• 제목/요약/키워드: Worm

검색결과 942건 처리시간 0.026초

소빅 웜을 통한 웜 발전동향 (Worm evolution trend through Sobig worm variant)

  • 박재우;김원호
    • 한국사이버테러정보전학회:학술대회논문집
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    • 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
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    • pp.175-180
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    • 2004
  • 2003년 초, 소빅 웜이 발견되었다. 이후 계속적인 변종이 발견되었으며, win32.sobig.F는 많은 피해를 야기하였다. 또한 간단하게 수정된 변종 웜들(넷스카이 웜과 베이글 웜의 경쟁적인 변종 웜)의 출현으로 심각한 피해가 예상된다. 본 논문에서는 소빅 웜과 변종 웸들을 분석하고 이를 중심으로 향후 발생할 악성코드의 발전 동향을 미리 예측하여 1.25 인터넷 대란과 같은 사고를 예방하고자 한다.

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시각기반 웜 자세의 기구학적 모형화 (Vision-based Kinematic Modeling of a Worm's Posture)

  • 도용태;탄콕키옹
    • 제어로봇시스템학회논문지
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    • 제21권3호
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    • pp.250-256
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    • 2015
  • We present a novel method to model the body posture of a worm for vision-based automatic monitoring and analysis. The worm considered in this study is a Caenorhabditis elegans (C. elegans), which is popularly used for research in biological science and engineering. We model the posture by an open chain of a few curved or rigid line segments, in contrast to previously published approaches wherein a large number of small rigid elements are connected for the modeling. Each link segment is represented by only two parameters: an arc angle and an arc length for a curved segment, or an orientation angle and a link length for a straight line segment. Links in the proposed method can be readily related using the Denavit-Hartenberg convention due to similarities to the kinematics of an articulated manipulator. Our method was tested with real worm images, and accurate results were obtained.

내시경 로봇을 위한 웜구동 방사형 이동메커니즘 (Radial Type Locomotive Mechanism with Worm for Robotic Endoscope)

  • 김경대;이승학;김병규;박종오
    • 제어로봇시스템학회논문지
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    • 제8권3호
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    • pp.220-225
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    • 2002
  • In this paper, we suggest a new locomotive mechanism fur self-propelling robotic endoscope which could substitute conventional endoscope. Many researchers proposed inchworm-like mechanism for self-propelling robotic endoscope. But it could not be commercialized because they did not solve the limitation caused by clamping. Therefore, we suggest a new radial-type locomotive mechanism with worm. It can propel itself in any situation and take passive-steering because of radial type. In addition, it can be miniaturized with worm. In this paper, we evaluate the mechanism in the dead pig colon as well as under various environments, and verify the performance fur robotic endoscope.

워엄 스크루 가공을 위한 플래내터리 밀링의 공구 간섭 시뮬레이션 (The Cutting Tool-workpiece Interference Simulation for Worm Screw Machining by Planetary Milling)

  • 이민환;김선호;안중환
    • 한국정밀공학회지
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    • 제26권12호
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    • pp.47-54
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    • 2009
  • A worm screw is widely used in a geared motor unit for motion conversion from rotation to linear. For mass production of a high quality worm, the current rolling process is substituted with the milling process. Since the milling process enables the integration of all operations of worm manufacturing on a CNC(Computer Numerical Control) lathe, productivity can be remarkably improved. In this study, the tooling system for planetary milling on a CNC lathe to improve machinability is developed. However, the cutting tool-workpiece interference is important factors to be considered for producing high quality worms. For adaptability of various worms machining, the tool-workpiece interference simulation system based on a tool-tip trajectory model is developed. The developed simulation system is verified through several kinds of worms and experimental results.

복합공구대용 B축 회전테이블 웜 기어의 정/동적 안정성 및 피로에 관한 연구 (A Study on the Static/Dynamic Stability and the Fatigue Damages for the Worm Gear in the B-Axis Rotary Table of a Mill Turret)

  • 김재실;강승희
    • 한국기계가공학회지
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    • 제13권5호
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    • pp.107-115
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    • 2014
  • Highly functional mill turrets have been developed and continuously improved to shorten the manufacturing time and enable multiple uses. Among these, a mill turret with B-axis rotary table was developed. The B-axis rotary table should be evaluated for structural integrity. Moreover, its worm and worm gear for transmitting power should be able to endure fatigue damage. Therefore, this article presents a structural analysis of this type of B-axis rotary table and confirms its static stability by comparing the stress results to the allowable stress levels. Next, the dynamic stability of the rotary table was investigated via a mode analysis and a harmonic analysis in a range determined by the results of a modal analysis. Finally, a worm gear set, the main part that drives the rotary table, is analyzed for fatigue and to estimate its lifetime. The results of the fatigue analysis allowed a prediction of the life of the worm gear set. The analytical results show that the B-axis rotary table has good structural integrity.

