Comparative Analysis Of Reliability Research Articles

Comparative Analysis of Reliability in On-Time Monitoring Data for NO3–N, BTEX, and TOC: Commercialized Sensors versus Spectroscopic Methods

Comparative Analysis of Reliability in On-Time Monitoring Data for NO₃–N, BTEX, and TOC: Commercialized Sensors versus Spectroscopic Methods

Detection of AI-generated Writing in Students’ Assignments: A Comparative Analysis of Some Tools' Reliability

Detection of AI-generated Writing in Students’ Assignments: A Comparative Analysis of Some Tools' Reliability

Comparative Analysis of Reliability, Cost and Performance of Three and Five-Phase Synchronous Reluctance Machine Drive Systems With and Without Permanent Magnets

Comparative Analysis of Reliability, Cost and Performance of Three and Five-Phase Synchronous Reluctance Machine Drive Systems With and Without Permanent Magnets

Comparison of Travel Time Reliability of Different Bus Service Providers: A Case Study of Airport to Narayan Gopal Chowk Route, Kathmandu

The diminishing preference for the public transportation system in the Kathmandu Valley has been a longstanding issue, attributed to factors such as uncontrolled urbanization, increased motorization, inadequate transit infrastructure, and diminished reliability. The issue of less reliability of public transport in Kathmandu has drawn significant interest of public authorities, policy makers, planners and researchers. The lack of reliability in the public transportation system may compel commuters to choose personal vehicles, primarily motorcycles and cars. The increase in these smaller vehicles, sharing routes with larger ones, not only leads to an increase in congestion but also diminishes overall reliability. Hence, it becomes imperative to maintain the public transport system at an optimal level of reliability. Thus, this research focuses on the performance of public transport, particularly buses, employing measures of travel time reliability. Planning time and planning time index are used as a measure of the travel time reliability. This study includes a comparative analysis of the travel time reliability among different bus service providers operating on the case study route. On board technique was adopted to collect the data. Among the different public service providers operating in the area, four bus service providers Mahanagar Yatayat, Mahasagar Yatayat, Mayur Yatayat and Khwopa Yatayat were selected for this study. The comparison of travel time reliability among various bus service providers was conducted using an Analysis of Variance (ANOVA) test and post-hoc test.

Consequences of the Improved Wave Statistics on a Hull Girder Reliability of Double Hull Oil Tankers

This paper investigates the change in hull girder failure probabilities and partial safety factors caused by the implementation of the new procedure for direct computation of wave loads recommended by the International Association of Classification Societies (IACS). Differences between new and previous procedures are primarily related to the different associated scatter diagrams, and secondarily due to the assumptions on wave spectrum, wave energy spreading, and ship speed. This study performs a comparative structural reliability analysis of the global longitudinal bending of five oil tankers of different sizes between two procedures for wave load computation. Firstly, failure probabilities are compared, and secondly, modified partial safety factors are proposed, resulting in similar failure probabilities according to two separate procedures. It is found that implementation of the new revision of the IACS procedure for direct computation of wave loads results in a reduction of the minimum required ultimate vertical bending capacity of a ship hull by 10%. In addition to the novel investigation of the safety of oil tankers using a revised wave scatter diagram, this study offers a new rapid method for calculation of extreme vertical wave bending moments based on the regression of the parameters of the Weibull function, used for the long-term probability distribution of wave-induced loads.

Time-dependent seismic reliability analysis of rocking cold-formed steel frame based on improved HOMM

