• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.133-141
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• 2005

The object of this study is to present performance by applying six sigma quality management to a construction company. The research method involves to investigate and analyze data regarding six sigma projects in S construction company and a questionnaire survey from the personnel of the S construction company. The results of this study are as follows 1) S construction company utilized the six sigma quality management for 258 projects during the years of 2003 and 2004 and this bring the effect of cost reduction for quality. Moreover, before using the six sigma quality management, the average level of sigma in this company was around 2.8, after using this, the level increased to 3.6. Particularly, the construction management part, the level increased from 1.3 to 2.6.2) respondents recognize that quality management costs by applying six sigma is reduced. but there is only a little operational efficiency because it is In the early stage of applying six sigma quality management.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.5
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• pp.20-27
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• 2007

In this paper, Air-interface protocols of ISO 18000-6 Type A and B applied to RFID system in UHF band are analyzed, and those algorithms are realized. Also, the improved anticollision algorithms for the Type A and B of ISO 18000-6 protocol are proposed and the performances are compared. As the results, reduction ratio of total tag recognition time of the improved ISO 18000-6 Type A algorithm is 35.2 % for 100 tags and 24.3% for 1000 tags with respect to standard algorithm, respectively. And the reduction ratio of the improved ISO 18000-6 Type B algorithm is 6.0% for 100 tags and 6.6% for 1000 tags. Therefore, the improved anticollision algorithm proposed in this paper is the advanced method improving the performance of tag recognition in the RFID system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.105-111
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• 2008

Mobility support for mobile networks will be important to minimize the packet overhead, to optimize routing, to reduce handoff latency, and to reduce the volume of handoff signals. Mobile IPv6 (MIPv6) and Hierarchical MIPv6 (HMIPv6) are one of mobility management protocols (MMPs) that provides network layer mobility over all access technologies. However, the communication quality of these candidates is severely degraded during handoffs. As another way to improve the handoff performance of a mobile network by conventional MMPs such as MIPv6 and HMIPv6, we propose a Low Latency Handoff Scheme (LLHS) combining Fast MIPv6 (FMIPv6) with HMIPv6 extension with buffering function, in which Mobility Anchor Points (MAPs) buffer packets destined to the Mobile Routers (MRs) or MNs within a mobile network during handoffs. The simulation results show that the proposed scheme reduces transmission delay and packet loss in UDP communication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.87-90
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• 2007

Many moderncommunication technologies are developing based on internet protocol (IP) and there is many work to archive seamless mobility service. IETF proposed MIPv6 protocol that uses IPv6 to provide mobility services to mobile node however it has some limits like sending and receiving too many messages during binding update (BU) procedure. So, now a day it makes HMIPv6(Hierarchical Mobile IPv6). HMIPv6 solves overhead and transmission delay problem in MAP(Mobile Anchor Pointer), but it can't accomplish effectively Macro handover between MAPs. This paper introduces use of FMIPv6 and Selective handover mechanisms based on hierarchical MAP information in HMIPv6 for improvement of handover efficiency.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.337-345
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• 1990

The properties of three esterases (E2, E6 and E11) which were previously purified from Pieris rapae L. were determined and physiological role of E6 was inferred using immunological methods. Based on inhibitor study, all of the purified esterases were found to be carboxylesterases (EC 3.1.1.1). The Km values for E2, E6 and E11 were determined to be 6.89 X 10-$^4$M. 3.19 $\times$ l0-$^4$M and 3.69 X 10-$^4$M, respectively. The molecular weights of E2, E6 and E11 were estimated to be 42 KD, 81 KD and 174 KD, respectively. The isoelectric points of E2, E6 and E11 were estimated to be pH 5.54, pH 5.89 and pH 6.50, respectively. The concentration of E6 during development was highest at the late 5th instar larval stage and that according to organs at the same stage was highest in midgut. These results suggest that E6 might be a hydrolase involved in the digestion of dietary lipids.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.53-58
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• 2020

