• Journal of the Korea Society of Computer and Information
• /
• v.15 no.12
• /
• pp.85-92
• /
• 2010

There is an authentication method for participants with an encrypted ID and password as a symmetric-key in multilateral video conferencing. It is hard to manage when the security-keys makes many while the transportation processing for the encryption and decryption get complicated when the video conferencing involves a number of participants and the third party as an attackers to gain unauthorized symmetric-key to access video conference which makes a problem less secrecy. This study suggests three ways to enhance security in video conference: first, we present PKI-based X.509 certificate for authenticating the participants of multilateral conferencing and we suggest to encode and decode the video conference media data using a secrecy key created by each of the conference participants; second, a more secured multilateral video conferencing can be expected in a group communication by using the participants secrecy key in creating and distributing group keys, where the group key will be renewed whenever there is change in the group member; and finally, we suggest to encode the RTP payload of the media data before transmission.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.898-901
• /
• 2005

In this paper, we design an authorization policy module which provides the safty and reliable authorization of the user to provide the resolution for authorization in distributed environments. PKI have been utilized much by an information security-based structure for Internet electronic commerce, it is developing X.509-based in various application field such as a network security. Especially, it provides good resolution for the authentication of the user in the situation not to meet each other, but it is not enough to provide the resolution of the authorization in distributed computing environments. In this paper, We provide AAS model, which can be used distributed resources by distributed users, and design AAS model which is an authorization policy module in the Linux-based Apache Web server.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.3
• /
• pp.920-925
• /
• 2010

A home network system is made up of home devices and wire and wireless network can not only be the subject of cyber attack from a variety factors of threatening, but also have security weakness in cases of hacking, vicious code, worm virus, DoS attack, tapping of communication network, and more. As a result, a variety of problems such as abuse of private life, and exposure and stealing of personal information arose. Therefore, the necessity for a security protocol to protect user asset and personal information within a home network is gradually increasing. Thus, this dissertation designs and suggests a home network security protocol using user authentication and approach-control technology to prevent the threat by unauthorized users towards personal information and user asset in advance by providing the gradual authority to corresponding devices based on authorized information, after authorizing the users with a Public Key Certificate.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.12
• /
• pp.1-8
• /
• 2009

Grid services offer SSO(single sign-on) mechanism using GSI(grid security infrastructure) based on X.509. However. portal applications in web environment use ID and password model for single sign-on. Grid portals means a system which provides grid services by integrating portlet contents on single web interface. In existing research such as GAMA and PURSE, SSO for a whole grid portal is figured out in the way that user is authenticated by ID and password in front and call grid service via GSI at back-end. Other types of web applications outside of portlet framework cannot unfortunately access grid service in SSO way in the existing researches, because the SSO mechanism is developed for portlet framework only. In this paper, we suggest a SSO mechanism based on ID and password model, which forwards authentication information and a GSI token for grid access among portlets and grid-enabled web applications. This mechanism is applied to MGrid for SSO, which consists of applications of java web start, applet, servlet, and etc. as also as portlets.

• Review of KIISC
• /
• v.8 no.3
• /
• pp.5-18
• /
• 1998

인터넷을 통한 상거래가 21세기에 중요한 상거래 수단이 될 전망이다. 인터넷 상거래 시스템은 공개키 암호시스템에 바탕을 두고 실현되고 있다. 공개키 암호 시스템의 폭넓은 사용은 사용자 공개키가 신뢰성이 있어야 안전성을 보장받을 수 있다. 공개키 기반 구조는 이를 위하여 구축되어야 한다. 따라서 안전하고 신뢰성 있게 공개키를 관리하고 공표하기 위한 공개키 기반 구조는 인터넷전자상거래 시스템뿐만 아니라 정부 기간 통신망에서도 매우 중요한 역할을 수행할 것이다. 공개키 기반 구조는 기본적으로 공개키를 CA의 서명용 비밀키로 서명한 공개키 인즌서를 활용한다. 본 고에서는 공개키 기반 구조를 정의하고, 공개키 기반 구조에서 사용될 보안 알고리듬을 살펴보며, X.509 인증서 구조와 종류, 보안 알고리듬 및 보안 정책을 식별하기위한 OID(Object ID) 와 통신 개체를 확인하기 위한 X.500 DN(Distinguished Name)를 정의하고, 믿음의 연결 고리인 인증경로, 인증 경로의 검증 방안, 새로운 요구사항인 인증 경로의 제한, 인증서 발행 및 발급을 위한 인증서 정책, 그리고 인증서 관리 방법 등을 인터넷 공개키 구조인 PKIX문서를 중심으로 기술한다. 또한 공개키 기반 구조를 위한 규격을 제시한다.

