• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.180-190
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• 2008

There have been researches into digital Watermarking technology or Fingerprinting vigorously to safeguard Protective rights for knowledge and poverty for digital contents. DRM(Digital Rights Management) is not only Protective rights for knowledge and poverty, but also management and systems that are necessary to put out, circulate and use for contents. This paper proposes two kinds of ideas. One is protecting contents from illegal acts such as illegal copies when the contents are in the process of circulation. The other is the protocol that can give users convenience. Hidden Agents are used so that contents are protected from illegal copies and illegal use in the contents and cuts off those illegal acts. The Agent will be installed without any special setup. In addition, it can replace roles of Watermarking as a protection. Therefore, this paper shows the solution of illegal copies that happens frequently.

• Korean Journal of Materials Research
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• v.22 no.12
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• pp.658-663
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• 2012

The electrical properties of a laminated SMD type PTC thermistor for microcircuit protection were investigated as a function of polymer blowing agent addition. Green ceramics for multilayered $BaTiO_3$-based PTCRs were formed by doctor blade method of barium titanate powders; we successfully laminated the sintered ceramic chips to obtain 10 layer chip PTCRs with PTC effect. The sintered density increases with increasing sintering temperature. The electrical properties of the sintered samples were strongly dependent on the calcination and addition of a polymer blowing agent. When $BaTiO_3$ powders containing 0.2 mol% of $Y_2O_3$ were calcined at $1000^{\circ}C$ for 2 hrs, the resistivity jump was of 1-2 orders of magnitude. The resistivity at room temperature increases according to the polymer blowing agent addition. Also, the sample using the calcined powder showed a lower resistivity than that of the sample prepared using powders without calcinations. With an increase in the OBSH, the magnitude of the resistivity jumped as a function of the temperature increase. The resistivity of the sintered bodies after the addition of 0.5 wt% polymer blowing agent at $1290^{\circ}C$ for 2 h was shown to be about $8.5{\Omega}{\cdot}cm$; the jump order of the sintered bodies was shown to be on the order of $10^2$.

• Journal of the Korea Institute of Building Construction
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• v.16 no.5
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• pp.405-412
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• 2016

In order to examine the possibility of practical use of concrete at low-temperature environment using high early strength cement with cold resistance admixture, an experimental study on workability, freezing temperature and compressive strength of the mortar with different types of anti-freezer, water reducing agent and accelerator for freeze protection at low-temperature were evaluated. Compressive strength was increased in use of anti-freezer, especially SN anti-freezer was higher than CN anti-freezer. 0min flow was increased, the 20min flow was decreased. And 20min flow was improved in use of FR, RT water reducing agent. CF, LS accelerator for freeze protection, regardless of the type of water reducing agent, compressive strength was increased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.31-36
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• 2002

Recently, more interests in surface treatment of structure with water repellent agent are steadily increased, But, investigation of its properties such as protection, durability, morphology of micro structure is not sufficient. Therefore, This paper is aimed for the investigation of water repellent property and change of morphology of micro pores in mortar that is treated by water repellent agent(Inorganic polymer based material). Water repellent property, water absorption coefficient, air permeability, porosity and the observation of micro structure was investigated in different water repellent agent type. The test results indicated that water repellent treated mortar showed low absorption coefficient and air permeability(breathing effect). This is why inorganic polymer is coated at the wall of capillary and micro pores, also, the volume of micro pore is reduced without the change of morphology in micro structure.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.947-950
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• 2002

디지털 컨텐츠의 지적 재산권 보호를 위한 디지털 워터마킹 기술 및 핑거프린팅의 연구가 활발히 진행되고 있다. DRM(Digital Rights Management)는 디지털 컨텐츠 지적 재산권 보호뿐만 아니라 컨텐츠에 대한 출판, 유통 및 사용에 필요한 관리와 보호체계이다. 본 논문에서는 컨텐츠 유통과정에서 발생할 수 있는 불법 복사와 같은 불법 행동에 대해 컨텐츠를 안전하게 보호하며 사용자에게 편의성을 제공 할 수 있는 프로토콜을 제시할 것이며 또한 지불의 효율적 사용을 위해 분할성 기능과 함께 화폐 추적과 사용자 추적 기능을 Hidden Agent에 포함하여 제안한다. 이 Hidden Agent는 특별한 설치가 필요 없이 컨텐츠 내에 내포되어 있어 컨텐츠에 대한 지불, 불법복사 및 불법사용에 대해 체크함으로써 불법복사의 사용을 차단할 수 있도록 한다. 또한 사용자들에게 숨겨져 있기 때문에 워터마킹의 역할 또한 대신할 수 있다. 따라서 본 논문에서는 유통과정에서 가장 빈번하게 나타날 수 있는 지불과 불법 복사에 대하여 Hidden Agent를 이용하여 해결하였다.

• Membrane and Water Treatment
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• v.7 no.1
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• pp.1-10
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• 2016

Ultrafiltration is known to be one of the most commonly applied techniques in water treatment. Membrane fouling is the main limiting factor in terms of process efficiency and restricting it to the manageable degree is crucial. Natural organic matter is often found to be a major foulant in surface waters. Among many known fouling prevention techniques, the membrane chemical cleaning is widely employed. This study focuses on evaluating the cleaning efficiency of polymeric and ceramic membranes with the use of various chemicals. The influence of cleaning agent type and its concentration, membrane material and its MWCO, and cleaning process duration on the recovery of membrane flux was analyzed. Results have shown that, regardless of membrane type and MWCO, the most effective cleaning agent was NaOH.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.217-219
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• 2003

This paper presents a distance relaying algorithm for a transmission line protection with MAS. First, the voltage and fault current of the opposite side are represented as a function of those of the measuring end using source voltages of both ends. These voltages are assumed to be obtained from the transformers protecting agents, periodically in normal state. Then, the fault location expression, independent of fault resistance, is derived with voltage and current in only one end of faulted line used. The suggested algorithm is applied to a simple system with two power sources to show its effectiveness.

• The KIPS Transactions:PartC
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• v.15C no.3
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• pp.167-172
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• 2008

Fingerprinting scheme supports the copyright protection to track redistributors of digital content using cryptographic techniques. Fingerprinting schemes should guarantee buyer's anonymity and asymmetry for their privacy. Most of known fingerprinting schemes adopt public-key cryptosystems to achieve asymmetry and discrete logarithm problem or graph isomorphism problem to achieve anonymity. However, these schemes are not suited in mobile environment because of the drawbacks of requiring high computational complexity. In this paper, we propose an efficient fingerprinting scheme for mobile environment to provide not only asymmetry of the protocol but also transaction anonymity of the buyer. By employing symmetric encryption to encrypt the digital content and adopting agent to perform the protocols, the efficiency of the proposed scheme is improved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.382-388
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• 2011

This paper proposes a mechanism that guarantees secured performance against DDoS attack to protect data from free-roaming agent. Also, as it makes up QCRT(query chain relationship tree) structure which is an enhanced chain relation of existing chain relations that improves extension, It also finds malicious elements. The proposed mechanism extends chain relationship of agent as well by checking chain relation structure as a structure according to the route of agent. For it complements existing weakness with single-side chain relation extension, it guarantees secure performance against DDoS and truncation attacks from mobile agent.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.423-432
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• 2022

The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46mm) and males (4.20-4.62mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring's sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4^th or 5^th nymphs, the offspring's female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.