Cold-formed steel structures are particularly sensitive to seismic loads due to their relatively low ductility and limited energy dissipation capacity. Moreover, the small thickness of cold-formed steel structures makes them more susceptible to environmental influences, leading to corrosion and material degradation. Therefore, it is essential to quantitatively assess the seismic reliability of cold-formed steel structures from a lifecycle perspective. Current structural reliability design standards often focus on the ultimate strength at the component level while neglecting the global safety of structures. Additionally, it tends to neglect the time-variant characteristic of structural resistance due to the corrosion and degradation of materials. Therefore, the time-dependent seismic reliability analysis framework was proposed at the global structural level based on an improved high-order moment method (HOMM). It directly addresses the objective failure probabilities at the global structural level and takes into account the resistance degradation of structures in the design reference period. A comparative analysis of the time-dependent seismic reliability between rocking cold-formed steel frames and rigid cold-formed steel frames is conducted, focusing on load-bearing capacity limit states and deformation capacity limit states. The investigation indicates that the differences between time-dependent and time-independent seismic reliability indexes are substantial. For cold-formed steel structures subjected to prolonged exposure to the corrosive environment, it is recommended to consider the time-dependent degradation of structures.

Comparative reliability analysis of electric aircraft versions for NASA’s X-57 based on Lz-transform method

As the goals of air transport shift towards more-electric or all-electric airplanes, different drive train configurations have been explored recently. A major goal on the way towards the inclusion in commercial air traffic is high reliability. One of the experimental electric airplanes is NASA’s X-57 “Maxwell”, which consists of fourteen electric motors powered from a battery pack. The aim of this paper is to assess the reliability of the proposed design of the X-57 by using the Lz-transform approach, as well as to propose several alternative designs to its electric drive train, in order to use less vehicle mass on the motors and more on the battery pack, without sacrificing the original availability and expected performance, with a final goal to increase the flight range. The reliability analyses show that the replacement of X-57’s three-phase motors with six-phase ones greatly improves availability of the electric drive train due to the use of fault-tolerant electric machines. Additionally, all of the further proposed alternative designs have higher availability than the X-57. The alternatives with CHB inverter topologies generally achieved higher availability values and higher expected performance than the B6 variants. Finally, the use of a distributed propulsion system with smaller take-off motors leads to a motor-mass advantage compared to more conventional drive train designs.

Vibration reliability of steel beams prestressed by drawing

Introduction. Vibrations of building structures and mechanism parts were analyzed. The need to investigate the oscillation processes and vibration reliability of steel beams prestressed by web drawing was formulated. The subject of study is structural steel. The object of study is bimetallic steel beam prestressed without rods.Materials and methods. The scientific inquiry is based on the basics of structural mechanics of buildings and structures: superposition principle, differential equation of deflection curve of a bar, energy method, and methods of determination of stress-strain state of prestressed steel bars.Results. A comparative analysis of vibration reliability of non-prestressed beams and prestressed structures of equal bearing capacity was performed. Rotations of the beam supporting nodes loaded by prestressing forces and external impacts were determined by integration of differential equation of deflection curve of a split bar. The support moments in rigid supporting nodes of structures were determined on the basis of superposition principle. The developed methods of stressed condition of prestressed bars are the basis for determination of normal stresses in the sections of beams under study. The resultant stresses were obtained by algebraic addition of prestresses and stresses from external loads. Dynamic parameters of bearing capacity of beams were determined on the basis of works by I.M. Rabinovich and V.A. Kiselev. The oscillation circular frequency of conventional and prestressed beams was established, analytical expressions for determination of angular velocity of prestressed bending elements were formulated, and the dynamic deflections and factors of structures were determined. It is found that the circular frequency of prestressed beams hinged in supporting nodes compared to the circular frequency of conventional beams decreases by a factor of 1.4 and by a factor of 5.6 in beams with rigid supports. Angular velocity decreases by a factor of 1.4 (hinge supports) and 6.8 (rigid supports), respectively. The deflections of prestressed beams are reduced by a factor of 1,87: 11,9. There is a significant reduction in the stressed condition of prestressed structures.Conclusions. A hinged traditional beam under external and vibration loads in limit state is in the material yield zone and does not meet the first and second limit state conditions. These structures have the lowest vibration reliability. Prestressed structures are more reliable. With rigid supporting nodes, the moments of prestressing forces coincide with the supporting moments and produce hogging with the vector opposite to the external load deflection vector. In the limit state, total deflections are less than the external load deflections. Stresses in the structure decrease. Since load moments and beam deflections are initial parameters for dealing with dynamic strength tasks, we may state that prestressed beams with rigid supporting nodes have an increased vibration reliability.

