• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.502-508
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• 2007

This paper proposes a method to shut out all of the not certified network access packet by embodying the two-factor(MAC ADDRESS, ID/PASSWORD) authentication system. The Authenticating Gateway System takes over central server's policy and permit or hold up the packet by inherited policy. And checks the whether or not patched the OS version and getting influenced from computer virus. And takes the information about client's resources(H/W, S/W) without Agent in the client. That makes more stability of network operating circumstance and fast facing the attack from hackers. In the fixed mobile network circumstance, This method provides more simplicity and less expenses than IEEE802.1x authentication system(cisco nac).

• Journal of Life Science
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• v.30 no.12
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• pp.1101-1108
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• 2020

Tartary buckwheat is a grain with many flavonoids, such as rutin, quercetin, kaempferol, and myricetin. This study aimed to optimize extraction conditions to maximize the rutin, quercetin, and myricetin contents of tartary buckwheat sprout extracts using response surface methodology. A BoxBehnken design containing 15 experiments was employed to evaluate the effects of extraction conditions, such as temperature (X1, 50~70℃), extraction time (X2, 5~9 hr), and ethanol concentration (X3, 60~90%). The coefficients of determination (R2) for all the dependent variables (extraction temperature, extraction time, and extraction ethanol concentration) were determined to be over 0.95, indicating significance. The p-value of the model in lack of fit was over 0.1 than means, indicating that the model was well predicted. The optimal extraction conditions for rutin, quercetin, and myricetin contents were obtained at X1 = 51.03, X2 = 6.62, and X3 = 69.16, respectively. Under these optimal conditions, the predicted rutin, quercetin, and myricetin contents were 808.467 ㎍/ml, 193.296 ㎍/ml, and 37.360 ㎍/ml, respectively. For the validation of the model, ten experiments were performed and the experimental rutin and quercetin contents were measured at 802.84±8.49 ㎍/ml, 193.76±2.80 ㎍/ml, and 34.84±0.43 ㎍/ml, respectively. The experimental rutin and quercetin contents were similar to the predicted contents, but the experimental myricetin content was lower than predicted.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.204-207
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• 2002

공중무선랜은 오늘날 빠르게 증가하고 있는 무선인터넷 서비스에서 빠른 전송속도와 저렴한 설치비용 등으로 빠르게 성장하고 있는 중요한 기반요소로 평가되고 있다. 하지만 무선랜 시장에 대한 기대 뒤에는 보안에 대한 우려 또한 높아지고 있으며 로밍이나 핸드오버에 대한 수요가 커지고 있으나 실제로는 서비스 반경이 작고, 간섭에 의해 서비스 품질을 보장하기 어려우며 사용자 인증, 접근제어, 과금 부분에 있어 믿을 만한 초기 단말 인증이 보장되지 않아 도메인간 연동 문제가 쉽지 않다. 이러한 문제를 보완하여 초고속 멀티미디어 서비스를 제공할 수 있는 Mobile IP 기반 로밍 및 핸드오버에 대한 기반 기술 및 Mobile IP에 적용되는 사용자 인증 서비스에 대한 기반기술인 802.1x를 비롯하여 802.11f, Mobile IP등을 고려하여 이동성이 보장된 공중 무선랜 서비스를 위한 인증 방안을 제안하고 검증하며 제안된 방안은 차후로 ALL-IP 기반의 차세대 3G 이동통신망에서 이용될 수 있는 AAA 방안으로 확장하여 적용이 가능한 AAA 모델의 기반기술이 될 것이다.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.281-284
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• 2005

WPA is a security service that greatly increases data protection and access control on WLANs. WPA uses TKIP that is secure algorithm of 802.11i and 802.1X/EAP authentication. It provides enhanced secure ability with the dynamic security key to correct WEP's weaknesses. In this paper, we obtain measured data transmission time that by how to create secure key of WPA in the wired and wireless network. The result shows that the delay of data transmission time was not long even if used WPA.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.25-27
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• 2002

The crystal structure of KR-21042, N-(3-Phenylpropyl )-4-hydroxy-3-methoxyphenylacetamide, was determined by single crystal X-ray diffraction analysis. The compound was recrystallized from a mixture of ethylacetate and n-hexane in monoclinic, space group $P2_1/c$, with a = 16.622(1), b = 6.215(1), c = 15.802(1) ${\AA},{\;}{\beta}=104.97(1)$, and Z = 4 The calculated density is $1.261{\;}g/cm^3$The structure was solved by the direct method and refined by full matrix least-squares procedure to the fecal R value of 0.068 for 2332 observed reflections.

