• Title/Summary/Keyword: The Fragment

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Dynamic Packet Filtering for IP Fragments (IP Fragment 패킷을 위한 동적 패킷필터링 기법)

  • 김영호;손승원;박치항
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2003.12a
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    • pp.128-131
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    • 2003
  • 본 논문에서는 IP Fragment 패킷을 이용한 공격에 대해서 소개하고, 현재 사용되고 있는 패킷필터링 방법의 문제점을 극복하기 위한 동적인 패킷필터링 기법을 제안하고 있다. 기존 패킷필터링 방법이 IP 주소 또는 프로토콜 기반의 정적인 규칙에 의한 필터링 방법을 이용하는 반면, 본 논문에서 제안하는 방법은 IP Fragment 패킷에 대해서 단위 시간당 데이터 양으로 표현되는 트래픽에 기반한 패킷필터링 규칙이 동적으로 생성되도록 한다. 이렇게 동적으로 생성된 규칙은 이후 이상 트래픽이 발생되면 자동으로 차단규칙으로 변경되어 IP Fragment 패킷 공격으로부터 네트워크 호스트의 시스템 자원을 보호할 수 있도록 한다.

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Sorting $\kappa^-mer$ Table in DNA Fragment Assembly (DNA Fragment Assembly에서$\kappa^-$글자 테이블의 정렬)

  • 홍순철;박근수
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.733-735
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    • 2002
  • DNA fragment assembly 프로그램인 Phrap에서는 exact match를 찾기 위해 정렬된 k-글자 테이블 자료구조를 사용한다. 이것은 접미사 배열의 간단한 형태로서, DNA fragment assembly와 같은 응용에서는 접미사 배열보다 더 유용한 자료구조이다. 본 논문에서는 k-글자 테이블을 정렬하는 Manber-Myers, Quicksort, Radix sort 알고리즘을 살펴보고, 실험을 통해 그 중에서 가장 뛰어난 성능을 가지는 것이 Quicksort 알고리즘임을 보였다 또한 k-글자 테이블의 정렬 문제에 있어서는, 캐쉬-메모리 아키텍쳐에 최적화되어 계산복잡도 속에 숨어있는 상수를 최소화하는 것이 중요한 문제임을 밝힌다.

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Specific DNA fragment analysis of Salmonella pullorum and S gallinarum by subtraction PCR (RDA method(Subtraction PCR) 기법을 이용한 닭의 Salmonella pullorum과 S gallinarum의 specific DNA fragment 분리 연구)

  • Park Jae-Myoung;Lee Jong-Jin;Choi Hae-Yeon;Jo Woo-Yeong;Lee Kyung-Hyeon;Song Jae-Chan
    • Korean Journal of Veterinary Service
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    • v.28 no.1
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    • pp.1-21
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    • 2005
  • Pullorum disease and Fowl typhoid are kind of poultry specific disease for poultry. The peculiar character of these poultry specific diseases is that it can be infected by transmitting vertically and horizontally, also it is hard to be discovered by clinical sign, and pathology or immunology. So, to develop the PCR method which distinguishes these two genetically similar diseases of separated the specific DNA fragment from each strain and use it for differential diagnosis by subtraction PCR method. Standard strain of S gallinarum and S pullorum, and field isolation strain were verified by biochemistry, It confirmed existence of plasmid by using the PFGE. Then, Isolated DNA from it and used it as materials for the experiment. After cutting genomic DNA of two strains by using Sau 3Al, It ligated primer to tester DNA for PCR amplification and separated specific DNA fragment bacteria with method of subtraction PCR. And, It confirmed that it is a piece of unique DNA in every bacteria using base sequence of separated DNA fragment. 1. The six specific DNA fragment were separated from the DNA of S gallinarum and S pullorum by the subtraction PCR method. 2. In the result of comparison after setting base sequence of each fragment, each separated base sequence of DNA fragment they did not correspond to each other 3. As the result of each DNA fragment is derived from the each strain of DNA, and there was no homology of genomic DNA level in mutual. 4. The fragment originated in plasmid and includes S pullorum did not separate. 5. In the result of searching base sequence in Genebank, it partially shows homology in Salmonella enterica, S typhimurium, S dublin, Escherichia coli, Shigella flexneri, Yersinia pestis, Klebsiella pneumoniae. 6. Primer design by S gallinarum DNA 2, 3 fragment used PCR, They are positive reaction in only S gallinarum at 276, 367 bp position.