Analysis of a Collision-Affected M/GI/1/ /N Retrial Queuing System Considering Negative Customers and Transmission Errors

This paper considers a retrial G-queue with collisions, transmission errors, and a finite number of sources, where service and repair time are both general distributions. The number of sources (terminals) is finite and a source cannot generate new requests until the channel (server) finishes its work, i.e., the rate at which new primary requests are generated varies inversely with the number of data frame (customer) in the system. A collision occurs when service requests arrive at a busy channel, and transmission errors prevent data frames from leaving the system after completing service. Two types of arrivals are considered. Negative customers will break down the system in the busy state and remove the customer under service. The application of our model is indicated, with a particular emphasis on communication networks such as the local-area networks (LAN) with CSMA/CD protocol. Recursive formulas have been derived to calculate the stationary joint distributions and the Laplace transform of reliability function by applying the discrete transformations method along with the supplementary variables technique (SVT). Furthermore, the comparative performance and reliability analysis have been conducted numerically. Numerical examples are provided to investigate the sensitivity of different parameters on performance measures and reliability indicators.

A comparative analysis of interobserver reliability and intraobserver reproducibility of the Oswestry-Bristol Classification and the Dejour Classification for trochlear dysplasia of the knee.

Classifying trochlear dysplasia (TD) is useful to determine the treatment options for patients suffering from patellofemoral instability (PFI). There is no consensus on which classification system is more reliable and reproducible for the purpose of guiding clinicians' management of PFI. There are also concerns about the validity of the Dejour Classification (DJC), which is the most widely used classification for TD, having only a fair reliability score. The Oswestry-Bristol Classification (OBC) is a recently proposed system of classification of TD, and the authors report a fair-to-good interobserver agreement and good-to-excellent intraobserver agreement in the assessment of TD. The aim of this study was to compare the reliability and reproducibility of these two classifications. In all, six assessors (four consultants and two registrars) independently evaluated 100 axial MRIs of the patellofemoral joint (PFJ) for TD and classified them according to OBC and DJC. These assessments were again repeated by all raters after four weeks. The inter- and intraobserver reliability scores were calculated using Cohen's kappa and Cronbach's α. Both classifications showed good to excellent interobserver reliability with high α scores. The OBC classification showed a substantial intraobserver agreement (mean kappa 0.628; p < 0.005) whereas the DJC showed a moderate agreement (mean kappa 0.572; p < 0.005). There was no significant difference in the kappa values when comparing the assessments by consultants with those by registrars, in either classification system. This large study from a non-founding institute shows both classification systems to be reliable for classifying TD based on axial MRIs of the PFJ, with the simple-to-use OBC having a higher intraobserver reliability score than that of the DJC.

Comparative Reliability Analysis between Horizontal-Vertical-Diagonal Code and Code with Crosstalk Avoidance and Error Correction for NoC Interconnects

Ensuring reliable data transmission in Network on Chip (NoC) is one of the most challenging tasks, especially in noisy environments. As crosstalk, interference, and radiation were increased with manufacturers' increasing tendency to reduce the area, increase the frequencies, and reduce the voltages. So many Error Control Codes (ECC) were proposed with different error detection and correction capacities and various degrees of complexity. Code with Crosstalk Avoidance and Error Correction (CCAEC) for network-on-chip interconnects uses simple parity check bits as the main technique to get high error correction capacity. Per this work, this coding scheme corrects up to 12 random errors, representing a high correction capacity compared with many other code schemes. This candidate has high correction capability but with a high codeword size. In this work, the CCAEC code is compared to another well-known code scheme called Horizontal-Vertical-Diagonal (HVD) error detecting and correcting code through reliability analysis by deriving a new accurate mathematical model for the probability of residual error Pres for both code schemes and confirming it by simulation results for both schemes. The results showed that the HVD code could correct all single, double, and triple errors and failed to correct only 3.3 % of states of quadric errors. In comparison, the CCAEC code can correct a single error and fails in 1.5%, 7.2%, and 16.4% cases of double, triple, and quadric errors, respectively. As a result, the HVD has better reliability than CCAEC and has lower overhead; making it a promising coding scheme to handle the reliability issues for NoC.

