A Cost Effective Block Framing Scheme for Underwater Communication

In this paper, the Selective Multiple Acknowledgement (SMA) method, based on Multiple Acknowledgement (MA), is proposed to efficiently reduce the amount of data transmission by redesigning the transmission frame structure and taking into consideration underwater transmission characteristics. The method is suited to integrated underwater system models, as the proposed method can handle the same amount of data in a much more compact frame structure without any appreciable loss of reliability. Herein, the performance of the proposed SMA method was analyzed and compared to those of the conventional Automatic Repeat-reQuest (ARQ), Block Acknowledgement (BA), block response, and MA methods. The efficiency of the underwater sensor network, which forms a large cluster and mostly contains uplink data, is expected to be improved by the proposed method

High-Performance PVC Gel for Adaptive Micro-Lenses with Variable Focal Length.

This paper presents a bio-inspired adaptive micro-lens with electrically tunable focus made of non-ionic high-molecular-weight polyvinyl chloride (PVC) gel. The optical device mimics the design of the crystalline lens and ciliary muscle of the human eye. It consists of a plano-convex PVC gel micro-lens on Indium Tin Oxide (ITO) glass, confined with an annular electrode operating as an artificial ciliary muscle. Upon electrical activation, the electroactive adhesive force of the PVC gel is exerted on the annular anode electrode, which reduces the sagittal height of the plano-convex PVC gel lens, resulting in focal length variation of the micro-lens. The focal length increases from 3.8 mm to 22.3 mm as the applied field is varied from 200 V/mm to 800 V/mm, comparable to that of the human lens. The device combines excellent optical characteristics with structural simplicity, fast response speed, silent operation, and low power consumption. The results show the PVC gel micro-lens is expected to open up new perspectives on practical tunable optics

Antioxidant and Antiadipogenic Activities of Galkeun-Tang, a Traditional Korean Herbal Formula

Galkeun-tang (GKT; Galgen-tang in Chinese and Kakkon-to in Japanese), a traditional herbal formula, has been used for treatment of the common cold. Here, we report in vitro antioxidant and antiadipogenic effects of GKT. GKT increased the activities of scavenging 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. GKT also significantly reduced the malondialdehyde (MDA) generation during low-density lipoprotein (LDL) oxidation and the electrophoretic mobility of oxidized LDL, indicating inhibitory effects of GKT on Cu2+-mediated oxidation of LDL. Regarding antiadipogenic activity, GKT treatment significantly suppressed lipid accumulation, triglyceride production, and glycerol-3-phosphate dehydrogenase (GPDH) activity in differentiated 3T3-L1 adipocytes. Consistent with this, GKT significantly reduced the secretion of leptin, a major adipokine, in differentiated 3T3-L1 adipocytes. Overall, our findings suggest that GKT has the potential for antioxidative and antiadipogenic properties