Samsung

About: Samsung is a company organization based out in Seoul, South Korea. It is known for research contribution in the topics: Layer (electronics) & Signal. The organization has 134067 authors who have published 163691 publications receiving 2057505 citations. The organization is also known as: Samsung Group & Samsung chaebol.

Twenty-eight-day inhalation toxicity study of silver nanoparticles in Sprague-Dawley rats

Abstract: The antibacterial effect of silver nanoparticles has resulted in their extensive application in health, electronic, and home products. Thus, the exposed population continues to increase as the applications expand. Although previous studies on silver dust, fumes, and silver compounds have revealed some insights, little is yet known about the toxicity of nano-sized silver particles, where the size and surface area are recognized as important determinants for toxicity. Thus, the inhalation toxicity of silver nanoparticles is of particular concern to ensure the health of workers and consumers. However, the dispersion of inhalable ambient nano-sized particles has been an obstacle in evaluating the effect of the inhalation of nano-sized particles on the respiratory system. Accordingly, the present study used a device that generates silver nanoparticles by evaporation/condensation using a small ceramic heater. As such, the generator was able to distribute the desired concentrations of silver nanoparticles to chambers containing experimental animals. The concentrations and distribution of the nanoparticles with respect to size were also measured directly using a differential mobility analyzer and ultrafine condensation particle counter. Therefore, the inhalation toxicity of silver nanoparticles was tested over a period of 28 days. Eight-week-old rats, weighing about 283 g for the males and 192 g for the females, were divided into 4 groups (10 rats in each group): a fresh-air control, a low-dose group (1.73 x 10(4)/cm3), a middle-dose group (1.27 x 10(5)/cm3), and a high-dose group (1.32 x 10(6) particles/cm3, 61 microg/m3). The animals were exposed to the silver nanoparticles for 6 h/day, 5 days/wk, for a total of 4 wk. The male and female rats did not show any significant changes in body weight relative to the concentration of silver nanoparticles during the 28-day experiment. Plus, there were no significant changes in the hematology and blood biochemical values in either the male or female rats. Therefore, the initial results indicated that exposure to silver nanoparticles at a concentration near the current American Conference of Governmental Industrial Hygienists (ACGIH) silver dust limit (100 microg/m3) did not appear to have any significant health effects.

Robust Feature Matching for Remote Sensing Image Registration via Locally Linear Transforming

Abstract: Feature matching, which refers to establishing reliable correspondence between two sets of features (particularly point features), is a critical prerequisite in feature-based registration. In this paper, we propose a flexible and general algorithm, which is called locally linear transforming (LLT), for both rigid and nonrigid feature matching of remote sensing images. We start by creating a set of putative correspondences based on the feature similarity and then focus on removing outliers from the putative set and estimating the transformation as well. We formulate this as a maximum-likelihood estimation of a Bayesian model with hidden/latent variables indicating whether matches in the putative set are outliers or inliers. To ensure the well-posedness of the problem, we develop a local geometrical constraint that can preserve local structures among neighboring feature points, and it is also robust to a large number of outliers. The problem is solved by using the expectation–maximization algorithm (EM), and the closed-form solutions of both rigid and nonrigid transformations are derived in the maximization step. In the nonrigid case, we model the transformation between images in a reproducing kernel Hilbert space (RKHS), and a sparse approximation is applied to the transformation that reduces the method computation complexity to linearithmic. Extensive experiments on real remote sensing images demonstrate accurate results of LLT, which outperforms current state-of-the-art methods, particularly in the case of severe outliers (even up to 80%).

Contrast enhancement system using spatially adaptive histogram equalization with temporal filtering

Abstract: In this paper we propose a block-overlapped histogram equalization system for enhancing contrast of image sequences. The proposed system has various applications such as video door phone, security video cameras, in addition to the original target video camcorders.

Molecular Communication in Fluid Media: The Additive Inverse Gaussian Noise Channel

Abstract: In this paper, we consider molecular communication, with information conveyed in the time of release of molecules. These molecules propagate to the transmitter through a fluid medium, propelled by a positive drift velocity and Brownian motion. The main contribution of this paper is the development of a theoretical foundation for such a communication system; specifically, the additive inverse Gaussian noise (AIGN) channel model. In such a channel, the information is corrupted by noise that follows an IG distribution. We show that such a channel model is appropriate for molecular communication in fluid media. Taking advantage of the available literature on the IG distribution, upper and lower bounds on channel capacity are developed, and a maximum likelihood receiver is derived. Results are presented which suggest that this channel does not have a single quality measure analogous to signal-to-noise ratio in the additive white Gaussian noise channel. It is also shown that the use of multiple molecules leads to reduced error rate in a manner akin to diversity order in wireless communications. Finally, some open problems are discussed that arise from the IG channel model.