• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1559-1565
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• 2014

Cellulase and xylanase are main hydrolysis enzymes for the degradation of cellulosic and hemicellulosic biomass, respectively. In this study, our aim was to develop and test the efficacy of a rapid, high-throughput method to screen hydrolytic-enzyme-producing microbes. To accomplish this, we modified the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening. Targeted microbial samples were initially cultured on agar plates with both cellulose and xylan as substrates. Then, isolated colonies were subcultured in broth media containing yeast extract and either cellulose or xylan. The supernatants of the culture broth were tested with our modified DNS screening method in a 96-microwell plate, with a $200{\mu}l$ total reaction volume. In addition, the stability and reliability of glucose and xylose standards, which were used to determine the enzymatic activity, were studied at $100^{\circ}C$ for different time intervals in a dry oven. It was concluded that the minimum incubation time required for stable color development of the standard solution is 20 min. With this technique, we successfully screened 21 and 31 cellulase- and xylanase-producing strains, respectively, in a single experimental trial. Among the identified strains, 19 showed both cellulose and xylan hydrolyzing activities. These microbes can be applied to bioethanol production from cellulosic and hemicellulosic biomass.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.8
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• pp.259-270
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• 2015

In this paper, we study and implement ways for users to easily apply and manage the DNSSEC in a domestic environment. DNSSEC is the DNS cache information proposed to address the vulnerability of modulation. However, DNSSEC is difficult to apply and manage due to insufficient domestic applications. In signing keys for efficient and reliable management of DNSSEC, we propose proactive monitoring SW and signing keys. This is an automatic management s/w signing key for DNSSEC efficient and reliable management and to provide a monitoring of the signing key. In addition to the proposed details of how DNSSEC signing key update and monitoring progress smoothly, we expect that the present study will help domestic users to apply and manage DNSSEC easily.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2131-2136
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• 2003

Since the number of user-requests increases dramatically on the Internet, the servers and networks can be swamped unexpectedly without any prior notice. Therefore, the end-users are waiting or refused for the responses of the contents from the originating servers. To solve this problem, it has been considered that a distributed web caching system efficiently utilizes structural elements of the network. Because a distributed web caching system uses the caches that are close to end-users on the network, it transmits the contents to users faster than the original network system. This paper proposes a simple client-based distributed web caching system(2HRCS) that client can directly perform object allocation and load balancing without an additional DNS for load balancing in CARP (Cache Array Routing Protocol) and GHS (Global Hosting System) that are the recent distributed web caching system protocol. The proposed system reduces the cost of setup and operation by removing DNS that needs to balance the load in the existing system. The system has clients with consistent hashing method, so it extends its environment to other distributed web caching system that has caches of different capacity. A distributed web caching system is composed and tested to evaluate the performance. As a result, it shows superior performance to consistent hashing system. Because this system can keep performance of the existing system and reduce costs, it has the advantage of constructing medium or small scale CDN (Contents Delivery Network).

• Review of Korean Society for Internet Information
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• v.14 no.3
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• pp.5-20
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• 2013

ICANN has been governing the Domain Name System(DNS) "technically" since 1998. The architecture is called Internet Governance, and it brings about many different discourses; "What does that govern?", "Who delegate its role to ICANN?"," How could the regime ensure fairness?" etc. This article will analyze on Internet Governance by applying the government approach of Foucault, and try to compare two parts, the 'core' and the 'edge' of Internet Governance for method. Whereas the 'core' of it refers the site that be governed by the formal contract directly, the 'edge' as the rest of it means informal friendly relations with ICANN. The 'core' rule was stemmed from technological community such as IAB or IETF historically. They had invented new world and its population to integrate the technical order as protocol and the semiotic order as language, that be based on new government mode. On the other hand, ".KR" domain, one of the 'edges', has been evolved into more heterogeneous system, through contest and conflict between traditional state and Internet Governance. The governed object of ".KR" domain is situated in the crossing of each other the 'protocol user', the 'language-semiotic user' and the' geographical resident'. Here the 'geographical resident' rule was weird for DNS, so that shows the internal lack of Internet Governance. It needs to move to the concept of 'Hangeul(Korean-language) user' rather than the 'geographical resident'.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.262-265
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• 2015