Investigation of Temperature Dependence of mmWave Power Amplifier Large-Signal Reliability Performance

This work aims to study the temperature dependence on the long-term reliability of a power amplifier (PA) cell fabricated using 40-nm partially depleted-silicon on insulator (PD-SOI) nFET under dc and large-signal RF stress. Voltage swing caused by large RF signals complicates the stress mechanism due to frequent switching of stress from conducting to nonconducting. The impact of temperature on the time slope exponent ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> ) is also analyzed to understand the degradation mechanism at different temperatures. The values of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> are found to increase with the temperature pointing to the generation of new defects at the interface. A comparative reliability analysis is presented for dc, small-, and large-signal performance under varied accelerated dc and large-signal stress at drain and gate for different temperatures. Unity gain frequencies are also temperature sensitive and show high degradation at elevated temperatures. In our study, we have investigated the lifetime as a function of temperature of the PA operating in compression. It is observed that the lifetime is more than ten years when the PA operates at room temperature, which deteriorates as the measurement chuck temperature rises.

A comparative radiation analysis of reconfigurable memory technologies: FinFET versus bulk CMOS

This work describes a comparative radiation reliability analysis between two reconfigurable devices with different manufacturing technology: 28 nm CMOS-based and 16 nm FinFET based FPGAs. The analysis is based on a proton radiation test campaign performed at the PSI radiation facility. As application circuit, a multi-core computational engine was implemented on each one of the reconfigurable devices. The radiation sensitivity has been reported in terms of the SEU cross-section of the configuration memory bits. Results have shown a higher sensitivity of 28 nm CMOS with respect to 16 nm FinFET. Moreover, a detailed comparison of detected Single Event Multiple Upsets (SEMUs) clusters for both technology is reported.

Comparative Reliability Analysis of Milling Teeth Manufactured by Conventional Cutting Processes and Laser Cladding

This paper presents the estimation of the main reliability indices of two milling teeth types. The comparative analysis referred to milling teeth manufactured by conventional cutting processes, made of 41Cr4 (type I), and milling teeth manufactured by high-productivity welding loading processes, namely, laser cladding (type II). To analyze the distributions of the lifetime data specific to milling teeth types, the correlation coefficient value was considered. Goodness-of-fit analysis indicated that normal distribution was adopted in order to conduct parametric estimates of the reliability indices. Point estimations of the parameters and estimations with 95% confidence intervals of the components’ lifetimes were performed, applying the least squares estimation method. Compared to the type II milling teeth, lower values of the reliability function were estimated for the type I milling teeth. The type II milling teeth displayed higher values for the statistical parameters, with a mean of 6 h, while the mean of the failure of the type I milling teeth was 5.2 h. In addition, a more pronounced hazard rate for the type I milling teeth compared to the type II milling teeth was observed.

Порівняльний аналіз надійності фіксації черезвертлюгових переломів стегнової кістки із застосуванням звичайного та подовженого проксимального стегнового стрижня

