Design Flaws Research Articles

Analysis of risk indicators for implant failure in patients with chronic periodontitis

Dental implant restoration shows an effective method for the rehabilitation of missing teeth. The failure rate of periodontal implants in patients with chronic periodontitis is associated with periodontal flora, inflammation, and long-term periodontal bone resorption caused by chronic periodontitis. However, the therapeutic effects of dental implant restoration on inflammation in patients with chronic periodontitis have not addressed. The purpose of this study is to evaluate the risk indicators for inflammation, bone loss and implant failure in patients with chronic periodontitis. A total of 284 patients with dental implant restoration were recruited and divided into periodontally healthy patients (n = 128) and chronic periodontitis patients (n = 156). Periodontal indices including probing depth (PD), sulcus bleeding index (SBI), plaque index (PLI), gingival bleeding (GIL) and bleeding on probing (BOP) were compared in two groups. Inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) levels at baseline, 6 and 12 months after surgery, and the implant survival rate at 12 months after surgery, as well as the risk factors associated with failure of dental implant were also assessed. Outcomes demonstrated that patients in the chronic periodontitis group had higher values of periodontal indices than those in the periodontally healthy group. All inflammatory parameters in the chronic periodontitis group were higher than those in the periodontally healthy group and negatively associated with the chronic periodontal index (CPI) in chronic periodontitis patients. Chronic periodontitis patients had higher the prevalence of mucositis and peri-implantitis than patients with healthy periodontium. Implant diameter, length and design was associated with the risk of implant failure for chronic periodontitis patients receiving dental implant. The cumulative implant failure rate and incidence of implant fractures for chronic periodontitis patients at 12 months after surgery were 12.10% and 7.23% (p < 0.05), respectively, while were lower in the heathy periodontitis patients. Location, diameter, implant design, immediate loading and bone defect were risk indicators for bone loss for dental implant patients. The risk factors associated with failure of dental implant was higher in chronic periodontitis patients than patients in the periodontally healthy group (14.25% vs. 4.92%, p < 0.05). In conclusion, data in the current study indicate that inflammation is a risk indicator bone loss, implant fracture and implant failure in patients with chronic periodontitis.

Another Evidence to not Employ Customized Masked Hardware

As a well-studied countermeasure against side-channel analysis attacks, there is a general interest in applying masking to different cryptographic functions executed on different platforms. On the one hand, despite their high performance, masked hardware implementations are dedicated to specific algorithms, making them inflexible. On the other hand, applying masking on software involves serious challenges including significant overhead in terms of efficiency and difficulties to maintain theoretical security guarantees in practice. As a result, a line of research has been devoted to enable masked operations in flexible platforms (i.e., microprocessors) by including some masked modules in their hardware, hence a combination of flexibility and performance. In such scenarios, RISC-V is a natural choice as hardware can be adjusted to the extended instruction set. One such attempt presented at CHES 2021 is known as SCARV, which extends the Instruction Set Architecture (ISA) of a RISC-V core with a rich number of first-order masked operations on both Boolean and arithmetic masked operands. In this work, we conduct a comprehensive analysis of SCARV. Instead of relying on empirical measurements to demonstrate security, we utilize tool-assisted evaluations. Through these evaluations, we identified a couple of design flaws that lead to leakage in the masked implementations hosted by the corresponding processor. These flaws are primarily due to the lack of composability of cascaded components. While heuristic and ad-hoc design principles can result in secure, small, and efficient designs, they lack formal security proofs, which may lead to security flaws, like those we report here. Consequently, this work serves as a motivation for using composable masked modules and tool-assisted evaluations when constructing complex circuits.

