P2P에서 전자서명을 이용한 정보보호 시스템의 보안에 대한 신뢰성 향상

이정기,김길준 조선대학교 전자정보통신연구소 2003 電子情報通信硏究所論文誌 Vol.6 No.1

정보사회로 진행되어 감에 따라 개인과 개인간의 정보공유 모델인 P2P는 중앙서버가 필요 없이 다른 사용자들과 정보를 주고받을 수 있는 장점으로 지속적으로 발전하고 있다. 또한 정보통신 기술의 급속한 발달과 정보통신망 확산으로 P2P에서 전자문서를 이용하는 전자거래는 증가할 추세에 있다. 그러나 이러한 인터넷을 이용한 전자거래가 우리에게 커다란 편익을 주는 것은 사실이지만 전자문서를 이용한 전자거래는 여러 가지 문제점을 안고 있다. 바로 정보화의 순기능 뒤에 숨어 있는 정보화의 역기능이다. 전자문서를 이용한 정보전달은 비접촉, 비 대변으로 이루어지기 때문에 전달 당사자간에 상대방의 신원확인이 어렵고 타인으로 위장하여 전자문서 등을 부정하게 사용할 위험이 있다. 또한 전자문서는 유통되는 과정에서 위·변조가 용이하고, 문서작성사실을 입증하기 곤란 한다. 이러한 문제점을 해소되기 전에는 P2P에서 전자문서를 이용한 전자거래가 활성화가 어려울 것이다. 본 논문에서는 전자문서를 이용한 전자거래에 있어서 상대방의 신원확인 전자문서의 위·변조 확인 및 문서작성 사실의 부인을 방지하여 전자문서를 안전하고 신뢰성 있게 이용 할 수 있는 여건을 조성 할 수 있도록 공개키 암호기술에 기반을 두는 방식을 사용하여 P2P에서 전자서명을 이용한 전자거래 보안에 대한 신뢰도를 향상시킬수 있도록 하였다.

A. 高校 科學 (生物·地球科學) 및 數學科 探究學習의 評價模型 定立과 評價紙 開發

李相協,權炳奎,林在圭,孫文求,吳岱燮,楊洪準,梁承榮,姜用熙,林成圭,金正遠,金吉民,兪正在 경북대학교 과학교육연구소 1982 科學敎育硏究誌 Vol.6 No.-

Currently the evaluation of high school science and mathematics learning has been too much knowledge-centered without concerning the inquiring ability or scientific attitude. This study, therefore, was made for the purpose of establishing of evaluation model for high school science (biology and earth science) and mathematics learning and its evaluation items. In this paper, the research was done about three fields, biology, earth science and mathematics. 1. For the biology, the evaluation methods of inquiry learning were studied with the foreign references, and proper evaluation items were suggested. 2. For the earth science, after analizing 5 kinds of earth science textbook of current using in high school, essential 19 items were selected. 5 of them were tested in test group and control group, then, the results were analized. 3. For the mathematice, the teaching elements of「Set」and「Flow chart」in mathematics (Ⅰ) were selected and structured. Detailed teaching objects were established and evaluation items were introduced.

컴퓨터 모의실험을 이용한 Stop-and-wait ARQ 기법 성능 평가

이용학,이호준,최길용,장재신 인제대학교 2012 仁濟論叢 Vol.27 No.1

ARQ schemes are commonly used in various communication areas, for instance TCP protocol, to combat communication packet errors and there are three different types of ARQ protocol. In this paper, the performance of stop-and-wait ARQ scheme is evaluated with computer simulation and then compared with analytical results. Two different traffic generation modes are considered: the first one is the saturated traffic model and the other one is periodic arrival model based on exponential distribution. For performance measures, link utilization and average packet delay are used in this paper. According to numerical results, it is known that performance results from computer simulations coincide well with those by mathematical analysis. For the further study, we will continue to carry performance evaluations of two other ARQ schemes, go-back-N ARQ and selective repeat ARQ schemes.

發癌物質과 非發癌物質의 DNA-Modifying Activity에 대한 量子生物學的 解釋

李佶俊,林周相,宋寧大,徐榮培,朴柄珏 嶺南大學校 基礎科學硏究所 1990 基礎科學硏究 Vol.10 No.-

LCAOMO calculation has been carried out for thirty chemical carcinogens and nine metabolites of them. The LUMO electron density which is a measure of ability electron to be accepted and observed DNA-Modifying activity which is a measure of mutation relationship was considered. It was found that the sum of LUMO electron density of 1, 2, 4-positions of a relevant trans-butadiene type (F??) in the compound was correlative to DNA-Modifying activity. This means that carcinogenesis closely relate to mutagensis, since the LUMO electron density is a measure of carcinogenic activity of carcinogens as shown earlier. It was also found that LUMO electron density of 1, 2, 4-positions in compounds increase with their metabolic activation. This is in agreement with the experimental result that carcinogen is more electrophilic as metabolic activation. In conclusion, it may be possible to give a theoretical interpretation on the mutation of chemical carcinogens and explain theoretically the fact that the compound have a strong elestrophilicity on metabolic activation.

