1,721,233 research outputs found
Kim Jong Min
No full text학위논문(석사)--아주대학교 일반대학원 :지식정보보안학과,2011. 2IETF RFC 2574에서 기술된 SNMP 메시지 인증 및 암호화 서비스용 키 분배 방식은 SNMP 매니저의 패스워드를 기반으로 Localized Key를 생성하는 알고리즘을 사용한다. 이는 SNMP 매니저의 패스워드 노출 방지를 위해 매니저가 지리적으로 분산된 SNMP 에이전트들을 설치해야 한다는 문제점과 에이전트에 SNMP메시지를 전송하는 시점에서 Localized Key가 계산되어 SNMP 메시지의 전송지연 문제점을 내포하고 있다.
본 논문에서는 SNMP 매니저뿐만이 아니라 해당 네트워크 망에 관련된 다른관계자도 에이전트 설치가 가능하고 SNMP메시지 전송지연을 제거할 수 있도록 RFC 2574에서 제안한 SNMPv3 USM(User-based Security Model)에 RSA 키 분배 방식을 적용하는 방안과 생성된 Localized Key를 비휘발성 저장매체에 저장하는 방안을 제안하였다.
RSA 키 분배 방식 적용과 Localized Key 저장을 통해 SNMP에이전트 추가의 용이함과 SNMP 메시지 전송 지연 시간 감소를 수식 도출과 테스트를 통해 증명하였다. 하지만 공격자들로부터 저장된 키들을 보호하기 위한 추가적인 보안설비 및 연구가 필요하다.제１장 서 론 1
제２장 관련연구 3
제１절 SNMPv1의 구조 3
제２절 SNMPv2의 구조와 암호화 및 인증 7
제３절 SNMPv3의 구조와 보안 모델의 특징 11
제３장 공개 키를 적용한 SNMPV3 USM 19
제１절 SNMPv3 USM 키 분배 방식 문제점 19
제２절 RSA 키 분배 알고리즘 적용 방안 제안 22
제３절 RFC2574방식과 비교 24
제４절 제안방안의 보안성 분석 28
제４장 결론 33
참 고 문 헌 35Maste
Time-dependent optical transmission and photoinduced anisotropic property of amorphous thin film
No full text학위논문(석사) - 한국과학기술원 : 물리학과, 1986.2, [ iv, 72 p. ]한국과학기술원 : 물리학과
자외선 표면처리가 탄소섬유/에폭시 복합재료의 접착강도에 미치는 영향
No full text학위논문(석사) - 한국과학기술원 : 기계공학전공, 2003.2, [ vii, 66 p. ]In the last few decades composites materials, especially fiber-reinforced composites, have been applied increasingly to various fields e.g. sports, automobile, aircraft and defense industries which manufacture high value-added products. As the applications of composite structures increased, various adhesion technologies to join composite parts on the structures have been developed in order to meet the required adhesion performance.
In this work, the surface modification of carbon/epoxy composites was investigated using UV (ultraviolet ray) surface treatment to increase adhesion strength between the carbon/epoxy composites and adhesives. After UV surface treatment, XPS (X-ray photoelectron spectroscopy) tests were performed to analyze the surface characteristics of the carbon/epoxy composites. Comparing the adhesion strengths with the surface characteristics, the effects of the surface modification of carbon/epoxy composites by UV surface treatments on the adhesion strengths were investigated qualitatively and quantitatively.한국과학기술원 : 기계공학전공
진공단열체 심재의 유효열전도계수에 관한 실험적 연구
No full text학위논문(석사) - 한국과학기술원 : 기계공학전공, 2010.2, [ vi,67 p. ]A measurement apparatus is designed and fabricated to measure the effective thermal conductivity of a VIP (Vacuum Insulation Panel) core specimen under various vacuum states and external loads. Using the apparatus, the effective thermal conductivity \It{k_{eff}} of open-cell rigid PU foam, glass paper, silica gel and artificial staggered beam are measured and compared with theoretical models. Theoretical model of open-cell rigid PU foam has relative error of 8%; on the other hand, those of glass paper and silica gel deviate over 20%. That of staggered beam shows over 60% of relative error. Among the four specimens, glass paper and staggered beam are better than others in view of \It{k_{eff}}, while glass paper is preferred for the longer service time as a core of the VIP.한국과학기술원 : 기계공학전공
Highly Reliable Memristive-Switching Memory Devices Enabled by Nanotransfer Printing based on Self-Assembled Nanotemplate
No full textCOVID-19: An Early Review of Its Global Impact and Considerations for Parkinson's Disease
No full textWhile many infectious disorders are unknown to most neurologists, coronavirus disease 2019 (COVID-19) is very different. It has impacted neurologists and other health care workers, not only in our professional lives but also through the fear and panic within our own families, colleagues, patients and their families, and even in the wider public. COVID-19 affects all sorts of individuals, but the elderly with underlying chronic conditions are particularly at risk of severe disease, or even death. Parkinson's disease (PD) shares a common profile as an age-dependent degenerative disorder, frequently associated with comorbidities, particularly cardiovascular diseases, so PD patients will almost certainly fall into the high-risk group. Therefore, the aim of this