• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1015-1018
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• 2015

모바일 디바이스가 기존이 PC 시장규모를 압도하면서 기하급수적으로 많은 모바일 앱이 출시되고 있다. 수많은 모바일 앱 중에서 사용자들은 배우기 쉽고, 직관적으로 사용하기에 용이한 모바일 앱을 선택하려는 경향을 보인다. 그러나 모바일 앱 사용성의 중요성이 증대됨에도 불구하고 모바일 앱에서의 사용성에 대한 연구는 미미한 실정이다. 현 GUI 사용성 테스트는 많은 시간이 소요되고 주관적인 평가에 의존하는 단점이 존재한다. 본 논문은 사용자들이 앱을 조작하는 터치 입력 데이터를 기반하여 EFSM(Extended Finite State Machine)에 인자를 추가한 형태로 모델링 후 개발자의 예상 시나리오와 비교하여 GUI 사용성 저해요소를 검출하는 기법을 제안하고 있다. 이와 같은 반-자동화된 방법을 통해 모바일 앱 상에서의 사용성을 측정할 수 있다. 제안된 기법을 구현한 도구의 구조를 설명하고 사용성 저해 요소 검출하는 과정을 기술하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6214-6242
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• 2019

Routing in mobile ad hoc networks is performed in a distributed fashion where each node acts as host and router, such that it forwards incoming packets for others without relying on a dedicated router. Nodes are mostly resource constraint and the users are usually inclined to conserve their resources and exhibit selfish behaviour by not contributing in the routing process. The trust and reputation models have been proposed to motivate selfish nodes for cooperation in the packet forwarding process. Nodes having bad trust or reputation are detected and secluded from the network, eventually. However, due to the lack of proper identity management and use of non-persistent identities in ad hoc networks, malicious nodes can pose various threats to these methods. For example, a malicious node can discard the bad reputed identity and enter into the system with another identity afresh, called whitewashing. Similarly, a malicious node may create more than one identity, called Sybil attack, for self-promotion, defame other nodes, and broadcast fake recommendations in the network. These identity-based attacks disrupt the overall detection of the reputation systems. In this paper, we propose a reputation-based scheme that detects selfish nodes and deters identity attacks. We address the issue in such a way that, for normal selfish nodes, it will become no longer advantageous to carry out a whitewash. Sybil attackers are also discouraged (i.e., on a single battery, they may create fewer identities). We design and analyse our rationale via game theory and evaluate our proposed reputation system using NS-2 simulator. The results obtained from the simulation demonstrate that our proposed technique considerably diminishes the throughput and utility of selfish nodes with a single identity and selfish nodes with multiple identities when compared to the benchmark scheme.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.95-99
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• 2002

3.5KHz subbottom profiling systems are useful for delineating of shallow (up to 10~100m below the sea bottom) geological structure. These systems are generally used to image geological structures with less than 1m of vertical resolution. However swell in the sea is quite often higher than 1m, causing degradation in the quality of the 3.5KHz subbottom profiles. In this paper, we show the quality of digitally recorded data can be enhanced by the suppression of swell effect. Prior to suppression of swell effect, sea bottom detection procedure was applied using the characteristics that the amplitude of sea bottom reflection is high. To suppress the swell effect, we applied moving average method and high-cut filtering method using the extracted water depth of adjacent traces. Acceptable results were obtained from both methods. In the case of bad quality data or shallow data interfered with direct wave, the suppression of swell effect is difficult due to incorrect sea bottom detection.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.27-34
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• 2013

In wireless sensor networks, sensors need to communicate with each other to send their sensing data to the administration node and so they are susceptible to many attacks like garbage packet injection that cannot be prevented by using traditional cryptographic approaches. A behavior-based detection is used to defend against such attacks in which some specialized monitoring nodes overhear the communications of their neighbors to detect bad packets. As monitoring nodes use more energy, it is desirable to use the minimal number of monitoring nodes to cover the whole or maximal part of the network. The monitoring nodes can either be selected among the deployed normal nodes or differ in type from normal nodes. In this study, we have developed an algorithm for selecting the predefined number of monitoring nodes needed to cover the maximum number of normal nodes when the different types of normal nodes and monitoring nodes are deployed. We also have investigated experimentally how the number of monitoring nodes and their transmission range affect the connection ratio of the monitoring nodes and the coverage of the normal nodes.

