공개키 기반 구조에서의 고속 인증 경로 탐색 서버의 설계 및 구현

이주남,유종덕,이구연 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

In the field of secure information systems including electronic commerces, public key infrastructure(PKI) is widely used for secure services. The more PKI domains are established, the more needs are required for cross-domain certifications. Furthermore, each country has many certificate authorities(CA) which require more complex cross certification. We may need a fast algorithm in order to find the possible certification paths. This will be more indispensible in the growing PKI systems. We designed and implemented the high-speed certification path discovery algorithm. Also, we investigated the feature of operation of the system.

暗渠排水에서 Grove의 公式에 關한 考察

周載洪,李裕根 진주산업대학교 1979 論文集 Vol.17 No.-

Grover's formula had played an important role to develop the theory for descent of the undergroundwater level in the underdrainage. Fall velocity of the underground water level gives a big effect to the cultivation of crops in the wet land. As a result of Grover's theory into pratice, Dr Yamazaki Hujio had found that was a big error. As applicating in experiment plots to Grover's fomula, obtained results are as follows. 1. As you see in the table(1), the result of experiment of Dr Yamazaki Hujio was existent higher value of v than the result of Grover's fomula. The result of fomula(Yc=127e-0.0496t) which resolved to apply a big value of v is existent a calculation mistake. it has been found a phenomenon that the water go not down into the underground, conversely going up. 2. As you see in the table(1),(2),(3) compared with Grover's fomula(1),(2) the value of y_c is a big error in regard to the value of t. 3. As you see in the table(3), (4) the result of applicating in my experiment plots, Grover's fomula is approximate with regard to the actual value.

기계적 자극이 치주인대 세포의 osteoprotegerin과 receptor activator of nuclear factor κB ligand mRNA 발현에 미치는 영향

이기주,이승일,황충주,,옥승호,전옥순 대한치과교정학회 2005 대한치과교정학회지 Vol.35 No.4

본 연구는 치주인대 세포에 지속적이고 점진적 인장력을 가하여 치아 이동 시 형성되는 인장부위의 기계적 자극에 대한 생화학적 전달과 치조골 흡수와 생성 조절 기전을 이해하고자 하였다. 치주인대 세포가 배양된 유연한 성장 표면을 가진 배지에 지속적이고 점진적인 인장력을 가하고 골흡수 인자인 PGE_(2)와 골형성 인자인 ALP의 생성량을 1, 3, 6, 12시간 후에 측정하여 정량비교하였고 파골세포 분화기전을 조절하는 OPG, RANKL의 인자들과 matrix metalloproteinase (MMP)-1, -8, -9, -13, tissue inhlbitor of matrix metalloproteinase (TIMP)-1의 인자들을 역전사 중합효소 연쇄반응 검사하여 m-RNA 발현을 비교한 결과, 치주인대 세포에 인장력을 가한 경우 대조군보다 PGE_(2)의 농도가 적었고 (p<0.05) ALP의 농도 변화는 없었으며 OPG의 mRNA 발현이 증가하였으나, RANKL의 mRNA 발현은 감소하였다. 그리고 TIMP-1과 MMP-1, -8, -9, -13의 mRNA 발현이 대조군과 차이가 없었다. 이상의 연구에서 사람의 치주인대 세포는 점진적이고 지속적인 인장력에 대한 반응으로 PGE_(2)의 생성과 RANKL의 mRNA 발현은 감소하고 OPG의 mRNA 발현은 증가하여 골흡수를 억제하는 효과를 보이는 것으로 나타났다. Tooth movement is a result of mutual physiologic responses between the periodontal ligament and alveolar bone stimulated by mechanical strain. The PDL cell and osteoblast are known to have an influence on bone formation by controlling collagen synthesis and alkaline phosphatase activation. Moreover, recent studies have shown that the PDL cell and osteoblast release osteoprotegerin(OPG) and the receptor activator of nuclear factor κB ligand (RANKL) to control the level of osteoclast differentiation and activation which in turn influences bone resorption. In this study, progressively increased, continuous tenslonal force was applied to PDL cells. The objective was to progressively increased. continuous tensional force was applied to PDL cells. The objective was to find out which kind of biochemical reactions occur after tensional force application and to illuminate the alveolar bone resorption and apposition mechanism. Continuous and progressively increased tensile force was applied to PDL cells cultured on a petriperm dish wlth a flexible membrane. The amount of PGE_(2) and ALP synthesis were measured after 1, 3, 6 and 12 hours of force application. Secondly, RT-PCR analysis was carried out for OPG and RANKL whlch control osteoclast differentiation and MMP-1, -8, -9, -13 and TIMP-1 which regulate the resolution of collagen and resorption of the osteoid layer. According to the results, we concluded that progressively increased, continuous force application to human PDL cells reduces PGE_(2) synthesls, and increases OPG mRNA expression.

