Miracle-dz/UniFAR-FTUs huggingface dataset:
Analytical Solution for Moisture Diffusion with Initial Non-Uniform Moisture Concentration used in Bake Time Study in Electronics Packaging

Insufficient dry baking is a potential concern for both suppliers and users in semiconductor packaging. The purpose of the bake by suppliers is to remove most residual moisture prior to sealing the devices in dry bags and avoid device damage during subsequent board-level solder reflow. Dry baking by the user, however, is required whenever the recommended floor-life limits are exceeded at the user’s site. Excessive bake times are a manufacturing cycle time concern for both suppliers and users. IPC/JEDEC J-STD-033 provides the conditions for bake prior to dry pack for various moisture sensitivity levels and various configurations of packages. The recommended bake time was based on a one-dimensional moisture diffusion analysis. However, the equation used in the calculations of the bake time tables was not given. In this paper, we derived the analytical solution for one-dimensional moisture diffusion with non-uniform initial moisture concentration. We applied this equation in various scenarios and provided the numerical results for both bake times in both bake time tables for suppliers and users, respectively. It was shown that for most of the package thickness, the moisture absorption is often far from saturated after typical accelerated moisture-soak conditions defined in IPC/JEDEC J-STD-020. As a result, the moisture diffusion state is not in equilibrium. Consequently, baking will initially force moisture to diffuse inwards toward critical interfaces before the total gradient can begin to decrease. This means that the moisture-sensitive package may be potentially at risk if baking time is too short, even if the overall moisture weight loss appears significant. In this paper, a detailed parametric study will be conducted for a multi-step analysis, including moisture diffusion during absorption and desorption during oven baking.
A Millimeter-Wave Circularly Polarized Antenna

A millimeter-wave circularly polarized (CP) magnetoelectric dipole (ME-dipole) antenna is presented in this paper. The antenna consists of a pair of metal dipoles, and a metal cavity, a feeding SIW. The simulated 10-dB impedance bandwidth is 4.7% (37.3.2-39.1 GHz) and the 3-dB AR bandwidth is 7.2% (36.1-38.9 GHz). The simulated peak gain is 8.53 dBic at 39 GHz.
Some Practical Deductions From the Theory of Lubrication of Short Cylindrical Bearings

In this paper the author tells of desirable characteristics which a fluid lubricant should have, and explains the effects of viscosity. He develops a theory with many mathematical equations on the phenomena of longitudinal flow of lubricants in bearings. Conclusions are given regarding general design and operation of bearings, the load carrying capacity, the power loss, and the ultimate rise in temperature of a bearing operating continuously with a particular eccentricity ratio.
Sex Differences in Patterns of Childhood Traumatic Experiences in Chinese Rural-To-Urban Migrant Children

Background: Children and adolescents are likely to be exposed to various types of childhood traumatic experiences (CTEs) with gender-specific patterns. Rural-to-urban migrant children have been demonstrated a greater risk of CTE exposure than local children. However, no study has investigated sex differences in the patterns of CTEs and predictive factors among Chinese children. Methods: A large-scale questionnaire survey of rural-to-urban migrant children (N = 16,140) was conducted among primary and junior high schools in Beijing. Childhood trauma history, including interpersonal violence, vicarious trauma, accidents and injuries was measured. Demographic variables and social support were also examined. Latent class analysis (LCA) was utilized to examine patterns of childhood trauma, and logistic regression was used to examine predictors. Results: Four classes of CTEs were found among both boys and girls, labeled low trauma exposure, vicarious trauma exposure, domestic violence exposure, and multiple trauma exposure. The possibility of various CTEs in the four CTE patterns was higher among boys than girls. Sex differences also manifested in predictors of childhood trauma patterns. Conclusions: Our findings shed light on sex differences in CTE patterns and predictive factors in Chinese rural-to-urban migrant children, suggesting that trauma history should be considered along with sex, and sex-specific prevention and treatment programs should be developed.
Incremental clustering and expansion for faster optimal planning in decentralized POMDPs