Evaluation of the biomechanics of Aramany class I obturators of different designs using numerical and experimental methods. Part II: Stress distribution

Evidence regarding stress evaluations of removable obturators with Aramany class I defects is lacking. Whether the stress distribution on Aramany class I prostheses can be improved by modifying the currently used designs is also unclear. The purpose of part II of this study was to evaluate the stress distribution in different designs of Aramany class I obturators using finite element analysis (FEA) and photoelastic stress analysis. Four finite element and 8 photoelastic models, including 2 acrylic resin base obturators retained with 2 Adams clasps, 2 linear, 2 tripodal, and 2 fully tripodal design obturators, were used in this study. The frameworks were fabricated on the casts obtained from a modified printed model. Vertical and oblique loads were applied on 2 points (anterior and posterior) of the models. The quantitative measurement was done by measuring the fringe orders and von Mises values to compare the influences of occlusal forces on the obturator components and their supporting structures. The qualitative evaluation was done by visual color mapping to identify the stress concentration. In the photoelastic analysis, the anterior abutments of the tripodal showed the highest stress, followed by the fully tripodal obturators, while, in FEA, the anterior abutments of the linear design received the most in both vertical and oblique load. The central incisor received the most stress in photoelastic (3 or more fringe orders) and FEA (687.3 and 150.1MPa for vertical and oblique loads, respectively), followed by the lateral incisors. Upon posterior loading, the base of the defect of the linear design demonstrated the most stress in photoelastic (3 or more fringes) and FEA (94.3 and 130.5MPa for vertical and oblique loads, respectively). The acrylic resin base obturator retained with Adams clasps demonstrated the lowest stress distribution in abutments and their supporting bone upon anterior and posterior loads. Upon vertical and oblique load application, the fully tripodal design was comparable with the tripodal in terms of stress distribution. Both designs were better than the linear in response to the same loading. The stress was concentrated at the anterior palatal part of the obturator, the base of the defect, and the junction of the metal and acrylic resin part of the prostheses upon anterior and posterior loading, respectively.

The Wear Behaviour of a New Eccentric Meshing Reducer with Small Teeth Difference

Eccentric meshing reducers are widely used in agriculture, industrial robots, and other fields due to their ability to achieve a high reduction ratio within a compact volume. However, the contact wear problem seriously affects the service performance of the eccentric meshing reducer, thereby limiting their range of applications. To effectively address this issue, this study involved a stress analysis of the contact pairs and a surface wear analysis of a new eccentric meshing reducer. The wear equation for the contact pairs was derived using Archard’s wear theory, incorporating geometric and material parameters from both the reducer gear contact pair and the spline contact pair. In parallel, a wear simulation was conducted by integrating the UMESHMOTION subprogram with ALE adaptive grids. Additionally, the effects of load amplitudes on contact pair stress and surface wear were systematically investigated. It is revealed that the contact pair stress of the reducer gear was higher than that of the spline contact pair. Furthermore, the internal spline exhibited the highest wear rate, followed by the output shaft gear, external spline, and input shaft gear, in that order. This work provides a comprehensive and in-depth understanding of the wear behaviors of general reducers with small teeth differences and offers valuable scientific references for design optimization, fault diagnosis, and maintenance strategy formulation.

Phased Array Ultrasonic Inspection of Composite Fuselage Panel

Abstract The composite fuselage panel is a crucial component in large civil aircraft, necessitating higher detection rates and efficiency. Phased array ultrasonic testing can enhance the efficiency and defect detection rate; however, it is essential to consider the structural characteristics of the fuselage to ensure reliable identification of design defects. Based on the material properties, structural features, and defect detection requirements of composite fuselage panels, a test block reflecting their characteristics was designed and fabricated with various prefabricated defects. Ultrasonic phased array method was employed for a series of testing parameter optimization experiments and defect detectability analysis. The detected flaws were quantitatively analyzed and compared with those obtained using conventional ultrasonic automatic scanning techniques to validate the effectiveness of the developed ultrasonic phased array method. The feasibility of utilizing phased array ultrasonics for nondestructive evaluation of wide-body airliner composite fuselage panels is confirmed.

