• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권12호
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• pp.6175-6189
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• 2019

To slove the security and efficiency problem of anonymous authentication in vehicular ad-hoc network (VANET), we adopt the bilinear pairing theory to propose an identity-based batch anonymous authentication scheme for VANET. The tamper-proof device in the on-board unit and the trusted authority jointly realize the anonymity of vehicle identity and the signature of messages, which further enhances the security of this scheme, as well as reduces the overhead of trusted authority. Batch authentication can improve the efficiency of anonymous authentication for VANET. Security and efficiency analyses demonstrate that this scheme not only satisfies such security properties as anonymity, non-forgeability and non-repudiation, but also has advantage in time and space complexity. Simulation results show that this scheme can achieve good performance in real-time VANET communication.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1264-1286
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• 2018

In this paper, a novel background prior-based salient object detection framework is proposed to deal with images those are more complicated. We take the superpixels located in four borders into consideration and exploit a mechanism based on image boundary information to remove the foreground noises, which are used to form the background prior. Afterward, an initial foreground prior is obtained by selecting superpixels that are the most dissimilar to the background prior. To determine the regions of foreground and background based on the prior of them, a threshold is needed in this process. According to a fixed threshold, the remaining superpixels are iteratively assigned based on their proximity to the foreground or background prior. As the threshold changes, different foreground priors generate multiple different partitions that are assigned a likelihood of being foreground. Last, all segments are combined into a saliency map based on the idea of similarity voting. Experiments on five benchmark databases demonstrate the proposed method performs well when it compares with the state-of-the-art methods in terms of accuracy and robustness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권5호
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• pp.1653-1670
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• 2022

The fear that location privacy may be compromised greatly hinders the development of location-based service. Accordingly, some schemes based on the distributed architecture in peer-to-peer network for location privacy protection are proposed. Most of them assume that mobile terminals are mutually trusted, but this does not conform to realistic scenes, and they cannot make requirements for the level of location privacy protection. Therefore, this paper proposes a scheme for location attribute-based security authentication and private sharing data group, so that they trust each other in peer-to-peer network and the trusted but curious mobile terminal cannot access the initiator's query request. A new identifier is designed to allow mobile terminals to customize the protection strength. In addition, the caching mechanism is introduced considering the cache capacity, and a cache replacement policy based on deep reinforcement learning is proposed to reduce communications with location-based service server for achieving location privacy protection. Experiments show the effectiveness and efficiency of the proposed scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5218-5233
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• 2018

The coexisting wireless body area networks (WBAN) is a very challenging issue because of strong inter-networks interference, which seriously affects energy consumption and spectrum utilization ratio. In this paper, we study a power control strategy with nearest neighbor nodes distribution for coexisting WBAN based on stochastic geometry. Using homogeneous Poisson point processes (PPP) model, the relationship between the transmission power and the networks distribution is analytically derived to reduce interference to other devices. The goal of this paper is to increase the transmission success probability and throughput through power control strategy. In addition, we evaluate the area spectral efficiency simultaneously active WBAN in the same channel. Finally, extensive simulations are conducted to evaluate the power control algorithm.

• International Journal of Computer Science & Network Security
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• 제21권5호
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• pp.199-210
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• 2021

Recently, research in blockchain technology has grown in popularity. Most of these researches have pointed out designing and improving conceptual structures to create digital systems that are more secure, accessible, and effective. Although blockchain offers a wide range of advantages, it also has some pitfalls. This research aims to present an understanding of the properties of blockchain, the advantages, pitfalls, and applications based on blockchain technology. To achieve the goal of understanding blockchain technology concepts, a systematic literature review approach was introduced. 93 papers were chosen and reviewed in total. Therefore, this research provides a summary of recent studies that have been published in the field of blockchain. Moreover, we have created concept maps and tables that aid in a deep understanding of blockchain technology concepts and exhibit some of the blockchain applications. In blockchain-based applications, we focused on two areas, namely the Internet of Things (IoT) and healthcare.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (A)
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• pp.98-99
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• 2007

• 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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• 한국정보과학회언어공학연구회 2002년도 제14회 한글 및 한국어 정보처리 학술대회
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• pp.277-284
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• 2002

본 논문은 신문기사에서 중요한 문장을 추출(Extract)하는데 있어서, 기존에 기장 우수한 방법인 전문기반 방법(Lead-based method)과 제목을 이용한 유사도 측정방법(Title-based method)의 문제점을 해결하기 위해서, 육하원칙 활성화도를 이용하여 신문기사를 효과적으로 요약할 수 있는 방법과 알고리즘을 제안하였다. 본 연구에서는 먼저, 제목(Title)과 전문(Lead)에서 중복출현하지 않는 육하원칙 구성성분을 결합하고, 본문은 각 문장에서 육하원칙 구성성분의 재사용성과 육하원칙 구성성분의 범주 증감을 파악하여 육하원칙 활성화도를 구하고, 전문기반 방법을 응용하여 각 문장의 상대적인 중요도에 따라 최종적인 가중치를 부여함으로써, 신문기사에서 중요한 문장을 효과적으로 추출할 수 있는 가중치 계산식을 제안하였다. 실험문서는 조선일보 웹사이트에서 제공하는 신문기사 100건을 대상으로 하였으며, 요약율이 30%일 경우 제안한 방법의 정확률은 74.7%로 기존의 전문기반(Lead-based method)방법보다 6.7% 향상되었다.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.65-71
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• 2006

Based on the smoothness criterion of minimum curvature variation of the curve, tangent angle constraints guaranteeing an optimized geometric Hermite (OGH) curve both mathematically and geometrically smooth is given, and new methods for constructing composite optimized geometric Hermite (COH) curves are presented in this paper. The comparison of the new methods with Yong and Cheng's methods based on strain energy minimization is included.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1571-1574
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• 2004

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권11호
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• pp.4268-4289
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• 2020

Advanced traffic signal timing method plays very important role in reducing road congestion and air pollution. Reinforcement learning is considered as superior approach to build traffic light timing scheme by many recent studies. It fulfills real adaptive control by the means of taking real-time traffic information as state, and adjusting traffic light scheme as action. However, existing works behave inefficient in complex intersections and they are lack of feasibility because most of them adopt traffic light scheme whose phase sequence is flexible. To address these issues, a novel adaptive traffic signal timing scheme is proposed. It's based on actor-critic reinforcement learning algorithm, and advanced techniques proximal policy optimization and generalized advantage estimation are integrated. In particular, a new kind of reward function and a simplified form of state representation are carefully defined, and they facilitate to improve the learning efficiency and reduce the computational complexity, respectively. Meanwhile, a fixed phase sequence signal scheme is derived, and constraint on the variations of successive phase durations is introduced, which enhances its feasibility and robustness in field applications. The proposed scheme is verified through field-data-based experiments in both medium and high traffic density scenarios. Simulation results exhibit remarkable improvement in traffic performance as well as the learning efficiency comparing with the existing reinforcement learning-based methods such as 3DQN and DDQN.