• 정보보호학회논문지
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• 제25권2호
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• pp.479-487
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• 2015

IT 발전에 따라 스마트홈 서비스는 네트워크 기반의 스마트 디바이스를 통해 원격 서비스, 모니터링 서비스 등 다양한 서비스를 제공하고 있다. 그러나 스마트홈 환경에서는 악성 디바이스를 통한 데이터 위 변조, 불법 인증, 프라이버시 침해 등과 같은 보안 위협들이 존재한다. 이러한 보안 위협들에 대응하기 위한 스마트홈 환경에서의 보안에 대한 연구가 활발히 진행되고 있으나 디바이스 관리를 위한 연구는 초기 단계에 머물고 있으며, 스마트홈 환경에서의 그룹키 관리에 대한 연구가 부족한 실정이다. 따라서 본 논문에서는 스마트홈 환경에서 안전한 디바이스 관리를 위한 그룹키 관리 기법을 제안한다.

• 한국군사과학기술학회지
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• 제13권2호
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• pp.296-303
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• 2010

The term "spoofing" refers to the transmission of counterfeit signals to provide undetectable falsification of GPS service. A spoofing can be accomplished using information from open literature which defines the signal format and the data structure. Spoofing is intended either to produce erroneous navigation solutions or saturate the processor of the victim receiver. The GPS receiver has no way to get rid of the effect of a spoofing because GPS receivers for civil service do not have an anti-spoofing scheme. This paper analyzes the spoofing characteristics, spoofing methods and environment conditions. And the spoofing effects on GPS receiver are analyzed in detail using the designed software-based spoofer and the Nordnav receiver.

• 대한임베디드공학회논문지
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• 제12권4호
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• pp.259-266
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• 2017

GPS was developed for military purposes. As a result, it is used as a military important means such as guided weapons and strategy / tactics. However, GPS depends on the communication infrastructure and is affected by interference signals. In this paper, we propose a secure micro - web page - based smart map that can enhance security without relying on communication infrastructure on the battlefield. The proposed system consists of general smartphone, security QR, central server and smart map. Only use the network when downloading the security key and SmartMap before the task starts. During operation, the smartphone transmits and receives data using a secure QR. The security QR inserts the security code to prevent forgery and falsification and confirms whether the data is authentic by checking whether the smart phone is forged or not. As a result of implementation, we solved communication security problem of existing technology by using location based service without relying on communication infrastructure.

• 노동경제논집
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• 제39권3호
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• pp.75-97
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• 2016

본 논문에서는 학업성취도가 낮은 학생이 학업성취도가 보통 이상 학생의 학업성취도에 미치는 친구효과를 추정하였다. 친구효과 추정을 위해 2009년에 시행되었던 학력향상중점학교 정책이 수반하는 회귀불연속설계를 이용하였다. 중학교를 대상으로 한 국가수준 학업성취도 평가 전수 자료를 이용하여 분석한 결과, 이러한 친구효과는 존재하였음을 확인하였다. 구체적으로는 학력향상중점학교 정책으로 학업성취도 미달학생 비중이 1%p 감소할 때, 보통 이상 학생의 비중이 5%p 이상 증가하였다. 더 나아가서 이러한 친구효과는 다양한 강건성 검정 하에서도 여전히 존재함을 보였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3414-3434
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• 2016

Classical key generation is complicated to update and key distribution generally requires fixed infrastructures. In order to eliminate these restrictions researchers have focused much attention on physical-layer (PHY-layer) based key generation methods. In this paper, we present a PHY-layer fingerprints based fuzzy key generation scheme, which works to prevent primary user emulation (PUE) attacks and spectrum sensing data falsification (SSDF) attacks, with multi-node collaborative defense strategies. We also propose two algorithms, the EA algorithm and the TA algorithm, to defend against eavesdropping attacks and tampering attacks in mobile cognitive radio networks (CRNs). We give security analyses of these algorithms in both the spatial and temporal domains, and prove the upper bound of the entropy loss in theory. We present a simulation result based on a MIMO-OFDM communication system which shows that the channel response characteristics received by legitimates tend to be consistent and phase characteristics are much more robust for key generation in mobile CRNs. In addition, NIST statistical tests show that the generated key in our proposed approach is secure and reliable.