Assessment of Web Security Vulnerabilities for Common Open Source Virtualization Software

Open-source hypervisors have emerged as an integral technology for virtualizing server resources in cloud and data center computing. Hypervisor security efficiency is determined by virtual machine isolation, which is a de facto adoption factor in the selection process, as well as its ability to respond to web attacks. This paper assesses the security performance of Proxmox VE and XenServer for type 1 hypervisors, and Kernel Virtual Machine and Oracle Virtual Box for type 2 hypervisors. Security analysis was conducted using common exposures extracted from vulnerability databases and mapped against the OWASP 2013 and 2017 projects. For clarity, experiments were carried out on a testbed with prebuilt virtual machines, each hosting one hypervisor installed as an attack target. Kali Linux was configured in one virtual machine to run recursive penetration testing for information gathering, vulnerability detection, penetration attempts, and exploitation of weak spots. The infrastructure was set in both homogeneous and heterogeneous execution environments, with a series of tests nested with each other. All four hypervisors are vulnerable to physical kernel isolation, as unprivileged users can gain root access and launch guest-to-guest and host-to-guest attacks. Among the two, guest-to-guest attacks were found to be more common than host-to-guest attacks, indicating that virtual machine isolation is weaker than the underlying host. Type 1 hypervisors have a lower rate of host-to-guest attacks than guest to-guest attacks, implying that XenServer and Proxmox VE provide better isolation than KVM and OVB due to the near-native speed, security, and efficiency of their virtual machines. All four hypervisors were found to be vulnerable to buffer overflow exploits and error-triggering sensitive information leaks, which were primarily caused by adopter default misconfigurations in the deployment process rather than software design flaws. This implies that greater efforts are required by open-source adopters when shifting from physical to virtual computing.

Innovative design to achieve a multi-band electromagnetic wave stealth.

Metamaterials have opened up a new field of electromagnetic wave stealth that can achieve cross-band electromagnetic wave stealth through high electromagnetic wave absorption and low infrared emission. However, traditional cross-band stealth metamaterials make covering the terahertz band challenging and have certain design flaws. This Letter introduces an innovative cross-band electromagnetic wave stealth metasurface design that can achieve cross-band stealth in the infrared, microwave, and THz bands. We use phase change materials and the gradient principle to achieve GHz and THz cross-band absorption. We also design surface height-covered low infrared emitting materials, which give them lower infrared emissivity. These functions give it enormous potential in military applications, and using phase change materials for cross-band absorption also provides new, to our knowledge, ideas for multifunctional stealth materials.

Investigating the impact of a window air conditioner with H-14 HEPA filter on lessening SARS-COV-2 aerosols

This research breaks new ground by proposing a unique solution to combat SARS-COV-2 aerosols: modifying a readily available window air conditioner’s indoor blower to accommodate a HEPA (high-efficiency particulate air) filter. While traditional public health measures like lockdowns and mask-wearing remain crucial, this study explores an innovative engineering approach to air purification within homes and offices. The widespread impact of COVID-19 across various sectors—agriculture, manufacturing, finance, and more—necessitates exploring diverse solutions. Current efforts to utilize HEPA filters in HVAC systems face limitations. These filters, while highly effective at capturing airborne particles, increasingly impede airflow and require substantial pressure, posing challenges for standard HVAC systems to maintain efficient operation. This study addresses this critical gap by proposing a targeted modification to a specific window air conditioner (AC) model (GJC07AF-K3RNB9D) to incorporate an H-14 HEPA filter. Utilizing cutting-edge design tool (CF-TURBO) and advanced simulation software (STARCCM +), the research will provide a new blower specifically optimized for this application. This virtual testing will meticulously evaluate the modified system’s performance, ensure optimal airflow, predict noise levels, and identify any potential design flaws before implementing the modification in a physical prototype. The success of this study could pave the way for the development of increasingly efficient and accessible HEPA-based air purification solutions for everyday use, particularly in areas with limited resources. Furthermore, this research can be a valuable foundation for future work aimed to increasingly improve indoor air quality (IAQ).

