Learning Delaunay Triangulation using Self-attention and Domain Knowledge

Delaunay triangulation is a well-known geometric combinatorial optimization problem with various applications. Many algorithms can generate Delaunay triangulation given an input point set, but most are nontrivial algorithms requiring an understanding of geometry or the performance of additional geometric operations, such as the edge flip. Deep learning has been used to solve various combinatorial optimization problems; however, generating Delaunay triangulation based on deep learning remains a difficult problem, and very few research has been conducted due to its complexity. In this paper, we propose a novel deep-learning-based approach for learning Delaunay triangulation using a new attention mechanism based on self-attention and domain knowledge. The proposed model is designed such that the model efficiently learns point-to-point relationships using self-attention in the encoder. In the decoder, a new attention score function using domain knowledge is proposed to provide a high penalty when the geometric requirement is not satisfied. The strength of the proposed attention score function lies in its ability to extend its application to solving other combinatorial optimization problems involving geometry. When the proposed neural net model is well trained, it is simple and efficient because it automatically predicts the Delaunay triangulation for an input point set without requiring any additional geometric operations. We conduct experiments to demonstrate the effectiveness of the proposed model and conclude that it exhibits better performance compared with other deep-learning-based approaches

EPIC: Graph Augmentation with Edit Path Interpolation via Learnable Cost

Graph-based models have become increasingly important in various domains, but the limited size and diversity of existing graph datasets often limit their performance. To address this issue, we propose EPIC (Edit Path Interpolation via learnable Cost), a novel interpolation-based method for augmenting graph datasets. Our approach leverages graph edit distance to generate new graphs that are similar to the original ones but exhibit some variation in their structures. To achieve this, we learn the graph edit distance through a comparison of labeled graphs and utilize this knowledge to create graph edit paths between pairs of original graphs. With randomly sampled graphs from a graph edit path, we enrich the training set to enhance the generalization capability of classification models. We demonstrate the effectiveness of our approach on several benchmark datasets and show that it outperforms existing augmentation methods in graph classification tasks

3D visualization technique for occluded objects in integral imaging using modified smart pixel mapping

In this paper, we propose a modified smart pixel mapping (SPM) to visualize occluded three-dimensional (3D) objects in real image fields. In integral imaging, orthoscopic real 3D images cannot be displayed because of lenslets and the converging light field from elemental images. Thus, pseudoscopic-to-orthoscopic conversion which rotates each elemental image by 180 degree, has been proposed so that the orthoscopic virtual 3D image can be displayed. However, the orthoscopic real 3D image cannot be displayed. Hence, a conventional SPM that recaptures elemental images for the orthoscopic real 3D image using virtual pinhole array has been reported. However, it has a critical limitation in that the number of pixels for each elemental image is equal to the number of elemental images. Therefore, in this paper, we propose a modified SPM that can solve this critical limitation in a conventional SPM and can also visualize the occluded objects efficiently

Design and Implementation of EMB System

The EMB(Electric Mechanical Brake) system is replacing the former hydrodynamic brake system. A brake system is a nonlinear system which applies a different compressive force depending on the position of the brake pad. The EMB system operates the brake by the motor instead of the hydrodynamic system. So the new design of brake caliper and the development of the motor controller and the invertor are needed. The gap between the pads shall be controlled exactly to operate an accurate force control. The new algorithm to compensate the pad abrasion and the disk abrasion is needed. In this paper, the mechanical part are designed to operate the brake and the EMB controller are designed and implemented with a motor controller and an inverter. The EMB controller model is verified by the MATLAB. The initialization algorithm is developed to compensate the pad abrasion and the backlash of the gear to make the same gap between the disk and the pad. The suggested algorithm detects the pad gap equally and the force depending on the pad gap is measured consistently

