Min-gu Lee

Due to the special characteristics (limited battery power, limited computing capability, low bandwidth, need to collect sensor data from multiple fixed-location source nodes to a sink node that may be mobile, etc.) of wireless sensor networks, routing algorithms designed for general mobile ad hoc networks may not be directly applicable to wireless sensor networks. In one possible routing scheme for wireless sensor networks, each node maintains up-to-date hop-distances and next-hop nodes to the m

Abstract This study investigated the capture of carbon dioxide (CO 2 ) and its chemical conversion to high‐purity calcium carbonate salt, which has potential uses in a range of industrial sectors. Indirect inorganic aqueous carbonation methods were used, with seawater‐based industrial wastewater as the source of metal ions. The alkanolamine absorbent solutions of monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA) were used at typical industrial concentrations of 30 wt%

최근 NFC(Near Field Communcation) 기반 통신 기능을 채용한 스마트기기 및 OS 등이 확산됨에 따라 기존 RFID를 이용하던 다양한 응용 분야에 대하여 NFC로의 대체가 진행되고 있다. 대표적으로 출입 통제나, e-ticket, 전자 결제 등의 분야에서 NFC가 RFID를 대체하고 있다. 기존의 RFID는 수동적 통신 기능만 제공하여 충분히 안전한 인증 및 권한 검증 방법을 제시하지 못하였으나, 능동형 통신기능을 제공하는 NFC를 활용하면 보다 안전한 인증 방식을 제공하여 다양한 응용에서 요구하는 보안 요구사항을 만족시킬 수 있다. 그러므로 본 논문은 NFC의 능동형 통신 기능을 활용하여 신용카드 결제, 출입통제 시스템 등에 활용될 수 있는 능동형 인증 방식을 제공할 수 있는 방법으로 EAP(Extensible Authentication Protocol)과 AAA(Authentication. Authorization and Accounting) 규약을 활용하는

Anthocyanin oligomers (AOs) are phytochemicals synthesized by fermenting anthocyanins extracted from grape skins and are more biologically active than monomeric anthocyanins. In this study, we evaluate the effects of an AO on triple-negative MDA-MB-231 and HER2-overexpressing SK-BR-3 breast cancer cells. The cell viability of MDA-MB-231 and SK-BR-3 cells was significantly inhibited in a concentration-dependent manner by AO treatment for 24 h, while delphinidin (a monomeric anthocyanin) had no ef

Previous routing algorithms for mobile ad-hoc networks (MANETs) have focused on finding short-distance path(s) between communicating nodes. However, due to the dynamic and unreliable communication nature of MANETs, previously determined paths can easily become disconnected. Although dynamic routing can be used to circumvent this problem, determining a new route each time a packet needs to be sent involves a lot of overhead. An alternative form of dynamic routing involves maintaining valid routes

Based on recent advances in technology, many robots are developed and they are used in a hazardous environment such as military operation, fire, and building collapse and so on. Among them, reconnaissance robot should be able to perform various missions which people can not do. So it needs the capability of moving with hiding its position on rough terrain, overcoming obstacles, and guaranteeing its efficiency of reconnaissance. For this reason there are in progress of researching biomimetic robo

The purpose of this research is to develop a new 3D LIDAR sensor, named KIDAR-B25, for measuring 3D image information with high range accuracy, high speed and compact size. To measure a distance to the target object, we developed a range measurement unit, which is implemented by the direct Time-Of-Flight (TOF) method using TDC chip, a pulsed laser transmitter as an illumination source (pulse width: 10 ns, wavelength: 905 nm, repetition rate: 30kHz, peak power: 20W), and an Si APD receiver, which

In real-time simulation, the simulated system should display the same (or very close) timing behavior as the target system. The simulation accuracy is increased as the simulation time unit is decreased. Although there are several models for such systems, the TMO model is particularly appropriate due to its natural support for real-time distributed object-oriented programming. This paper discusses the results of the implementation of a real-time airplane-landing simulator on a distributed computi

The introduction of distributed generation (DG) into distribution systems is expanding due to carbon neutral policies. DG with intermittent output characteristics brings frequent voltage variations in distribution systems. Generally, a step voltage regulator (SVR) is installed in the long distribution line and controls its voltage, which has limits of stable voltage regulations due to the slow tap-changing rate, switching losses, and short life span. To solve those problems, this paper proposes

Wireless devices that communicate using the IEEE 802.11 protocol can be used to create mobile ad-hoc networks (MANETs). Many interesting applications using MANETs are realizable if real-time channels can be supported on such networks. However, frames are commonly dropped (and thus must be retransmitted) in wireless networks due to interference from other wireless devices and transmission range problems. To provide real-time communication in such networks, statistical real-time channels can be us