• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.243-246
• /
• 2003

The design of router that converts IP packets from IPv4 network to IPv6 network using embedded Linux toolkit based on processor is presented. As an address transition platform, IPv6 module is transplanted to Linux using processor and the experiment was done with IPv4 and IPv6. In order to build the test network, it is constructed with Tunneling mechanism of IPv4 and IPv6 network. The packet value is obtained about 2$\mu$sec on average a 2 hops on the ICMP ping6.

• Bulletin of the Korean Chemical Society
• /
• v.21 no.6
• /
• pp.613-617
• /
• 2000

p-(2-Vinyloxyethoxy)benzylidenemalononitrile (4a), methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b), 3,5-dimethoxy-4-(2'-vinyloxyethoxy)benzylidenemalononitrile (5a), methyl 3,5-dimethoxy-4-(2'-vinyloxy-ethoxy) benzylidenecyanoacetate (5 b), o-(2 -vinyloxyethoxy)benzylidenemalononitrile (6a), methyl o-(2-viny-Ioxyethoxy) benzylidenecyanoacetate (6b), 1,3-di-(2',2'-dicyanovinyl)-5-methyl-2-(2'-vinyloxyetioxy)benzene (7a), l,3-di-(2'-carbomethoxy-2'-cyanovinyl)-5-methyl-2-(2'-vinyloxyethoxy)benzene (7b), 2,3,4-tri-(2'-viny-Ioxyethoxy) benzylidenemalononitrile (8a), methyl 2,3,4-tri-(2'-vinyloxyethoxy)benzylidenecyanoacetate (8b), 2,4,6-tri-(2'-vinyloxyethoxy)benzylidenemalononitrile (9a), and methyl 2,4,6-tri-(2'-vinyloxyethoxy)benzyl-idenecyanoacetate(9b) were prepared by the condensation of the corresponding benzaldehyde 1-3 with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 4, 6, and 8 polymerized readily with radical initiators to yield crosslinked polymers 10, 12, and 14. However, compounds 5, 7, and 9 were inert to radical initiators due to the steric hindrance. The resulting polymers 10, 12, and 14 were not soluble in common solvents showing a thermal stability up to $300^{\circ}C$.

• Journal of the Korean Chemical Society
• /
• v.33 no.4
• /
• pp.419-425
• /
• 1989

Various 1-methyl-1,2,4-triazinium iodides were easily synthesized by the reaction of various 1,2,4-triazines and methyl iodide in acetone. When methyl iodide salts of 1,2,4-triazine derivatives were treated with $K_3Fd(CN)_6$ in 10% NaOH solution, 1-methyl-1,2,4-triazole derivatives as the main products were obtained by ring contraction. In addition to 1-methyl-1,2,4-triazole derivatives, 1,6-dihydro-6-oxo-1,2,4-triazine derivatives as the minor products were also obtained when there were no substitutents in $C_6$-position of 1,2,4-triazines. The formation of pseudo base by $OH^-$ and then oxidation to either 1,6-dihydro-6-oxo-1,2,4-triazines or 1-methyl-1,2,4-triazoles were suggested as the mechanism of the ring contraction. This mechanism also verified that the position of quaternization was neither $N_2$ nor $N_4$ but 1-nitrogen of 1,2,4-triazine.

• The Journal of Advanced Prosthodontics
• /
• v.6 no.6
• /
• pp.512-520
• /
• 2014