Techniques of XML Fragment Stream Organization for Efficient XML Query Processing in Mobile Clients (이동 클라이언트에서 효율적인 XML 질의 처리를 위한 XML 조각 스트림 구성 기법)

  • Ryu, Jeong-Hoon;Kang, Hyun-Chul
    • The Journal of Society for e-Business Studies
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    • v.14 no.4
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    • pp.75-94
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    • 2009
  • Since XML emerged as a standard for data exchange on the web, it has been established as a core component in e-Commerce and efficient query processing over XML data in ubiquitous computing environment has been also receiving much attention. Recently, the techniques were proposed whereby an XML document is fragmented into XML fragments to be streamed and the mobile clients receive the stream while processing queries over it. In processing queries over an XML fragment stream, the average access time significantly depends on the order of fragments in the stream. As such, for query performance, an efficient organization of XML fragment stream is required as well as the indexing for energy-efficient query processing due to the reduction of tuning time. In this paper, a technique of XML fragment stream organization based on query frequencies, fragment size, fragment access frequencies, and an active XML-based indexing scheme are proposed. Through implementation and performance experiments, our techniques were shown to be efficient compared with the conventional XML fragment stream organizations.

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The Development of 20 mm Test Barrel with Replaceable Powder Chamber Type (약실교환방식의 20 mm 시험용 총열 개발)

  • Lee, Jin-Sung;Lee, Young-Shin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.4
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    • pp.630-638
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    • 2011
  • A new smooth bore test barrel was developed to be used in sensitivity assessment test for explosives and fragment impact test. The bore diameter of the barrel is 20 mm, and the powder chamber is designed to be replaceable with the 12.7 mm, 20 mm and 30 mm type chamber. The test results showed the wide range of fragment velocity from 400 to 2000 m/s, included the fragment velocity requirement of the fragment impact test(alternate procedure #1) in MIL-STD-2105B. The stability of the bullet trajectory was checked by test shots and the structural safety of the system has been confirmed through the stress analysis and the interior ballistics analysis of the barrel.

A New Approach to Fragment Assembly in DNA Sequencing

  • Pevzner, Pavel-A.;Tang, Haixu;Waterman, Micheal-S.
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2001.08a
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    • pp.11-35
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    • 2001
  • For the last twenty years fragment assembly in DNA sequencing followed the "overlap - layout - consensus"paradigm that is used in all currently available assembly tools. Although this approach proved to be useful in assembling clones, it faces difficulties in genomic shotgun assembly: the existing algorithms make assembly errors and are often unable to resolve repeats even in prokaryotic genomes. Biologists are well-aware of these errors and are forced to carry additional experiments to verify the assembled contigs. We abandon the classical “overlap - layout - consensus”approach in favor of a new Eulerian Superpath approach that, for the first time, resolves the problem of repeats in fragment assembly. Our main result is the reduction of the fragment assembly to a variation of the classical Eulerian path problem. This reduction opens new possibilities for repeat resolution and allows one to generate error-free solutions of the large-scale fragment assemble problems. The major improvement of EULER over other algorithms is that it resolves all repeats except long perfect repeats that are theoretically impossible to resolve without additional experiments.