In modern society, the spread of computers and smart phones, the Internet has become part of life. Therefore, the most places, wired/wireless router is installed. Crackers can attack the user to use the router by exploiting network vulnerabilities. therefore, the administrator is able to try cracker variety of attacks sloppy router, vaccine is installed also computer and smartphone users, appearance and address of the usual Internet is not deer medium and similar. In this paper, we look at a method for preventing in each attack seen for typical network attacks.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.79-84
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• 1988

Dye materials and cross linking agents were used for the determination of $\beta$-glucanase activities. The objective of this study was to prepare the blue coloured substrates which are sensitive, specific and simple for the determination of $\beta$-glucanase in malt and Bacillus subtilis K-4-3 enzymes. This method is based on the principle of measuring colorimetrically the split product of coloured and cross linked substrate. The best coupling of dye stuff of $\beta$-glucan was cibacron blue 3G-A and the colour released can suitably be measured at 623nm. Optimal concentration of dye and cross linking agents was 1.5g and 1.25$m\ell$ under 0.1N NaOH. The sensitivity comparison proved that the stained $\beta$-glucan method is much more sensitive than the DNS method to determine reducing sugar released by the enzyme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.6
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• pp.49-57
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• 2010

In the near future IPTV services will be emerged the various types through Internet, but IMS based IPTV service is one of the very attractive IPTV services. This paper describes the interconnecting architectures of Web based IPTV contents provider to IMS(IP Multimedia System) network and describes the three difference architectures as method to find its IP address. One is the architecture using DNS or HSS to find IP address of Web based IPTV contents provider and connecting gateway function to I-CSCF in IMS. The other is the architecture connecting gateway AS to ISC interface of S-CSCF in IMS. This paper describes the characteristics of traffic generating due to interconnect the Web contents provider, and the traffic model of each architectures. The proposed each architecture is emulated the session establishment delay characteristics in CoD service of IPTV by the simulation. This paper shows that the architecture connecting gateway AS to ISC interface of S-CSCF is the excellent method compare to other two methods in view of the session establishment delay.

• Journal of Convergence Society for SMB
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• v.3 no.2
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• pp.33-39
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• 2013

Recently, lots of anti-phishing schemes have been developed. Several products identify phishing sites and show the results on the address bar of the internet browser. However, they determine only by domain names or IP addresses. Although this kind of method is effective against recent DNS Pharming attacks, there is still a possibility that hidden attacks which modifies HTML codes could incapacitate those anti-phishing programs. In this paper, the cognitive approach which compares images to decide phishing or Pharming is presented by using system tray and balloon tips that are hard to fake with pop-ups or flash in order for users to compare pictures from connecting sites and system tray. It differs from an old method that a program analyzes IP or domains to judge if it is phishing or Pharming. Therefore, proposed method effective cognitive approach against phishing and Pharming attacks.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.105-106
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• 2003

The spectral eddy viscosity model is investigated through the large eddy simulation of the decaying and forced isotropic turbulence. It is shown that the widely accepted 'plateau and cusp' model overpredicts resolved kinetic energy due to the amplification of energy at intermediate wavenumbers. Whereas, the simple plateau model reproduces a correct energy spectrum. This result overshadows a priori tests based on the filtered DNS or experimental data. An alternative method for the validation of subgrid-scale model is discussed.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.611-613
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• 2000

이 논문은 TCP/IP 기반 지역 망 내에서 개인용 컴퓨터의 사용에 있어 인터넷 프로토콜의 주소 충돌 해결 방법에 대하여 연구하였다. 현재 컴퓨터의 수는 계속해서 늘고 있지만 사용자는 IP 주소에 대한 지식이 없음으로 인해 고의나 실수로 자신의 것이 아닌 다른 사람의 IP 주소를 사용할 수 있고, 이로 인해 원래 사용자가 네트웍을 사용할 수 없게 된다. 본 논문은 사전에 지역 망 내의 관리 대상 컴퓨터들의 주소정보를 DNS 서버상에서 수집하여 현재 사용하는 주소 정보가 저장된 정보가 같은 지를 검사하는 방법으로 IP 조소 충돌 검출 방법을 제시하였다.