PURPOSE. The purpose of this study was to assess the surface characteristics and the biocompatibility of zirconium (Zr) coating on Ti-6Al-4V alloy surface by radio frequency (RF) magnetron sputtering method. MATERIALS AND METHODS. The zirconium films were developed on Ti-6Al-4V discs using RF magnetron sputtering method. Surface profile, surface composition, surface roughness and surface energy were evaluated. Electrochemical test was performed to evaluate the corrosion behavior. Cell proliferation, alkaline phosphatase (ALP) activity and gene expression of mineralized matrix markers were measured. RESULTS. SEM and EDS analysis showed that zirconium deposition was performed successfully on Ti-6Al-4V alloy substrate. Ti-6Al-4V group and Zr-coating group showed no significant difference in surface roughness (P>.05). Surface energy was significantly higher in Zr-coating group than in Ti-6Al-4V group (P<.05). No difference in cell morphology was observed between Ti-6Al-4V group and Zr-coating group. Cell proliferation was higher in Zr-coating group than Ti-6Al-4V group at 1, 3 and 5 days (P<.05). Zr-coating group showed higher ALP activity level than Ti-6Al-4V group (P<.05). The mRNA expressions of bone sialoprotein (BSP) and osteocalcin (OCN) on Zr-coating group increased approximately 1.2-fold and 2.1-fold respectively, compared to that of Ti-6Al-4V group. CONCLUSION. These results suggest that zirconium coating on Ti-6Al-4V alloy could enhance the early osteoblast responses. This property could make non-toxic metal coatings on Ti-6Al-4V alloy suitable for orthopedic and dental implants.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.1
• /
• pp.75-83
• /
• 2008

In this paper, we propose an efficient algorithm that assigns single temporary IPv4 address and port number to improve efficiency of IPv4 address that is allocated in DSTM service. And, we have analyzed the elementary functions for DSTM and have designed the functional modules. Also, we have implemented the DTI interface for encapsulation and decapsulation of IPv6 packets. The performance analysis and comparison are investigated whether the appropriate interworking service is possible or not. Our observation results show that the performance of IPv4 over IPv6 tunneling is suitable to DSTM service due to the reduction of delay by eliminating checksum calculations in the header of IPv6 tunneling.

• Food Science and Preservation
• /
• v.9 no.3
• /
• pp.282-286
• /
• 2002

This study was conducted to improve the storability of onion bulbs by loading method under room temperature and to reduce the rot caused by field open storage. Allium cepa cv. Changnyungdeago, late strain, was used for the test at the storage condition of 1-row-6-stairs, 2-rows-6-stairs, 4-rows-6-stairs, 1-rows-8-stairs, 2-rows-8-stairs, and 4-rows-8-stairs. The results obtained art as follows: The mean temperature was maintained lowly 1.6∼3.2$\^{C}$ in 1-row-6-stairs and 1.3∼2.6$\^{C}$ in 2-rows-6-stairs in contrast to 4-rows-8-stairs and the relative humidity was high when loading rows increased. The rotting rates in 1-row-6-stairs, 2-rows-6-stairs, 4-rows-6-stairs, 1-rows-8-stairs, 2-rows-8-stairs, and 4-rows-8-stairs were 11.4%, 11.6%, 12.4%, 14.6%, 13.9% and 16.6%, respectively, and became higher with increased rows and stairs of loading. Total weight loss of onion bulbs were l2.2%, 12.7%, 13.8%, 15.5%, 15.2% and 18.0% in 1-row-6-stairs, 2-rows-6-stairs, 4-rows-6-stairs, 1-row-8-stairs, 2-rows-8-stairs, and 4-rows-8-stairs, respectively. The rot of onion bulbs was caused mainly by Fusarium sp., Aspergilus sp., Botrytis sp., and bacteria.

• Convergence Security Journal
• /
• v.3 no.1
• /
• pp.73-84
• /
• 2003

The IPv4 that used to be generally used as a medium of computer communications in 1980s has reached its limits now. IPv6 (IP Version 6) is being prepared to solve the limitations of the IPv4. However, the biggest problem of IPv6 is that it is not compatible with the IPv4. To resolve the compatibility issue, Dual Stack, Tunneling and Header Converting methods have been proposed. The Header Converting method allows communications between the IPv4 and IPv6 networks with the converter. This method's strength is that it is easy to embody and the procedures for embodiment is simple. However, this method still contains the weaknesses that the existing IPv4 has. On the current document, the Header Converting method among the three methods is discussed to resolve the problems this method has. To solve the Header Converting method's weakness, the security problem between sections, the IP Header field values are converted to the relative field values and IPSec (IP Security) and ESP (Encapsulation Security Payload) are applied. The proposed "Encrypted Header Converting Method" that is encrypted in packet units has solved the weakness that the pre-existing Header Converting method used to have.d to have.