Cephalosporium acremonium var. M-10에 의한 Cephalosporin C 생산에 관한 연구

이호근,현형환,오두환,유주현 연세대학교 산업기술연구소 1990 논문집 Vol.22 No.2

The microorganism which produces Cepholsoporin C, has been selected from Cephalosporium acromonium by U.V radiation. Among the mutants, Cephalosporium acremonium var. M-10 was showed the highest Cephalosporin C productivity. On the basis of physiologieal characteristics, the difference hetween Cephalosporium acremonium var. M-10 and Cephalosporium acromonium was that the mutant did not assimilate sodium acetate, potassium nitrate, sodium nitrate. By using Cephalosporium acremonium var. M-10, the optimum conditions for the production of cephalosporin C on the rotary shaker were pH 7.0 soluble starch 4.0 w/v%, (NH₄)₂SO₄0.75w/v%,, CaCl ₂w/v%, soy bean meal 2w/v%, oleic acid 0.09w/v%, methionine 0.3w/v%, at 30℃ for 120 hours, respectively. On the study of time course, it revealed that the peak appeared at the stationery phese. The amount of Cephalosgorin C produced in this medium by mutant was about two times larger than that by Cephalosporium acremonium.

무선 ATM에서의 동적 슬롯 할당 알고리즘

이지현,유소영,서주하 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.A

In recent years, the predominant part in telecommunications is mobile communications. The next generation network is extending today's voice-only mobile networks to multi-service networks. ATM Network is possible to carry such multi-media traffic and it will be expect to use wireless ATM for the future mobile access network. One of manly important aspects for the performance of wireless ATM is the Medium Access Control (MAC) protocol. The MAC protocol must be able to satisfyingly handle the different ATM services (CBR, VBR, ABR and UBR) with their radically different performance requirements. Additionally, the MAC protocol must be able to cope with the complex radio environment where fading, multi-path propagation interference and burst-errors further complicate the situation. In this paper, a dynamic slot allocation algorithm in wireless ATM is proposed for an efficient channel sharing/media access at the MAC layer. We use equivalent capacity in the allocation of slots for VBR traffic which is variable along the time. It is simple and effective slot allocation method for VBR service. In particular, we consider the slot allocation of a session consisted of several connections for requirement of multimedia traffic. Simulation shows that the cell loss ratio is reduced by re-allocation of extra slots in Mobile Terminal (MT).

좌측흉수로 발현된 Boerhaave 증후군 1예

이준,변유미,조민근,조주연,원경준,김영대,박찬국,김만우,유재근,서홍주,이석기 朝鮮大學校 附設 醫學硏究所 2008 The Medical Journal of Chosun University Vol.33 No.2

구토 후 발생한 토혈을 주소로 내원한 환자에서 좌측 늑막 삼출 동반 시 식도 파열의 가능성을 고려하여 흉수 천자 및 지속적인 흉부 단순 촬영의 추적관찰이 필요하며 식도 파열이 배제된 후 환자의 생체 징후 및 토혈 양을 파악하여 내시경 검사 시기를 신중히 결정하는 것이 좋을 것으로 생각된다. 본 증례는 토혈을 주소로 내원하여 Mallory-Weiss 증후군 의심 하에 내시경을 통한 치료 시행 후 추적 관찰에 의해 진단된 Boerhaave 증후군을 경험하였기에 보고하는 바이다. Boerhaave's syndrome is a spontaneous perforation of the esophagus most commonly resulting from a sudden increase in intraesophageal pressure combined with negative intrathoracic pressure caused by straining or vomiting. Surgery should generally be performed within 24 hours because mortality approached 30 to 50 percent in which surgery was delayed. Therefore, early diagnosis and prompt surgical repair are critical for survival. We have experienced a case of Boerhaave's syndrome in a patient presenting with hematemesis with left pleural effusion without any signs or symptoms of pneumomediastinum or pneumothorax.

