• Journal of Digital Contents Society
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• v.19 no.4
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• pp.639-647
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• 2018

A common core network is the one of main architectural principles in 3GPP 5G System which has common interfaces with different multiple accesses. 3GPP 5G System Phase 1 (Release 15) supports Untrusted Non-3GPP access as well as 3GPP access with common interfaces. Non-3GPP Interworking Function (N3IWF) has been defined to interface with a UE and a core network for supporting Untrusted Non-3GPP access in 3GPP Release 15. However, interworking with Trusted Non-3GPP access is under study to be completed in 3GPP 5G System Phase 2 (Release 16). Therefore, this paper proposes a Trusted Non-3GPP access network architecture and related signaling procedures, and then the implementation based on the proposal shows how to interwork between Trusted Non-3GPP access and the 5G core network. In our proposal, N3IWF can interwork with either Untrusted or Trusted Non-3GPP access without any architectural modification or addition of 3GPP 5G system Phase 1.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.2
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• pp.1-8
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• 2011

In this study, In order to evaluate reliable of MODIS GPP, the MODIS GPP and Flux tower measured GPP were compared to evaluate the use of method on 8 days composite MODIS GPP. The 2008 Flux data ($CO_2$ Flux and air temperature) measured in Seolmacheon watershed ($8.48\;km^2$) were used. The Flux tower GPP was estimated as the sum of $CO_2$ Flux and $R_{ec}$ (ecosystem respiration) by Lloyd and Taylor method (1994). The summer Monsoon period from June to August mostly contributed the underestimation of MODIS GPP by cloud contamination on MODIS pixels. The 2008 MODIS GPP and Flux tower GPP of the watershed were $1133.2\;g/m^2/year$ and $1464.3\;g/m^2/year$ respectively and the determination coefficient ($R^2$) after correction of cloud-originated errors was 0.74 (0.63 before correction). Even though effect of Cloud-Originated Errors was eliminated, Solar radiation and Temperature are affected at GPP. Measurement of correct GPP is difficult. But, If errors of MODIS GPP analyze on Cloud Moonsoon Climate in korea and eliminated effect of Cloud-Originated Errors, MODIS GPP will be considered GPP increasing of 9 %. There, Our results indicate that MODIS GPP show reliable and useful data except for summer period in Moonsoon Climate.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.3
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• pp.137-144
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• 2004

3GPP(3rd Generation Project Partnership)-WLAN(Wireless Local Area Network) interworking refers to the utilization of resources and access to services within the 3GPP system by the WLAN UE(User Equipment) and user respectively. The intent of 3GPP-WLAN Interworking is to extend 3GPP services and functionality to the WALN access environment. We propose an efficient mechanism for the setup of UE-initiated tunnels in 3GPP-WLAN interworking. The proposed mechanism is based on a secret key which is pre-distributed in the process of authentication and key agreement between UE and 3GPP AAA(Authentication, Authorization Accounting) server. Therefore it can avoid modular exponentiation and public key signature which need a large amount of computation in UE. Also the proposed scheme provides mutual authentication and session key establishment between UE and PDGW(Packet Data Gateway).

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.2
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• pp.132-139
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• 2007

The Moderate Resolution Imaging Spectroradiometer (MODIS) regularly provides the eight-day gross primary productivity (GPP) at 1 km resolution. In this study, we evaluated the uncertainties of MODIS GPP caused by errors associated with the Data Assimilation Office (DAO) meteorology and a biophysical variable (fraction of absorbed photosynthetically active radiation, FPAR). In order to recalculate the improved GPP estimate, we employed ground weather station data and reconstructed cloud-free FPAR. The official MODIS GPP was evaluated as +17% higher than the improved GPP. The error associated with DAO meteorology was identified as the primary and the error from the cloud-contaminated FPAR as the secondary constituent in the integrative uncertainty. Among various biome types, the highest relative error of the official MODIS GPP to the improved GPP was found in the mixed forest biome with RE of 20% and the smallest errors were shown in crop land cover at 11%. Our results indicated that the uncertainty embedded in the official MODIS GPP product was considerable, indicating that the MODIS GPP needs to be reconstructed with the improved input data of daily surface meteorology and cloud-free FPAR in order to accurately monitor vegetation productivity in Korea.

• Journal of Korea Spatial Information System Society
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• v.4 no.2 s.8
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• pp.23-34
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• 2002

Various tries are in progress to expand the usability of wireless telecommunication harminized internet technology. The most typical example among those services is LBS(Location Based Service). Nowaday, Standards for telecommunication system of LBS centers round on 3GPP(3rd Generation Partnership Project) and 3GPP2. In this paper we compare the telecommunication system of 3GPP and 3GPP2 in order to make domestic standards of telecommunication system to provide LBS. First, we investigate network models and interfaces of GSM(Global System for Mobile) and ANSI(America National Standard Institute)-41/PCS1900 - Telecommunication type of 2nd generation. Also we consider those of UMTS (Universal Mobile Telecommunication System) and cdma2000 - Telecommunication type of 3nd generation. Then we analysis function components for LBS of each network models details.

• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.215-226
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• 2012

NASA MODIS GPP provides a useful tool to monitor global terrestrial vegetation productivity. Two major problems of NASA GPP in regional applications are coarse spatial resolution ($1.25^{\circ}{\times}1^{\circ}$) of DAO meteorological data and cloud contamination of MODIS FPAR product. In this study, we improved the NASA GPP by using enhanced input data of high spatial resolution (3 km${\times}$3 km) WRF meteorological data and cloud-corrected FPAR over the North Korea. The improved GPP was utilized to investigate characteristics of GPP interannual variation and spatial patterns from 2000 to 2008. The GPP varied from 645 to 863 $gC\;m^{-2}\;y^{-1}$ in 2000 and 2008, respectively. Mixed forest showed the highest GPP (1,076 $gC\;m^{-2}\;y^{-1}$). Compared to NASA GPP (790 $gC\;m^{-2}\;y^{-1}$);FPAR enhancement increased GPP (861) but utilization of WRF data decreased GPP (710). Enhancements of both FPAR and meteorological input resulted in GPP increase (809) and the improvement was the greatest for mixed forest regions (+10.2%). The improved GPP showed better spatial heterogeneity reflecting local topography due to high resolution WRF data. It is remarkable that the improved and NASA GPPs showed distinctly different interannual variations with each other. Our study indicates improvement of NASA GPP by enhancing input variables is necessary to monitor region-scale terrestrial vegetation productivity.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.2
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• pp.1-6
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• 2000

In this paper, simulations are performed using standards proposed by 3GPP and 3GPP2. From the view point of performance analysis based on Turbo code specification, performance of Turbo code in AWGN, proposed by 3GPP, is compared. To make comparison, experimental result of Turbo code that is performed on one of the many block sizes proposed by 3GPP2 in Rayleigh fading channel, is provided. Performance of Turbo decoders using Max_Log MAP and Log MAP are compared.

• Information and Communications Magazine
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• v.21 no.7
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• pp.49-65
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• 2004

IMT-2000, 즉 3G 이동통신은 3GPP와 3GPP2 등을 중심으로 표준화가 진행되어 왔다. 그에 따라 3GPP의 W-CDMA와 3GPP2의 cmdma2000 표준은 물론, 고속 패킷 전송을 위한 이들의 진화 표준인 3GPP의 HSDPA와 3GPP2의 EV-DO 및 EV-DV 표준이 제정되어 이미 서비스가 제공되고 있거나 관련 기술을 개발하고 있는 단계이다. 또한 현재는 이들을 보다 진화시킨 표준개발도 진행되고 있다.(중략)

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.4
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• pp.149-153
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• 1999

This paper proposes a new security system for the next generation mobile telecommunication system The system is based on the network domain security of the 3GPP. The system provides confidentiality and integrity services in the RLC layer, the second layer of 3GPP. Our system has merits in that it can provide security services without any modification to the 3GPP protocol and has low transmission voerhead. Security algorithm and mode are controlled by the RRC layer, the third layer of 3GPP.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.251-267
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• 2021

Remotely sensed vegetation indices (VIs) are empirically related with gross primary productivity (GPP) in various spatio-temporal scales. The uncertainties in GPP-VI relationship increase with temporal resolution. Uncertainty also exists in the eddy covariance (EC)-based estimation of GPP, arising from the partitioning of the measured net ecosystem CO2 exchange (NEE) into GPP and ecosystem respiration (RE). For two forests and two agricultural sites, we correlated the EC-derived GPP in various time scales with three different near-surface remotely sensed VIs: (1) normalized difference vegetation index (NDVI), (2) enhanced vegetation index (EVI), and (3) near infrared reflectance from vegetation (NIRv) along with NIRvP (i.e., NIRv multiplied by photosynthetically active radiation, PAR). Among the compared VIs, NIRvP showed highest correlation with half-hourly and monthly GPP at all sites. The NIRvP was used to test the reliability of GPP derived by two different NEE partitioning methods: (1) original KoFlux methods (GPP_Ori) and (2) machine-learning based method (GPP_ANN). GPP_ANN showed higher correlation with NIRvP at half-hourly time scale, but there was no difference at daily time scale. The NIRvP-GPP correlation was lower under clear sky conditions due to co-limitation of GPP by other environmental conditions such as air temperature, vapor pressure deficit and soil moisture. However, under cloudy conditions when photosynthesis is mainly limited by radiation, the use of NIRvP was more promising to test the credibility of NEE partitioning methods. Despite the necessity of further analyses, the results suggest that NIRvP can be used as the proxy of GPP at high temporal-scale. However, for the VIs-based GPP estimation with high temporal resolution to be meaningful, complex systems-based analysis methods (related to systems thinking and self-organization that goes beyond the empirical VIs-GPP relationship) should be developed.