Soo-ah Choi

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capill

This paper simulates an environment similar to the operational environment of intelligent remote control smart landmines on the battlefield and describes a method for configuring a wireless personal area network in which the control unit(Master node) wirelessly controls smart landmines(Slave nodes) and manages the separation of slave nodes from the master node. We propose a study on a method of grouping by direction using the characteristics of directional antennas without a location tracking de

Recently, the bilinear pairings such as the Weil and the Tate pairings defined on algebraic curves over a finite field have found applications in the design of cryptographic protocols. One useful application in mobile environments is for secure group communication over a public network. The members in the group need to establish a common group key that will be used to encrypt messages to be broadcast to the group. Furthermore, it is important to update the group key with low computational costs

Wireless transmission technology is rapidly accepting commercial models for broadband wireless communication packet services. Even though the protocol of broadband wireless communication may momentarily require high processing power, the average throughput in a terminal is not high. This work analyzes the processing time on a hardware platform to provide insight intotime latency at the turnaround time in a time division duplexing (TDD) operation. Considering the latency, this paper shows a proce

Nitrogen-doped TiO2 particles have been successfully prepared using titanium tetraisopropoxide as the Ti source and urea as the nitrogen source. As-prepared nitrogen-doped TiO2 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller method (BET) and ultraviolet-visible light (UV-vis) absorption spectra techniques. Photocatalytic degradation of Methylene Blue (MB) has been carried out in both solar light (UV-vis) and the visible region (λ=420 nm).

본 연구에서는 토양에서 지하수의 흐름에 영향을 미치는 주요한 인자인 토양입자의 크기 및 입자들의 혼합 패턴에 따라 Darcy 의 법칙에서 제시되어 있는 투수계수가 변화하는 양상을 검토하여 토양 환경에서의 물의 흐름에 대한 해석을 시도하였다. 또한 물의 온도 및 농도 변화에 따른 투수계수의 양상을 파악하였다. 그 결과, 토양입자의 크기 및 혼합패턴에 대한 투수계수는 입자의 크기에 비례하는 경향을 보였으며, 조합에 따라 공극률의 영향을 많이 받았다. 특히 단일입자에 비해 크기가 다른 모래 시료를 혼합한경우 크기가 작은 단일입자의 투수계수값보다 낮은 값을 나타내었다. 또한 온도 증가에 따라 지하수의 투수계수가 증가하였으며, 지하수 내 이온의 농도에 따라 투수계수가 감소하였다. 본 연구결과는 토양 환경에서 지하수의 거동을 해석하는데 있어 토양의 특성이 반영되는 현상에 의미있는 자료로 활용될 것으로 기대된다.