네트워크 침입방지 시스템을 위한 고속 패턴 매칭 가속 시스템

김선일,Kim Sunil 한국정보처리학회 2005 정보처리학회논문지 A Vol.12 No.2

패턴 매칭(Pattern Matching)은 네트워크 침입방지 시스템에서 가장 중요한 부분의 하나며 많은 연산을 필요로 한다. 날로 증가되는 많은 수의 공격 패턴을 다루기 위해, 네트워크 침입방지 시스템에서는 회선 속도로 들어오는 패킷을 처리 할 수 있는 다중 패턴 매칭 방법이 필수적이다. 본 논문에서는 현재 많이 사용되고있는 네트워크 침입방지 및 탐지 시스템인 Snort와 이것의 패턴 매칭 특성을 분석한다. 침입방지 시스템을 위한 패턴 매칭 방법은 다양한 길이를 갖는 많은 수의 패턴과 대소문자 구분 없는 패턴 매칭을 효과적으로 다룰 수 있어야 한다. 또한 여러 개의 입력 문자들을 동시에 처리 할 수 있어야 한다. 본 논문에서 Shift-OR 패턴 매칭 알고리즘에 기반을 둔 다중 패턴 매칭 하드웨어 가속기를 제시하고 여러 가지 가정 하에서 성능 측정을 하였다. 성능 측정에 따르면 제시된 하드웨어 가속기는 현재 Snort에서 사용되는 가장 빠른 소프트웨어 다중 패턴 매칭 보다 80배 이상 빠를 수 있다. Pattern matching is one of critical parts of Network Intrusion Prevention Systems (NIPS) and computationally intensive. To handle a large number of attack signature fattens increasing everyday, a network intrusion prevention system requires a multi pattern matching method that can meet the line speed of packet transfer. In this paper, we analyze Snort, a widely used open source network intrusion prevention/detection system, and its pattern matching characteristics. A multi pattern matching method for NIPS should efficiently handle a large number of patterns with a wide range of pattern lengths and case insensitive patterns matches. It should also be able to process multiple input characters in parallel. We propose a multi pattern matching hardware accelerator based on Shift-OR pattern matching algorithm. We evaluate the performance of the pattern matching accelerator under various assumptions. The performance evaluation shows that the pattern matching accelerator can be more than 80 times faster than the fastest software multi-pattern matching method used in Snort.

전기차 구동 모터 시스템의 중국 인증(CCC, CQC)

김선일(Sunil Kim),이용균(Yongkyun Lee),엄대식(Daesik Eom),이인석(Inseok Lee) 전력전자학회 2016 전력전자학술대회 논문집 Vol.2016 No.7

Cooled EGR 적용을 통한 노후 경유 운행차 NOx 저감

김선일(Sunil Kim),안광만(Kwangman An),김현수(Hyunsoo Kim),박진일(Jinil Park),이종화(Jonghwa Lee),최회명(Hoimyung Choi) 한국자동차공학회 2015 한국자동차공학회 학술대회 및 전시회 Vol.2015 No.11

외과적 근관치료의 핵심

김선일(Sunil Kim) 대한치과의사협회 2017 대한치과의사협회지 Vol.55 No.8

Endodontic surgery is a procedure to treat apical periodontitis or abscess in cases that did not heal after nonsurgical treatment or retreatment. This might include situations with persistent intracanal infection after root canal treatment. Other reasons might be found in extraradicular infection, such as bacterial biofilm on the apical root surface or bacteria within the lesion. For many years, the treatment standard was the traditional approach with surgical burs and amalgam for root-end filling. Endodontic microsurgery is the most recent step in the evolution of endodontic surgery, applying not only ultrasonic tip and biocompatible filling materials but also incorporating high-power magnification and illumination. Although many studies have been published that advocate the use of modern technique, the traditional techniques are still widely used in the surgery community. The purpose of this study was to demonstrate the endodontic microsurgery procedure including the root-end preparation and filling with the use of a surgical operating microscope.

적정기술 관점에서 보는 근관 충전

김선일(Sunil Kim) 대한치과의사협회 2018 대한치과의사협회지 Vol.56 No.10

Obturation is a important procedure of root canal treatment. Canal filling should be both provide a hermetic seal for the root canal system and eliminate leakage channel from the oral cavity. Gutta-percha have been the standard material of choice for root canal obturation. Canal filling has been aimed at maximizing the amount of gutta-percha and minimizing the amount of sealer. However recently, single cone technique has been introduced that include calcium silicate-based sealer and single gutta-percha cone. It is important to select an obturation technique that offers consistency and is easy to use. From the standpoint of appropriate technology, the single cone technique is thought to be useful for general dentist.

