Proof Test Research Articles

A dynamic system reliability analysis model on safety instrumented systems

This paper introduces a novel hybrid dynamic model for complex systems reliability assessment. The model synergizes expert knowledge elicitation and an enhanced Dempster-Shafer Theory (DST) with Dynamic Bayesian Networks (DBNs) modeling, aiming to surmount the limitations such as uncertainty and static modeling inherent in traditional methods. The proposed model is deployed on a Safety Instrumented System (SIS) designed to prevent runaway reactions within a Continuously Stirred Tank Reactor (CSTR), considering factors such as system degradation, human interventions, and proof testing on system reliability. The analysis pinpointed the logic solver subsystem as the principal vulnerability within the assessed SIS, leading to targeted recommendations to bolster system reliability. The outcomes offer insights for a wide range of safety-critical systems aiming to augment the safety and efficacy of SISs, thereby advancing safety and resilience management across various complex engineering systems, particularly in contexts where field data is scant.

Blockchain Handshaking with Software Assurance: Version++ Protocol for Bitcoin Cryptocurrency

Cryptocurrency software implements cryptocurrency operations (including the distributed consensus protocol and peer-to-peer networking) and often involves the open-source community. We design a software assurance scheme for cryptocurrency and advance the cryptocurrency handshaking protocol by providing the verification capability of the Bitcoin software by peers and preventing any potential peer from establishing a connection with modified Bitcoin software. Since we focus on Bitcoin (the most popular cryptocurrency) for implementation and integration, we call our scheme Version++, built on and advancing the current Bitcoin handshaking protocol based on the Version message. Our Version++ protocol providing software assurance is distinguishable from previous research because it is permissionless, distributed, and lightweight for its cryptocurrency application. Our scheme is permissionless since it does not require a centralized trusted authority (unlike the remote software attestation techniques from trusted computing); it is distributed since the peer checks the software assurances of its own peer connections; and it is designed for efficiency/lightweight to support the dynamic nature of the peer connections and large-scale broadcasting in cryptocurrency networking. Utilizing Merkle Tree for the efficiency of the proof verification, we implement and test Version++ on Bitcoin software and conduct experiments in an active Bitcoin node prototype connected to the Bitcoin Mainnet. Our prototype-based performance analyses demonstrate the lightweight design of Version++. The peer-specific verification grows logarithmically with the number of software files in processing time and in storage. Furthermore, the Version++ verification overhead is small compared to the version-verack handshaking process; we measure the overhead to be 0.524% in our local networking environment between virtual machines and between 0.057% and 0.282% (depending on the peer location) in our more realistic cloud-based experiments with remote peer machines.

MAMBO: An empirical galaxy and AGN mock catalogue for the exploitation of future surveys

Current and future large surveys will produce unprecedented amounts of data. Realistic simulations have become essential for the design and development of these surveys, as well as for the interpretation of the results. We present MAMBO, a flexible and efficient workflow to build empirical galaxy and active galactic nucleus (AGN) mock catalogues that reproduce the physical and observational properties of these sources. We started with simulated dark matter (DM) haloes, to preserve the link with the cosmic web, and we populated them with galaxies and AGN using abundance matching techniques. We followed an empirical methodology, using stellar mass functions, host galaxy AGN mass functions, and AGN accretion rate distribution functions studied at different redshifts to assign, among other properties, stellar masses, the fraction of quenched galaxies, or the AGN activity (demography, obscuration, multiwavelength emission, etc.). As a proof test, we applied the method to a Millennium DM lightcone of 3.14 $ deg^2$ up to a redshift of $z=10$ and down to stellar masses of $ M \, M_ We show that the AGN population from the mock lightcone presented here reproduces with good accuracy various observables, such as state-of-the-art luminosity functions in the X-ray up to $z 7$ and in the ultraviolet up to $z 5$, optical/near-infrared colour-colour diagrams, and narrow emission line diagnostic diagrams. Finally, we demonstrate how this catalogue can be used to make useful predictions for large surveys. Using Euclid as a case example, we compute, among other forecasts, the expected surface densities of galaxies and AGN detectable in the Euclid $H_ E $ band. We find that Euclid might observe (on $H_ E $ only) about $10^ $ and $8 $ type 1 and 2 AGN, respectively, and $2 $ galaxies at the end of its $ deg^2$ Wide survey, in good agreement with other published forecasts.