This article presents the state-of-the-art in optimal solution methods for decentralized partially observable Markov decision processes (Dec-POMDPs), which are general models for collaborative multiagent planning under uncertainty. Building off the generalized multiagent A* (GMAA*) algorithm, which reduces the problem to a tree of one-shot collaborative Bayesian games (CBGs), we describe several advances that greatly expand the range of Dec-POMDPs that can be solved optimally. First, we introduce lossless incremental clustering of the CBGs solved by GMAA*, which achieves exponential speedups without sacrificing optimality. Second, we introduce incremental expansion of nodes in the GMAA* search tree, which avoids the need to expand all children, the number of which is in the worst case doubly exponential in the node's depth. This is particularly beneficial when little clustering is possible. In addition, we introduce new hybrid heuristic representations that are more compact and thereby enable the solution of larger Dec-POMDPs. We provide theoretical guarantees that, when a suitable heuristic is used, both incremental clustering and incremental expansion yield algorithms that are both complete and search equivalent. Finally, we present extensive empirical results demonstrating that GMAA*-ICE, an algorithm that synthesizes these advances, can optimally solve Dec-POMDPs of unprecedented size.
Remineralization of Dentinal Lesions Using Biomimetic Agents: A Systematic Review and Meta-Analysis

The objective of this article was to systematically provide an up-to-date review on the different methods of remineralizing human dentine using different biomimetic agents. The authors performed a systematic search within PubMed, Scopus, and Web of Science in addition to the grey literature in Google Scholar® using MeSH terms. The PICO question was P: human teeth dentinal sections; I: application of biomimetic remineralizing agents; C: other non-biomimetic approaches; O: extent of remineralization and physical properties of remineralized dentine. The initially identified studies were screened for titles and abstracts. Non-English articles, reviews, animal studies, studies involving the resin–dentine interface, and other irrelevant articles were then excluded. The other remaining full-text articles were retrieved. Bibliographies of the remaining articles were searched for relevant studies that could be included. A total of 4741 articles were found, and finally, 39 full-text articles were incorporated in the current systematic review. From these, twenty-six research studies used non-collagenous protein (NCP) analogs to biomineralize dentine, six studies used bioactive materials derived from natural sources, six studies used zinc hydroxyapatite, and one study used amelogenin peptide to induce hydroxyapatite formation on the surface of demineralized dentine. Additive effects of triclosan and epigenin were assessed when combined with commonly available NCPs. Overall, a moderate risk of bias was observed and, hence, the findings of the included studies could be acceptable. A meta-analysis of some similar studies was performed to assess the depth of remineralization and elastic modulus. Despite having high heterogeneity (I2 > 90), all the studies showed a significant improvement in biomimetic remineralization efficacy as compared to the control. All the included studies carried out a functional remineralization assessment and found a 90–98% efficacy in the extent of remineralization while the elastic modulus reached 88.78 ± 8.35 GPa, which is close to natural dentine. It is pertinent to note the limitations of these studies that have been carried out in vitro under controlled settings, which lack the effects of a natural oral environment. To conclude, the authors suggest that the biomimetic remineralization of dentine using NCP analogs, bioactive materials, and natural products carries significant potential in treating dentinal lesions; however, more long-term studies are needed to assess their clinical applications in vivo.
Longitudinal Shrinkage of Wood

Longitudinal shrinkage of wood ordinarily is so small as to be considered negligible, and no allowance is made for it for most uses. There are uses, however, for which even the small longitudinal shrinkage of normal wood is an important factor, and others in which the shrinkage along the grain of abnormal wood is so large as to be a serious handicap. This paper gives information on the shrinkage of wood along the grain about which very little has been published.
Sensing-Aware Machine Learning Framework for Extended Lifetime of IoT Sensors

Bluetooth Low Energy (BLE) beacon network is one of the essential infrastructures for many IoT and smart city applications that involve a plethora of sensing tasks. However, the BLE beacon network usually suffers from poor reliability and high maintenance costs due to the short-lived battery lifetime. Multiple works have attempted to extend the lifetime via energy harvesting hardware, adaptive advertising interval by user existence-aware operation, and energy-efficient routing schemes. However, few attempts were made to reduce the energy consumption related to sensing tasks. In light of this shortcoming, a sensor information-aware framework is proposed to adjust the sensing task interval adaptively based on the predicted portion of changes of the sensor measurements. Furthermore, to estimate the impact of varying sensing task intervals on the amount of sensed information, a model that correlates energy and amount of information is proposed. The sensor portion of changes is predicted with a novel neural network, coined oracle-interpreter network, that significantly reduces the energy consumption while upkeeping a good prediction accuracy by leveraging two independent neural networks tailored for feature extraction and prediction tasks. The effectiveness of the proposed framework is verified by comprehensive simulations based on real-life data. The results demonstrate that the proposed framework can effectively reduce the energy consumption involved in sensing tasks up to 30%, machine learning tasks up to 60%, and finally, extend the lifetime up to 75%.
SAR Image De-nosing Based on Wavelet Packet Transform and Adaptive Threshold