• Journal of Radiation Protection and Research
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• v.33 no.4
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• pp.173-181
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• 2008

To ensure the performance of radon detectors, three passive radon detectors ($RadTrak^{(R)}$, $Radopot^{(R)}$, and $E-PERM^{(R)}$)have been reviewed. The difference ratios of RadTrak and Radopot tested in the radon standard chamber were -13.2% and -6.0%, respectively, which were in good accordance within 20% of the value measured by $AlphaGUARD^{(R)}$. To ensure the performance of the long term measurement, the 3 detectors were installed at the same position of approximately one hundred of dwellings for one year. The correlation curve between RadTrak and Radopot shows good agreement with a correlation coefficient ($R^2$) of 0.91. However, The correlation curve between E-PERM and Radopot shows bad agreement ($R^2$ = 0.021). In addition, the distribution map of annual mean indoor gamma dose rate measured with E-PERM was not in accordance with the distribution map of outdoor gamma dose rate measured by Portable Ion Chamber. According to the results, some requisites for the selection of the radon passive detectors in the large-scale indoor radon survey were discussed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.4
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• pp.55-62
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• 2007

This paper proposes a defective pixel detection algorithm and its hardware structure for CCD/CMOS image sensor. In previous algorithms, the characteristics of image have not been considered. Also, some algorithms need quite a time to detect defective pixels. In order to make up for those disadvantages, the proposed defective pixel detection method detects defective pixels efficiently by considering the edges in the image and verifies them using several frames while checking scene-changes. Whenever scene-change is occurred, potentially defective pixels are checked and confirmed whether it is defective or not. Test results showed that the correct detection rate in a frame was increased 6% and the defective pixel verification time was decreased 60%. The proposed algorithm was implemented with verilog HDL. The edge indicator in color interpolation block was reused. Total logic gate count was 5.4k using 0.25um CMOS standard cell library.

• Smart Media Journal
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• v.12 no.10
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• pp.71-84
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• 2023

Paralichthys olivaceus accounts for a large proportion, accounting for more than half of Korea's aquaculture industry. However, about 25-30% of the total breeding volume throughout the year occurs due to diseases, which has a very bad impact on the economic feasibility of fish farms. For the economic growth of Paralichthys olivaceus farms, it is necessary to quickly and accurately diagnose disease symptoms by automating the diagnosis of Paralichthys olivaceus diseases. In this study, we create training data using innovative data collection methods, refining data algorithms, and techniques for partitioning dataset, and compare the Paralichthys olivaceus disease symptom detection performance of four object detection deep learning models(such as YOLOv8, Swin, Vitdet, MvitV2). The experimental findings indicate that the YOLOv8 model demonstrates superiority in terms of average detection rate (mAP) and Estimated Time of Arrival (ETA). If the performance of the AI model proposed in this study is verified, Paralichthys olivaceus farms can diagnose disease symptoms in real time, and it is expected that the productivity of the farm will be greatly improved by rapid preventive measures according to the diagnosis results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1950-1958
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• 2016

Today, technique for precisely positioning vehicles is very important in C-ITS(Cooperative Intelligent Transport System), Self-Driving Car and other information technology relating to transportation. Though the most popular technology for vehicle positioning is the GPS, its accuracy is not reliable because of large delay caused by multipath effect, which is very bad for realtime traffic application. Therefore, in this paper, we proposed the Vision-Based High Accuracy Vehicle Positioning Technology. At the first step of proposed algorithm, the ROI is set up for road area and the vehicles detection. Then, center and four corners points of found vehicles on the road are determined. Lastly, these points are converted into aerial view map using homography matrix. By analyzing performance of algorithm, we find out that this technique has high accuracy with average error of result is less than about 20cm and the maximum value is not exceed 44.72cm. In addition, it is confirmed that the process of this algorithm is fast enough for real-time positioning at the $22-25_{FPS}$.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.295-301
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• 2010

Flow accelerated corrosion(FAC) of carbon steel pipes in nuclear power plants has been known as one of the major degradation mechanisms. It could have bad influence on the plant reliability and safety. Also detection of FAC is a significant cost to the nuclear power plant because of the need to remove and replace insulation. Recently, the interest of the guided wave testing(GWT) has grown because it allows long range inspection without removing insulation of the pipe except at the probe position. If GWT can be applied to detection of FAC damages, it will can significantly reduce the cost for the inspection of the pipes. The objective of this study was to determine the capability of GWT to identify location of FAC damages. In this paper, three kinds of techniques were used to measure the amplitude ratio between the first and the second welds at the elbow area of mock-ups that contain real FAC damages. As a result, optimal inspection technique and minimum detectability to detect FAC damages drew a conclusion.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.67-73
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• 2001

This paper resents a developed measuring device of resistive leakage current and a fundamental discussion of deterioration diagnosis for Zinc Oxide(ZnO) arrester blocks. We have developed the leakage current detection device for ageing test and durability evaluation for ZnO arrester blocks. The resistive leakage current can be used as an indicator to discriminate whether the ZnO arrester blocks is in good state or in bad. The resistive leakage current measuring system with the compensation circuit was designed and fabricated. The sauce tests for ZnO arrester blocks were investigated by observing the resistive leakage current together with fast Fourier transform analysis. The proposed monitoring systems for the resistive leakage current can effectively be used to investigate the electrophysical properties of ZnO arrester blocks in laboratory and to develop the techniques of forecasting the deterioration of ZnO arresters in electric power systems.