoftenamplifyHFprogression,tendtodominatetheclinicalpicture and therapeutic approach, and some of these mechanisms have been identified as therapeutic targets in HF.
Blockade of the renin-angiotensin-aldosterone system (preferably with an angiotensin receptorneprilysin inhibitor, but alternatively with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers together with mineralocorticoid receptor antagonist) and sympathetic nervous system (with b-blockers) is now considered a fundamental element of pharmacologic therapy for all patients with advanced HF and reduced ejection fraction. Autonomic modulation (vagal nerve stimulation or baroreflex stimulation) in advanced HF tends to benefit functional variables (qualityof life,NewYork HeartAssociation class, 6-minutewalking distance), whereas improvement in the outcomes (total mortality, HF hospitalizations) still remains uncertain. Fluid overload with central and/or peripheral congestion characterize the clinical picture of advanced HF and is the main reason for hospital admission in these patients; distinction of different clinical patterns of congestion with different underlying mechanisms may improve the management of fluid overload in advanced HF. Recent clinicaltrials have shown that the following novel therapiestargeting impairedpathophysiologic pathways in advanced HF seem to improve patients’ outcomes: (1) vericiguat, a soluble guanylate cyclase stimulator; (2) omecamtiv mecarbil, a selective cardiac myosin activator; (3) sodium-glucose cotransporter 2 inhibitors; (4) ferric carboxymaltose, for patients with concomitant iron deficiency. Better understanding of the pathophysiology underlying HF progression may allow characterization of novel mechanisms that can be targeted in order to revert to a natural pathway of HF development and progression. |
مقاله انگلیسی |
6 |
Advances in Electrical Engineering, Electronics and Energy: Global Developments in New Energy Technologies and Development of Energy Technology from the Micro to the Macro-Scale
پیشرفتها در مهندسی برق، الکترونیک و انرژی: تحولات جهانی در فناوریهای انرژی جدید و توسعه فناوری انرژی از مقیاس خرد تا مقیاس کلان-2021 Global warming and increasingly severe weather events have given a new and increasingly urgent focus
to energy technology. Currently there is major growth in novel technologies such as energy harvesting,
self-powering wearable devices, and options enabling a move to a post carbon future using a range of
advanced materials (for example, carbon-based nanomaterials), especially for low power devices. By
contrast, large thermal energy development is focused on either using renewable energy or developing
thermal boilers with high electrical efficiency and low emissions. Electrical energy efficiency of 50% or
more is increasingly being held out as feasible in the next several decades. However, most of these
advancements concerning large boilers depend heavily on materials development, which can be an
extremely slow process. Genuinely new approaches which might include improved fusion energy
technology, or ultra large batteries, or even devices built on systems employing superconductivity are
also possible, although it seems unlikely that any such technologies will play a critical role in achieving
greenhouse goals in the next decade, but they might well become important to achieve 2050 targets.
Renewables remain one of the most promising frontiers, but they need to be made cheaper and
combined with better energy storage.
|
مقاله انگلیسی |
7 |
The role of accounting conservatism in M&A target selection
نقش محافظه کاری حسابداری در انتخاب هدف M&A-2021 Mergers and acquisitions (M&As) are among the most important investment
activities for companies, but they contain great risks. We investigate the role
of accounting conservatism in M&A target selection and risk. We find that
for risk-averse reasons, firms with high accounting conservatism are likely to
acquire profitable targets and avoid loss-making targets. When such firms
acquire loss-making targets, the conservatism’s risk-control role reduces
M&A risk and increases M&A performance, but only when control of the target is transferred and the acquirer has high long-term debt and low management power. Furthermore, accounting conservatism reduces risk by
increasing the maturity match between cash flow and debt. Our results suggest
that accounting conservatism plays not only a risk-averse role but also a riskcontrol role, providing new evidence for the usefulness of accounting conservatism in M&A decisions.