Aimed at the problem that the SAR remote sensing pictures are interfered by noises during the detection and transmission,a method based on wavelet packet and level dependent adaptive threshold is proposed in this paper. By using this method, the SAR pictures can be decomposed in a more elaborate method compared to the traditional wavelet transform,and then,the noises in the SAR pictures are elimina-ted by the adaptive threshold method. The experiment results show that this method can eliminate the noi-ses in the SAR pictures efficiently; The PSNR and the subjective vision of the results have better perform-ances than the result of wavelet transform method.
Reducing Delay for Delay-Sensitive Applications in Smart Home Networks Using Openflow Protocol

Smart home networks are one of the important applications of the Internet of Things, and the importance of quality of service (QoS) in such networks is increasing day by day. Many studies have focused on distributing traffic fairly between several paths to improve throughput in the network, but in smart home networks, there are some applications that require a small delay such as VOIP and live broadcasting. The advent of software-defined networking through the OpenFlow protocol has made multipath routing simpler through routing frameworks that are programmable to the desire of the network operator and to the network conditions. In this paper we present a new method for redirecting traffic considering delay-sensitive data, where we distribute the traffic among several paths depending on the balance between bandwidth and delay link. Our results show that when route delay increases significantly, the bulk of traffic is transmitted through the route with the least delay, which in turn reduces delay and improves QoS for these applications.
Second Language Learning Through an Emergent Narrative in a Narrative-Rich Customizable Metaverse Platform

EFL students often struggle with second language (L2) learning, particularly because they learn L2 out of context, which they find unmeaningful and demotivating. To provide a meaningful context for L2 learning and make learning more interesting, the present study utilized a customizable metaverse platform. First, we developed a scenario of a rose theft, and then based on that, we created a town in the metaverse, which offered a variety of multimodal language input and missions to solve the problem and identify the thief. The entire activity was developed grounded in constructivist language learning principles (e.g., contextualized, motivating, interactive, and task-based learning), thus, learners could explore, play, and learn in the playful constructivist space. In total, 72 Korean EFL students participated in the activity. The study employed a mixed method for more robust research. Quantitative data (the pre- and posttests and the postsurvey) indicated that the students had a great interest in the activity and the learning outcome increased. Qualitative data (the students’ journals, the interviews with the teachers, and the screen recordings) further evidenced the students’ enjoyment of the activity. Particularly, the screen recordings showed how the students participated in the activity in the metaverse, collaboratively created an emergent narrative through interaction, and produced their own narrative to reach the answer. The study suggested pedagogical implications for using the metaverse for L2 learning based on the results of the study.
SolvationAnalysis: A Python toolkit for understanding liquid solvation structure in classical molecular dynamics simulations

1 Materials Science Division, Lawrence Berkeley National Laboratory, United States of America 2 Australian National University, Australia 3 Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, China 4 Energy Storage & Distributed Resources Division, Lawrence Berkeley National Laboratory, United States of America 5 Department of Materials Science, University of California, United States of America 6 Molecular Foundry, Lawrence Berkeley National Laboratory, United States of America DOI: 10.21105/joss.05183
Judging similarity versus judging difference

A key feature of the polytomous Rasch model is that it entails a single classification process into one of a set of ordered response categories. The first aim of this article is to make explicit two processes in rubric designs that bring about such classifications, and identify implications of the distinction between them. The first process involves judgements of similarity, typified by judgements that a performance is similar to a category description. The second process involves judgements of difference. It is typified by judgements that a performance is better than a category description. In this article, each process is explicated using a hypothetical context in which assessors compare performances with exemplars. The second aim is to demonstrate that, for reporting purposes, judgements of similarity are recommended, particularly when results are interpreted by persons with limited knowledge of the Rasch model and its parameters. In judgements of similarity, category descriptions are located at the peak of each category probability curve, at the point of highest probability in each the category, with thresholds located between them. This is easier to interpret than judgements of difference, where category descriptions are located at the thresholds, and where the point of highest probability has no material reference. This is explicated using a simple real-world example. Implications for rubric design are discussed, as well as implications for related types of instruments, such as attitudinal measures and pairwise comparisons.
Algorithm for Low Thrust Optimal Interplanetary Transfers with Escape and Capture Phases

