• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.208-217
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• 2012

This paper presents two adaptive fingerprint matching methods. First, we experiment an adaptive threshold selection of 1:N matching system in order to raise the reliability of the matching score. Second, we propose a adaptive threshold selection using fitting algorithm for high speed matching. The experiment was conducted on the NITZEN database, which has 5247 samples. Consequently, this paper shows that our suggested method can perform 1.88 times faster matching speed than the bidirectional matching speed. And, we prove that FRR of our suggested method decreases 1.43 % than that of the unidirectional matching.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.141-143
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• 2004

In this present the transient control of SBS chaos induced instability in Brillouin-active fiber systems is described. The inherent optical feedback by the backscattered Stokes wave in optical fiber systems leads to instabilities in the form of optical chaos. At weak power, the nature of the Brillouin instability can occur at before threshold. At strong power, the temporal evolution above threshold is periodic and at higher intensity can become chaotic. Multistable periodic states, makes transition to logic 'on' or 'off'. It can make theoretically potential large memory capacity.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1593-1596
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• 2015

실시간 영상회의 시스템은 네트워크 및 버퍼링의 지연으로 사용자 정보의 전달이 시스템 간에 효율적으로 이루어지지 않고 있어 실시간성이 완벽하게 보장되지 않고 있는 것이 현실이다. 하지만, 네트워크 인프라의 보강과 지터 지연에 대한 연구는 활발하지만, 버퍼링에 대한 연구는 미흡한 상태이다. 본 논문에서는 버퍼링 지연에 따른 문제 해결을 위한 FRCB(Frame-Rate Control Buffer) 관리 기법을 제안하고자 한다. FRCB는 버퍼의 Overflow와 Underflow를 방지하기 위한 FTH(Fist-play THreshold)와 STH(Slow-play THreshold)로 구성되며, CPU 부하가 높은 상황에서도 좋은 성능을 보여 고품질의 실시간 영상회의에 적합함을 보였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.5
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• pp.627-634
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• 2006

We have proposed the methods how to control the slope of CMOS inverter's characteristic and how to shift it in y axis. We control the MOS transistor threshold voltage for these methods. By observing that two transistors are in saturation region at the center of the CMOS inverter's characteristic, we have presented how to make the characteristic for one pole neuron. The circuit level simulation is used for verifying the proposed method. PSpice(OrCAD Co.) is used for circuit level simulation.

• Journal of IKEEE
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• v.24 no.4
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• pp.1011-1016
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• 2020

We propose a framework called Stacked Gated Recurrent Unit - Infrequent Residual Analysis (SG-IRA) that detects anomalies in time-series data that can be trained on streams of raw sensor data without any pre-labeled dataset. To enable such unsupervised learning, SG-IRA includes an estimation model that uses a stacked Gated Recurrent Unit (GRU) structure and an analysis method that detects anomalies based on the difference between the estimated value and the actual measurement (residual). SG-IRA's residual analysis method dynamically adapts the detection threshold from the population using frequency analysis, unlike the baseline model that relies on a constant threshold. In this paper, SG-IRA is evaluated using the industrial control systems (ICS) datasets. SG-IRA improves the detection performance (F1 score) by 5.9% compared to the baseline model.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.405-409
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• 2020

This paper proposes time management system for unmanned aerial vehicle (UAV) network. The computers of the UAVs need time synchronization that time offset does not exceed the minimum interval of data samples for errorless data blending between the computers. The proposed time management system is composed of time synchronization and general management systems for UAV control. The systems communicate each other for time information and control signals. The synchronization system uses improved version of existing time offset estimation that network time protocol (NTP) uses. The time synchronization is operated when the time offset of any UAV exceeds threshold that preconfigured by the general management system. The demonstration of prototype shows stable time synchronization satisfying preconfigured threshold.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.45-56
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• 2010

This paper reports a new mechanism for congestion controls. The proposed congestion detection algorithm can be provided with delay and unnecessary energy consumption. Conventional congestion control methods decide congestion by queue occupancy or mean packet arrival rate of MAC layer only, however, our method can perform precise detection by considering queue occupancy and mean packet arrival rate. In addition, the congestion avoiding method according to congestion degree and scheduling method using priority for real time packets are proposed. Finally, simulation results show that proposed congestion detection and control methods outperforms conventional scheduling schemes for wireless sensor network.

• Journal of Environmental Impact Assessment
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• v.14 no.5
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• pp.317-335
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• 2005

This paper is primarily intended to propose a new concept of "aggregate control of road density" which is defined as the area-wide road surface per watershed area. An empirical study for experimental sites was conducted to confirm how a standard GIS technology can be used to assist in estimating the road density in terms of total volume threshold control. Guidelines for a replicable methodology are presented to provide a strong theoretical basis for the standardization of factors involved in the estimation of the road space threshold; the meaningful classification of road types, delination of watershed boundary, interpretation for distribution trends of road density etc. A variety of visual maps using overlay analysis can be generated over large areas quickly and easily to show the fact that some degree of road space already exists in the experimental sites. They could be used as an evidence to limit further construction of road network in comparison with other tributary watershed. It is anticipated that this research output could be used as a valuable reference to confirm the potential of introducing the new concept of "site specific road density" to support more scientific and objective decision-making in the process of road construction project.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.133-145
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• 2008

The purpose of this study was to investigate the taste sensitivity in patients with oral mucosal diseases(Oral lichen planus(OLP), Recurrent apthous ulcer(RAU)) using electrogustometer. One hundred and seventy three subjects were included for the study and they were categorized into 2 groups(control 100, patient 73) and patient group was investigated in the Department of Oral Medicine, Pusan National University Hospital from April, 2005 until January, 2007. Control group was investigated in the clinics at Inchen Metroplitan city and Cheongju city from February to August, 2006. The electrical taste thresholds were measured by using an electrogustometer for the 4 different sites(tongue tip, tongue lateral, circumvallate papilla and soft palate) in oral cavity. The results were as follows ; 1. The electrical taste threshold in patient group was significantly decreased than that in the control group(p<0.001). 2. The electrical taste threshold, in terms of the chronicity and lesion multiplicity, was not significantly changed in patient group. 3. The electrical taste threshold was not significantly changed in Dexan only and Dexan+Prs combination treated group. 4. The electrical taste threshold, in terms of treatment progress(no response vs half response vs complete response), was not significantly changed. However subjective index which was determined by NAS(Numerical Analogy Scale) was significantly increased in no response group but significantly decreased in complete response group(p<0.001)

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.67-73
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• 2008

To investigate the change of taste sensitivity which follows after treatment for xerostomia, from September, 2006 to July, 2007, we categorized the patients, who were diagnosed as xerostomia in Oral Medicine, College of Dentistry, Busan National University, as subject group and from September, 2007 to December. The patients who were not diagnosed as systemic disease were categorized as control group. The results were as follows ; 1. Taste threshold comparison showed the differences at tongue lateral, tongue tip, circumvallate papilla between subject and control. 2. Taste threshold comparison showed no difference in male between subject and control. 3. Taste threshold comparison showed decrease in whole tongue except soft palate in female. 4. Taste threshold comparison showed no difference between first and second visit, but there was a tendency to change in circumvallate papilla.