Актуальність. Проблема лікування хворих із навколосуглобовими переломами проксимального відділу стегнової кістки в наш час не може вважатися остаточно вирішеною. За даними різних авторів, їх частота становить від 20 до 53,3 % серед усього числа постраждалих з переломами стегна і виникають вони частіше у старечому віці (60 %), ніж у літньому (40 %). При лікуванні переломів проксимального відділу стегнової кістки широко впроваджуються малоінвазивні, малотравматичні технології застосування проксимального стегнового стрижня Troсhanteric Gamma Nail G 3 (Stryker), PFN A (Synthes), ChFN (ChM). Використовують як звичайний, так і подовжений варіант проксимального стегнового стрижня. Здійснюються спроби обґрунтування придатності механічних остеоімплантатів на основі імітаційного комп’ютерного моделювання, що відображають деякі аспекти поведінки системи «кістка — імплантат», з використанням методу скінченних елементів. У роботі шляхом імітаційного комп’ютерного моделювання досліджено поведінку біомеханічної системи «фіксатор — кістка» з визначенням її напружено-деформованого стану при застосуванні звичайного та подовженого проксимального стегнового стрижня (PFN), який забезпечує оптимальні біомеханічні та біологічні умови для зрощення черезвертлюгових переломів. Мета роботи. Порівняльний аналіз стабільності остеосинтезу кісткових фрагментів черезвертлюгових переломів стегнової кістки типу А2 та А3 із застосуванням звичайного та подовженого проксимального стегнового стрижня. Матеріали та методи. На основі аксіальних сканів спіральної комп’ютерної томографії моделей стегнової кістки за допомогою програмного пакета Mimics і Solid Works створено імітаційні 3-D-моделі проксимального відділу стегнової кістки з вертлюговими переломами типу А2 та А3 з їх фіксацією за допомогою звичайного та подовженого проксимального стегнового стрижня (PFN). Подальші розрахунки напружено-деформованого стану (НДС) методом скінченних елементів здійснювали у програмному середовищі ANSYS. Ключовими показниками для проведення порівняльного аналізу обрані отримані шляхом розрахунків значення НДС — інтенсивності напружень (за Мізисом) у фіксуючих конструкціях і в ділянці перелому та переміщення (Total Deformations) у площині перелому. Розрахунки НДС проводили для інтактної моделі та для кожного з типів переломів А2 та А3 із застосуванням для фіксації звичайного та подовженого проксимального стегнового стрижня без блокуючих гвинтів, з одним та двома блокуючими гвинтами. Результати. Подовжений стрижень забезпечує більш надійну фіксацію кісткових відламків стегнової кістки при обох типах переломів. Показники напружень на кістки та фіксатори значно знижуються, а навантаження на біомеханічну конструкцію «кістка — фіксатор» розподіляються між усіма елементами моделі більш рівномірно, не створюючи локальних концентраторів напружень та не перевищуючи межі міцності матеріалу. Переміщення по площині перелому при подовженому стрижні зменшуються приблизно в 10 разів для всіх комбінацій «перелом/фіксатор». Варіювання кількістю блокуючих гвинтів при остеосинтезі проксимальним стегновим стрижнем змінює характер поведінки біомеханічної конструкції «кістка — фіксатор». Застосування одного або двох блокуючих гвинтів викликає незначне зростання показників напружень по площині перелому при переломі типу А2 та їх зменшення при переломі типу А3. Але зміна напружень є незначною, більш важливим моментом є те, що при додаванні блокуючих гвинтів переміщення по площині перелому зменшуються для переломів як типу А2, так і типу А3, що свідчить про надійнішу фіксацію відламків і більш стабільний остеосинтез. Висновки. За даними комп’ютерного моделювання обидва варіанти PFN забезпечують достатню фіксацію відламків і стабільність остеосинтезу при хірургічному лікуванні черезвертлюгових переломів типу А2 та А3. Застосування подовженого PFN-стрижня забезпечує більш надійну фіксацію кісткових фрагментів порівняно зі звичайним стрижнем PFN при черезвертлюгових переломах стегнової кістки типу А2 та А3 та не залежить від кількості застосованих блокуючих гвинтів. Проведене дослідження дозволить визначити диференційований підхід до лікування осіб із черезвертлюговими переломами стегнової кістки, покращить ефективність надання медичної допомоги цій тяжкій категорії хворих.

Математичне моделювання остеосинтезу черезвертлюгових переломів типу А1 із застосуванням різних металевих фіксаторів

Із метою визначення оптимального виду остеосинтезу при оперативному лікуванні черезвертлюгових переломів типу А1 проведено комп’ютерне моделювання напружень на металеві фіксатори (пластина DHS та PFN-стрижень). Визначено, що найбільш біомеханічно обґрунтованою при черезвертлюгових переломах типу А1 є модель PFN-стрижня у варіанті без застосування гвинтів для дистального блокування, про що свідчать мінімальне напруження на металевому фіксаторі та наявність оптимальної мікрорухливості між кістковими відламками. Проведене дослідження дозволить визначити диференційований підхід до лікування хворих із черезвертлюговими переломами стегнової кістки, покращить ефективність надання медичної допомоги цій категорії тяжких хворих.