• Annual Conference on Human and Language Technology
• /
• 2018.10a
• /
• pp.504-509
• /
• 2018

Neural machine translation (NMT) has recently achieved the state-of-the-art performance. However, it is reported failing in the word sense disambiguation (WSD) for several popular language pairs. In this paper, we explore the extent to which NMT systems are able to disambiguate the Korean homographs. Homographs, words with different meanings but the same written form, cause the word choice problems for NMT systems. Consistent with the popular language pairs, we discover that NMT systems fail to translate Korean homographs correctly. We provide a Korean word sense disambiguation tool-UTagger to use for improvement of NMT's translation quality. We conducted translation experiments using Korean-English and Korean-Vietnamese language pairs. The experimental results show that UTagger can significantly improve the translation quality of NMT in terms of the BLEU, TER, and DLRATIO evaluation metrics.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.6
• /
• pp.2839-2843
• /
• 2013

In this study, the relation between the corneal refractive power and the tear break-up time(TBUT) was analyzed. The results can be effectively used in eye clinics and served as the reference on wearing the contact lenses. We had measured the radius of the corneal of university students who are in the range of 21 to 27 year-old and who don't have eye disease. The corneal refractive power was calculated by using the radius of the corneal. And TBUT is the time when the mire image is distorted first time. The relation between the corneal refractive power and TBUT in right eye was a linear as 'y=37.921-0.610x', in which the larger the refractive power of the cornea is, the shorter TBUT is(negative relationship; r=-0.462, p=0.010). The relation in left eye was also a negatively linear as 'y=41.894-0.695x'(r=-0.509, p=0.004). Consequently, in both eyes the corneal refractive power and TBUT have a negative correlation when myopia is a high. It is possible to predict TBUT, which is necessary in deciding on wear of contact lenses, by measuring the corneal radius of subjects.

• BMB Reports
• /
• v.28 no.6
• /
• pp.509-514
• /
• 1995

A putative secondary structure of the mRNA for the human hepatitis B virus (HBV) X gene is proposed based on not only chemical and enzymatic determination of its single- and double-stranded regions but also selection by the computer program MFOLD for energy minimum conformation under the constraints that the experimentally determined nucleotides were forced or prohibited to base pair. An RNA of 536 nucleotides including the 461-nucleotide HBV X mRNA sequence was synthesized in vitro by the phage T7 RNA polymerase transcription. The thermally renatured transcripts were subjected to chemical modifications with dimethylsulfate and kethoxal and enzymatic hydrolysis with single strand-specific RNase T1 and double strand-specific RNase V1, separately. The sites of modification and cleavage were detected by reverse transcriptase extension of 4 different primers. Many nucleotides could be assigned with high confidence, twenty in double-stranded and thirty-seven in Single-stranded regions. These nucleotides were forced and prohibited, respectively, to base pair in running the recursive RNA folding program MFOLD. The results suggest that 6 different regions (5 within X mRNA) of 14~23 nucleotides are Single-stranded. This putative structure provides a good working model and suggests potential target sites for antisense and ribozyme inhibitors and hybridization probes for the HBV X mRNA.

• Journal of the Korean Chemical Society
• /
• v.30 no.6
• /
• pp.500-509
• /
• 1986

For the development of new type cell, a study on new electrolyte, $AgI-Ag_8S_3SO_4$ system has been carried out by using electrical conductivity measurement, DTA and X-ray powder diffraction method. From both X-ray powder diffraction and DTA method, it is clearly known that 20mole% $ Ag_8S_3SO_4$-AgI system forms single phase, having monoclinic structure. It is also found that 20mole% $Ag_8S_3SO_4$-AgI system is purely $ Ag^+ $cation conduction from results of conductivity measurement by applying 4-probe method.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.509-515
• /
• 1997

Crude papain was extracted from papaya latex under various conditions. Extraction conditions of crude papain were optimized by the response surface methodology (RSM). Extraction yield of papain was affected by concentration of $NaHSO_3$, extraction time and pH. Three independent factors were chosen to determine their effects on the various responses and the function was expressed in terms of a quadratic polynomial equation, which measures the linear, quadratic and interaction effects. According to the results of RSM, the stationary point for quantitatively dependent variable was found to be the maximum point for extraction yield. Optimum conditions of papain extraction were 4% of $NaHSO_3$, 120 min of extraction time and pH 7.6. Under these conditions, 793.16 mg of papain per g latex was extracted from papaya latex.