• Proceedings of the IEEK Conference
• /
• 2000.06a
• /
• pp.89-92
• /
• 2000

In this paper, we consider the interworking methods for Internet layer 3 protocols. The legacy protocol for Internet is IPv4(IP version 4). The ability of IPv4 is not enough for modern real time multimedia communication services. So IPv6(IP version 6) protocol was suggested to resolve the problems of IPv4. 6Bones(IPv6 Backbones) have also constructed from 1996 in many countries. The 6Bones should be interoperatable to the legacy internet. To support all data services including voice and video, IP protocol should be enhanced because the characteristics of modern network services are requiring QoS(Quality of Service) functions, plug and play, security, mobility and so on. So a new IP protocol, IPv6, has been developing to meet the requirements. In this paper, some migration methods for internets are described. We first describe the protocol compatibility problems and suggest some solutions and scenario to solve the problems.

• YAKHAK HOEJI
• /
• v.51 no.1
• /
• pp.56-62
• /
• 2007

Twelve epoxy and hydroxydiosgenin derivatives (DI-1${\sim}$DI-12) were synthesized from diosgenin (25(R)-5-spirosten-3${\beta}$-ol). Diosgenin was epoxidized with m-chloroperoxybenzoic acid (mCPBA) to oxidize 25(R)-4${\alpha}$,5${\alpha}$-epoxyspirostane (DI-1). Diosgenin was reacted with DDQ to form 25(R)-1,4,6-spirostatrien-3-one (DI-2), which was treated with 30% H$_2$O$_2$ to give 25(R)-1${\alpha}$,2${\alpha}$-epoxy-4,6-spirostadien-3-one (DI-3) and treated with mCPBA to form 25(R)-6${\alpha}$,7${\alpha}$-epoxy-1,4-spirostadien-3-one (DI-7), respectively. DI-3 was reduced with NaBH$_4$ to afford 25(R) -1${\alpha}$,2 ${\alpha}$-epoxy-4,6-spirostadien-3${\beta}$-ol(DI-4) and reacted with Li metal in absolute ethanol to form 25(R)-2-ethoxy-1,4,6-spirostatrien-3-one (DI-5). DI-7 was reduced with NaBH$_4$ to produce 25(R)-3${\beta}$,7${\alpha}$-dihydroxy-4-spirostene (DI-8) and treated with Li metal in liquid ammonia to produce 25(R)-7${\alpha}$-hydroxy-4-spirosten-3-one (DI-9). DI-2 was reduced with NaBH$_4$ to form 25(R) -4,6-spirestadien-3${\beta}$-ol(DI-10), which was stirred with 30% H$_2$O$_2$ to synthesize 25(R)-4,6-spirostadien-3-one (DI-11) and reacted with mCPBA to give 25(R)-4${\beta}$,5${\beta}$ -epoxy-6-spirosten-3${\beta}$-ol (DI-12), respectively. The antinociceptive effects of synthesiz ed compounds were measured by hot plate method and compound DI-7 signifcantly exhibited antinociceptive effect. DI-2 decreased the serum triglyceride and total cholesterol levels in poloxamer P-407 injected rat.

• YAKHAK HOEJI
• /
• v.46 no.6
• /
• pp.369-374
• /
• 2002

Dilithiation of 4-(pivaloylamino)pyridine (5) followed by reaction with tetraisopropylthiuram disulfide(TITD) gave rise to 3-(diisopropyldithiocarbamato)-4-(pivaloylamino)pyridine (6). 3-Mercapto-4H-pyrrolopyridine(2) was synthesized from compound 6 by two methods. The first method was that compound 6 was treated with 5M-HCl to form 2-t-butylthiazolo[5,4-c]pyridine (7) and hydrolysed in refluxing 10％ NaOH and solid NaOH to prepare bis(4-amino-3-pyridyl)disulfide (8). And compound 8 was reacted with 2,5-dimethoxytetrahydrofuran and NaBH$_4$ to afford compound 2. The second method was that compound 6 was hydrolysed with 10％ NaOH and followed to react with 2,5-dimethoxytetrahydrofuran to form compound 11. And then compound 11 was treated with 20％ ethanolic KOH solution to synthesize compound 2.