Zero-trust design and assurance patterns for cyber–physical systems

Security is paramount in all mission-critical domains, including the aerospace industry. Cyber-attacks are increasing both in number and sophistication. Zero-trust is an emerging initiative that has proven very effective for enterprise systems in the Information Technology domain; however, research is lacking on applicable zero-trust mechanisms and their assurance for cyber–physical systems (CPS). We have already identified various zero-trust mechanisms in our previous work. In this paper, we present our zero-trust architecture design patterns and provide a methodology for the assurance of these mechanisms. Towards this objective, we have identified an initial set of assurance patterns covering individual zero-trust components in a system design. Our design and assurance patterns are made available to system engineers in pattern libraries. Engineers can model system architectures and utilize one or more of these patterns to provide design assurance based on individual zero-trust security requirements to improve the overall system cyber-security. To demonstrate our approach, we apply our assurance patterns to an unmanned aerial vehicle surveillance application. We discuss how our framework leverages the use of these patterns to develop zero-trust-enabled systems with different security requirements. Furthermore, our assurance patterns enable engineers to identify any design flaws and correct them during the initial system design phase, thus saving development time, effort, and cost. As a result, the overall approach can be utilized to design system models with specific zero-trust security requirements to improve the security posture of a CPS.

Characterization of the Design and Performance of Commercialized Sodium-Ion Batteries

The escalating demand for energy storage solutions has spurred the commercialization of sodium-ion batteries (NIBs), prompting a paradigm shift from laboratory research to real-world applications. The success of commercial NIBs hinges on their ability to meet stringent performance metrics, ensuring competitiveness in the large-scale energy storage market. Manufacturing new cell chemistries is complex, and if the cells have design flaws and/or manufacturing defects it could hinder their performance and safety. We will present detailed findings of the NIB cell design, construction, and performance of commercialized 18650 format NIBs. The cell design and construction will be analyzed using 3D X-ray computed tomography and cell teardowns with materials analysis. In addition, the electrochemical performance of these cells will be investigated over a range of rates and temperatures. This study will provide insight into the quality and performance of some of the early to market commercialized NIBs and how it could affect their use in large scale energy storage.

Acupuncture for clinical improvement of endometriosis-related pain: a systematic review and meta-analysis

BackgroundEndometriosis is a common chronic gynecological condition characterized by the presence of endometrial tissue outside the uterine cavity, leading to chronic inflammation, pelvic nodules and masses, pelvic pain, and infertility. Acupuncture has been shown to improve pain associated with endometriosis by modulating abnormal levels of prostaglandins, β-endorphins, dynorphins, electrolytes, and substance P. This review aims to evaluate the clinical efficacy of acupuncture in treating endometriosis, specifically focusing on its efficacy in relieving pain associated with endometriosis.MethodsA comprehensive search was conducted in eight databases (PubMed, EMBASE, Cochrane, Web of Science, China National Knowledge Infrastructure (CNKI), the China Biology Medicine (CBM), Wanfang, and Weipu database) to identify randomized controlled trials (RCTs) published from database inception to December 16, 2022, which investigated the use of acupuncture for endometriosis-related pain. Two researchers independently screened articles, extracted data, and assessed methodological quality using the Cochrane Collaboration’s risk of bias tool. Meta-analysis was performed using Stata statistical software.ResultsA total of 1991 articles were identified, and ultimately, 14 studies involving 793 patients (387 in the acupuncture group and 359 in the control group) were included. The control interventions in the included studies included placebo, traditional Chinese medicine (TCM), and Western medicine treatments. Meta-analysis results showed that compared to the control group, acupuncture treatment for pain associated with endometriosis demonstrated significant reductions in pain severity [SMD = − 1.10, 95% CI (− 1.45, − 0.75), P < 0.001], improved response rate [RR = 1.25, 95% CI (1.09, 1.44), P = 0.02], and decreased serum CA-125 levels [SMD = − 0.62, 95% CI (− 1.15, − 0.08), P = 0.024]. Furthermore, subgroup analysis revealed that electroacupuncture and auricular acupuncture were superior to the control group in reducing pain severity, while auricular acupuncture and warm needling showed greater clinical efficacy compared to the control group. However, there were no significant differences between electroacupuncture or fire needling and the control group in terms of pain relief. The findings suggest that acupuncture is effective in improving pain associated with endometriosis.ConclusionsIn conclusion, acupuncture is effective in alleviating dysmenorrhea and pelvic pain associated with endometriosis, reducing serum CA-125 levels, decreasing the size of nodules, improving patients’ quality of life, and lowering the recurrence rate. However, it should be noted that the current evidence is limited by the design and quality flaws of the original studies, as well as a lack of research specifically focusing on subtypes of acupuncture. Therefore, caution should be exercised when interpreting the results.

