Korea Institute of Patent Information

Seoul, South Korea

Korea Institute of Patent Information

Seoul, South Korea
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Bok K.-S.,Chungbuk National University | Kwak D.-W.,Korea Institute of Patent Information | Yoo J.-S.,Chungbuk National University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

In this paper, we propose a resource discovery scheme of mobile P2P with data dissemination that considers the interests and mobility of the peer. The proposed scheme manages a local information table, a resource index table, and a routing table in local database to enhance the accuracy and cost of the resource discovery. Each peer is recognized through a signal function and then the cost of data dissemination is reduced by timestamp messages. The transmitted resource is stored in the resource index table by ranking function. Our ranking function considers the distance, direction and peer's interest item in order to improve the performance of a resource discovery. © 2011 Springer-Verlag.


Kim K.-S.,Korea Institute of Patent Information | Jin G.-W.,Woosong University
Communications in Computer and Information Science | Year: 2012

To find a balance point of quality required and network lifetime is a significant topic in wireless sensor network. In this paper, a duty-cycle type sleep/wakeup scheme with the barriers coverage is addressed to balance prolonged network lifetime and object detection quality. Proposed algorithm builds intruder detecting groups of sensor nodes and calculates the optimal duty-cycle ratio. The simulation results show network lifetime is prolonged with objective detection quality met. © 2012 Springer-Verlag.


Bok K.S.,Chungbuk National University | Kwak D.W.,Korea Institute of Patent Information | Yoo J.S.,Chungbuk National University
KSII Transactions on Internet and Information Systems | Year: 2012

Recently, along with the innovative development of wireless communication techniques and mobile devices, mobile P2P services in mobile wireless networks have gained a lot of attention. In this paper, we propose a resource discovery scheme with data dissemination over mobile P2P networks. In the proposed scheme, each peer manages a local information table, a resource index table, and a routing table in a local database to enhance the accuracy and cost of resource discovery. The local information table stores the status of a mobile peer, and the resource index table stores the resource information of the neighbor peers via the ranking function. The routing table is used to communicate with the neighbor peers. We use a timestamp message to determine whether or not the resource index table will be changed before the resource information is exchanged. Our ranking function considers the interest and mobility of the mobile peer and prioritizes the resource information transmitted from the neighbor peers. It is shown via various experiments that the proposed scheme outperforms the existing scheme. © 2012 KSII.


Lee K.,Hanyang University | Ko K.-Y.,Korea Institute of Patent Information | Ahn J.,Hanyang University
Thin Solid Films | Year: 2013

This paper reports a simple process to enhance the extraction efficiency of photoluminescence from Eu-doped yttrium oxide (Y2O3: Eu3 +) thin-film phosphor. The two-dimensional (2D) SiO2 photonic crystal layer was fabricated by vacuum nano-imprint method using a conventional spin-on dielectric solution as a nano-imprint resin and a 2D patterned Si stamp. The applied pressure and temperature of the patterning and annealing process facilitates the conversion of the spin-on dielectric solution into a SiO2 hemisphere structure resulting in high definition transfer of the 2D reverse pattern of the Si mold. The light extraction efficiency of the Y2O3: Eu3 + thin-film phosphor assisted by 2D SiO2 photonic crystal layer was approximately 1.72 times higher than that of the conventional Y2O3: Eu3 + thin-film phosphor. © 2013 Elsevier B.V.


Kim K.-K.,Hanyang University | Ko K.-Y.,Korea Institute of Patent Information | Ahn J.,Hanyang University
Journal of Nanoscience and Nanotechnology | Year: 2013

This paper reports simple process to enhance the extraction efficiency of photoluminescence (PL) from Eu-doped yttrium oxide (Y2O 3:Eu3+) thin-film phosphor (TFP). Two-dimensional (2D) photonic crystal layer (PCL) was fabricated on 2O3:Eu 3+ phosphor films by reverse nano-imprint method using TiO 2 nanoparticle solution as a nano-imprint resin and a 2D hole-patterned PDMS stamp. Atomic scale controlled Al2O3 deposition was performed onto this 2D nanoparticle PCL for the optimization of the photonic crystal pattern size and stabilization of TiO2 nanoparticle column structure. As a result, the light extraction efficiency of the 2O3:Eu3+ phosphor film was improved by 2.0 times compared to the conventional 2O3:Eu3+ phosphor film. Copyright © 2013 American Scientific Publishers.


Ryu J.T.,Korea Institute of Patent Information | Ron B.-H.,Ajou University | Ryu K.Y.,Ajou University | Yoon M.,Dankook University
KSII Transactions on Internet and Information Systems | Year: 2012

Owing to its simplicity and flexibility, the session initiation protocol (SIP) has been widely adopted as a major session-management protocol for Internet telephony or Voice-over IP (VoIP) services. However, SIP has faced various types of security threats. Call-disruption attacks are some of the most severe threats they face, and can greatly inconvenience consumers. In this paper, we analyze such SIP call-disruption attacks, and propose a method for detecting and counteracting them by extending the SIP INFO method with authentication. Using the proposed method, both the target user and the SIP server can detect the existence of a call-disruption attack on a user and counteract the attack. We demonstrate the effectiveness of the proposed method from the viewpoint of computational complexity by configuring a test-bed with an Asterisk SIP proxy server and an SIP performance (SIPp) emulator. © 2012 KSII.