Enhanced self-cementation of arsenic-contaminated soil via activation of non-thermal plasma-irradiated ferromanganese: A mechanistic investigation

The self-cementation characteristics of arsenic (As)-contaminated soil were comprehensively investigated in this study. Different non-thermal plasma-irradiated binary (hydro)oxides of polyvalent ferromanganese (poly-Fe-Mn) were synthesized and exploratorily dispersed to soil samples to activate solidification and stabilization during the self-cemented process. The maximum compressive strength of 56.35 MPa and the lowest leaching toxicity of 0.004 mg/L were obtained in the proof test under optimal conditions (i.e., the mass ratio of the poly-Fe-Mn to the soil sample of 0.05; the mass ratio of the composite alkali activator (NaOH + CaO) to the soil sample of 0.25; the mass ratio of CaO to NaOH of 1.5; the mass ratio of the DI water to the binder of 0.515). The composite alkaline activator primarily contributed to the strength formation of the self-cemented matrix while the poly-Fe-Mn significantly influenced the reduction of the As-leaching toxicities. The poly-Fe-Mn maintained diffusion-controlled polycondensation and strengthened the nucleation process during self-cementation. The amount of water and the dosage of poly-Fe-Mn caused an interactive influence on the self-cemented solidification of contaminated soils. The solidified samples with poly-Fe-Mn exhibited better thermal decomposition than their counterparts, reflecting the enhancement of poly-Fe-Mn to the matrix. Some minerals including C-S-H, kaolinite, gehlenite, diopside sodian, augite, and albite were matched in the samples, directly demonstrating the geopolymerization-steered self-cementation of the As soil. The employment of poly-Fe-Mn not only reinforced the immobilization of As pollutants in the matrix but also induced the self-cementation of soils by intensifying the composite alkaline-activated geopolymerization kinetics.

Optimizing coolant loop design across the stator core: A research study

Liquid cooling is widely used on high power motors. Optimal design of the coolant loop could help rise the power density. The coolant channels are placed across the stator core in this research. The heat dissipation performances of the coolant channel with different designs are compared and analyzed through simulation. Experiments were carried out to verify the simulation results and the feasibility of the cooling method. The results show that the coolant loop should be placed tightly close to the slots. The heat dissipation performance of the optimized coolant loop is efficient compared to the jacket cooling design. The coolant channels across the stator core could remain sealed under a 0.5 Mpa pressure at least according to the air proof test. The coolant pressure within the channels could be reduced efficiently through increasing the parallel loop number or moving the channels away from the slots properly. The winding temperature of the measured values and the simulated results of the motor with jacket cooling is within 2 °C.

Mutual Linearity of Nonequilibrium Network Currents.

For continuous-time Markov chains and open unimolecular chemical reaction networks, we prove that any two stationary currents are linearly related upon perturbations of a single edge's transition rates, arbitrarily far from equilibrium. We extend the result to nonstationary currents in the frequency domain, provide and discuss an explicit expression for the current-current susceptibility in terms of the network topology, and discuss possible generalizations. In practical scenarios, the mutual linearity relation has predictive power and can be used as a tool for inference or model proof testing.

Experimental Investigation of Material Flow and Welding defects in Friction Welding process of Cu-SS Dissimilar Materials

Abstract: A particular form of welding that makes use of the heat produced by friction is called friction welding. A pressure force contacts the surfaces of two materials that need to be connected; one is rotating while the other is at rest. In order for the heat produced by the continuous friction to continue rising, friction is applied continually to the second contact surface. In this study, dissimilar friction welding between grade 308 L stainless steel (SS) and copper (Cu) is investigated for a pipe joint design with a wall thickness of 1.50 mm and an outer diameter of 13 mm. The machine RPM, dwell duration, friction time, and friction force are the constant parameters that are used. The maximum ultimate tensile strength of 764 MPa, or almost 128% of the SS base material, was found in the SS to SS weld sample and 104 MPa, or nearly 80% of the Cu basis material, in the CU to CU weld sample. The most significant maximum tensile strength of 349 MPa was achieved by SS to Cu. In along with the study of the mechanical behavior and microstructure, the weld quality was evaluated using corrosion behavior analysis and leak proof testing.

