• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4224-4243
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• 2021

Cognitive radio (CR) is a feasible intelligent technology and can be used as an effective solution to spectrum scarcity and underutilization. As the key function of CR, cooperative spectrum sensing (CSS) is able to effectively prevent the harmful interference with primary users (PUs) and identify the available spectrum resources by exploiting the spatial diversity of multiple secondary users (SUs). However, the open nature of the cognitive radio networks (CRNs) framework makes CSS face many security threats, such as, the malicious user (MU) launches Byzantine attack to undermine CRNs. For this aim, we make an in-depth analysis of the motive and purpose from the MU's perspective in the interweave CR system, aiming to provide the future guideline for defense strategies. First, we formulate a dynamic Byzantine attack model by analyzing Byzantine behaviors in the process of CSS. On the basis of this, we further make an investigation on the condition of making the fusion center (FC) blind when the fusion rule is unknown for the MU. Moreover, the throughput and interference to the primary network are taken into consideration to evaluate the impact of Byzantine attack on the interweave CR system, and then analyze the optimal strategy of Byzantine attack when the fusion rule is known. Finally, theoretical proofs and simulation results verify the correctness and effectiveness of analyses about the impact of Byzantine attack strategy on the throughput and interference.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.559-562
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• 2003

본 논문에서는 인터넷 역기능에 있어 가장 큰 문제로 인식되고 있는 음란사이트에 대한 현황과 이에 대한 지금까지의 정책적, 기술적 대응책에 대한 고찰을 행하고자 한다. 또한 지금까지의 기술적인 방법 등이 목록기반과 단어기반에 기초한 방법이기 때문에 음란사이트 차단이 제대로 되지 않은 경우가 있었다. 이를 위해 본 논문에서는 신호처리에 기반한 음란 유해 사이트에 대한 차단 방법을 제안하고자 한다. 특히 본 논문은 음란 유해 사이트에 대한 현황과 전체 시스템의 개요, 그리고 음향분석에 기초한 음란 유해 사이트 차단 방법에 대해 주로 다루고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.563-566
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• 2003

음란 유해 사이트는 70만개에 육박하고 있으며 초등학생들에게도 매일 평균 2개씩의 음란 사이트 안내에 대한 메일이 가고 있는 등 이에 대한 사회적 대응이 필요한 시점이 되었다. 특히 한글로 된 음란 유해 사이트가 세계 2위이며 그 증가율은 세계 1위인 상황이기 때문에 더 더욱 이를 차단하기 위한 기술적 방법론이 개발되어야만 하는 실정이다. 본 논문에서는 이를 위해 신호처리기법에 기반한 음란 유해 사이트 차단 방법을 제안하고자 한다. 전체 시스템중 본 논문은 영상에 기반하여 음란 유해 사이트를 차단하는 방법을 제안하고자하며 실험에 의해 본 논문의 유용성을 입증하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.645-648
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• 2004

본 논문은 유해콘텐츠를 접속하는 동기를 통하여 이를 효과적으로 차단하기 위한 전체적 방법에 대한 제시를 행하고자 한다. 이를 위해 첫째, 인터넷 유해 콘텐츠의 접속 동기를 분석한다. 또한 인터넷 유해 콘텐츠를 접속하는데 있어 가장 큰 요소인 스팸메일에 대해 실태 파악 및 분석을 행하고자 한다. 이를 위해 우선적으로 스팸메일이 증가하는 이유, 스팸메일 발송자가 전자우편을 수집하는 방법 그리고 각종 스팸메일 방지 방안 및 스팸 방지 기술에 대해 기술하고자 한다. 또한 수신측에서 행해지고 있는 스팸메일 차단에 대해 여과를 안 하는 이유 등에 대해 조사함으로써 스팸메일 차단에 대한 연구 방향을 잡기 위한 기초 자료로 삼고자 하며 이를 기초로 이메일을 수집 단계에서부터 차단이 이루어 지게 하기 위한 종합적 차단 방법에 대해 제안하고자 한다.

