137 research outputs found
Evaluation on Property and Reliability of Micro-bump Joint between Si Chip and Flexible Substrate
No full textA Duration Prediction Using a Material-Based Progress Management Methodology for Construction Operation Plans
No full textPrecise and accurate prediction models for duration and cost enable contractors to improve their decision making for effective resource management in terms of sustainability in construction. Previous studies have been limited to cost-based estimations, but this study focuses on a material-based progress management method. Cost-based estimations typically used in construction, such as the earned value method, rely on comparing the planned budget with the actual cost. However, accurately planning budgets requires analysis of many factors, such as the financial status of the sectors involved. Furthermore, there is a higher possibility of changes in the budget than in the total amount of material used during construction, which is deduced from the quantity take-off from drawings and specifications. Accordingly, this study proposes a material-based progress management methodology, which was developed using different predictive analysis models (regression, neural network, and auto-regressive moving average) as well as datasets on material and labor, which can be extracted from daily work reports from contractors. A case study on actual datasets was conducted, and the results show that the proposed methodology can be efficiently used for progress management in construction
Fluorinated Epoxy Hybrid Material for Transparent Low-k Passivation Layer on Oxide Thin Film Transistors
No full textScalable, Highly Pure, and Diameter‐Sorted Boron Nitride Nanotube by Aqueous Polymer Two‐Phase Extraction
No full textBoron nitride nanotube (BNNT) has attracted recent attention owing to its exceptional material properties; yet, practical implementation in real-life applications has been elusive, mainly due to the purity issues associated with its large-scale synthesis. Although different purification methods have been discussed so far, there lacks a scalable solution method in the community. In this work, a simple, high-throughput, and scalable purification of BNNT is reported via modification of an established sorting technique, aqueous polymer two-phase extraction. A complete partition mapping of the boron nitride species is established, which enables the segregation of the highly pure BNNT with a major impurity removal efficiency of > 98%. A successful scaling up of the process is illustrated and provides solid evidence of its diameter sorting behavior. Last, towards its macroscopic assemblies, a liquid crystal of the purified BNNT is demonstrated. The effort toward large-scale solution purification of BNNT is believed to contribute significantly to the macroscopic realization of its exceptional properties in the near future.
A Realistic Decision Making for Task Allocation in Heterogeneous Multi-agent Systems
No full textAbstractTask allocation is one of the keys to maximize organizational benefits by handling as many tasks as possible. Many computational multi-agent systems use agent's capability for task allocation. When a task arrives at the queue to be delivered a task allocator will determine which takes the task by finding the best-capable agent. In real world situation, each agent should not only consider the new task with their capability, but also tasks that they are currently handling before sending their capability to the task allocator. This research study proposes a CPU-scheduling based algorithm to allow agents to perform rational decision making when they think that they can handle the new task while taking care of its current tasks. The result shows that applying algorithm provide a significant improvement of their performance
Curvature-based interface restoration algorithm using phase-field equations
No full textIn this study, we propose a restoration algorithm for distorted objects using a curvaturedriven flow. First, we capture the convex-hull shaped contour of the distorted object using the mean curvature flow. With the supplemented mass on the captured feature, we evolve the constraint mean curvature flow to a steady state, preserving the non-distorted region. With respect to the mass, we select a restorative shape by considering the square of the curvature derivative. The Allen-Cahn and Cahn-Hilliard equations are applied to the generated restored image from the implicit curvature motions represented by the order parameter. We impose the Dirichlet boundary condition for the order parameter and the Neumann boundary for the chemical potential to fix the feature and to inherit the mass conservation, respectively. We provided examples of the restoration of half-circle and parentheses-shaped objects to reconstruct a circle shape. © 2023 Lee, Choi. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.11Nsciescopu
Reasons for Turnover Intention among Direct Care Workers in Korea’s Long-Term Care Insurance
No full textThis study explored reasons for turnover intention among direct care workers under the Korean long-term care insurance (LTCI) system. The author conducted semi-structured interviews with 19 care workers. The study revealed four main themes underlying the intention of care workers to change or leave their jobs. Care workers struggled with demanding working conditions, and their salaries were low. Moreover, the relationships with their directors and supervisors was not good, since some care workers felt that their directors despised them or gave them inappropriate instructions, and their supervisors did not complete administrative work fairly. Lastly, some workers’ health conditions prevented them from carrying out their care work. The results have implications for working practices of care workers, prices of LTCI services, training of directors and supervisors, and coverage of occupational health and safety insurance for care workers
Fleet management for earthmoving operation in the phase of detail estimation using mixed integer nonlinear programming
No full textEarthmoving operations generally account for about a quarter of the construction budget in high-way constructions. Feasible planning is thus required for delivering the successful performance of such projects. Selecting the best fleet for the operation is one of the crucial factors affecting both duration and cost. However, owing to changing operating circumstances and the uncertainty of construction projects, this task is yet conducted based on the experience of site managers. The existing literature has witnessed that discrete event simulation (DES) and references such as the construction standard production rate (CSPR) are used to assist the decision-making. Those methods have shown limitations for practical application due to the need for expert knowledge of simulation modeling and time-consuming efforts for data collection. Accordingly, this study proposes a more efficient method of using mixed integer nonlinear programming (MINLP) in multi-objective problems, enabling optimal fleet information derivation based on given circumstances. The proposed method uses the CSPR-based mathematical equations for the consideration of productivity generated by the types and sizes of equipment. A comparative study of the proposed method and a DES approach was given for further discussions
Formal Security Reassessment of the 5G-AKA-FS Protocol: Methodological Corrections and Augmented Verification Techniques
No full textThe 5G-AKA protocol, a foundational component for 5G network authentication, has been found vulnerable to various security threats, including linkability attacks that compromise user privacy. To address these vulnerabilities, we previously proposed the 5G-AKA-Forward Secrecy (5G-AKA-FS) protocol, which introduces an ephemeral key pair within the home network (HN) to support forward secrecy and prevent linkability attacks. However, a re-evaluation uncovered minor errors in the initial BAN-logic verification and highlighted the need for more rigorous security validation using formal methods. In this paper, we correct the BAN-logic verification and advance the formal security analysis by applying an extended SVO logic, which was adopted as it provides a higher level of verification compared to BAN logic, incorporating a new axiom specifically for forward secrecy. Additionally, we enhance the ProVerif analysis by employing a stronger adversarial model. These refinements in formal verification validate the security and reliability of 5G-AKA-FS, ensuring its resilience against advanced attacks. Our findings offer a comprehensive reference for future security protocol verification in 5G network
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