A Taxonomy of UK Reaction-to-Fire Standard Testing: The Role of Black Boxing of Expertise

Fire testing enables an individual or an organisation to make a claim about how a material, product, or system will perform in operational use. This paper describes and analyses the various reaction-to-fire tests that have used over the last 100 years in the UK. By analysing the commonalities and differences between these tests we propose a ‘taxonomy of testing’. We suggest that tests may be classified by the degree to which users may unthinkingly apply the results—without leading to negative fire safety outcomes. We propose three categories: unrepresentative tests; model tests; and technological proof tests. Unrepresentative tests are those which do not mimic building fire scenarios, but have thresholds so conservative that users need not consider whether the test was applicable to their intended application. Model tests are those based on ‘models’ of expected fire scenarios—users must therefore be confident that the model is sufficiently similar to their application. Technological proof tests are those which provide a more realistic test of a real building system—users must carefully analyse the similarities between their test and the real building before applying the results. From this we conclude that where user competence is low, policymakers should cite only unrepresentative (and conservative tests) within their guidance. Conversely where user competence is high, policy makers may more safety cite model or technological proof tests. The kinds of tests that may be safely cited in guidance are therefore indelibly linked to the expertise of the user.

Development of machine learning based classifier for the pressure test result prediction of type IV composite overwrapped pressure vessels

The stringent safety regulations of type IV composite overwrapped pressure vessels (COPVs) for commercial vehicles mandate a certification process involving pressurization up to 1050 bar, with the critical requirement of withstanding burst pressures of 1570 bar. Analyzing proof test data is crucial to enhance and ensure tank safety regarding burst pressure. In this study, we developed various machine learning classifiers for structure health monitoring and damage prediction of COPVs. The classifiers were trained using a substantial amount of acoustic emission data collected during burst and pressure cycling tests. The test results were employed as label inputs during the training process. Statistical features were extracted per time unit and trained using Naive Bayes, Logistic Regression, Decision Tree, XGBoost, and TabNet models. Upon training the data collected from the burst pressure test, TabNet, Decision Tree, and XGBoost achieved classification accuracies above 0.94. Notably, TabNet demonstrated also the best performance for the pressure cycling test with an accuracy of 0.98. Furthermore, TabNet provided visualizations of feature sensitivity in relation to classification results. This study marks the first development of a machine learning classifier for predicting the damage state of COPV tanks in commercial applications pertaining to required safety tests.

Effectiveness of Indonesia’s Simple Proof Test in Comparison to the US Code

Objective: This paper aims to analyze (1) simply proving the elements for bankruptcy under Article 2(1) jo. 8(4) Law No. 37 of 2004 (“Bankruptcy Law”), and (2) its effectiveness in comparison to bankruptcy in the US. This paper assesses also distinctive judgement between the bankruptcy system of Indonesia and the US even when relying on the same forms of evidence. Legal experts and advocates recognize Indonesia’s Simple Proof Test for bankruptcy as ineffective and ‘too simple’ where Courts turn a blind eye to rule out matters requiring a thorough legal and factual assessment, hence the current Bankruptcy Bill basing future revisions on United States (“US”) practices. However, the simple proof test remains. Methods: This research is a normative legal research with applying the statutory and comparatives approach to analyze the research questions concerned with descriptive qualitative. Conclusions: The result of this research found that applying the same standards in an entirely different regime would not reap the benefits intended. Therefore, a thorough assessment should replace the simple proof test entirely.

Structural integrity of 15-5PH stainless steel flow formed pressure vessel for launch vehicle applications

15-5 PH stainless steel is a martensitic precipitation-hardenable stainless steel (0.07C-15Cr-5Ni-3.5Cu-Fe). Presently, high strength low alloy steel, AFNOR 15CDV6 is used for the fabrication of Thrust Vector Control system of satellite launch vehicle. These pressure vessels are used for storing strontium perchlorate, intended for attitude (pitch and yaw) control of the launch vehicle during first stage. The tanks are fabricated through welding of rolled plates, machined rings, and end domes from forgings. AFNOR 15CDV6 steel is prone for corrosion and requires alumina barrier coating to protect from strontium perchlorate. Therefore, as a superior alternative, 15-5PH steel with improved corrosion resistance, simple heat treatment avoiding distortion was selected for the fabrication of pressure vessel. In order to improve the structural integrity of the pressure vessel, flow forming technology was adopted for realization of cylindrical portion of the tank, which eliminated the long seam weld joint and reduced the number of circumferential weld joints. As a part of the developmental program, the tank was designed, shells were flow formed and welded with end domes and were directly aged. The fabricated tank was subjected to a series of pressure tests followed by final burst test for estimating structural margins and ensuring quality requirements.This paper describes the design of the pressure vessel, process followed for manufacture, qualification program adopted and detailed metallurgical analysis carried out on the burst tested hardware. The 15-5PH pressure vessel has successfully withstood the proof pressures and test results are better than the predicted analysis results, indicating structural integrity of the pressure vessel for flight.