A provably secure authenticated key agreement protocol for industrial sensor network system

SummaryThe convergence of reliable and self‐organizing characteristics of Wireless Sensor Networks (WSNs) and the IoT has increased the utilization of WSN in different scenarios such as healthcare, industrial units, battlefield monitoring and so forth, yet has also led to significant security risks in their deployment. So, several researchers are developing efficient authentication frameworks with various security and privacy characteristics for WSNs. Subsequently, we review and examine a recently proposed robust key management protocol for an industrial sensor network system. However, their work is incompetent to proffer expedient security and is susceptible to several security attacks. We demonstrate their vulnerabilities against man‐in‐the‐middle attacks, privileged insider attacks, secret key leakage attacks, user, gateway, and sensor node impersonation attacks, and offline password‐guessing attacks. We further highlight the design flaw of no session key agreement in Itoo et al. Therefore to alleviate the existing security issues, we devise an improved key agreement and mutual authentication framework. Our protocol outperforms Itoo et al.'s drawbacks, as demonstrated by the comprehensive security proof performed using the real‐or‐random (ROR) model and the formal verification accomplished using the Automated Validation of Internet Security Protocols (AVISPA) tool.

Human-centered design for flexible and inclusive housing

ABSTRACT Studies on collective housing rarely adopt a human-centered perspective. This study introduces a model for designing and analyzing residential buildings based on the user experience (UX) of apartments. The analysis focuses on two areas: a morphological review of the conditions of flexibility and adaptability of fundamental areas of households and a UX analysis with a functional evaluation of basic daily uses of the apartments, displayed through a graphic assessment during the project definition stage. Applied to residential projects in Barcelona, this analysis shows endemic defects in housing design, such as dimensional deficiencies, a lack of spatial versatility, and unforeseen functionalities, which pose a risk to gender hierarchies at home.

Preface

Abstract In the midst of the rapidly evolving landscape of technological advancements, the field of mechanical instrumentation and automation has emerged as a pivotal cornerstone in driving industrial progress and scientific exploration. It is with this recognition that we gathered once again for the 2024 5th International Conference on Mechanical Instrumentation and Automation (ICMIA 2024), a forum that aims to showcase the latest research achievements, foster collaborations, and pave the way for innovative solutions in this dynamic domain. The ICMIA 2024, held in Wuhan, China, from April 19th to 21st, 2024 via hybrid form, serves as a gathering place for experts, scholars, researchers, and practitioners from around the world. It provides a unique platform to share insights, discuss challenges, and explore opportunities in the field of mechanical instrumentation and automation. This conference serves not only as a showcase for the latest research but also as a catalyst for cross-disciplinary collaborations and knowledge exchange. The keynote speakers at ICMIA 2024 brought with them a wealth of experience and expertise. Their presentations, focusing on cutting-edge research and industry applications, provided valuable insights into the current state of the art and future directions of mechanical instrumentation and automation. Among them, Prof. Ning Sun (Nankai University, China) made a speech on Intelligent Control for Complex Underactuated Cranes with Applications. He first shared some of his team’s recent results on dynamics analysis, motion planning, and intelligent control of different crane systems, and then discussed some of their extended and related researches on robotic systems with similar dynamic characteristics. We are grateful to these esteemed speakers for sharing their knowledge and insights. The collected papers in this volume represent the culmination of rigorous research and innovative ideas presented at ICMIA 2024. These papers span a wide range of topics, including but not limited to Mechanical and Instrument Design, Instrument Science and Technology, Electronic Design Automation, Fault Diagnosis and Maintenance Theory, Automatic Detection and Instrumentation, Intelligent Instrument System, and their applications in various industrial sectors. The authors, representing a diverse array of backgrounds and institutions, have contributed their valuable research to this volume, reflecting the global reach and impact of the conference. The selection process for these papers was rigorous and thorough. All submitted papers were subjected to peer review by experts in the field, ensuring the highest standards of quality and relevance. The accepted papers were then carefully curated and compiled into this volume, providing a comprehensive overview of the latest advancements in mechanical instrumentation and automation. We are proud to present this collection of papers as a testament to the excellence and vibrancy of the research community in this field. We hope that this volume will serve as a valuable resource for researchers, practitioners, and students alike, inspiring new ideas, fostering collaborations, and propelling the field of mechanical instrumentation and automation forward. List of Committee Member is available in this Pdf.

