• ETRI Journal
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• v.37 no.1
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• pp.186-196
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• 2015

In resource-constrained, low-cost, radio-frequency identification (RFID) sensor-based mobile ad hoc networks (MANETs), ensuring security without performance degradation is a major challenge. This paper introduces a novel combination of steps in lightweight protocol integration to provide a secure network for RFID sensor-based MANETs using error-correcting codes (ECCs). The proposed scheme chooses a quasi-cyclic ECC. Key pairs are generated using the ECC for establishing a secure message communication. Probability analysis shows that code-based identification; key generation; and authentication and trust management schemes protect the network from Sybil, eclipse, and de-synchronization attacks. A lightweight model for the proposed sequence of steps is designed and analyzed using an Alloy analyzer. Results show that selection processes with ten nodes and five subgroup controllers identify attacks in only a few milliseconds. Margrave policy analysis shows that there is no conflict among the roles of network members.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.12
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• pp.62-67
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• 2012

In this paper general purpose voltage source inverter drives are equipped with an under-voltage protection mechanism, causing the system to shut down within a few milliseconds after a power interruption in the main input sources. When a power interruption occurs finish, if the system is a large inertia restarting the load a long time is required. This paper suggests modifications in the control algorithm in order to improve the sag ride-through performance of ac inverter. The new proposed strategy recommends maintaining the DC-link voltage constant at the nominal value during a sag control algorithm, experimental results are presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.4
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• pp.673-677
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• 2016

In this study, In order to measure foot pressure, it makes analyzing device using multi-pressure sensor. This device was limited frequency band to 5Hz by using low-pass filter and MCU was detected signal every milliseconds. After wearing the device, the result was confirmed by blue-tooth to measure wirelessly. Also, we propose an algorithm to obtain the walking pattern using a time table in each of the detected peak from the pressure sensor. Using the algorithm, right walking pattern and abnormal pattern was detected. The results can be reflected more individual walking patterns than when using a conventional methods and also, developed device was no restriction on the human activity.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.4
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• pp.412-419
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• 2016

The firing noise produced at artillery test range or military training ground is impulsive burst noise which energy is generated within tens of milliseconds and distributed an isolated burst of sound energy separated to one by one noise. The long range propagation of this noise is affected by a caliber of gun, amount of propellant, distance between source and receiver, ground and meteorological condition. In this paper, main influence parameters have been described based on experimental analysis of measured data. It is considered that this analysis result can be used as useful materials for study of effective firing noise management and development of propagation model.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.7
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• pp.801-810
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• 1999

The purpose of present research was to get characteristics and basic knowledges of electrorheological(ER) suspension. To observe behaviors of the ER suspensions. transparent conductive plates were used to visualize the flow of ER suspensions between two parallel plate electrodes. The influence of flowing speed and intensity of electric field on the ER fluid were examined in circle-shaped electric field, and it takes several hundred milliseconds that suspensions in flow cluster. The present study also conducts a numerical analysis adopting the Bingham model. It is found that simple Bingham model can not property describe the flow behavior in the parallel plates.

• The Korean Journal of Legal Medicine
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• v.39 no.4
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• pp.115-119
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• 2015

We investigated event-related potentials (ERPs) to estimate the accuracy of eyewitness memories. Participants watched videos of vehicles being driven dangerously, from an anti-impaired driving initiative. The four-letter license plates of the vehicles were the target stimuli. Random numbers were presented while participants attempted to identify the license plate letters, and electroencephalograms were recorded. There was a significant difference in activity 300-500 milliseconds after stimulus onset, between target stimuli and random numbers. This finding contributes to establishing an eyewitness recognition model where different ERP components may reflect more explicit memory that is dissociable from recollection.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.5
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• pp.227-237
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• 2019

Ultra-low latency control is one of the characteristics of 5G cellular network services, which means that the control loop is handled in milliseconds. To achieve this, it is necessary to identify time delay factors that occur in all components related to CPS control loop, including new 5G cellular network elements such as MEC, and to optimize CPS control loop in real time. In this paper, a novel CPS architecture for ultra-low latency control of CPS is designed. We first define the ultra-low latency characteristics of CPS and the CPS concept model, and then propose the design of the control loop performance monitor (CLPM) to manage the timing information of CPS control loop. Finally, a case study of MEC-based implementation of ultra-low latency CPS reviews the feasibility of future applications.

• Current Applied Physics
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• v.18 no.11
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• pp.1261-1267
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• 2018

In this paper, an off-axis digital holographic microscopy compensated with self-hologram rotation is presented. The process is implemented via subtracting the unwrapped phase maps of the off-axis parabolic hologram and its rotation $180^{\circ}$ to eliminate the tilt induced by the angle between the spherical object wave O and the plane reference wave R. Merit of the proposed method is that it can be done without prior knowledge of physical parameters and hence can reconstruct a parabolic hologram of $1024{\times}768$ pixels within tens of milliseconds since it doesn't require a digital reference wave. The method is applied to characterize rough gold bumps and the obtained results were compared with those extracted from the conventional reconstruction method. The comparison showed that the proposed method can characterize rough surfaces with excellent contrast and in realtime. Merit of the proposed method is that it can be used for monitoring smaller biological cells and micro-fluidic devices.

• Medical Lasers
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• v.8 no.1
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• pp.39-42
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• 2019

A 50-year-old Korean female with oral erythro-leukoplakia was treated using a 532-nm Diode laser at 6 Watts with a pulsed width of 25 milliseconds. After two months following the laser treatment, the resected region was well-healed without any significant scar contracture. We suggest that the use of the 532-nm Diode laser can be a safe and effective treatment modality for patients suffering from oral leukoplakia.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.139-149
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• 1989

Although tail flick reflex (TFR) in rats has been used as a classic model of the nociceptive test to evaluate the action of analgesics, there have been few studies on the origin of the latent period of TFR. Present study was performed to elucidate the mechanism of increase in latency of TFR by morphine in anesthetized rats. Tail skin and dorsolateral tail nerve were stimulated electrically and EMG activities were recorded from abductor caudae dorsalis muscle participating in tail flick reflex. In the case of noxious radiant heat stimulation to tail, the tail flick tension was recorded before and after administration of morphine. Then changes in latency and conduction velocity of peripheral nerve were evaluated. The results obtained were as follows: 1) The latencies of TFR evoked by the electrical stimulation of tail skin and dorsolateral tail nerve were all within 40 ms and were elongated by several milliseconds from control after the administration of morphine. Peripheral conduction velocities of tail flick afferent nerve were within the range of 10-25 m/s. 2) The conduction velocity of peripheral nerve was significantly reduced after morphine administration, therefore the afferent time (utilization time+conduction time to spinal cord) was significantly increased. But the time for central delay and efferent time was not affected by morphine. 3) The conduction velocity under room temperature $(20-25^{\circ}C)$ was significantly reduced after morphine while that under vasodilation state $(40{\sim}42^{\circ}C)$ increased, 30 min and 45 min after morphine. The conduction velocity under vasodilation state without treatment of morphine increased continuously 4) The latency in tension response of TFR evoked by electrical stimulation was elongated by several milliseconds from control while the latency evoked by noxious radiant heat was elongated by several seconds compared with that of control. From the above results, it could be concluded that: 1) the increased latency of TFR evoked by electrical stimulation of the tail after morphine administration was due to the reducton in conduction velocity of peripheral nerve, which was the secondry effect of morphine on the peripheral vasomotion and 2) increased latency of TFR evoked by noxious radiant heat was also due to the same effect of morphine and the increase in cutaneous insulation to the noxious heat.