• 스마트미디어저널
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• 제4권4호
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• pp.9-17
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• 2015

최근 지능형 범죄가 늘면서 첨단 보안 기술에 대한 요구가 점차 늘어나고 있다. 현재까지 보고된 위, 변장 영상 검출방법은 실용화를 위하여 정확도 개선이 요구된다. 본 논문에서는 사람의 얼굴에 대하여 동공의 반사도를 이용하여 위조 영상을 판별하고 아다부스트를 이용하여 만든 얼굴 부분별 검출기를 사용한 얼굴 변장 영상을 판별한다. 제안된 시스템은 다중 스케일 가버 특징 벡터를 기반으로 눈의 위치를 찾은 후 템플릿 매칭을 통해서 정확히 찾아진 눈 위치의 동공을 조사하여 최대값과 최소값을 구하여 위조 여부를 판별하고 부분별 검출기를 사용하여 눈과 코의 검출 여부를 판단하여 각각 선글라스와 마스크의 착용 여부를 판단하고 선글라스&마스크 검출기를 사용하여 얼굴이 검출되지 않았을 경우를 대비하였다. 실험을 통하여 본 논문에서 제안한 방법이 더욱 신뢰성 높은 위, 변장판별시스템임을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2067-2080
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• 2016

Cooperative spectrum sensing (CSS) for vacant licensed bands is one of the key techniques in cognitive radio networks. Currently, sequential probability ratio test scheme (SPRT) is considered as a powerful soft decision approach to improve the sensing result for CSS. However, SPRT assumes all secondary users (SU) are honest, and thus offering opportunities for malicious SUs to launch the spectrum sensing data falsification attack (SSDF attack). To combat such misbehaved behaviors, recent efforts have been made to trust mechanism. In this paper, we argue that powering SPRT with traditional trust mechanism is not enough. Dynamic SSDF attackers can maintain high trust in an alternant process of submitting honest or false sensing data, resulting in difficultly detecting them. Noting that the trust value of dymamic SSDF attackers behave highly volatile, a novel trusted SPRT scheme (VSPRT) based on volatility decay analysis is proposed in this paper to mitigate the harmful effect of dynamic SSDF attackers in the process of the soft-decision data fusion, and thus improving the accuracy of the final sensing result. Simulation results show that the VSPRT scheme outperforms the conventional SPRT schemes.

• 무역상무연구
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• 제70권
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• pp.109-133
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• 2016

As for Korea, China is very important because of an advantageous geological accessibility and high economic dependency. Therefore, the Korean government announced its plan to establish 5billion dollars' investment from Greater China (including Hong Kong and Singapore) and the government has put much effort into accommodating more Chinese investment by diversifying investment channels from Greater China. Under this major Chinese investment boom, it is crucial to conduct in-depth research on accommodation of Chinese investment and create a plan to establish Chinese capital investment that will benefit both the investing country and the countries receiving the investment. Hence, the present study analyzed current trends in Chinese investment for the Korean market, focusing on the stimulation methodology for establishing greater investment from China. To this end, this paper examined various investment characteristics of Chinese investors for the Korean market by researching investment development levels on different time lines and analyzing Chinese investment in Korea for a variety of industries. Through the research, the following study derived a more effective strategy to accommodate greater Chinese capital investment. There has been a worldwide increase in the number of letter of credit cases involving fraud recently. It may happen that the documents which are tendered to the banks under a documentary credit are forged, altered or fraudulent. Banks assume no liability or responsibility for the form, sufficiency, accuracy, genuineness or falsification of any documents.

• 한국지구과학회지
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• 제41권4호
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• pp.405-414
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• 2020

In this study, we analyzed the development of high school students' argumentation through their writings on socio-scientific Issues (SSI) related to the Climate Change Unit in the Earth Science I curriculum. Pre- and post-writing assignments on the two main causes of global warming were analyzed and compared. In addition, an in-depth interview of the focus group was conducted with 7 students who showed a distinct change in the level of argumentation. According to the results, 16 of 52 students remained at the same argumentation level in pre- and post-writing assignments, and students remaining at Level 2 among five levels had difficulty in understanding the Toulmin's argument pattern (TAP) structure. Using the TAP structure, 29 of 52 students demonstrated increased argumentation levels in the post-writing assignments. The conclusions include that writing lessons on SSI using the TAP in Earth science classes can improve the level of high school students' argumentative writing, and that the level of students' argumentation can develop with the elaboration of their level of falsification. Also, it is suggested that the science curriculum should increase students' science writing competencies by specifying science writing as one of the goals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.1-17
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• 2014

Cooperative spectrum sensing (CSS) is considered as a powerful approach to improve the utilization of scarce radio spectrum resources. However, most of CSS schemes assume all secondary users (SU) are honest, and thus offering opportunities for malicious SUs to launch the spectrum sensing data falsification attack (SSDF attack). To combat such misbehaved behaviors, recent efforts have been made to trust schemes. In this paper, we argue that powering CSS with traditional trust schemes is not enough. The rational SSDF attack is found in this paper. Unlike the simple SSDF attack, rational SSDF attackers send out false sensing data on a small number of interested primary users (PUs) rather than all PUs. In this case, rational SSDF attackers can keep up high trustworthiness, resulting in difficultly detecting malicious SUs in the traditional trust schemes. Meanwhile, a defense scheme using a novel trust approach is proposed to counter rational SSDF attack. Simulation results show that this scheme can successfully reduce the power of rational SSDF, and thus ensure the performance of CSS.