Comparative reliability analysis and enhancement of marine dual-fuel engines

ABSTRACT This paper was to examine the reliability and criticality of two dual-fuel marine engine systems and to compare them with a conventional diesel engine system with the utilization of the dynamic fault tree analysis. The results of reliability analysis for the dual-fuel engines indicate that the failure probability of the dual-fuel engine is 8.84% on average at 14,000 running hours whereas 8.48% for the diesel engines. This finding contrasts our intuition that the dual-fuel engines are of higher risk compared to the conventional diesel engines. Research findings, obtained from the reliability-centered maintenance, suggest an effective way of enhancing the safety of engine systems through predictive maintenance, based on the periodical maintenance of critical components. Therefore, it can contribute to improving the reliability of the whole systems in which mechanical components and fuel oil feed systems were identified as critical elements to diminish the system reliability significantly. It also highlights the importance of the proper maintenance of system components that would greatly enhance the safety levels by restoring systems back to their original operating condition, hence minimizing downtime and operating costs. Research outputs also offer meaningful insights about the association between the planned maintenance strategies and the system reliability.

Influence Factors and Comparative Analysis of Reliability of Building Structure Design

Influence Factors and Comparative Analysis of Reliability of Building Structure Design

Comparative Performance and Reliability Analysis of Doping and Junction Free Devices with High-κ/Vacuum Gate Dielectric

A comparative evaluation of channel hot carrier (CHC) reliability and pursuance of dopingless FET (DL JLFET) and junctionless FET (JLFET) are studied for various dielectrics and compared with conventional dielectric (SiO2) JLFET. The use of dielectrics such as vacuum near the drain and the high-κ (HfO2) near the source in DL JLFET (VacuHDL JLFET) allows better pursuance and reliability against channel hot carrier (CHC) effects. A simulation study has shown that the pursuance of VacuHDL in terms of Ion/Ioff ratio is improved by 4.5, 19.38 and 39.58 times, respectively, in comparison with vacuum based DL, HJL and JL. Similarly, the intrinsic delay of VacuHDL is improved by 9.5%, 56.8% and 58.7%, respectively, in comparison with VacuDL, VacuHJL and VacuJL. Hence, VacuHDL is a potential candidate for digital circuit applications. Further, we have found that vacuum-based HDL and HJL are more immunes against CHC stress and shown that the drain current of vacuHDL and vacuHJL is reduced by 6.9% and 17.5%, respectively, in comparison with conventional dialectic (SiO2) based DL and JL which is 10.4% and 20.5%. Hence, the incorporation of vacuum dielectric towards drain terminal is helpful in reducing CHC induced effect in comparison with conventional dielectric.

A Theoretical Approach for Reliability Within Information Supply Chains With Cycles and Negations

Complex networks of information processing systems, or information supply chains, present challenges for performance analysis. We establish a mathematical setting, in which a process within an information supply chain can be analyzed in terms of the functionality of the system&#x2019;s components. Principles of this methodology are rigorously defended and induce a model for determining the reliability for the various products in these networks. Our model does not limit us from having cycles in the network, as long as the cycles do not contain negation. It is shown that our approach to reliability resolves the nonuniqueness caused by cycles in a probabilistic Boolean network. An iterative algorithm is given to find the reliability values of the model, using a process that can be fully automated. This automated method of discerning reliability is beneficial for systems managers. As a systems manager considers systems modification, such as the replacement of owned and maintained hardware systems with cloud computing resources, the need for comparative analysis of system reliability is paramount. The model is extended to handle conditional knowledge about the network, allowing one to make predictions of weaknesses in the system. Finally, to illustrate the model&#x2019;s flexibility over different forms, it is demonstrated on a system of components and subcomponents.