• 제목/요약/키워드: 6

Search Result 289,859, Processing Time 0.136 seconds

A Study on the PP/PS Blends with Nylon 6 Reactive Compatibilizers (Nylon6계 반응 상용화제에 의한 PP/PS 블렌드에 관한 연구)

  • 서성식;이기윤;김성희;김동철;이승구
    • Polymer(Korea)
    • /
    • v.26 no.1
    • /
    • pp.71-79
    • /
    • 2002
  • RPP(maleic-anhydride grafted PP)and OPS(oxazoline grafted PS) do not react to each other, and thus show immiscibility. In this study, Nylons was added to RPP/OPS blend systems, as a reactive compatibilizer for enhancing the miscibility of the blends. When Nylon6 was added to the blends of RPP and OPS, RPP/Nylon6/OPS was produced. The effects of the molar ratio of Nylon6 on the RPP-Nylon6-OPS reaction were studied. Torque test and FT-IR analysis have been carried out to investigate the reaction of RPP/Nylon6/OPS system. The reaction torgue ratio and reaction efficiency show the maximum values at 1 : 0.66 : 1 and 1 : 1 : 1 (in moles) for RPP/Nylon6/OPS. In the RPP/Nylon6/OPS blends, their mechanical properties were changed with the molar ratio of Nylon6 and showed the highest value at molar ratio of 1.5. Physical properties and compatibility of RPP/Nylon6/OPS were compared with those of PP/Nylon6/OPS. Consequently, RPP/Nylon6/OPS plays a proper role as a reactive compatibilizer to the PP/PS blend system.

Authentication eXtention Scheme of Fast Handover for Secure NEMO-based PMIPv6 Networks (안전한 NEMO 기반 PMIPv6 네트워크를 위한 빠른 핸드오버를 지원하는 확장 인증기법)

  • Im, Illkyun;Jeong, Jongpil
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.13 no.5
    • /
    • pp.107-119
    • /
    • 2013
  • This paper reinforced security under the network evaluation of wire wireless integration of NEMO (NEwork MObility) supporting mobility and network-based PMIPv6 (Proxy Mobile IPv6). It also proposes $SK-L^2AS$ (Symmetric Key-Based Local-Lighted Authentication Scheme) based on simple key which reduces code calculation and authentication delay costs. Moreover, fast handover technique was also adopted to reduce handover delay time in PMIPv6 and X-FPMIPv6 (eXtension of Fast Handover for PMIPv6) was used to support global mobility. In addition, AX-FPMIPv6 (Authentication eXtension of Fast Handover for PMIPv6) is proposed which integrated $SK-L^2AS$ and X-FPMIPv6 by applying Piggybacks method to reduce the overhead of authentication and signaling. The AX-FPMIPv6 technique suggested in this paper shows that this technique is better than the existing schemes in authentication and handover delay according to the performance analysis.

A Novel Integration Mechanism of FMIPv6 and HMIPv6 to Reduce Loss and Out-of-Sequence Problem (패킷 손실과 순서 어긋남 문제를 해결할 수 있는 새로운 FMIPv6와 HMIPv6 통합 메커니즘)

  • Lee, Jae-Hwoon;Lim, Yu-Jin
    • Journal of KIISE:Information Networking
    • /
    • v.34 no.2
    • /
    • pp.110-119
    • /
    • 2007
  • Mobile IPv6 (MIPv6) enables a mobile node (MN) to maintain its connectivity with a correspondent node (CN) while changing its point of attachment. In MIPv6, packets sent from a CN to a MN during handover are lost. Several mechanisms including FMIPv6 and HMIPv6 have been proposed in order to minimize packet loss. However, such mechanisms still suffer from performance degradation due to not only packet loss but also out-of-sequence packets. In this paper, we propose I-FHMIPv6 to resolve packet loss as well as the out-of-sequence packet problem. In I-FHMIPv6, the flush message is newly defined in order to notify a home agent (HA) or CN of the fact that the binding cache entry of a MN is about to be updated. A MN receiving the flush message can know that there is no more packets transmitted via the previous route, which resolve the out-of-sequence packet problem. Moreover, with the proposed mechanism, we can minimize packet loss by integrating FMIPv6 and HMIPv6 efficiently. I-FHMIPv6 is evaluated by performing simulations, and the simulation results show that I-FHMIPv6 outperforms FMIPv6 and HMIPv6.