Differential Fault Attack on Lightweight Block Cipher PIPO

With the recent development of Internet of Things (IoT) devices, related security issues are also increasing. In particular, the possibility of accessing and hijacking cryptographic devices is also increasing due to the rapid increase in usage of these devices. Therefore, research on cryptographic technologies that can provide a safe environment even in resource-constrained environments has been actively conducted. Among them, there are increasing security issues of side-channel analysis for devices due to their physical accessibility. The lightweight block cipher PIPO was recently proposed in ICISC 2020 to address these issues. The PIPO has the characteristic of providing robust security strength while having less overhead when using the side-channel analysis countermeasures. A differential fault attack is a type of side-channel analysis that induces fault in cryptographic operations and utilizes difference information that occurs. Differential fault attacks on the PIPO have not yet been studied. This paper proposed a single-bit flip-based differential fault attack on the lightweight block cipher PIPO for the first time. We show that simulations enable the recovery of the correct secret key with about 98% probability through 64 fault ciphertexts. Therefore, the PIPO does not provide security against differential fault attacks. When using the PIPO cipher on IoT devices, designers must apply appropriate countermeasures against fault injection attacks

Point-of-care lactate: a predictor of emergency medicine resource use and outcomes in infants with diarrhea

Purpose Fluid therapy for diarrhea-induced dehydration inadvertently increases emergency department length of stay (EDLOS). To prevent this delay, we investigated the usefulness of triage using point-of-care (POC) lactate in infants with diarrhea. Methods This study was performed on infants with diarrhea who visited the emergency department from January 2019 through December 2020. According to the POC lactate concentration and the Korean Triage and Acuity Scale (KTAS) level, the infants were separately divided into the low (< 2 mmol/L), moderate (2-3.9), and high (≥ 4) lactate groups and the mild (KTAS 4-5) and severe (1-3) groups, respectively. Using these 2 group designations, we compared variables regarding the emergency medicine resource use and outcomes. To predict the prolonged EDLOS (≥ median value) we performed logistic regression and receiver operating characteristic analyses. Results A total of 540 infants were included. The median of EDLOS was 169 minutes (interquartile range, 103-220). Fluid therapy was more frequently performed in the high lactate group than in the low-moderate lactate groups (85.0% vs. 60.4%-73.6%; P = 0.025). The high lactate and severe groups respectively showed higher rates of hospitalization (40.0% vs. 3.8%-7.6% [P < 0.001] and 10.9% vs. 1.4% [P = 0.015]), and longer median EDLOS (259 minutes vs. 147-178 [P < 0.001] and 185 vs. 131 [P = 0.001]) compared to the low-moderate lactate and mild groups. Compared to the KTAS, lactate is more strongly associated with the prolonged EDLOS (lactate, adjusted odds ratio, 4.80 [95% confidence interval, 1.87-15.34] vs. KTAS, 3.52 [1.90-6.54]). The areas under curve for lactate and for the KTAS were 0.66 (0.60-0.73) and 0.62 (0.55-0.69), respectively (P = 0.058). Conclusion In infants with diarrhea, POC lactate can be a predictor of emergency medicine resource use and outcomes

Synthesis and Characterization of Polycarbonate Copolymers Containing Benzoyl Groups on the Side Chain for Scratch Resistance

The purpose of this study was to enhance the scratch resistance of polycarbonate copolymer by using 3,3′-dibenzoyl-4,4′-dihydroxybiphenyl (DBHP) monomer, containing benzoyl moieties on the ortho positions. DBHP monomer was synthesized from 4,4′-dihydroxybiphenyl and benzoyl chloride, followed by the Friedel-Craft rearrangement reaction with AlCl3. The polymerizations were conducted following the low-temperature procedure, which is carried out in methylene chloride by using triphosgene, triethylamine, bisphenol-A, and DBHP. The chemical structures of the polycarbonate copolymers were confirmed by 1H-NMR. The thermal properties of copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry, and also surface morphologies were assessed by atomic force microscopy. The scratch resistance of homopolymer film (100 μm) changed from 6B to 1B, and the contact angle of a sessile water drop onto the homopolymer film also increased