Guaranteeing the \~O(AGM/OUT) Runtime for Uniform Sampling and OUT Size Estimation over Joins

We propose a new method for estimating the number of answers OUT of a small join query Q in a large database D, and for uniform sampling over joins. Our method is the first to satisfy all the following statements. - Support arbitrary Q, which can be either acyclic or cyclic, and contain binary and non-binary relations. - Guarantee an arbitrary small error with a high probability always in \~O(AGM/OUT) time, where AGM is the AGM bound OUT (an upper bound of OUT), and \~O hides the polylogarithmic factor of input size. We also explain previous join size estimators in a unified framework. All methods including ours rely on certain indexes on relations in D, which take linear time to build offline. Additionally, we extend our method using generalized hypertree decompositions (GHDs) to achieve a lower complexity than \~O(AGM/OUT) when OUT is small, and present optimization techniques for improving estimation efficiency and accuracy.Comment: 19 page

Transcriptional Profiling Shows Altered Expression of Wnt Pathway– and Lipid Metabolism–Related Genes as Well as Melanogenesis-Related Genes in Melasma

Melasma is a commonly acquired hyperpigmentary disorder of the face, but its pathogenesis is poorly understood and its treatment remains challenging. We conducted a comparative histological study on lesional and perilesional normal skin to clarify the histological nature of melasma. Significantly, higher amounts of melanin and of melanogenesis-associated proteins were observed in the epidermis of lesional skin, and the mRNA level of tyrosinase-related protein 1 was higher in lesional skin, indicating regulation at the mRNA level. However, melanocyte numbers were comparable between lesional and perilesional skin. A transcriptomic study was undertaken to identify genes involved in the pathology of melasma. A total of 279 genes were found to be differentially expressed in lesional and perilesional skin. As was expected, the mRNA levels of a number of known melanogenesis-associated genes, such as tyrosinase, were found to be elevated in lesional skin. Bioinformatics analysis revealed that the most lipid metabolism-associated genes were downregulated in lesional skin, and this finding was supported by an impaired barrier function in melasma. Interestingly, a subset of Wnt signaling modulators, including Wnt inhibitory factor 1, secreted frizzled-related protein 2, and Wnt5a, were also found to be upregulated in lesional skin. Immunohistochemistry confirmed the higher expression of these factors in melasma lesions

A Study on Facial Expression Change Detection Using Machine Learning Methods with Feature Selection Technique

Along with the fourth industrial revolution, research in the biomedical engineering field is being actively conducted. Among these research fields, the brain-computer interface (BCI) research, which studies the direct interaction between the brain and external devices, is in the spotlight. However, in the case of electroencephalograph (EEG) data measured through BCI, there are a huge number of features, which can lead to many difficulties in analysis because of complex relationships between features. For this reason, research on BCIs using EEG data is often insufficient. Therefore, in this study, we develop the methodology for selecting features for a specific type of BCI that predicts whether a person correctly detects facial expression changes or not by classifying EEG-based features. We also investigate whether specific EEG features affect expression change detection. Various feature selection methods were used to check the influence of each feature on expression change detection, and the best combination was selected using several machine learning classification techniques. As a best result of the classification accuracy, 71% of accuracy was obtained with XGBoost using 52 features. EEG topography was confirmed using the selected major features, showing that the detection of changes in facial expression largely engages brain activity in the frontal regions

Improving the Accuracy of Intersection Counts and Densities for Measuring Urban Street Network Compactness and Resilience

USDOT Grant 69A3551747109Caltrans 65A0674Intersection counts are ubiquitous in transportation planning practice and research. They are frequently normalized by area to calculate intersection density, the most common measure of compact street network design in planning practice. However, due to the nature of typical street network data (centerlines) and the typical tools used to count intersections (desktop geographic information systems [GIS]), traditional methods of counting intersections can significantly overcount them. This project addresses this long-standing problem of intersection count bias. First, it develops and distributes an algorithm to automatically and correctly calculate intersection counts and densities anywhere in the world, using a novel topological consolidation method. Second, it conducts a worldwide empirical assessment of traditional intersection counting methods\u2019 bias to quantify the importance of measurement bias and to validate our algorithm. Third, it assesses this bias\u2019s impact on resilience simulations\u2019 results and identifies the street network design characteristics that are most related to resilience. In transportation planning, innumerable downstream models and measures \u2014 from energy efficiency certification schemes to resilience simulations \u2014 rely on intersection counts as input data. A full accounting of input data bias and better methods to overcome misrepresentations of intersections are necessary for data-driven, evidence-based planning for sustainable transportation networks that support active and resilient travel

Rapid access to polycyclic N-heteroarenes from unactivated, simple azines via a base-promoted Minisci-type annulation