Location Recognition Mechanism of Mobile Node for Fast Handover on Proxy Mobile IPv6 (프록시 모바일 IPv6에서 빠른 핸드오버를 위한 이동단말의 위치인지 메커니즘)

  • Bae, Sang-Wook;Kim, Hee-Min;Oudom, Keo;Han, Sun-Young
    • Journal of KIISE:Information Networking
    • /
    • v.37 no.6
    • /
    • pp.459-465
    • /
    • 2010
  • Mobile IPv6(MIPv6) features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Proxy Mobile IPv6 (PMIPv6) got over the limit of MIPv6 problems. MIPv6 features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Research on PMIPv6, which features network-based mobility is actively in progress in order to resolve these issues. PMIPv6 is emerging as a new paradigm that can overcome the limitations of the existing MIPv6. Nevertheless, such PMIPv6 also incurs problems during hand-over. While it offers a solution to node-based problems, it does, too, create long delay times during hand-over. Since MN (Mobile Node) has been sensing its own movements on MIPv6, fast handover can be done easily. However it can't apply fast handover like MIPv6, as it can't apply fast handover like MIPv6 In this paper, the author solved hand-over problem on MIPv6. MAG knows location information of MN and if MN moves into other MAG's area, Location Server gives MN information to the MAG. Therefore, this mechanism makes hand-over process easier.

6TALK : Implementation of NAT-PT/SIIT and enhanced ALG

  • 이주철;호용근;신명기;김형준
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2002.11a
    • /
    • pp.701-705
    • /
    • 2002
  • This paper describes implementation of IPv6-IPv4 transition toolbox named as 6TALK(IPv6 TrAansLator of Krv6) and some scenarios using 6TALK which enables IPv6 island to connect other IPv6 island or IPv4 island seamlessly. 6TALK implements some transition mechanisms suggested in NGTrans Working Group of IETF. Those mechanisms are composed of basic mechanism, tunneling, and applied mechanism such as DSTM. 6TALK provides functions which enable IPv6 network at the edge of existing network to communicate with IPv4 network by using these transition mechanisms. As major transition mechanisms in 6TALK we adopt NAT-PT/SIIT and DSTM/DSTM options and as implementation environment we use Linux Kernel 2.4.18 and Netfilter framework. Software modules implemented in Linux kernel was ported to hardware box using Motorola MPC 8260 processor. The transition mechanisms used in 6TALK are the ones predicted to be used in initial transition step to IPv6.

  • PDF

Organotitanium Chemistry (IV). The Molecular and Electronic Structure of $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH\;and\;Ti(OC_6H_5)_4{\cdot}C_6H_5OH$ (유기티탄 화학 (제4보). $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH\;및\;Ti(OC_6H_5)_4{\cdot}C_6H_5OH$의 분자 및 전자구조)

  • Lee Hoosung;Uh Young Sun;Sohn Youn Soo
    • Journal of the Korean Chemical Society
    • /
    • v.19 no.2
    • /
    • pp.92-97
    • /
    • 1975
  • The molecular and electronic structures of $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH\;and\;Ti(OC_6H_5)_4{\cdot}C_6H_5OH$ have been studied by employing cryoscopic and electronic spectroscopic methods. The cryoscopic data have shown that the dimeric tetraphenoxytitanium(Ⅳ) phenolate in solid undergoes complete dissociation into monomer in solution and also the chlorocomplex starts dissociation around the concentration of 8 m mole/l. Therefore, these two Ti-complexes are pentacoordinated in dilute solution and the local symmetry of the titanium ion in these complexes seems to be trigonalbipyramid. The electronic spectra of $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH$ and $Ti(OC_6H_5)_4{\cdot}C_6H_5OH$ each show two band, systems, one vibration-structural band characteristic of the aromatic ring in the near UV and another visible band at 26.8 kK, 29.6 kK, respectively, which are assigned as a ligand to metal charge transfer band corresponding to $^1A_1''{\to}^1E'\;or\;^1E''$ transition.

  • PDF

Possibilities for Improvement in Long-term Predictions of the Operational Climate Prediction System (GloSea6) for Spring by including Atmospheric Chemistry-Aerosol Interactions over East Asia (대기화학-에어로졸 연동에 따른 기후예측시스템(GloSea6)의 동아시아 봄철 예측 성능 향상 가능성)

  • Hyunggyu Song;Daeok Youn;Johan Lee;Beomcheol Shin
    • Journal of the Korean earth science society
    • /
    • v.45 no.1
    • /
    • pp.19-36
    • /
    • 2024
  • The global seasonal forecasting system version 6 (GloSea6) operated by the Korea Meteorological Administration for 1- and 3-month prediction products does not include complex atmospheric chemistry-aerosol physical processes (UKCA). In this study, low-resolution GloSea6 and GloSea6 coupled with UKCA (GloSea6-UKCA) were installed in a CentOS-based Linux cluster system, and preliminary prediction results for the spring of 2000 were examined. Low-resolution versions of GloSea6 and GloSea6-UKCA are highly needed to examine the effects of atmospheric chemistry-aerosol owing to the huge computational demand of the current high resolution GloSea6. The spatial distributions of the surface temperature and daily precipitation for April 2000 (obtained from the two model runs for the next 75 days, starting from March 1, 2000, 00Z) were compared with the ERA5 reanalysis data. The GloSea6-UKCA results were more similar to the ERA5 reanalysis data than the GloSea6 results. The surface air temperature and daily precipitation prediction results of GloSea6-UKCA for spring, particularly over East Asia, were improved by the inclusion of UKCA. Furthermore, compared with GloSea6, GloSea6-UKCA simulated improved temporal variations in the temperature and precipitation intensity during the model integration period that were more similar to the reanalysis data. This indicates that the coupling of atmospheric chemistry-aerosol processes in GloSea6 is crucial for improving the spring predictions over East Asia.