Repairing of Reinforced Concrete T- section Beam with Web Opening Subjected to Torque by Using Ultra- High Performance concrete (UHPC)

Abstract Due to harsh weather factors, overloading, poor design, and material defects, reinforced concrete (RC) constructions’ early degradation has grown significantly over the last few decades. RC element repair is crucial to improving existing structures’ service life. Also, the transverse openings are frequently utilized in beams in modern structures to supply the service pipes. Because stresses are concentrated in a limited region above and below the opening, the presence of openings in concrete beams causes cracks to grow around the openings. Repairing, maintaining, and upgrading structural elements may be among the most important issues in civil engineering applications. This paper studies the effect of the presence of an opening and repairing of reinforced concrete T-section beam with web opening was subjected to torsion by using ultra-high performance concrete panels with a thickness of 20mm; The experimental work included casting seven beams: one beam without an opening and another beam with an opening, and five rest beams were repaired with UHPC panels in different locations. The results show the effect of an opening by decreasing the ultimate torque and increasing the ultimate angle of twist. The increase in ultimate torque for repairing beams compared to the control beam reached 153%, and a decrease in ultimate twist angle for repairing beams compared to the control beam reached 98%.

Crises in Texas and Australia: Failures of energy-only markets or unforeseen consequences of price caps?

The Australian National Electricity Market (NEM) and the Texas wholesale electricity market (ERCOT) are two of the most prominent examples of energy-only wholesale electricity markets in the world. In early 2021 and mid 2022 these markets suffered from unprecedented crises, prompting some commentators to question the energy-only market design. Both markets are now considering implementing a form of capacity mechanism. Are these crises evidence of a fundamental flaw in the energy-only market design, or something else? We argue that, although the crises were very different in form, both crises arose in part from the effect of price caps in the wholesale market. We set out a model of the optimal mix of generation technologies in a framework in which generators can invest to protect against extreme weather events. We show that a price cap (below VoLL) reduces incentives for investment in hardening generation. Rather than further lowering the price caps – as was done in Texas – we propose a range of reforms to strengthen and enhance the confidence in the wholesale market.

Green School Buildings and Environmental Holistic Elements Approach to Cope with Hot and Humid Climate Challenges – Bahrain Case Study

Public schools in Bahrain and in the Arabian Gulf Region are facing poor indoor and outdoor environments due to the prevailing problem of harsh hot humid weather most of the year. This leads to high consumption of energy, and other resources due to the nature function of the schools. This necessitates effective actions to fill the gap and address properly the climate issues, consumption of resources, and design challenges. Reviewing related literature indicated a lack of Arab region studies in this field, in contrast to Foreign Studies. This gap includes items such as knowledge, data collection, design flaws, performance, guidelines and others. The objectives of this article are to investigate, and identify factors, green elements and possible solutions contributing to sustaining green public-school buildings and the environment while saving national resources and meeting performance sustainable criteria for school buildings and students. Literature review and qualitative descriptive method are essential investigation methodologies. The goal of qualitative descriptive studies is a comprehensive summarization and categorical. Literature review was the main action in the process to start exploring prior research and published works on green school buildings. Collected data on research materials published by reliable professional institutions and research are reviewed, explored, identified, categorized, and summarized in outputs. These are discussed and analyzed to ensure their positive influence on schools’ buildings and address collective challenges. Findings can be summarized in the following outputs: Characteristics. Advantages. Guidelines and standards. Green Building Council’s influence. Performance and rating tools for schools and students. Statistics. Innovation and Case studies and Lessons learned. The first Bahrain green school case study will contribute to the exchange experience with others concerned. In conclusion, this article recommends greening school buildings and environment design through various sustainable elements that are included in the results to enhance school buildings, the environment and student performance.