Yu J.H.,Yonsei University | Yu J.H.,Daegu Gyeongbuk Medical Innovation Foundation | Cho S.O.,Yonsei University | Cho S.O.,Korea Institute of Patent Information | And 3 more authors.
International Journal of Biochemistry and Cell Biology | Year: 2015

Ataxia telangiectasia (AT) is caused by mutational inactivation of the ataxia telangiectasia mutated (Atm) gene, which is involved in DNA repair. Increased oxidative stress has been shown in human AT cells and neuronal tissues of Atm-deficient mice. Heme oxygenase-1 (HO-1) is an inducible antioxidant enzyme and protects cells against oxidative stress. The purpose of this study is to determine whether ATM induces antioxidant enzyme HO-1 and protects cells from oxidative stress-mediated apoptosis by driving the activation of PKC-δ and NF-κB, by increasing cell viability, and by downregulating DNA fragmentation and apoptotic indicators (apoptosis-inducing factor and cleaved caspase-3). AT fibroblasts stably transfected with human full-length ATM cDNA (YZ5 cells) or the empty vector (MOCK cells) were treated with H2O2 as a source of reactive oxygen species (ROS). As a result, transfection with ATM inhibited ROS-induced cell death and DNA fragmentation in MOCK cells. Transfection with ATM induced expression of HO-1 which was mediated by PKC-δ and NF-κB in H2O2-treated MOCK cells. ZnPP, an HO-1 inhibitor, and transfection with HO-1 siRNA increased ROS levels and apoptosis, whereas hemin, an HO-1 activator, reduced ROS levels and apoptosis in H2O2-treated YZ5 cells. Rottlerin, a PKC-δ inhibitor, inhibited NF-κB activation and HO-1 expression in H2O2-treated YZ5 cells. MOCK cells showed increased cell death, DNA fragmentation, and apoptotic indicators compared to YZ5 cells exposed to H2O2. In addition, transfection with p65 siRNA increased ROS levels and DNA fragmentation, but decreased HO-1 protein levels in H2O2-treated YZ5 cells. In conclusion, ATM induces HO-1 expression via activation of PKC-δ and NF-κB and inhibits oxidative stress-induced apoptosis. A loss of HO-1 induction may explain why AT patients are vulnerable to oxidative stress. © 2015 Elsevier Ltd. All rights reserved.


Park W.J.,Korea Institute of Patent Information
Communications in Computer and Information Science | Year: 2011

This paper is concerned with the unbalanced classification problem which occurs when there are significantly less number of observations of the target concept. The standard machine learning algorithms yield better prediction performance with balanced datasets. However, in real application, it is quite common to have unbalanced dataset with a certain class of interest having very small size. It will be problematic since the algorithm might predict all the cases into majority classes without loss of overall accuracy. In this paper, we propose an efficient way of selecting informative for active learning which does not necessitate a search through the entire dataset and allows active learning to be applied to very large datasets. Experimental results show that the proposed method decreases the prediction error of minority class significantly with increasing the prediction error or majority class a little bit. © 2011 Springer-Verlag.


Roh B.-H.,Ajou University | Kim J.W.,Ajou University | Ryu K.-Y.,Ajou University | Ryu J.-T.,Korea Institute of Patent Information
Computers and Security | Year: 2013

Since SIP uses a text-based message format and is open to the public Internet, it is exposed to a number of potential threats of denial of service (DoS) by flooding attacks. Although several approaches have been proposed to detect and counteract SIP flooding attacks, most of these do not provide effective countervailing schemes to protect normal messages from abnormal ones after attacks have been detected. In addition, these approaches have some limitations in large user environments for SIP-based multimedia services. In this paper, a whitelist-based countermeasure scheme is proposed, to protect both normal SIP users and servers from malicious flooding attacks. To construct the whitelist, a Bloom filter approach is used, to reduce memory requirements and computational complexity. We use the non-membership ratio as a measure for the attack detection, instead of using the message rate usually used in conventional schemes. It is shown that the proposed method can provide more robust detection performances. © 2013 Elsevier Ltd. All rights reserved.


Park W.J.,Korea Institute of Patent Information
2010 2nd International Conference on Information Technology Convergence and Services, ITCS 2010 | Year: 2010

The maintenance period, the time frame begging from the registration to the expiration of a patent, is an important property used to evaluate the patent's quality. To predict the maintenance period of a patent, a consistent classifier is desirable. The output of a classifier is usually determined by the value of a discriminant function and a decision is made based on this output which does not necessarily represent the posterior probability of the soft decision of classification. Thus, it is desirable that the output of a classifier be calibrated in such a way to include the posterior probability of class membership. For this purpose, the Class Probability Output Network (CPON) is devised. It is a new method of postprocessing for the probabilistic scaling of ' output. To predict the maintenance period of a patent, SVM, KLR, perceptron and perceptron with CPON are used in simulation. The simulation results using the perceptron with CPON demonstrated a statistically meaningful performance improvement over that of SVM, KLR and perceptron. © 2010 IEEE.

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