Texture Learning Domain Randomization for Domain Generalized Segmentation

Deep Neural Networks (DNNs)-based semantic segmentation models trained on a source domain often struggle to generalize to unseen target domains, i.e., a domain gap problem. Texture often contributes to the domain gap, making DNNs vulnerable to domain shift because they are prone to be texture-biased. Existing Domain Generalized Semantic Segmentation (DGSS) methods have alleviated the domain gap problem by guiding models to prioritize shape over texture. On the other hand, shape and texture are two prominent and complementary cues in semantic segmentation. This paper argues that leveraging texture is crucial for improving performance in DGSS. Specifically, we propose a novel framework, coined Texture Learning Domain Randomization (TLDR). TLDR includes two novel losses to effectively enhance texture learning in DGSS: (1) a texture regularization loss to prevent overfitting to source domain textures by using texture features from an ImageNet pre-trained model and (2) a texture generalization loss that utilizes random style images to learn diverse texture representations in a self-supervised manner. Extensive experimental results demonstrate the superiority of the proposed TLDR; e.g., TLDR achieves 46.5 mIoU on GTA-to-Cityscapes using ResNet-50, which improves the prior state-of-the-art method by 1.9 mIoU. The source code is available at https://github.com/ssssshwan/TLDR.Comment: ICCV 202

Electrochemical Investigation of High-Performance Dye-Sensitized Solar Cells Based on Molybdenum for Preparation of Counter Electrode

In order to improve the photocurrent conversion efficiency of dye-sensitized solar cells (DSSCs), we studied an alternative conductor for the counter electrode and focused on molybdenum (Mo) instead of conventional fluorine-doped tin oxide (FTO). Because Mo has a similar work function to FTO for band alignment, better formability of platinum (Pt), and a low electric resistance, using a counter electrode made of Mo instead of FTO lead to the enhancement of the catalytic reaction of the redox couple, reduce the interior resistance of the DSSCs, and prevent energy-barrier formation. Using electrical measurements under a 1-sun condition (100 mW/cm(2), AM 1.5), we determined that the fill factor (FF) and photocurrent conversion efficiency (eta) of DSSCs with a Mo electrode were respectively improved by 7.75% and 5.59% with respect to those of DSSCs with an FTO electrode. Moreover, we have investigated the origin of the improved performance through surface morphology analyses such as scanning electron microscopy and electrochemical analyses including cyclic voltammetry and impedance spectroscopy

Large-Scale Plasma Polymer Coating on Heat Exchanger Fins for Improving the Wettability

This research presents the results of the recently developed large-scale hydrophilic polymer coating by plasma polymerization, optimum plasma zone (OPZ) process. The excellent hydrophilicity of heat exchanger fin surface could give good effects to efficient drainage of condensate water as well as heat transfer performance. The hydrophilicity of layer treated by large-scale OPZ system is excellent irrespective of line speed from 0.6 m/min to 2.4 m/min. The good lateral uniformity of the hydrophilicity could be acquired in large scale OPZ treatment. The application of OPZ technique to the heat exchanger could enhance the efficiency of heat transfer, resulting from decrease of pressure drop. Due to long-term durability of hydrophilicity, the heat transfer performance improved by OPZ process cannot be deteriorated with operation cycle

Particulate counter electrode system for enhanced light harvesting in dye-sensitized solar cells

A particulate counter electrode with photo scattering and redox catalytic properties is applied to dye sensitized solar cells (DSSCs) in order to improve photo conversion efficiency and simplify the assembly process. Our particulate counter electrode acts as both a photo reflecting layer and a catalyst for reduction of electrolyte. The reflective and catalytic properties of the electrode are investigated through optical and electrochemical analysis, respectively. A short circuit current density enhancement is observed in the DSSCs without the need to add an additional reflecting layer to the electrode. This leads to a simplified assembly process. (C) 2013 Optical Society of Americ

모바일 와이맥스 시스템에서 인접 셀 간섭 완화를 위한 채널 추정

In orthogonal frequency division multiplexing based wireless system, a pilot signal is often employed to estimate channel state information (CSI). However, the received pilot signal is interfered by other cell interference in multi-cell environments. We consider the estimation of CSI by utilizing orthogonal preambles and channel correlation.Seoul R&BD Progra

Coulomb oscillations based on band-to-band tunneling in a degenerately doped silicon metal-oxide-semiconductor field-effect transistor

The Coulomb oscillations based on band-to-band tunneling through a valence band in silicon metal-oxide-semiconductor field-effect-transistors were discussed. It was found that the formation of tunnel barries and a quantum dot in a single-electron transistor structure originated from two p+ - p+ tunnel junctions and a p+ -doped channel with mesoscopic dimension, respectively. At liquid nitrogen temperature, the Coulomb-blockade oscillations with multiple peaks were also observed. Analysis shows that the single-electron charging effect based on band-to-band tunneling was confirmed using the electrical and thermal characterization of the quantum dots.open2

Basic study on the oil recovery in a hybrid heat pump using ammonia/water solution

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In an ammonia/water hybrid heat pump system which is a vapor compression cycle with a solution circuit, lubricating oil is commonly used for the compressor. Since Poly-Alpha-Olefin (PAO) oil which is commonly used for ammonia is immiscible with the ammonia/water solution, a proper oil recovery method is required for a smooth operation of the compressor. Although the oil separator installed at the outlet of the compressor removes most of the oil from the refrigerant vapor, some oil droplets are carried over and accumulated in the solution reservoir. Unlike the pure ammonia vapor compression system, the density of PAO oil is smaller than that of ammonia/water mixture which has the ammonia concentration of 30-40%, and the oil tends to rise and gather near the liquid/vapor interface. In this study, a method for oil recovery from the solution reservoir is suggested. In the present method, the mixture of the oil and the solution is drained into an oil separator having a narrow cylinder at the top, if the oil in the reservoir is greater than a certain amount. The oil droplets in the solution rise by buoyancy and gather at this upper narrow cylinder. The gathered oil is extracted and returned to the compressor by an oil recovery pump. Since the solution has to be returned to the reservoir as soon as the separation process is finished, the process time for the separation should be as short as possible. To predict the time for the separation, experiments and simulations have been carried out. The model using the multiphase segregated flow (MSF) showed that a proper choice of droplet diameter is necessary to predict a correct separation time. Also, a simulation model which is able to consider the effect of surface tension and droplet merging is needed to be developed.dc201