• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.59-61
• /
• 2022

Among indoor positioning system techniques using wireless APs, fingerprint techniques collect Mac information and reception strength of APs before performing positioning, build a radio map, and compare it with AP information collected during positioning. However, the existing Radio Map construction method has a problem in that signal interference occurs due to collisions of numerous APs depending on the indoor environment, and the signal strength search result is not always constant. Therefore, this paper compares the existing fixed radio map construction method and the variable radio map construction technique that actively analyzes and constructs the measurement area itself according to signal strength.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.1
• /
• pp.7-14
• /
• 2015

To implement an automatic picking system (APS) in distribution center with high precision and high dynamics, this paper presents a high gain observer-based robust speed controller design for a linear induction motor (LIM) drive. The force disturbance as well as the mechanical parameter variations such as the mass and friction coefficient gives a direct influence on the speed control performance of APS. To guarantee a robust control performance, the system uncertainty caused by the force disturbance and mechanical parameter variations is estimated through a high gain disturbance observer and compensated by a feedforward manner. While a time-varying disturbance due to the mass variation can not be effectively compensated by using the conventional disturbance observer, the proposed scheme shows a robust performance in the presence of such uncertainty. A Simulink library has been developed for the LIM model from the state equation. Through comparative simulations based on Matlab - Simulink, it is proved that the proposed scheme has a robust control nature and is most suitable for APS.

• Particle and aerosol research
• /
• v.9 no.2
• /
• pp.39-50
• /
• 2013

Real-time aerosol measuring instruments have been widely used for the measurement of atmospheric aerosol, diesel particulate matter, or material synthesis. A scanning mobility particle sizer (SMPS) measures the number size distribution of particles using electrical mobility detection technique. An aerodynamic particle sizer (APS) is used to determine the number concentration and the mean aerodynamic diameter of test particles. An electrical low-pressure impactor (ELPI) is a multi-stage impaction device to separate airborne particles into aerodynamic size classes using particle charging and electrical detection techniques. In this study, the performance of these instruments were evaluated to assess their ability to obtain mass concentrations from particle number concentration measurements made as a function of particle size. The effect of determination of particle density on the measurement of mass concentration was investigated for the three instruments.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.2
• /
• pp.95-102
• /
• 2009

To determine $SO_4^{2-}$ uptake and its assimilation in response to the exogenous $SO_4^{2-}$supply level in forage rape (Brassica napus L.), the concentration of this element in plant tissues and the activity of ATP sulfurylasc and APS reductase was measured after 25 hours of treatment (1.0 mM $SO_4^{2-}$, control; 0.1 mM $SO_4^{2-}$, S deficiency; 0 mM $SO_4^{2-}$, S deprivation). $SO_4^{2-}$ uptake and the concentration in the plant tissues significantly decreased in S-deficient and S-deprived condition, while it maintained at nearly same level in the control. The activity of ATP sulfurylase tended to increase with decreasing the exogenous $SO_4^{2-}$ supply, while that of APS reductase to decrease. A significant change in both enzymes responding to S-deprivation treatment was observed only young and middle leaves. The results indicated that $SO_4^{2-}$ assimilation in young leaf tissues would be much more sensitively responded to S-limited nutrition.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.2
• /
• pp.334-348
• /
• 2015

Widespread use of smart devices accompanies increase of use of access point (AP), which enables the connection to the wireless network. If the appropriate security is not served when a user tries to connect the wireless network through an AP, various security problems can arise due to the rogue APs. In this paper, we are going to examine the threat by evil-twin, which is a kind of rogue APs. Most of recent researches for detecting rogue APs utilize the measured time difference, such as round trip time (RTT), between the evil-twin and authorized APs. These methods, however, suffer from the low detection rate in the network congestion. Due to these reasons, in this paper, we suggest a new factor, packet inter-arrival time (PIAT), in order to detect evil-twins. By using both RTT and PIAT as the learning factors for the support vector machine (SVM), we determine the non-linear metric to classify evil-twins and authorized APs. As a result, we can detect evil-twins with the probability of up to 96.5% and at least 89.75% even when the network is congested.

• Microbiology and Biotechnology Letters
• /
• v.48 no.4
• /
• pp.506-514
• /
• 2020

4-Hydroxybenzyl alcohol (4-HB alcohol) is one of the major active components of Gastrodia elata Blume, with beneficial effects on neurological disorders such as headache, convulsive behavior, and dizziness. Here, we developed a metabolically engineered Corynebacterium glutamicum strain able to produce 4-HB alcohol from 4-hydroxybenzoate (4-HBA). First, the strain APS963 was obtained from the APS809 strain via the insertion of aroK from Methanocaldococcus jannaschii into the NCgl2922-deleted locus. As carboxylic acid reductase from Nocardia iowensis catalyzes the reduction of 4HBA to 4-hydroxybenzaldehyde (4-HB aldehyde), we then introduced a codon-optimized car gene into the genome of APS963, generating the GAS177 strain. Then, we deleted creG coding for a putative short-chain dehydrogenase and inserted ubiCpr encoding a product-resistant chorismate-pyruvate lyase into the pcaHG-deleted locus. The resulting engineered GAS355 strain accumulated 2.3 g/l 4-HB alcohol with 0.32 g/l 4-HBA and 0.3 g/l 4-HB aldehyde as byproducts from 8% glucose after 48 h of culture.

• The Optical Journal
• /
• v.9 no.6 s.52
• /
• pp.1-7
• /
• 1997

• Archives of Plastic Surgery
• /
• v.41 no.2
• /
• pp.109-110
• /
• 2014

• Archives of Plastic Surgery
• /
• v.43 no.3
• /
• pp.306-308
• /
• 2016

• Archives of Plastic Surgery
• /
• v.43 no.3
• /
• pp.225-228
• /
• 2016