Korea Electric Power Corporation (KEPCO) uses large amount of SF₆, one of the potent greenhouse gases, in electric equipment for electrical insulation. KEPCO is developing SF₆ recovery and purification technology to minimize the release of SF₆ into the environment, to secure certified emission reduction, and to save purchase cost of new SF₆ by reusing the refined SF₆. A prototype SF₆ purification system using cryogenic solidification technology has been built in demonstration scale. To evaluate the feasibility of the commercialization, the system has been operated to purify large amount of used SF₆ in a long-term operation and the performance has been economically evaluated. The system was stable enough for commercial operation such that it was able to purify 5.4 tons of used SF₆ from power transmission equipment in 2-month operation. Over 99% of the SF₆ was recovered from the used gas and the purity of the purified gas was over 99.7 vol%. The operation cost, which is the cost of refrigerant (liquid nitrogen), electricity and labor, per kilogram of purified SF₆ was 6,526 KRW. Considering the price of new SF₆ in Korea is about 15,000 KRW per kilogram this year, about 56% of the purchase cost can be saved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.4
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• pp.337-349
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• 2013

In this paper, we propose a new mobility management scheme, called i-FP(intelligent Fast PMIPv6). Our proposed i-FP scheme is addressed for solving the existing local mobility management problems from legacy frameworks. To move MN(Mobile Node) to other networks in one domain, i-FP employs three network entities which are extended from PMIPv6(Proxy Mobile IPv6), LMA(Local Mobility Anchor), MAG(Mobile Access Gateway) and MN. In i-FP, the three network entities can reduce the handover delay time of MNs. Also, i-FP uses an IP header swapping mechanism to avoid the traffic overhead and improve the throughput of network. To evaluate the performance of i-FP, we analyze our i-FP, HMIPv6(Hierarchical Mobile IPv6) and PMIPv6 which are legacy protocols of local mobility management in terms of various parameters. Finally, our i-FP scheme shows good performance(reduction of routing hops 10.2%, signaling costs 58.5% and handover delay 16.3%) than other network schemes for the total cost.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.783-792
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• 2001

It is well known that, in the near future, the lifetime of the IPv4 address space will be limited and available 32-bit IP network addresses will not be left any more. In order to solve such IPv4 address space problem in an effective way, the transition to the new version using IPv6 architecture is inevitably required. At present, it is impossible to convert IPv4 into IPv6 at a time, since the coverage and the size of today's Internet is too huge. Therefore, the coexistence of both IPv4 and IPv6 must be arranged in a special and practical fashion for rapid conversion on the whole. IP protocol translation has been proposed to ease the translation of the Internet from IPv4 to IPv6. This paper presents the design and implementation of a transparent transition service that translates packet header as they cross between IPv4 and IPv6 networks. IPv4/IPv6 Translation Protocol is written in c source code and is tested by the local test recommended by ISO, which has the most excellent error detection function. The test was processed with a test scenario and it was found that the results were successful.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.207-211
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• 1998

Melhylovorus sp. strain SS1 grown on methanol was found to show activities of key enzymes of the linear route, $NAD^+$-linked formaldehyde and formate dehydrogenases, and the cyclic route, hexulose-6-phosphate synthase, glucose-6-phosphate isomerase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase, for formaldehyde oxidation. The activities of the cyclic route enzymes were higher than those of the linear route enzymes. The bacterium also exhibited activities of the key enzymes of the ribulose monophosphate and Entner-Doudoroff pathways and transaldolase involved in the formaldehyde assimilation and the enzymes involved in the biosynthesis of extracellular polysaccharide. Cells grown in the presence of 2.3 mM ammonium sulfate were higher in the productivity of extracellular polysaccharide, but lower in the growth yield, than those grown in the presence 7.6 mM ammonium sulfate. The activities of 6-phosphogluconate dehydrogenase, phosphoglucomutase, and UDP-pyrophosphorylase in cells grown under nitrogen-limited condition were higher, but that of 6-phosphogluconate dehydratase/2-keto-3-deoxy-6-phosphogluconate aldolase was lower, than those in cells grown in the presence of sufficient amount of nitrogen source.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4B
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• pp.403-418
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• 2009

IP version 6 (IPv6) is a new If addressing scheme that has 128-bit address space. IPv6 is proposed to solve the address space problem of IP version 4 (IPv4) which has 32-bit address space. For a given IPv6 routing set, if a forwarding table is built using a trio structure, the trio has a lot more levels than that for IPv4. Hence, for IPv6 address lookup, the binary search on trio levels would be more appropriate and give better search performance than linear search on trio levels. This paper proposes a new IPv6 address lookup algorithm performing binary search on trio levels. The proposed algorithm uses a Bloom filter in pre-filtering levels which do not have matching nodes, and hence it reduces the number of off-chip memory accesses. Simulation has been performed using actual IPv6 routing sets, and the result shows that an IPv6 address lookup can be performed with 1-3 memory accesses in average for a routing data set with 1096 prefixes.