Sodium Dodecyl Sulfate의 분해반응에 대한 속도론적 연구

이길준,김종용,박병각 嶺南大學校 環境問題硏究所 1994 環境硏究 Vol.14 No.1

하천수에서 분리해 낸 SDS(Sodium Dodecyl Sulfate) 분해균주에 의하여 분해균주량의 변화와 SDS의 농도변화를 주어 SDS를 분해시킬 때 그 분해반응을 속도론적으로 연구하였다. 실험결과 SDS의 분해를 BOD로 표시하여 분해률을 측정한 속도식은 1차로 나타남을 알 수 있었다. 그리고 분해균주량의 변화와 SDS농도의 변화에 따른 속도상수는 분해규준량에는 영향을 받지 않으나 SDS의 농도에는 영향을 받음을 알 수 있었다. 그리고 활성화에너지는 5.304kcal/mol, 활성화 파라메타인 ???와 ???는 각각 4.69kcal/mol, -56.90 e.u.임을 알았다. Kinetic studies were carried out for change in BOD of SDS degradating microorganism isolated from river water. It is found that the decomposition of SDS is first order. Rate constants for the decomposition of SDS and its degrading microorganism found not to have an influence on variation of SDS-degrading microorganism but have an influence on SDS concentration. And thermodynamic parameters, Ea, ???? and ????, were obtained the value of 5.304kcal/mol, 4.69kcal/mol and -56.90 e.u., respectively.

레반다이어트 식품섭취가 비만여성의 신체구성성분, 혈중 렙틴 및 지질수준에 미치는 영향

이규성,유병렬,정락희,김문희,송봉준,이길자 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.2

This study was to varify the effects of levan diet administration on body composition, blood leptin level and lipids components (TC, TG, LDL-C, HDL-C) in obese women during 8 weeks. The subjects of study were divided into 20-29year group (n=15) and 30-39year group (n=15) randomly selected. Administration of Levan Diet in this study was 2 times (breakfast, lunch or dinner) per day, 11tablets per 1times. Statistical method for data processing produced mean and SD of total variable. To analyze difference between groups and periods had executed 2? ANOVA. This study was given conclusion as follows: First, systolic blood pressure showed decrease after administration of levan diet in 30-39years, but it was not statistically significant. Second, body weight and %fat gradually decreased according to the application period of levan diet administration in 20-29years and 30-39years, and it was statistically significant (p<.05). Third, blood leptin level and blood lipid levels (TC, TG, LDL-C) showed decrease after administration of levan diet in 20-29years and 30-39years, but it was not statistically significant. In conclusion, this study shows that the administration of levan diet play a positive role as assistant diet. Therfore, levan diet administration should be recommended as ergogenic aids for these who do obese adults.

A2024와 SM45C 마찰용접의 열전달 해석

이상윤,고준빈,명태식,김기길,강형모 大田産業大學校 2001 한밭대학교 논문집 Vol.18 No.-

The heat transfer mechanism initiating the friction welding is examined and a transient three dimensional heat conduction model for the welding of two dissimilar cylindrical metal bars is investigated. The cylindrical metal bars are made of materials made of A2024 and SM45C. Numerical simulations of heat flow are performed using the finite volume method. Respectively, Commercial FLUENT code is used in the heat flow simulation and maximum temperature and distribution of temperature are calculated. Temperature of friction welded joining face is compared with the temperature distribution measured by experiment and numerical simulation. The maximum temperature of friction welded joining face is lower than melting point of A2024-T6 aluminum alloy using insert metal. The temperature distribution of friction welded joining face with insert metal is more uniform than that of without insert metal

간경변 환자에서 콜히친 사용에 의한 호중구성 백혈구감소증 1예

이호찬,이헌주,김용길,박재현,김성준,박준석 영남대학교 의과대학 2009 Yeungnam University Journal of Medicine Vol.26 No.2

Colchicine is an alkaloid that has been used for treating acute gouty arthritis, psoriasis, scleroderma and Behcet's syndrome. Colchicine decreased liver fibrosis in rats with carbon tetrachloride induced cirrhosis and in patients with many liver diseases. Therapeutic oral doses of colchicine may cause nausea, vomiting, abdominal pain and diarrhea. The adverse effect of colchicine associated with the dose is bone marrow suppression, and especially neutopenia. Neutropenia has often been reported in patients have taken an overdose of colchicine. We describe a 64-year-old female liver cirrhosis patient with neutropenia that was induced by a therapeutic dose of colchicine.