review is to explore the risk of COVID-19 in PD based on the susceptibility to severe disease, its impact on PD disease severity, potential long-term sequelae, and difficulties of PD management during this outbreak, where neurologists face various challenges on how we can maintain effective care for PD patients without exposing them, or ourselves, to the risk of infection. It is less than six months since the identification of the original COVID-19 case on New Year's Eve 2019, so it is still too early to fully understand the natural history of COVID-19 and the evidence on COVID-19-related PD is scant. Though the possibilities presented are speculative, they are theory-based, and supported by prior evidence from other neurotrophic viruses closely related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Neurologists should be on high alert and vigilant for potential acute and chronic complications when encountering PD patients who are suspected of having COVID-19.Y
Analysis of PubMed and KoreaMed Indexed Korean Publications on COVID-19
No full textDuring the coronavirus disease 2019 (COVID-19) pandemic, publications on the disease have exploded globally. The present study analyzed PubMed and KoreaMed indexed COVID-19 publications by Korean researchers from January 1, 2020 to August 19, 2021. A total of 83,549 COVID-19 articles were recorded in PubMed and 1,875 of these were published by Korean authors in 673 journals (67 Korean and 606 overseas journals). The KoreaMed platform covered 766 articles on COVID-19, including 612 by Korean authors. Among the Journal of Korean Medical Science (JKMS) articles on COVID-19, PubMed covered 176 and KoreaMed 141 documents. Korean researchers contributed to 2.2% of global publications on COVID-19 in PubMed. The JKMS has published most articles on COVID-19 in Korea.N
MRI-Based Demonstration of the Normal Glymphatic System in a Human Population: A Systematic Review
No full textBACKGROUND: The glymphatic system has been described as one that facilitates the exchange between the cerebrospinal fluid (CSF) and interstitial fluid, and many recent studies have demonstrated glymphatic flow based on magnetic resonance imaging (MRI). We aim to systematically review the studies demonstrating a normal glymphatic flow in a human population using MRI and to propose a detailed glymphatic imaging protocol. METHODS: We searched the MEDLINE and EMBASE databases to identify studies with human participants involving MRI-based demonstrations of the normal glymphatic flow. We extracted data on the imaging sequence, imaging protocol, and the targeted anatomical structures on each study. RESULTS: According to contrast-enhanced MRI studies, peak enhancement was sequentially detected first in the CSF space, followed by the brain parenchyma, the meningeal lymphatic vessel (MLV), and, finally, the cervical lymph nodes, corresponding with glymphatic flow and explaining the drainage into the MLV. Non-contrast flow-sensitive MRI studies revealed similar glymphatic inflow from the CSF space to the brain parenchyma and efflux of exchanged fluid from the brain parenchyma to the MLV. CONCLUSION: We may recommend T1-weighted contrast-enhanced MRI for visualizing glymphatic flow. Our result can increase understanding of the glymphatic system and may lay the groundwork for establishing central nervous system fluid dynamic theories and developing standardized imaging protocols
How is China shaping Africa? The role of Chinese development projects on land cover transformation
No full textThis paper investigates the impact of Chinese development projects on the change of land covering in the African continent over the years 2000-2017 by means of a new gridded dataset. The geo-referenced panel dataset matches information on Chinese development projects with satellite data on the evolution of land surface. The econometric analysis shows that Chinese development projects have played a significant role in the transformation of the African land covering, and that the Chinese intervention in Africa has had a significant impact on the transition of land covering from natural to artificial surfaces
- …