Potential sources of threats in the designing and constructing process of aircrafts

Safety is the top priority in aviation. Air transport is one of the safest means of transport. This is the result of continuous activities aimed at eliminating sources of potential threats in all areas related to the performance of aviation operations. The key role in this respect belongs to the aircraft manufacturer. He is responsible for the design and construction of a newly built aircraft or helicopter and for its production process. He is responsible for supervising the operation. The article defines the sources of potential threats to the safety of air operations that lie within the manufacturer's competence. They include e.g. errors in design and construction, manufacturing defects, improper conduct of tests and proof tests, errors and deficiencies in the descriptive and operational documentation and training programs, as well as insufficient supervision over the operation process. The article discusses the potential sources of threats related to the design and construction phase of the aircraft, and also presents examples of errors and omissions in this field. The conclusions contained in the article are the result of the author's analysis of over 250 dangerous events that have taken place in modern commercial aviation. The source materials were protocols from the investigation of the causes of the analyzed accidents.

(Invited) Accelerating Electrocatalysts’ Activity and Stability Assessments

The standard approach to new electrocatalysts development and testing is prohibitively slow. Moreover, it fails to meet the complexity of real devices. As a rule, it consists of routinely repeated steps, including synthesis, physicochemical characterization, and electrochemical measurements. The latter is typically based on the application of rotating disk electrodes (RDE) as conductive solid support to carry electrocatalysts and bulk electrochemical cells with liquid electrolytes as the reaction media.The current work will contain two main parts presenting our recent approaches to tackling the abovementioned limitations of the classical electrochemical test systems. As a representative example, oxygen evolution reaction (OER) electrocatalysis in electrolytes of different pH is taken. It will be shown that bearing in mind the intrinsic limitations of the aqueous mode systems (AMSs), significant acceleration of electrocatalysts’ activity and stability measurements can be achieved by using coupled techniques based on different scanning flow cells.1, 2 This approach is ideal for quick multidimensional parameter space screening. However, further tests in real systems are necessary after identifying promising candidates. It will be shown that also this step can be accelerated using model gas diffusion electrode (GDE)-based setups.3, 4 Moreover, qualitatively different information, e.g. electrocatalyst dissolution assessment, can be achieved using GDE setups coupled to external analytics like inductively coupled plasma mass spectrometry (on-line ICP-MS). While it will be shown that using two approaches, facile screening and real-device level proof tests, are feasible, limitations and challenges will also be discussed, together with further directions to develop these techniques.

Implications of falsification theory and the constructivism paradigm in the development of science education and learning

Background: Science learning holds paramount significance in the advancement of science and technology. Two pivotal theories, falsification theory and the constructivism paradigm, profoundly influence the landscape of science education.
 Purpose: The purpose of this study is to explore the impact of falsification theory and the constructivism paradigm on the development of science learning. Falsification theory, pioneered by Karl Popper, underscores the necessity of rigorous testing and validation of scientific hypotheses, forming the bedrock for the evolution of scientific knowledge. Conversely, the constructivism paradigm accentuates the active role individuals play in constructing knowledge, emphasizing a student-centered approach that involves collaborative learning, and problem-solving.
 Design and methods: In this study, we delve into the implications of falsification theory and the constructivism paradigm in shaping science education. Falsification theory advocates for empirical proof and stringent testing of scientific hypotheses, while the constructivism paradigm promotes active student involvement in building their comprehension of scientific concepts. The study investigates how the integration of these two approaches can foster robust science learning environments, encouraging critical thinking, exploration, and profound understanding.
 Results: The synthesis of falsification theory and the constructivism paradigm in science learning holds promise for cultivating a rich educational experience. By finding a delicate balance between rigorous empirical testing and providing opportunities for active student engagement, educators can create a profound and meaningful learning journey for students. This integrated approach not only instills an appreciation for the scientific method but also nurtures a deep understanding of science concepts, ultimately shaping students into critical thinkers with a genuine enthusiasm for scientific exploration.