Evaluation of vitamin $B_6$ intake and status of 20- to 64-year-old Koreans

  • Kim, Young-Nam;Cho, Youn-Ok
    • Nutrition Research and Practice
    • /
    • v.8 no.6
    • /
    • pp.688-694
    • /
    • 2014
  • BACKGROUND/OBJECTIVES: Recent research regarding vitamin $B_6$ status including biochemical index is limited. Thus, this study estimated intakes and major food sources of vitamin $B_6$; determined plasma pyridoxal 5'-phosphate (PLP); and assessed vitamin $B_6$ status of Korean adults. MATERIALS/METHODS: Three consecutive 24-h diet recalls and fasting blood samples were collected from healthy 20- to 64-year-old adults (n = 254) living in the Seoul metropolitan area, cities of Kwangju and Gumi, Korea. Vitamin $B_6$ intake and plasma PLP were analyzed by gender and by vitamin $B_6$ supplementation. Pearson's correlation coefficient was used to determine associations of vitamin $B_6$ intake and plasma PLP. RESULTS: The mean dietary and total (dietary plus supplemental) vitamin $B_6$ intake was $1.94{\pm}0.64$ and $2.41{\pm}1.45mg/day$, respectively. Median (50th percentile) dietary intake of men and women was 2.062 and 1.706 mg/day. Foods from plant sources provided 70.61% of dietary vitamin $B_6$ intake. Only 6.3% of subjects consumed total vitamin $B_6$ less than Estimated Average Requirements. Plasma PLP concentration of all subjects was $40.03{\pm}23.71nmol/L$. The concentration of users of vitamin $B_6$ supplements was significantly higher than that of nonusers (P < 0.001). Approximately 16% of Korean adults had PLP levels < 20 nmol/L, indicating a biochemical deficiency of vitamin $B_6$, while 19.7% had marginal vitamin $B_6$ status. Plasma PLP concentration showed positive correlation with total vitamin $B_6$ intake (r = 0.40984, P < 0.0001). CONCLUSIONS: In this study, vitamin $B_6$ intake of Korean adults was generally adequate. However, one-third of subjects had vitamin $B_6$ deficiency or marginal status. Therefore, in some adults in Korea, consumption of vitamin $B_6$-rich food sources should be encouraged.

Mobility Management Scheme based on User Mobility QoS and Security-Effective Network in Heterogeneous Mobile Networks (이종의 모바일 네트워크에서 사용자 이동성 QoS와 보안효과적인 네트워크 기반의 이동성관리 기법)

  • Lee, Hyeungwoo;Jeong, Jongpil
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.15 no.2
    • /
    • pp.87-97
    • /
    • 2015
  • To support the efficient mobility MIPv6v, FMIPv6, HMIPv6 and host-based mobility management protocols have been developed. AAAC (Authentication, Authorization, Accounting and Charging) system is applied in this paper analyzed the the existing IPv6 PMIPv6, FPMIPv6 network security effective and IPv6 MMP (Mobile Management Protocol) Features and performance analysis is performed. And IPv6 MMP seamless transfer performance in terms of packet loss probability, will be analyzed. That can be efficiently used as a method for the integration of QoS and mobility so that you can manage and control the resources presented QoSB usage. Results of evaluation results showed a better overall fast handover structure of mobility management techniques. PMIPv6 and FPMIPv6 in many respects the most efficient structure that can be specifically, a fast handover of the structure of the network-based mobility management scheme showed the best results.

The Statistical Thermodynamic Approach to the Liquid-Vapor Interface of Binary Solution (이성분 용액의 액체-증기 계면에 대한 통계 열역학적 연구)

  • Hyungsuk Park
    • Journal of the Korean Chemical Society
    • /
    • v.15 no.3
    • /
    • pp.133-145
    • /
    • 1971
  • A method of theoretical calculation of the thermodynamic properties for liquid-vapor interface of binary solution is developed according to the transient state theory of significant liquid structure. The surface tensions, the adsorbed amounts at the liquid-vapor interface and the activity coefficients of the components for the solutions of $C_6H_{12}-C_6H_6$ $CCI_4-C_6H_6$, $CHCl_3-C_6H_6$, $CHCl_3-CCl_4$, $CCl_4-CS_2$ are calculated through the full ranges of the compositions.

  • PDF