지역사회 중심의 복음전도

김선일(Sunil Kim) 장로회신학대학교 세계선교연구원 2015 선교와 신학 Vol.37 No.-

공간과 시간은 인간을 구성하는 핵심 환경이다. 현대사회는 탈공간적 성향을 더욱 띠지만, 이는 반대로 기독교 복음의 공간적·지역적 잠재력을 다시 부각시켜준다. 따라서 오늘날 인간 번성을 위한 지역의 중요성이 재발견되고 이는 기독교 선교적 관점에서도 주목할 만하다. 하나님의 임재와 구원은 역사적으로 구체적인 공간에서 일어났으며 기독교적 도덕성과 성화도 지역공동체에서 증명된다. 이러한 지역과 공간에 대한 인식은 오늘날 공동체 붕괴의 위기에 직면한 한국사회에 중요한 안목을 준다. 특히 최근의 선교적 교회론은 지역사회 속에서 선교하시는 하나님을 발견하고 지역사회에 깊이 동화되는 선교와 전도의 과제를 일깨워준다. 지역에 천착하는 선교적 교회론에 비추어볼 때, 한국교회의 기존 지역중심 전도들은 긍정적 유산에도 불구하고 공동체적 연대감이라는 근본토대 위에서 재고될 필요가 있다. 본고는 이를 위해 지역을 향한 선교적 비전, 신실한 현존, 개인을 향한 공동체적 환대, 지역에서의 공공적 복음선포라는 새로운 방향성을 제시한다. Time and space are basic environment for human makeup. Even though contemporary society appears out of space, its de-localized tendency on the other hand awakens to the spatial and local potential of the gospel. This is worthwhile noting in light of the Christian mission. Divine presence and redemption takes place in a historically concrete space. Morality and sanctification can be also pursued in local communities. This awareness of locality and space offers ab important insight to the Korean church who encounters the crisis of the community breakdown. Churches need to realize their missional and evangelistic vocation in the local neighborhood, since God is already at work there. Missional church movement requires us to reconsider prior approaches of local evangelism and develop new evangelistic ministries in line with committment to joining God in the neighborhood. To this end this paper presents missional vision of the local community, faithful presence, the communal hospitality to individuals, and public proclamation of the gospel in the neighborhood.

균열 치아 진단방법과 한계

김선일(Sunil Kim),신수정(Su-Jung Shin) 대한치과의사협회 2024 대한치과의사협회지 Vol.62 No.1

It is difficult to diagnose differently from other diseases if patients have pain due to cracked teeth. The main reason why cracked tooth diagnosis is difficult is that there is no diagnostic method that can visualize and quantitatively evaluate the degree and depth of cracks. Bite tests, methylene blue staining, transillumination tests, and x-ray tests can be performed to diagnose cracked teeth. In this paper, I will explore the pros and cons of the methods used so far and discuss their effectiveness in diagnosing cracked teeth.

신도시주의 운동과 교회의 공동체성 회복에 대한 전망

김선일 ( Sunil Kim ) 한국기독교사회윤리학회 2006 기독교사회윤리 Vol.11 No.-

This article attempts to spell out the characteristics of New Urbanism, the architecture movement that calls for interdependence among residents, with neighborhoods where shops and home coexist, and streets and alleys are gathering face-to-face relationships for residents in a postmodern America. The purpose of this article is furthermore to explore its implications for Christian witness in a Korean context. New Urbanism has become a mantra for people interested in restoring urban centers and reconfiguring suburban sprawl. I also note that some Christian intellectuals are adopting the movement. It can be argued that some of the principles of New Urbanism serves as a perfect parallel for what we think the church should be involved in. For the purpose of this article, it is equally important to explore whether New Urbanism has a relevance for a Korean context to which this article turns to at the end of its discussion. As New Urbanism argues, this article cites suburban sprawl as an isolating factor for American people and many churches. The sprawl began in part because of federal subsides after World War II. The low-interest housing loans the government provided the veterans returning from the war applied only to new houses. The suburbs were born, neatly dividing people by economic class, which has caused isolations and disconnection between people while reducing social capitals. In some senses, churches followed people into the suburbs and adapted suburban development patterns, buying sizable plots of land, erecting a church and surrounding it with a surface parking lot. Churches then offered multiple programs to draw members, who drove to the site leaving neighborhood behind. This sprawl makes it more difficult for churches to achieve their ultimate objectives: build up of inclusive and redemptive community. As Christians we can advocate for New Urbanist concepts because they force people to share with one another, dwell among their neighbors and allow for a healthy exchange of ideas. IMany of the churched people often become a subculture separate from the outside world. They become so involved in church life that they are not involved in their neighborhoods. Then the church has become irrelevant to the community. Contrariwise, New Urbanism alarms us to engage our community to make the church more relevant to people outside the church. To introduce New Urbanism to Korea, I attempt to describe what we find in New Urbanism parallel to Korean urban planning. I see several commonalities with which both American and Korean societies are struggling with. But there are some marked differences we should take note of. First of all, Korean society has been strongly grounded in communal culture. Second, the geography of Korea with its high-density and small land provides opportunity to avoid the pitfalls that the American suburban sprawl engendered. Third, Koreans have been traditionally apt to share their own spaces in the front yard in addition to creating public spaces like sidewalks and streets. Thus the Korean version of New Urbanism should take this unique Korean cultural traits into account as well. With these factors in mind, I propose several ideas for Christian missions in light of New Urbanism. The first is a possibility that New Urbanist agenda can serve as the foundations to foster a plausibility structure for making Christian witness more viable through community-making in the local neighborhood. My belief is that a Christian building helps to set a tone for the entire community. The second is the potential of public space to create meaningful interactions between the Christian advocates and potential converts. The third is a way of understanding evangelism as allusive art rather than propositional confrontation because architecture itself transmits a certain message. Lastly, I contend that conversion experience needs to be und(social capital) as well as personal decision. In this way, any serious Christian advocates need to consider hospitality as a means of evangelism by opening their spaces to strangers and inviting the potential converts to experience Christian-shared social capitals.