Optimization of safety instrumented system performance and maintenance costs in Algerian oil and gas facilities

Gas processing industry is associated with high risks which have the potential to cause catastrophic accidents. Safety Instrumented Systems (SISs) are considered the most effective safety barriers in this sector aiming to prevent undesired events and mitigate their consequences. However, several factors can affect their performance including maintenance strategy in place. In this paper, a Stochastic Petri Net (SPN) model is proposed for evaluating maintenance strategies related to SIS. The model is applied to analyze the performance of an Emergency Shutdown System (ESD) in a Flared Gases Recovery Unit located at south Algerian field. Furthermore, the paper investigates the financial impact of proof tests, including direct costs (such as manpower, equipment, and transportation) and indirect costs (such as production losses and gas flaring tax). These costs can be effectively managed and reduced by optimizing proof test intervals and scheduling tests during planned plant shutdowns. The results demonstrate that the proposed Stochastic Petri Net (SPN) model successfully analyzes the impact of imperfect full and partial proof tests on PFD average values of Safety Instrumented Functions (SIFs). In addition, it has been shown through reliability analysis that the proposed model is able to minimize spare parts expenses leading to significant cost savings while maintaining the required safety integrity levels (SILs), about 60% benefit achieved within two years compared to the actual procurement process over same period.

Novel numerical approach for reliability-assurance of ceramics by combining self-crack-healing with proof testing

Ceramics exhibit stochastic fracture behavior due to internal and surface defects, thereby limiting their practical use. To address this issue, a combined method of ‘self-crack-healing’ and ‘proof testing’ has been proposed. However, to efficiently implement the method, a numerical analysis is required for preliminary investigation. This study establishes a finite element analysis methodology that enables the prediction of both strength recovery due to crack healing and the scatter of strength due to microstructural features. We determine the dependence of the scatter of the three-point bending strength on the healing conditions using the Weibull distribution and demonstrate the applicability of the proposed analysis method to proof tests. Results revealed that the proposed methodology can estimate the healing conditions and proof stresses by obtaining the microstructural information and oxidation kinetics parameters of the ceramic components in advance.

Antithesis of Human Rater: Psychometric Responding to Shifts Competency Test Assessment Using Automation (AES System)

This research is part of proof tests to a combination of statistical processing methods, collecting assessment rubrics in vocational education by comparing two systems, automated essay scoring and human rater. It aims to analyze the final assessment score of essays in Akademi Komunitas Negeri (AKN) Pacitan (Pacitan’s State Community College) and Akademi Komunitas Negeri (AKN) Blitar (Blitar’s State Community College) in East Java, Indonesia. The provisional assumption is that the results show an antithesis to the assessment of human feedback with an automated system due to the conversion of scores between the rubric and the algorithm design. As the hypothesis, algorithm-based score conversion affects automated essay scoring and human rater methods, which led to antithesis feedback. The validity and reliability of the measurement maintain the scoring consistency between the two methods and the accuracy of the answers. The novelty of this article is comparing between AES system and Human Rater using statistical methods. The research shows that there is a similar result using the psychometrics approach, which indicates different metaphor expressions and language systems. Thus, the objective of this study is to provide assistance in the advancement of an information technology system that utilizes a scoring mechanism merging computer and human evaluations, employing a psychological approach known as psychometric leads.