Streptomyces thermocyaneoviolaceus의 Xylanase 생산조건 및 Xylooligo당의 생산

주길재,박희동,최준호,이인구,이오석,권달호 慶北大學校農業科學技術硏究所 1998 慶北大農學誌 Vol.16 No.-

농산폐자원으로부터 기능성물질인 xylooligo당을 생산하기 위해서 내열성 균주인 S.thermocyaneoviolaceus가 생산하는 xylanase의 생산최적조건을 검토한 결과 0.8% 밀기울, 0.06% yeast extract, 0.06% bactopeptone, 0.05% MgSO₄·7H₂O, 0.005% FeSO₄·7H₂O, 0.05% KH₂PO₄및 0.2% K₂HPO₄를 함유한 배지(pH7.0)에서 50℃, 24시간 배양시 최고효소활성(2.47 unit/ml)의 배양상징액을 얻을 수 있었다. 효소의 최적반응조건은 pH5.5, 65℃였다. 또한 pH안정성을 조사한 결과 pH4.5∼9.5사이에서 4℃에서 12시간후에도 80% 이상의 효소활성을 유지하였고, 열 안정성은 60℃에서 1시간 처리후 94%이상의 효소활성을 유지하는 내열성이 있는 효소였다. 생산된 xylanase birchwood xylan 반응생성물을 TLC 및 HPLC로 확인해 본 결과, pH가 낮을수록(pH 5.0∼6.0) xylobiose와 xylotriose및 소량의 xylose의 양이 증가하였고, pH가 높을수록 (pH8.0∼9.0) X₄이상의 각종 xylooligo당의 양이 상대적으로 증가하였다. 또한 24 시간후에는 xylan의 상대량이 25% 이하로 감소하면서 주분해산물로 xylobiose가 생산되었으며 xylotriose와 xylose 및 X₄이상의 각종 xylooligo당이 생산되었다. A thermotolerant bacterium, Streptomyces thermocyaneoviolaceus which produced xylan-degrading enzymes, utilized excellently xylan of wheat bran by producing the enzymes in comparison with that of birchwood or oat spelts. Optimal enzyme production was achieved in WB medium containing 0.8% wheat bran, 0.06% yeast extract, 0.06% bactopeptone, 0.05% MgSO₄·7H₂O, 0.05% FeSO₄·7H₂O, 0.05% KH₂PO₄ and, 0.2% K₂HPO₄(pH 7.0) at 50℃ for 24 hrs. The optimal pH and temperature for the hydrolysis of xylan were pH 5.5 and 65℃, respectively. The enzyme activity was retained more than 80% at the range from pH 4.5 to pH 9.5 at 4℃ for 12 hrs and 94% on the heat-treatment at 65℃ for 1 hr. Xylobiose, xylotriose, xylose, and other xylooligosaccharides were produced as end products from hydrolysis of birchwood xylan by the xylanase of S. thermocyaneoviolceus.

골반내에 발생한 Proximal-type 유상피성 육종 1예

길준철,이상수,전병화,김성훈,손우석,목정은,박양순,강길현 대한부인종양 콜포스코피학회 2003 Journal of Gynecologic Oncology Vol.14 No.4

유상피성 육종은 매우 드문 악성 연조직 육종으로, 전형적인 경우들은 주로 젊은 남성의 수부, 전완부와 같은 신체의 원위부에 피하 혹은 심재성 피부 종괴로 발생하며, 조직학적 소견상 적은 비정형성을 나타내는 유상피성 세포와 방추형 세포의 증식에 의한 다발성 결절 형태의 배열을 보인다. 최근에 전형적인 유상피성 육종과 조직학적 유사성을 가지나 더 공격적인 형태인 proximal-type 유상피성 육종이 보고되었으며, proximal-type은 전형적인 유상피성 육종에 비하여 현저한 유상피성 세포의 발현과 매우 심한 비정형성을 나타내며, 세포가 매우 크고, 소포성 핵과 뚜렷한 핵소체를 보이며, 자주 rhabdoid 세포의 양상을 띈다. 임상적으로는 전형적인 형태에 비하여 호발 연령이 조금 늦고, 주로 체간부에, 특히 골반, 회음부, 생식기 등과 같은 심부에 발생하고, 더욱 공격적인 양상을 나타낸다. 저자들은 13세 소녀에서 원발부위를 알 수 없는, 골반내에 발생한 proximal-type 유상피성 육종 1예를 경험하여, 문헌 고찰과 함께 보고하는 바이다. Epithelioid sarcoma is a rare malignant soft-tissue sarcoma with an unknown histiogenesis, typically presenting as a subcutaneous or deep dermal mass lesion in the distal portions of the extremities of young adults. Recently, a more aggressive, so-called 'proximal-type' epithelioid sarcoma has been reported. In contrast to conventional epithelioid sarcoma, the proximal type is characterized by a predominantly large cell epithelioid cytomorphology, marked cytologic atypia, and frequent occurrence of rhabdoid features in most patients. Proximal-type epithelioid sarcoma has a predilection for appearing in the genitalia, especially the vulva, penis, pelvis and buttocks. Also this lesion appears to be somewhat more aggressive or at least metastasizes earlier than the conventional epithelioid sarcoma. We report a 13-year-old girl who presented with a buge mass filling the pelvic cavity which was painful, hard and fixed on palpation, and was radiologically diagnosed as a malignant germ cell tumors on the CT scan. The mass was surgically excised and pathologically proved to be an proximal-type epithelioid sarcoma of unknown origin.