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Reattachment procedure for treatment of fractured maxillary anterior teeth: two case reports (치관부 파절편 재부착술식을 이용한 상악전치부 치관파절의 치료에 대한 2건의 증례보고)

  • Choi, Yoorina
    • The Journal of the Korean dental association
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    • v.54 no.7
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    • pp.492-500
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    • 2016
  • Crown fractures are a common type of dental injuries and very frequently occurred on maxillary anterior teeth, area of requiring a rapid aesthetic recovery. Crown fragment reattachment is a simple and conservative method to restore the fractured teeth. The technique promotes esthetic outcomes as utilizing natural contour, shade, surface texture of teeth and gives mechanical similarity in terms of wear-resistance. Also it gives emotional positive responses to patients and requires less of chair time and costs. This case report presents two cases of crown fragment reattachments on maxillrary anterior teeth, including one complicated crown fracture and one uncomplicated crown fracture. If the fragment is available in cases of crown fractures, reattachment of fragment can be regarded as a predictable alternative. However, it is all the time important that a close conversation informing the patients about the limitations and prognoses of this treatment option.

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Secure Fragmentation Technique for Content-Centric Networking (콘텐츠 중심 네트워크를 위한 안전한 패킷 단편화 기술)

  • Hyun, Sangwon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.4
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    • pp.831-841
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    • 2017
  • This paper presents a secure and DoS-resistant fragment authentication technique for Content-Centric Networking (CCN). Our approach not only guarantees the authenticity of each fragment, but also provides a high resistance to DoS attacks through the immediate verification of fragment authenticity at interim nodes on the routing path. Our experimental results demonstrate that the proposed approach provides much stronger security than the existing approach, without imposing a significant overhead.

Effectiveness of a Hockey-Stick Probe to Localize a Catheter Fragment in a Dog

  • Kim, Kitae;Oh, Dayoung;Shin, Dongmin;Yoon, Junghee
    • Journal of Veterinary Clinics
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    • v.39 no.4
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    • pp.173-176
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    • 2022
  • Intravenous catheterization is a common procedure in human and veterinary medicine. Occasionally, a catheter might break within the blood vessel, and the fragment may cause embolization, infections, or other severe complications, and therefore must be removed promptly. For a successful and low-risk removal, the fragment should be localized accurately; however, ultrasound may be challenging to perform on small dogs due to inadequate probes. We report the case of a 2-year-old, 2.6 kg, intact female toy poodle that presented to the veterinary medical center owing to a recent onion intake; the owner requested to induce emesis. A 24 gauge peripheral intravenous catheter was inserted into the cephalic vein prior to the emetic injection. When the clinician removed the catheter, a device breakage was observed. A tourniquet was applied immediately proximal to the elbow. Ultrasonography was performed with a high-frequency small-footprint linear array transducer, also called a hockey-stick probe, to localize the fragment. An additional ultrasound was performed before surgery to confirm the location of the catheter piece, which migrated 5 cm proximally. Afterward, a surgical intervention allowed us to retrieve the fragment. This report highlights the effectiveness of a hockey-stick probe to determine the location of a catheter fragment in small breed dogs.

RESTORATION OF A FRACTURED INCISOR USING ORIGINAL TOOTH FRAGMENT : A CASE REPORT (치아 파절편 재부착을 이용한 수복의 임상증례 보고)

  • Kim, Ji-Yeon;Park, Ki-Tae
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.2
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    • pp.475-483
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    • 1997
  • Fracture of the crown in a permanent incisor is relatively common. When it occurs with pulp exposure, it presents both restorative and endodontic problems. In the restoration of a fractured incisor, reattachment of the original fragment or restoration with a composite resin is preferred over a temporary crown. If fractured fragment is intact, the tooth can be restored with reattachment of the fragment. An exposed pulp in a young crown-fractured incisor is usually treated with either pulp capping or pulpotomy depending on the size of an exposure and time elapsed since injury. However, in teeth showing vital and/or hyperplastic pulp tissue at the exposure, only superficial layers of the pulp and surrounding dentin should be removed : i.e. partial pulpotomy can be performed in immature as well as mature teeth. This paper reports 2 cases of crown-fractured permanent incisors with pulp exposure that had been treated by reattachment of original fragment followed by partial pulpotomy or partial pulpectomy. The following results are obtained. ; 1. Fragment reattachment is an acceptable semi-permanent restoration of crown fractured young permanent incisor. 2. Partial pulpotomy is recommended as the treatment of choice in crown-fractured permanent teeth with pulp exposure.

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