• Journal of the Korean Ceramic Society
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• v.30 no.10
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• pp.797-802
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• 1993

Graphite fiber intercalated compound was deintercalated at $25^{\circ}C$, 65% of humidity and its deintercalated compound was discussed, based on the X-ray diffraction analysis, electrical resistivity measurement, and UV/VIS spectrometer measurements. During deintercalation, the structure was changed in orderlongrightarrowdisorderlongrightarroworder, and resistivity was decreased in the disorder state of the structure, which reflectance minimum of the UV/VIS spectrum ranged from 660 to 750nm (1.88~1.65eV).

• 모자간호학회지
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• v.1
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• pp.34-44
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• 1991

The purposes of this study were to predict newborn birthweight by use of gestational period and fundal height and to identify growth curve of fundal height according to gestational period and growth curve of newborn birthweight according to fundal height. The subjects for the study were 802 women who delivered the normal newborn babies at Seoul National University Hospital from Sep. 1, 1981 to Aug.31, 1986. The data were collected bit chart review and analyzed nth SPSS program. The results of study were as follows : 1. The multiple regression equation ($R^2$=0.416) used for the prediction of newborn birthweight was y=(newborn birthweight, kg)=-4.421+0.075$x_1$(fundal height, cm)+0.053$x_2$(gestational period, weeks)+0.016$x_3$(abdominal girth, cm)+0.010$x_4$(maternal height, cm) 2. The growth curve of fundal height according to gestational period was obtained by polynomial regression. The regression equation was Y(fundal height, cm)=-36.78+18.58$log_ex$(gestational period, weeks) The growth curve of newborn birth weight according to fundal height was obtained by polynomial regression. The regression equation was Y(newborn birthweight, kg)=-8.09+3.27$log_ex$ (Fundal Height, cm) 3. In the following subgroups no significant difference was found in fundal height : engaged vs. nonengaged presentation, and nulliparous vs. multiparous women.

• Journal of Internet of Things and Convergence
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• v.1 no.1
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• pp.39-44
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• 2015

Organization is increasing the authorizing process to use public certificate and bio information. Certificate, has evolved to be able to parallel distributes the bio authentication and portable bio-authentication device. Authentication using an individual's PC and smart devices continue to generalize, while convenience for authentication is increased by comparison Study on cooperation with the security at the network level's a weak situation. If ask authentication method through the cooperation of the public certificate and bio information work with current network access control, there is a possibility to develop a more powerful security policy. by cooperation weaknesses against vulnerable personal authentication techniques on security token in a reliable and secure personal authentication techniques, such as bio-recognition, Bio Information for identification and to prevent exposing a methodology suggest to validate whether or not to carry out in this paper. In addition, organize the scenario that can work with the 802.1x network authentication method, and presented a proposal aimed at realization.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.449-455
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• 2018

For the size reduction, we propose a microstrip-fed monopole antenna with half X-slot in the radiation patch and cover WLAN dual band 2.4 GHz band (2.4 ~ 2.484 GHz) and 5 GHz band (5.15 ~ 5.825 GHz). The frequency characteristics such as impedance bandwidth and resonant frequencies were satisfied by optimizing the numerical values of various parameters, while the reflection loss in 5 GHz was improved by using defected ground structure (DGS). The proposed antenna is designed and fabricated on a FR-4 substrate with dielectric constant 4.3, thickness of 1.6 mm, and size of $24{\times}41mm^2$. The measured impedance bandwidths (${\mid}S_{11}{\mid}{\leq}-10dB$) of fabricated antenna are 450 MHz (2.27 ~ 2.72 GHz) in 2.4 GHz band and 1340 MHz (4.79 ~ 6.13 GHz) in 5 GHz band which sufficiently satisfied with the IEEE 802. 11n standard in dual band. In particular, radiation patterns which are stable as well as relatively omni-direction could be obtained, and the gain of antennas in each band was 1.31 and 1.98 dBi respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.8
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• pp.3201-3223
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• 2020

Wireless communication has become the promising technology in the recent times because of its applications in Internet of Things( IoT) devices. The IEEE 802.15.4e has become the key technology for IoT devices which utilizes the Time-Slotted Channel Hopping (TSCH) networks for the communication between the devices. In this paper, we develop a Two Level Scheduling Algorithm (TLSA) for scheduling multiple packets with different arrival rate at the source nodes in a TSCH networks based on the link activated by a centralized scheduler. TLSA is developed by considering three types of links in a network such as link i with packets arrival type 1, link j with packets arrival type 2, link k with packets arrival type 3. For the data packets arrival, two stages in a network is considered.At the first stage, the packets are considered to be of higher priority.At the second stage, the packets are considered to be of lower priority.We introduce level 1 schedule for the packets at stage 1 and level 2 schedule for the packets at stage 2 respectively. Finally, the TLSA is validated with the two different energy functions i.e., y = e^ax - 1 and y = 0.5x² using MATLAB 2017a software for the computation of average and worst ratios of the two levels.