Target Trial Emulation: A Call for More Widespread Use.

Causal inference methods intended for use with observational data have been widely available for decades, but barriers exist to their widespread adoption. These likely include lack of familiarity with several methodologic techniques often used in combination in these investigations such as inverse probability of treatment weighting and g-estimation, and the intensity of computational effort to employ these techniques. Even with these methods, critical design flaws undermine the ability to make valid causal inference in some studies. Identification of the need to explicitly pair study design elements with these causal inference methods led to development of a methodologic approach recently termed target trial emulation. This approach requires that investigators define a hypothetical randomized trial, emulate that hypothetical protocol in assembling the cohort and defining study elements and then conduct an analysis that attempts to mirror random treatment assignment. In the article by Heindel et al. (Am J Epidemiol. 2024;XXX(XX):XXXX-XXXX), the authors successfully emulate a target trial of systemic heparin during arteriovenous fistula creation on short-term endpoints by utilizing two existing randomized trials with key confounders available. Target trial emulation provides a framework to promote valid inference and generate high-quality contributions to the literature and its use should be expanded.

Study on the Bearing Capacity of the Polyethylene Pipe–Cured-In-Place Pipe Liner Composite Structure under External Pressure

Cured-in-place pipe (CIPP) technology is used to repair deformed municipal polyethylene (PE) pipes caused by design flaws, construction issues, or external loads. However, research on CIPP for PE pipes is limited, restricting its broader application. This research focuses on the mechanical response characteristics and failure modes of the composite PE pipe–CIPP liner structure under external loads. Using experimental setups involving comparative test groups with different diameters and wall thickness ratios (DR values, defined as the ratio of the pipe’s outer diameter to its wall thickness), this study evaluates the effects of the liner’s elastic modulus, the bonding effectiveness at the PE pipe–CIPP liner interface, and the initial ovality of the pipes on the load-bearing capacity. The experimental results reveal that CIPP liners substantially enhance the stiffness and load-bearing capacity of PE pipes, with improvements ranging from 200% to nearly 500% depending on the pipe’s DR value. A novel ring stiffness prediction model is also introduced and validated against the experimental data. This model provides a theoretical framework for understanding the complex interactions at the PE pipe–CIPP liner interface and aids in designing more resilient urban drainage systems.

MSCFS-RP: A Colored-Petri-Net-Based Analysis Model for Master–Slave Cloud File Systems with Replication Pipelining

As a typical information system, a cloud file system enables the storage, retrieval, and management of data on remote servers or server clusters. The reliable design of such systems is critical to ensure the security of data and availability of services. However, designing correct-by-construction systems is challenging due to the complexity of and concurrency inherent in cloud file systems. Further, existing works on cloud file system analysis often focus on specific systems or lack formal modeling and verification, leading to potential design flaws and security vulnerabilities. To address these issues, we propose MSCFS-RP, which is a formal analysis model based on colored Petri nets. Leveraging the strengths of colored Petri nets in representing diverse information types with colored tokens and defining explicit rules for concurrent interactions, our model captures the writing and reading processes of clients, meta servers, and clusters. With strong formalism and support for verification using CPN Tools, we rigorously evaluate key properties such as replication consistency under various scenarios. The results demonstrate that MSCFS-RP satisfies these properties, validating its effectiveness and trustworthiness in managing information within cloud storage systems.