Keyword: Target selection | Accounting conservatism | Risk aversion | Risk control |
مقاله انگلیسی |
8 |
How viable is password cracking in digital forensic investigation? Analyzing the guessability of over 3:9 billion real-world accounts
شکستن رمز عبور در تحقیقات پزشکی قانونی دیجیتال چقدر قابل اجرا است؟ تجزیه و تحلیل قابلیت حدس زدن بیش از 3:9 میلیارد حساب در دنیای واقعی-2021 Passwords have been and still remain the most common method of authentication in computer systems.
These systems are therefore privileged targets of attackers, and the number of data breaches in the last
few years attests to that. A detailed analysis of such data can provide insight on password trends and
patterns users follow when they create a password. To this end, this paper presents the largest and most
comprehensive analysis of real-world passwords to date e associated with over 3.9 billion accounts from
Have I Been Pwned. This analysis includes statistics on use and most common patterns found in passwords and innovates with a breakdown of the constituent fragments that make each password.
Furthermore, a classification of these fragments according to their semantic meaning, provides insight on
the role of context in password selection. Finally, we provide an in-depth analysis on the guessability of
these real-world passwords.
keywords: Password security | Password-based authentication | Context-based password cracking | Password strength meters |
مقاله انگلیسی |
9 |
Compensating over- and underexposure in optical target pose determination
Compensating over- and underexposure in optical target pose determination-2021 Optical coded targets allow to determine the relative pose of a camera, on a metric scale, from one image only. Furthermore, they are easily and efficiently detected, opening to a wide range of applications in robotics and computer vision. In this work we describe the effect of pixel saturation and non-ideal lens Point Spread Function, causing the apparent position of the corners and the edges of the target to change as a function of the camera exposure time. This effect, which we call exposure bias, is frequent in over- or underexposed images and introduces a systematic error in the estimated camera pose. We propose an algorithm that is able to estimate and correct for the exposure bias exploiting specific geometric features of a common target design based on concentric circles. Through rigorous laboratory experiments carried out in a highly controlled environment, we demonstrate that the proposed algorithm is seven times more precise and three times more accurate in the target distance estimation than the algorithms available in the literature.© 2021 Elsevier Ltd. All rights reserved. Keywords: Optical target | Target orientation | Image processing algorithm | Geometry | Ellipse fitting | Computer vision | Overexposure | Exposure compensation | Resection |
مقاله انگلیسی |
10 |
Impact of ambidexterity of blockchain technology and social factors on new product development: A supply chain and Industry 4:0 perspective
تأثیر دوسویه فناوری بلاکچین و عوامل اجتماعی بر توسعه محصول جدید: زنجیره تامین و چشم انداز صنعت 4:0-2021 This study develops a technology and social capital process aided product innovation conceptual model based on dynamic capability and supply chain ambidexterity theory. The strategy of organizational ambidexterity unbalancing technological and relational social capital factors between buyers and suppliers leads to a higher level of digital manufacturing capabilities and enhances buyers’ innovation potential, considering the sustainable practices in their processes to cope with Industry 4.0 manufacturing processes and sustainability challenges. The study empirically validates the model using data collected from 379 French manufacturing companies. This is the first study that examines how buyers perceive the role of blockchain technology in exploring and exploiting innovation management in the Industry 4.0 era. The study advances understanding on the theory of ambidex-terity of supply chains in buyer–supplier relationships. The study results show the positive effect between internal integration and blockchain technology as well as relational social capital factors in buyer–supplier relationships. The findings underscore the critical role of relational and technological capital in buyer–supplier relationships, specifically to act as a catalyst for exploiting internal capabilities to achieve the innovation targets. The unique findings state blockchain technology mediation is dominant in exploiting the internal capabilities and benefits buyers’ innovation orientation. Keywords: Buyer innovation | Blockchain technology | Supply chain ambidexterity | Relational capital | Industry 4.0 | Sustainability |
مقاله انگلیسی |