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Efficient differentially private kernel support vector classifier for multi-class classification
No full textIn this paper, we propose a multi-class classification method using kernel supports and a dynamical system under differential privacy. For small datasets, kernel methods, such as kernel support vector machines (SVMs), show good generalization performance with high-dimensional feature mapping. However, kernel SVMs have a fundamental weakness in achieving differential privacy because they construct decision functions based on a subset of the training data called support vectors. Furthermore, multi-class SVMs must decompose the training data into a binary class, which requires multiple accesses to the same training data. To address these limitations, we develop a two-phase classification algorithm based on support vector data description (SVDD). We first generate and prove a differentially private SVDD (DP-SVDD) by perturbing the sphere center in a high-dimensional feature space. Next, we partition the input space using a dynamical system and classify the partitioned regions using a noisy count. The proposed method results in robust, fast, and user-friendly multi-class classification, even on small-sized datasets, where differential privacy performs poorly
Autonomous vehicles and street design: Exploring the role of medians in enhancing pedestrian street crossing safety using a virtual reality experiment
No full textAs traffic lanes and on-street parking spots can potentially be downsized with the introduction of autonomous vehicles (AVs), the possibility of additional spare road space becoming available arises in future urban streets. While discussions on converting the leftover space into pedestrian-friendly alternatives exist, allocating that limited space to which alternative is foreseen to be another practical issue shared in both urban and transportation planning. However, evidence-based guidance on the issue provided from the actual verification on whether or to what extent the proposed alternatives may have an effect seems to be absent. Therefore, with an emphasis on pedestrian safety, this study focused on the "median strip" alternative as a first example and, through a VR simulation experiment aimed at empirically examining its suggested role on enhancing street crossing safety and further exploring its possible influence on pedestrians' trust toward autonomous driving. With 99 participants, perceived safety (individual assessments of safety), performance-based safety (crossing success/abandonment and collision occurrence), and trust were either questioned or recorded for nine scenarios with varying crossing conditions. A combination of multilevel models and cross-tabulation results indicate that medians seem especially significant in ensuring the performance-based safety results of pedestrians even when AVs are driving at high speeds or with smaller gaps, thus suggesting it a win-win option for both. Insights and implications on the role and management of medians in future streets are further provided
The Implementation and Analysis of Facial Expression Customization for a Social Robot
No full textSocial robots, which are mainly used by individuals, emphasize the importance of human-robot relationships (HRR) more compared to other types of robots. Emotional expression in robots is one of the key factors that imbue HRR with value; emotions are mainly expressed through the face. However, because of cultural and preference differences, the desired robot facial expressions differ subtly depending on the user. It was expected that a robot facial expression customization tool may mitigate such difficulties and consequently improve HRR. To prove this, we created a robot facial expression customization tool and a prototype robot. We implemented a suitable emotion engine for generating robot facial expressions in a dynamic human-robot interaction setting. We conducted experiments and the users agreed that the availability of a customized version of the robot has a more positive effect on HRR than a predefined version of the robot. Moreover, we suggest recommendations for future improvements of the customization process of robot facial expression
MSH2-MSH3 promotes DNA end resection during homologous recombination and blocks polymerase theta-mediated end-joining through interaction with SMARCAD1 and EXO1
No full textDNA double-strand break (DSB) repair via homologous recombination is initiated by end resection. The extent of DNA end resection determines the choice of the DSB repair pathway. Nucleases for end resection have been extensively studied. However, it is still unclear how the potential DNA structures generated by the initial short resection by MRE11-RAD50-NBS1 are recognized and recruit proteins, such as EXO1, to DSB sites to facilitate long-range resection. We found that the MSH2-MSH3 mismatch repair complex is recruited to DSB sites through interaction with the chromatin remodeling protein SMARCAD1. MSH2-MSH3 facilitates the recruitment of EXO1 for long-range resection and enhances its enzymatic activity. MSH2-MSH3 also inhibits access of POL theta, which promotes polymerase theta-mediated end-joining (TMEJ). Collectively, we present a direct role of MSH2-MSH3 in the initial stages of DSB repair by promoting end resection and influencing the DSB repair pathway by favoring homologous recombination over TMEJ
Carbide-mediated catalytic hydrogenolysis: defects in graphene on a carbonaceous lithium host for liquid and all-solid-state lithium metal batteries
No full textLithium metal is the most promising anode for next-generation lithium batteries. Nonetheless, its non-uniform Li nucleation, dendritic growth, and infinite volume variation lead to rapid cell failure and hinder its practical application. Here, we propose a defective graphene shell grown on a carbon matrix as a stable lithium metal host via carbide-mediated catalytic hydrogenolysis. It has numerous nano-channels with defective graphene shells on its surface, which can effectively guide the dendrite-free Li deposition and accommodate a rational amount of metallic Li without severe cell volume change. Due to these features, the host exhibits good cycle stability (87.2% after 500 cycles) and low dimension variation (9 mu m) in carbonate electrolyte full-cell evaluations. In addition to its good performances in the carbonate electrolyte, our versatile Li host, acting as a Li-ion flux regulating interlayer, also achieves an improved cycling performance in the argyrodite Li6PS5Cl based high energy density all-solid-state battery full-cell configuration
Carbon productivity and volatility
No full textThis study investigates the relationship between firm-level carbon productivity and volatility. With increasing interest in sustainable investing and inclusion of carbon productivity in financial assessments, we examine whether the market considers firms with high carbon productivity as less risky. Using U.S. firm-level carbon emission data, we find that carbon productivity is negatively associated with total and idiosyncratic volatilities. Our main findings hold under propensity score matching and coarsened exact matching. We also show that this relationship is significant when the binding intergovernmental regulations such as the Paris Agreement is active
Correspondence between development of cytotoxic edema and cerebro spinalfluid volume and flow in the third ventricle after ischemic stroke
No full textObjectives
The importance of monitoring cerebrospinal fluid for the development of edema in ischemic stroke has been emphasized; however, studies on the relationship between intraventricular cerebrospinal fluid behavior and edema through longitudinal observations and analysis are rare. This study aimed to investigate the correlation between the development of cytotoxic edema and cerebrospinal fluid volume and flow in the third ventricle after ischemic stroke.