구강내 미생물에 대한 서양산 고추냉이(Armoracia rusticana) 뿌리 추출물의 항균효과

유난영,박호원,이주현,서현우 대한소아치과학회 2006 大韓小兒齒科學會誌 Vol.33 No.3

견고 구외 골신장술을 이용한 구순구개열 환아의 치험례 : CASE REPORT

유난영,박호원,,김성민,이주현,서현우 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.4

구순구개열 환자에서는 이른 시기에 시행된 수술로 인한 구순이나 구개부의 반흔 형성으로 섭식장애나 발음장애를 동반한 상악의 열성장이 나타나게 된다. 때로는 집중적인 교정치료 후에도 심한 상악골 저형성증을 보이며, 이러한 경우 성장이 완료된 후에 골이식을 동반한 악교정 수술로 상악골을 전방이동시켜 안모의 개선을 도모하기도 한다. 그러나 이러한 상악골의 전방이동은 연조직의 과도한 신장으로 인한 술후회귀현상, 추가적인 골이식이 필요하다는 한계를 가지고 있다. 골신장술은 이러한 한계점을 극복하는 최신 치료방법으로 구순구개열 환자, 두개골 융합증을 나타내는 환자 등에서 상악골을 포함한 두개 안면골의 개선에 많이 이용되고 있다. 특히 구외장치를 이용하는 골신장술은 골신장기간 중에 견인 방향의 조절이 보다 쉬우며, 충분한 양의 골신장이 가능하여 보다 좋은 결과를 얻을 수 있다. 본 증례는 상악 열성장을 보이는 구순구개열 6세 7개월의 여자 환아로, 변형된 구내 프로씨 1형 골전단술(modified Le Fort I osteotomy) 후 두개골을 고정원으로 이용하는 견고 구외 골신장술을 통해 상악골을 전진시켜 양호한 결과를 얻었기에 이를 보고하는 바이다. Patients with cleft lip and palate present severe maxillary hypoplasia due to scar of lip and palate, often accompanied by compromised mastication, speech abnormalities. Sometimes maxillary hypoplasia persist even though active orthodontic treatment was done. In theses cases, patients born with cleft lip and palate will be potential candidates for maxillary advancement with bone grafting after growth to correct the functional deformities and improve aesthetic facial proportions. But, maxillary advancement using standarf surgical approaches has several limitations: increased relapse tendency after maxillary advancement, necessity of additional bone graft and mandibular setback surgery. Distraction osteogenesis is current treatment modality to overcome these limitations, thus has become popular for treatment of maxillary hypoplasia associated cleft lip and palate, craniosyntosis. Especoally, rigid external distraction, contrary to internal device, has adbantages; better vector control of osteotomized segment, effective traction of the bony segments, the ease of the application and removal the distraction device. This study showed that relatively successful result could be generated by using rigid external distraction osteogenesis(RED) in the case of cleft lip and palate with severe maxillary hypoplasia, 6 years 7 months old.

한국인 환자에서 Vancomycin의 집단약동학 (Population Pharmacokinetics)에 관한 연구

유경상,배균섭,이주연,조주연,장인진,신상구,신완균 大韓臨床藥理學會 1998 臨床藥理學會誌 Vol.6 No.2

쌍태아에서 제 1태아의 분만 후 제 2태아의 지연분만 : 중례보고

김주환,서민정,유희정,노권일,조대현,박정규,이정헌,조성남,손영수 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.3

With the widespread use of fertility medications and techniques of in vitro fertilization, multiple gestation has become epidemic in modern obstetric practice. Delivery of the initial fetus in a multiple gestation usually is followed by delivery of the subsequent fetus or fetuses shortly thereafter. However in rare circumstances, the delivery is delayed for days due to disappearance of uterine contraction after delivery of the first fetus. When uterine activity ceases after the delivery of the first neonate, a policy of nonintervention may be considered in case of an immature or very premature delivery, in order to achieve a gestational age for the remaining fetus(es) more compatible with neonatal survival. We report a case of twin gestation with prolongation of the delivery interval between the twins for 46 days.