Comparison of Loading-Displacement Relationships and Energy-Storing Properties of the Jaipur Foot Against Low-, Mid-, and High-Activity Prosthetic Feet Using Static Proof Testing

ABSTRACT Introduction The Jaipur foot is a low-cost prosthetic foot developed in Jaipur, India. Despite its worldwide use, few data are available on its mechanical properties. In general, there is a lack of objective data on the mechanical performance of prosthetic feet, hindering the objectivity of the prosthetic foot prescription process. The aim of this project was to compare the properties of the Jaipur foot with three prosthetic feet of differing activity levels (a SACH foot and two ESPFs) used commonly in the UK National Health Service (NHS), specifically evaluating loading-displacement relationships and energy-storing properties. Materials and Methods Static proof testing was performed on the four prosthetic feet (BMVSS Jaipur foot, 1D10 Dynamic, 1C30 Trias, and 1C60 Triton) using ISO:10328 methods. Loading-displacement graphs for the forefoot and heel were produced, from which instantaneous stiffness at forces typical of walking and running was produced and energy-storing properties were calculated. Results The Jaipur foot demonstrated the highest heel stiffness at both walking and running forces, the highest forefoot stiffness at walking forces, and the lowest energy return of the four feet overall. The ESPFs demonstrated the lowest forefoot stiffness, along with the highest energy returns. Conclusions Although low cost and cultural requirements should be taken into account, these data have demonstrated the inferior energy-storing properties of the Jaipur foot compared with Western prosthetic feet, using ISO methods to allow future cross-study comparison. Clinical Relevance The mechanical and energy-storing data from this study can be compared with other research using ISO methods to make the prosthetic prescription process more objective, allowing the most appropriate choices to be made for patients.

Penalaran Siswa SMA dalam Pembuktian Matematika pada Materi Trigonometri Ditinjau dari Kemampuan Matematika

Reasoning in mathematical proof is a thinking process to draw conclusions based on logical ideas by rebuilding previous knowledge and connecting it with current knowledge in order to demonstrate the truth of a mathematical statement supported by logical arguments. To be able to know students' reasoning in mathematical proving is associated with problem solving because problem solving and reasoning have a close relationship. Differences in students' mathematical abilities allow for differences related to reasoning in mathematical proof. The purpose of this study is to describe the reasoning of high school students with high, medium and low mathematical abilities in proving mathematics on trigonometry material.
 This study used a qualitative approach with a descriptive research type. The research subjects consisted of 3 students from class X, namely students with high, medium and low mathematical abilities. The research data were obtained from the results of mathematical ability tests, mathematical proving tests, and interviews. Mathematical ability tests were used for the selection of research subjects, mathematical proof tests were used to find out how students reasoned in proving mathematics on trigonometry material and interviews were conducted to find out more clearly about the explanation of the reasoning process written by the subjects on the mathematical proof test.
 The results showed that the three students understood the problem by identifying information that was known and that was not known to students with high mathematical ability and logical reasons, but students with moderate and low mathematical ability, there were statements that were not accompanied by logical reasons. In planning the completion, students with high mathematical ability are accompanied by logical reasons but students with moderate and low mathematical ability have statements that are not accompanied by logical reasons. In carrying out the completion plan students with high mathematical ability can solve problems according to plan accompanied by logical reasons, for students with moderate mathematical ability can solve problems according to plan, even though there are statements that are not accompanied by logical reasons, but students with low mathematical ability they cannot solve problems and did not succeed in carrying out according to the plan because they were confused about proceeding with problem solving. In re-examining the process and results, students with high ability get conclusions from their completion and examine the process from the start, starting from reading the problem, planning, implementing plans and conclusions with logical reasons, for students with moderate mathematical ability getting conclusions from their completion and checking their calculations with logical reasons. However, students with low mathematical ability did not get a conclusion from the solution because they could not solve the problem and did not re-examine the process.

Students' mathematical argumentation ability when proving mathematical statements based on self-efficacy

Argumentation as an aspect of problem-solving has been studied in mathematics education. However, mathematical proof still needs to be resolved further. This study investigates students' mathematical argumentation skills when proving mathematical statements based on their self-efficacy. The research subjects were 43 mathematics education students at a university in Aceh Province who had taken a number theory course. The study used a qualitative approach with a case study design: students’ mathematical proving self-efficacy. Data was obtained using self-efficacy questionnaires and mathematical proof test instruments that experts have validated, while the data triangulation used was an in-depth interview. The results of this study reveal that students' mathematical argumentation skills in proving mathematical statements have differences based on their self-efficacy. The mathematical argumentation ability of students with high self-efficacy involves all aspects of argumentation well so that the construction of the proof is scientifically correct. Meanwhile, the argumentation ability of students with moderate or low self-efficacy still does not involve essential aspects of argumentation. So, the proof results are not scientifically correct because they have not arrived at the proper conclusion.