CAN 네트워크를 위한 내장형 ORB 프로토콜의 설계

김기문(Kimoon Kim),김선일(Sunil Kim),김태형(Taehyung Kim),전광일(Gwangil Jeon),홍성수(Seongsoo Hong) 한국정보과학회 1999 한국정보과학회 학술발표논문집 Vol.26 No.2Ⅲ

많은 내장형 시스템이 분산 제어 방식을 채용하고 있는 현재, 소프트웨어 개발자들이 이기종으로 구성된 시스템의 설계 및 관리에 많은 어려움을 겪고 있다. 이에 따라 범용 통신 미들웨어인 CORBA, DCOM 등을 내장형 시스템에 사용하고자 하는 요구가 높아지고 있으나 이들은 분산 내장형 시스템의 고유한 제약 조건을 만족하지 못해 내장형 시스템에 사용된 전례가 드물다. 본 논문은 표준 CORBA의 ORB 프로토콜인 GIOP가 CAN 네트워크와 같은 내장형 콘트롤러 네트워크에 적용되었을 때 드러나는 문제점을 살펴보고, 이러한 고찰의 결과에 근거해 내장형 시스템 환경에 최적화된 새로운 ORB 프로토콜, EIOP (Embedded Inter-ORB Protocol)을 제안한다.

Return-Oriented Programming 공격 방어를 위한 간접 분기 목적 주소 검증 기법

박수현,김선일,Park, Soohyun,Kim, Sunil 한국정보처리학회 2013 정보처리학회논문지. 컴퓨터 및 통신시스템 Vol.2 No.5

Return-Oriented Programming(ROP)는 기존 return-to-libc의 발전된 형태로 프로그램의 코드 영역에 있는 가젯을 조합하여 공격자가 원하는 모든 기능을 수행할 수 있는 코드 재사용 공격 기법이다. ROP 공격을 방어하는 기존 방어 기법들은 동적 실행 흐름 분석으로 인한 높은 성능 부하를 보이거나 ROP 공격에 대한 부분적인 방어만 가능하였다. 본 논문에서 제시하는 간접 분기 목적 주소 검증 기법(Indirect Branch Target Address Verification)은 간접 분기문의 목적 주소가 유효한지 검사해서 ROP 공격을 탐지하며, ROP 공격의 대부분을 방어할 수 있다. 또한 동적 실행 흐름 분석이 필요 없기 때문에 낮은 성능 부담을 보인다. SPEC CPU 2006 벤치마크를 대상으로 한 성능평가에서 15%보다 적은 성능 부하를 보였다. Return-Oriented Programming(ROP) is an advanced code-reuse attack like a return-to-libc attack. ROP attacks combine gadgets in program code area and make functions like a Turing-complete language. Some of previous defense methods against ROP attacks show high performance overhead because of dynamic execution flow analysis and can defend against only certain types of ROP attacks. In this paper, we propose Indirect Branch Target Address Verification (IBTAV). IBTAV detects ROP attacks by checking if target addresses of indirect branches are valid. IBTAV can defends against almost all ROP attacks because it verifies a target address of every indirect branch instruction. Since IBTAV does not require dynamic execution flow analysis, the performance overhead of IBTAV is relatively low. Our evaluation of IBTAV on SPEC CPU 2006 shows less than 15% performance overhead.