Materials and methods
The ventricle and edema regions were obtained using apparent diffusion coefficients and T2 and subdivided into lateral/ventral 3rd ventricles and cytotoxic/vasogenic (or cyst) edema, respectively. In rat models of ischemic stroke, the volume and flow (via the pseudo-diffusion coefficient [D*]) of the ventricles and edema volumes were longitudinally monitored for up to 45 days after surgery.
Results
The volume of cytotoxic edema increased in the hyperacute and acute phases, whereas the volume (r = -0.49) and median D* values (r = -0.48 in the anterior-posterior direction) of the ventral 3rd ventricle both decreased, showing negative correlations with the volume of cytotoxic edema. In contrast, the volume of vasogenic edema/cyst was positively correlated with the volume (r = 0.73) and median D* values (r = 0.78 in the anterior-posterior direction) of the lateral ventricle in the subacute and chronic phases.
Conclusions
This study showed that the evolution of cerebrospinal fluid volume and flow in the ventricles was associated with edema progression at different time points in the ischemic stroke brain. This provides an efficient framework for monitoring and quantifying the interplay between cerebrospinal fluid and edema
Molecular degradation mechanism of segmented polyurethane and life prediction through accelerated aging test
No full textPolyurethane (PU) has numerous applications in daily life, such as coating, cushions, and insulation materials. It is also used as an encapsulation material for sensors. In the case of PU used as an encapsulant, PU elastomer containing an ether-based polyol is generally used and has a long lifespan in a general environment. However, it is challenging to predict its lifespan when used as an encapsulation material for sonar sensors because PU is exposed to the filling liquid. It is required to accurately predict the encapsulation material's lifespan to ensure the sensor's safety. For the exact estimation of PU lifespan, an accelerated aging experiment was conducted on PU elastomer in a filling solution at various temperatures. Fourier transform infrared spectroscopy was used to track the chemical changes in the PU elastomer, and it was observed that both urethane and urea bonds were degraded. Modulated differential scanning calorimetry and thermogravimetric analysis were also used to study changes in the structure of PU elastomer by heat aging. The tensile strength, elongation, and hardness of the heat-aged elastomer at various temperatures were obtained, and the Arrhenius plots were constructed. Finally, the lifespan was considered when the tensile strength was 70% of the initial state by using the ASTM D2000 standard. Thus, the lifespan of PU at 25 ??C was calculated to be 12.2 years
Uncertainty analysis of future summer monsoon duration and area over East Asia using a multi-GCM/multi-RCM ensemble
No full textThis study examines the spatiotemporal characteristics of the summer monsoon rainy season over East Asia using six regional climate models (RCMs) participating in the Coordinated Regional Domain Experiment (CORDEX) East Asia Phase II project. The framework combining multiple global climate models (GCMs) with multiple RCMs produces a larger spread in summer monsoon characteristics than driving GCMs only, enabling a better quantification of uncertainty factors. On average, the RCM simulations reproduce the observed summer monsoon duration and area better than the corresponding boundary GCMs, implying the added values of downscaling. Both the area and duration of the East Asian summer monsoon are projected to increase by the late 21st century, more strongly in high emission scenarios than in low emission scenarios, particularly in China. Different responses between scenarios, which indicate warming mitigation benefits, only become significant in the late 21st century due to large intersimulation uncertainties. Analysis of variance results show that uncertainty in future monsoon area and duration is larger between boundary GCMs than between RCMs over East Asia and its coastal subregions. A strong intersimulation relationship between RCMs and GCMs supports that boundary GCMs substantially diversify downscaled RCM projections through different climate sensitivities. Furthermore, the distinct subregional responses in future monsoon area and duration emphasize the importance of fine-resolution projections with appropriate uncertainty measures for better preparing region-specific adaptation plans