The paper addresses the problem of optimizing an interplanetary transfer considering the Sun and planets gravity elds. We study the escape and capture problem, with a general dynamical formulation. This problem is a benchmark for a generalized method solving N-body problems, which could consider intermediate swing-bys without explicit constraints. The patched conic approximation is not used, and the trajectory is optimized in one piece. The problem is thus very sensitive due to the escape and capture spiraling phases. With an initial indirect formulation approach we eventually construct a modied gradient method. The method is able to tackle sensitive problems. The method is fully described and an algorithm is presented. Two examples are presented. The rst example deals with Earth to Mars escape and capture problems. The second example demonstrated the eciency of the method to deal with intermediate swing-by optimization.
Design and Analysis of Control Strategies for a Stand-Alone VSI with LC Output Filter

The primary constraint limiting the possible band-width of current regulators in digital systems is pulse width modulated (PWM) delays. Control system delays, in particular, have a negative impact on converter performance. This paper proposes effective designs of the proportional integral derivative and proportional resonant controllers for the two-level voltage source inverter (2L-VSI) in association with the LC filter. Both strategies include a design process for the voltage and current loops that considers the closed-loop transfer functions. The cross-over criterion is used to develop both control strategies while taking the needs of the application into consideration. The theoretical analysis is verified by simulation tests that are carried out in compliance with UPS standards.
Evolutionary Hybrid Genetic-Firefly Algorithm for Global Optimization

The paper presents the Evolutionary Hybrid Genetic-Firefly algorithm for the optimization of complex problems and to search global solution more precisely. In this algorithm the idealized rules of the firefly algorithm i.e. swarm behaviour is combined together with the evolutionary strategy, i.e. the survival of the fitness strategy of the genetic algorithm to evolve a Hybrid algorithm. In the hybrid evolution the genetic algorithm searches the solution space for global minimum and the Firefly algorithm improves the precession of the potential candidate solution. The proposed strategy was implemented on various benchmarking test functions to evaluate the general performances of the individual algorithms and Hybrid Genetic-Firefly algorithm in terms of rate of convergence, precession and robustness to find the global best solution. The simulation results clearly illustrate that the proposed strategy is very effective in finding the global solution precisely
Symmetry Reduction and Solution to the Three-Dimensional Incompressible Navier-Stokes Equations

Lie symmetry methods,which are proposed to study the invariant solutions of differential equations under specify conditions and symmetry reductions,simplify the process of solving the differential equations.Stokes-Helmholtz decomposition theorem was first applied to transform Navier-Stokes equation into a scalar partial differential equation;then,Lie symmetry method was employed to obtain the symmetry groups of the scalar partial differential equation.An analytic solution and its similarity solutions were also proposed.
An Anatomy of Monopsony: Search Frictions, Amenities and Bargaining in Concentrated Markets

We contribute a theory in which three channels interact to determine the degree of monopsony power and therefore the markdown of a worker’s spot wage relative to her marginal product: (1) heterogeneity in worker-firm-specific preferences (non-wage amenities), (2) firm granularity, and (3) offand on-the-job search frictions. We use Norwegian data to discipline each channel and then reproduce new reduced-form empirical relationships between market concentration, job flows, wages and wage inequality. In doing so we provide a novel method for clustering occupations into local labor markets. Our main exercise quantifies the contribution of each channel to income inequality and wage markdowns. The average markdown is 21 percent in our baseline estimation. Removing nonwage amenity dispersion narrows them by a third. Giving the next-lowest-ranked competitor a seat at the bargaining table narrows them by half, suggesting that granularity and strategic interactions in the bargaining process is an important source of markdowns. Removing search frictions narrows them by two-thirds. Each counterfactual reduces wage inequality and increases welfare. JEL codes: E2, J2, J42
The fractional order PI control for an energy saving electro-hydraulic system

In an electro-hydraulic system (EHS), the throttling phenomenon of the hydraulic valve leads to the problem of low utilization efficiency of hydraulic energy and severe increases in temperature. To alleviate this problem, this paper presents a type of one-chamber-controlled hydraulic circuit. In some applications where elastic load is dominant, this hydraulic circuit can achieve a significant energy-saving effect. For a valve-controlled system, the orifice non-linearity and the slowly varying parameter significantly influence the control performance of the electro-hydraulic system. With this aim in mind, the orifice compensation method is proposed to deal with the orifice non-linearity. Based on the compensation, the fractional order proportional–integral (FOPI) controller is adopted to deal with the problem of fluid parameter variation. In the controller designing process, this paper proposes a controller parameter tuning method based on system frequency characteristic data. Simulation and experiment results show that the strategy presented in this paper can reduce the energy losses dramatically and, at the same time, the control performance of electro-hydraulic system can be guaranteed.