• Journal of The Korean Association of Information Education
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• v.12 no.2
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• pp.203-211
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• 2008

The purpose of this study was to develop an education system to protect elementary school students from inappropriate information and verify the effect of the program. It was deemed necessary that an education system be developed for the cultivation of appropriate information selection and self-censorship of inappropriate Internet information. To this time, however, schools have not placed great importance on this concept because of the lack of the documents and the teaching strategies. Our system gives support on three levels to a learning course according to collected documentation. The learner receives not only feedback activities and results from others and the teacher, but also counsel from the teacher about difficulties. The system implementing this methodology indicated that both the students' recognition of harmful information and their moral values were improved as the result of applying the system in a local elementary school.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.829-835
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• 2017

Recently, the health issues triggered by fine dust matters occurred in higher frequency. Having adverse effects on health, particulate matters affect the human body indoors as well as outdoors. There is thus a need for a system to measure the concentration of particulate matters and control harmful particulate matters for human health in the indoor spaces where people live. The present study applied Internet of Things(IoT) technologies in order to increase the efficiency of the conventional fine dust measurement system. Especially, for the bidirectional communication environment, directly construct a separate server and applied to the system instead of a free cloud server also we used it directly in the school lab and home. When the proposed system is used in schools and homes, it can recognize the indoor environment quickly and it is expected that this will gradually contribute to the health of the individual. Users can also check the server data outside and deal with the current indoor situations.

• Journal of Internet Computing and Services
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• v.14 no.3
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• pp.35-46
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• 2013

As mobile terminal environment gets matured, the use of Android platform based mobile terminals has been growing high. Recently, the number of attacks by malicious application is also increasing as Android platform is vulnerable to private information leakage in nature. Most of these malicious applications are easily distributed to general users through open market or internet and an attacker inserts malicious code into malicious app which could be harmful tool to steal private data and banking data such as SMS, contacts list, and public key certificate to a remote server. To cope with these security threats more actively, it is necessary to develop countermeasure system that enables to detect security vulnerability existing in mobile device and take an appropriate action to protect the system against malicious attacks. In this sense, this paper aggregates diverse system events from multiple mobile devices and also implements a system to detect attacks by malicious application.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.8
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• pp.2688-2703
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• 2022

Research on the advanced detection of harmful objects in airport cargo for passenger safety against terrorism has increased recently. However, because associated studies are primarily focused on the detection of relatively large objects, research on the detection of small objects is lacking, and the detection performance for small objects has remained considerably low. Here, we verified the limitations of existing research on object detection and developed a new model called the Small Hazardous Object detection enhanced and reconstructed Model based on the You Only Look Once version 5 (YOLOv5) algorithm to overcome these limitations. We also examined the performance of the proposed model through different experiments based on YOLOv5, a recently launched object detection model. The detection performance of our model was found to be enhanced by 0.3 in terms of the mean average precision (mAP) index and 1.1 in terms of mAP (.5:.95) with respect to the YOLOv5 model. The proposed model is especially useful for the detection of small objects of different types in overlapping environments where objects of different sizes are densely packed. The contributions of the study are reconstructed layers for the Small Hazardous Object detection enhanced and reconstructed Model based on YOLOv5 and the non-requirement of data preprocessing for immediate industrial application without any performance degradation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.231-239
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• 2021

The purpose of this study was to understand how a dental hygienist is viewed by students in terms of both image and job /employment perception using structural equations. This together with the incorporation of available online information would help in collating the necessary data for ensuring adequate manpower of dental hygienists' in the future. The collected data were analyzed using SPSS Statistics 24.0 and AMOS Graphics 21.0 statistics packages. It was found that students who perceive employment positively have a positive image of a dental hygienist even if a new infectious disease were to occur. They appreciate that a negative image of a dental hygienist's job during an epidemic could cause a negative perception of employment as a dental hygienist. Those who think negatively of the internet as a source of information believe that the internet has a lot of false information, is harmful, promotes anxiety, and has been shown to promote negative perceptions about employment as a dental hygienist. Those who think positively of internet information think that dental hygienists are susceptible to infection and can transmit infection, which has been shown to negatively affect their perception of employment. In conclusion, it is important to form an image of a dental hygienist through the recognition of the correct internet information in the period of new infectious diseases.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.168-168
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• 2004