• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.159-164
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• 2000

In SRM drive, The accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. As the speed increased, the amount of the switching angle deviation from the preset values is increased by the sampling period. Therefore, in this paper the low cost liner encoder for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is presented. and it is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1707-1714
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• 2015

The neural bases underlying within or between-language picture naming was investigated by using event-related fMRI. The present suudy explorered the following two goals: The first is to compare cortical activation areas relevant to naming process in native and foreign language, and to decide whether the activation pattern of the foreign word will be the same as native words or not. The next is to find the cerebral areas involved only in alternating language switching between native and foreign language condition. Differential activation patterns were observed for language switching against one-language. Both naming tasks all activated the left inferior frontal gyrus (LIFG) as expected. However the differences in naming between languages were reflected in the activation amount of the LIFG, namely more activation in naming the native language than the foreign language. Especially, naming of the foreign word from English showed the similar area and size in activation with native language suggesting that the process of borrowed noun resembles that of native common noun. And the language switching between languages newly activated the right middle frontal gyrus as well as the left inferior frontal areas. The right middle frontal gyrus engagement in switching conditions obviously identified that right hemisphere is recruited in code switching possibly with respect to meta-cognition controlling language index at a subconscious level.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.332-335
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• 2020

Drop casting, a solution process, is a simple low-cost fabrication technique that does not waste material. In this study, we elucidate the effect of the concentration of a InGaZnO solution on the electrical properties of drop-cast oxide thin-film transistors. The higher the concentration the larger the amount of remnant InGaZnO solutes, which yields a thicker thin film. Accordingly, the electrical properties were strongly dependent on the concentration. At a high concentration of 0.3 M (or higher), a large current flowed but did not lead to switching characteristics. At a concentration lower than 0.01 M, switching characteristics were observed, but the mobility was small. In addition to a high mobility, sufficient switching characteristics were obtained at a concentration of 0.1 M owing to the appropriate thickness of the semiconductor layer. This study provides a technical basis for the low-cost fabrication of switching devices capable of driving a sensor array.

• Journal of the Korean Physical Society
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• v.80
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• pp.1076-1080
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• 2022

For preventing a sneak current in the 3D cross-point array, the selection device is essentially necessary and an n-MOSFET has been used for the selection device. However, the three-terminal electrodes of n-MOSFET make to achieve a high density of a cross-point array difficult. As a solution, using a selector having two terminal electrodes has been intensively researched. We presented that the CuGeS₂/GeS₂-based super-linear-threshold-switching (SLTS) selector device with the insertion of optimal TiN liner thickness exhibited outstanding electrical characteristics and reliability. The dependency of electrical characteristics and reliability on various TiN liner thicknesses were investigated. In addition, the principles of reliability and electrical characteristics improvement were understood through the energy dispersive spectroscopy elemental mapping and line profile of Cu. The adequate amount of Cu distributed in GeS₂ resistive switching layer is a key factor to achieve excellent electrical characteristics and reliability for an ultra-high-density 3D cross-point array cell.

• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.527-538
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• 2004

In this paper, we present the flow aggregation method and the FLTC(flow lasting time control) algorithm to reduce the number of flows and solve the scalability problem in high speed IP switching networks. The flow aggregation based on the destination address could reduce the total number of flows, improve the label efficiency, and increase the total amount of the switched packets. The FLTC algorithm also eliminates the waste of label by deleting the flow binding efficiently. With the traces of real Internet traffics, we evaluate the performance of these schemes by simulation. The label efficiency, the average number of label used, and the percentage of packets switched and the number of packets switched are used as performance measures for this simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.150-155
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• 2009

Hysteresis current regulator has been used widely because of its simple principle and structure. However, when the current band width is too narrow or the applied voltage is relatively too high, the switching frequency increases abruptly and it makes large amount of heat. In this study, for single phase current control, the hysteresis current control is executed by adding 0 mode state and comparing the slope of the current reference, which decreases the switching frequency so much and make the current control much stable. These were proved with computer simulations.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.71-76
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• 2015

In this paper, we propose a system model which effectively transmits the data and conducts RF energy harvesting in a wireless communication network of LTE and 5G. Through time switching and power splitting schemes, we find a time & power ratio to show the good performance according to the standard that we set up for transmitting a signal and conducting RF energy harvesting. So selecting optimal time & power ratio, we can efficiently transfer data to other drones and harvest the amount of harvested power simultaneously we desire. Also, according to conducting the performance analysis, we can compare an ideal receiver with the proposed system model. And, we suggest a future direction of research.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4930-4951
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• 2018

The deep learning based speech enhancement has shown considerable success. However, it still suffers performance degradation under mismatch conditions. In this paper, an adaptation method is proposed to improve the performance under noise mismatch conditions. Firstly, we advise a noise aware training by supplying identity vectors (i-vectors) as parallel input features to adapt deep neural network (DNN) acoustic models with the target noise. Secondly, given a small amount of adaptation data, the noise-dependent DNN is obtained by using $L_2$ regularization from a noise-independent DNN, and forcing the estimated masks to be close to the unadapted condition. Finally, experiments were carried out on different noise and SNR conditions, and the proposed method has achieved significantly 0.1%-9.6% benefits of STOI, and provided consistent improvement in PESQ and segSNR against the baseline systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4933-4956
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• 2016

Use-After-Free (UAF) is a common lethal form of software vulnerability. By using tools such as Web Browser Fuzzing, a large amount of samples containing UAF vulnerabilities can be generated. To evaluate the threat level of vulnerability or to patch the vulnerabilities, automatic deduplication and exploitability determination should be carried out for these samples. There are some problems existing in current methods, including inadequate pertinence, lack of depth and precision of analysis, high time cost, and low accuracy. In this paper, in terms of key dangling pointer and crash context, we analyze four properties of similar samples of UAF vulnerability, explore the method of extracting and calculate clustering eigenvalues from these samples, perform clustering by fast search and find of density peaks on a large number of vulnerability samples. Samples were divided into different UAF vulnerability categories according to the clustering results, and the exploitability of these UAF vulnerabilities was determined by observing the shape of class cluster. Experimental results showed that the approach was applicable to the deduplication and exploitability determination of a large amount of UAF vulnerability samples, with high accuracy and low performance cost.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.277-283
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• 1999

For the purpose of leading horse mackerel Trachurus japonicus schools, mackerel Scomber japonicus schools and arrow squid Todarodes pacificus schools, which migrate to the Cheju coast and are caught by the set-net, to the set-net by attracting lamps, we made five attracting lamps and took a practical experiment in the Gwiduk and Dongbuk set-net fishing ground. In the set-net with two bag-nets, we compared the amount of catch of both bag-nets by the means of switching on and off the each attracting lamps in order, switching off the attracting lamps in order which had been switched on and moving an attracting lamp.In the bag-net with an attracting lamp, horse mackerel, mackerel and arrow squid were caught the most, on the other hand, yellow tail Seriola quinqueradiata, striped mullet Mugil cephalus were caught in large quantities in the bag-net without attracting lamp. File fish Stephanolepis cirrhifer, Dusky spinefoot Siganus fuscescens were caught evenly in both bag-nets regardless of an attracting lamp.This result indicates that the amount of horse mackerel, mackerel, arrow squid can be increased by the use of attracting lamps in the set-net fishing method.