Conventional synthetic methods to yield polycyclic heteroarenes have largely relied on metal-mediated arylation reactions requiring pre-functionalised substrates. However, the functionalisation of unactivated azines has been restricted because of their intrinsic low reactivity. Herein, we report a transition-metal-free, radical relay pi-extension approach to produce N-doped polycyclic aromatic compounds directly from simple azines and cyclic iodonium salts. Mechanistic and electron paramagnetic resonance studies provide evidence for the in situ generation of organic electron donors, while chemical trapping and electrochemical experiments implicate an iodanyl radical intermediate serving as a formal biaryl radical equivalent. This intermediate, formed by one-electron reduction of the cyclic iodonium salt, acts as the key intermediate driving the Minisci-type arylation reaction. The synthetic utility of this radical-based annulative pi-extension method is highlighted by the preparation of an N-doped heptacyclic nanographene fragment through fourfold C-H arylation. The functionalisation of unactivated azines has been restricted because of their intrinsic low reactivity. Here the authors show a transition-metal-free, radical relay pi-extension approach to produce N-doped polycyclic aromatic compounds directly from simple azines and cyclic iodonium salts

Temporal Effects of Environmental Characteristics on Urban Air Temperature: The Influence of the Sky View Factor

This study examines the relationship between air temperature and urban environment indices, mainly focusing on sky view factor (SVF) in Seoul, Korea. We use air temperature data observed from 295 automatic weather stations (AWS) during the day and night in Seoul. We conduct a spatial regression analysis to capture the effect of spatial autocorrelation in our data and identify changes in the effects of SVF on air temperature, while conducting the regression model for each dataset according to the floor area ratio (FAR). The findings of our study indicate that SVF negatively affects air temperature during both day and night when other effects are controlled through spatial regression models. Moreover, we address the environmental indices associated with day-time and night-time air temperatures and identify the changing effects of SVF on air temperature according to the areal floor area ratio of the analysis datasets. This study contributes to the literature on the relationship between SVF and air temperature in high-density cities and suggests policy implications for improving urban thermal environments with regard to urban design and planning

Resilient by Design: Simulating Street Network Disruptions across Every Urban Area in the World

Street networks allow people and goods to move through cities, but they are vulnerable to disasters like floods, earthquakes, and terrorist attacks. Well-planned network design can make a city more resilient and robust to such disruptions, but we still know little about worldwide patterns of vulnerability, or worldwide empirical relationships between specific design characteristics and resilience. This study quantifies and measures the vulnerability of the street networks of every urban area in the world then models the relationships between vulnerability and street network design characteristics. To do so, we simulate over 2.4 billion trips across more than 8,000 urban areas in 178 countries, while also simulating network disruption events representing floods, earthquakes, and targeted attacks. We find that disrupting high-centrality nodes severely impacts network function. All else equal, networks with higher connectivity, fewer chokepoints, or less circuity are less vulnerable to disruption's impacts. This study thus contributes a new global understanding of network design and vulnerability to the literature. We argue that these design characteristics offer high leverage points for street network resilience and robustness that planners should emphasize when designing or retrofitting urban networks

Improvement of Radiant Heat Efficiency of the Radiant Tube Used for Continuous Annealing Line by Application of Additive Manufacturing Technology

This study presents the application of additive manufacturing (AM) technology to a W-type INCONEL radiant tube (RT) used to improve its radiant heat efficiency. Appropriate dimensions of honeycomb structure were determined from finite element (FE) analysis and the resulting increase in radiant heat was computed. The honeycomb patterns on the RT surfaces were printed using the directed energy deposition (DED) method. Radiant heat efficiency of a prototype RT with a honeycomb pattern printed was examined in a pilot furnace emulating the continuous annealing line (CAL). Finally, soundness of the prototype RT was tested on-site on the actual the CAL of No. 3 CGL in POSCO Gwangyang Steel Works. The results revealed that partial FE analysis, which predicts the amount of radiant heat by partially modeling the RT structure rather than modeling the entire RT structure, is suitable for overcoming the limitation of the computer memory capacity and calculating the design parameters of honeycomb patterns. The DED is suitable for printing honeycomb patterns on RT with large and curved surfaces. The average amount of gas consumed to maintain 780 °C and 880 °C for 1440 min was reduced by 10.42% and 12.31%, respectively. There were no cracks and no gas leaks on the RT surface in an annual inspection over three years

Examining culture-specific sport consumption in a host country: The roles of ethnic identity and acculturation

This study examined the moderating effects of acculturation on the relationships between ethnic identity, fan identification, and culture-specific sport consumption behaviours for ethnic minority individuals living in a host country (i.e., United States in this study). To achieve this purpose, two theoretical models were developed: (a) the Ethnic Player Sport Consumption Model and (b) the Native Sport Consumption Model. A total of 394 participants of Northeast Asian descent were recruited from four large cities in the United States. The empirical results supported two hypotheses out of the four. Specifically, the results indicated that ethnic identity significantly influenced culture-specific sport consumption behaviours through fan identification in both models. However, there were no significant moderating effects of acculturation in the theoretical relationships among ethnic identity, fan identification, or culture-specific sport consumption behaviours. Sport marketers can utilize the findings of this study to design culture-based marketing strategies in order to attract ethnic minority individuals to the sport marketplace