Egg Laying Capacity of Hap/orchis taichui (Digenea: Heterophyidae) in Humans

  • Sato, Megumi;Sanguankiat, Surapol;Pubampen, Somchit;Kusolsuk, Teera;Maipanich, Wanna;Waikagul, Jitra
    • Parasites, Hosts and Diseases
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    • 제47권3호
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    • pp.315-318
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    • 2009
  • Quantitative fecal egg counts represented as the number of eggs per gram of feces (EPG) are generally a reliable parameter to estimate the worm burden of intestinal and hepatic parasitoses. Although Haplorchis taichui (Digenea: Heterophyidae) is one of the most common minute human intestinal flukes, little is known about the relationship between EPG and the actual worm burden in patients or the severity of the disease. In the present study, fecal samples were collected from 25 villagers in northern Thailand before and after praziquantel treatment. The EPG values of each participant were determined by the modified cellophane thick smear method, and adult worms were collected from the whole stool after the treatment. Eggs per day per worm (EPDPW) of H. taichui were estimated 82 from egg counts and expelled worms. The EPG was not well correlated with the worm burden, and a reverse correlation was observed between the EPDPW and the worm burden.

고소작업차용 웜기어 감속기의 최적설계 및 해석에 관한 연구 (Study on Optimal Design and Analysis of Worm Gear Reducer for High Place Operation Car)

  • 김태현;장정환;이동규;김래성;류성기
    • 한국기계가공학회지
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    • 제14권6호
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    • pp.98-103
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    • 2015
  • Swing reducers are widely used in special vehicles that have swing motions. Generally, compact swing reducers were constituted by a worm gear pair. Worm gears are one of the most important technical devices for transmitting torque between spatially crossed axes. Due to their high transmission ratio and compact structure, they are widely used in power transmission applications where high reduction is required. This paper presented approaches to improve the transmission efficiency and assembling performance of 3.5 ton class worm gear swing reducers. Worm wheel and the case of swing reducers were optimized and certified by a finite element method. Finally, an actual swing reducer was processed and assembled to test the performance.

연결설정 지연 단축을 위한 바이러스 쓰로틀링의 가변 비율 제한기 (Variable Rate Limiter in Virus Throttling for Reducing Connection Delay)

  • 심재홍
    • 정보처리학회논문지C
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    • 제13C권5호
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    • pp.559-566
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    • 2006
  • 연결요청(connection request) 패킷의 전송비율을 일정 비율 이하로 제한함으로써 월 발생을 탐지하는 바이러스 쓰로틀링(virus throttling)은 대표적인 웜 조기 탐지 기술 중의 하나이다. 기존 바이러스 쓰로틀링은 비율 제한기의 주기를 고정시키고 지연 큐 길이를 감시하여 웜 발생 여부를 판단한다. 본 논문에서는 가중치 평균 지연 큐 길이를 적용하여 비율 제한기의 주기를 자율적으로 조절하는 알고리즘을 제안하고, 가중치 평균 지연 큐 길이에 따른 다양한 주기결정 기법을 제시한다. 실험결과 제안 알고리즘은 웜 탐지시간에는 크게 영향을 미치지 않으면서도 연결설정 지연시간을 단축하여 사용자가 느끼는 불편함을 줄여 줄 수 있음을 확인하였다.

복수 인터넷 웜의 확산 방식 연구 (The Propagation Dynamics of Multiple Internet Worms)

  • 신원
    • 한국정보통신학회논문지
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    • 제19권12호
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    • pp.2858-2864
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    • 2015
  • 최근 인터넷 웜은 악성코드 중 가장 빠른 속도로 확산하면서 정보 유출, 시스템 결함 등을 일으킬 수 있는 주요한 위협이 되고 있다. 특히, 복수의 인터넷 웜과 변종 웜이 동시 다발적으로 확산하면서 기존 인터넷 웜 대응 방식으로는 한계가 된다는 것을 여실히 보여주고 있다. 이러한 다양한 인터넷 웜에 효과적으로 대응하기 위해서는 복수 웜의 확산 방식을 이해하는 것이 필수적이다. 본 논문에서는 기존의 단일 웜 확산 모델을 개선하여 복수 변종 웜 확산에 대한 정확한 모델링을 목표로 하고, 다양한 실험을 통하여 복수 웜 확산의 양상을 분석한다.

생산공법차이에 따른 죽력과 누에가루를 배합한 약물이 db/db mouse의 혈당강하에 미치는 영향 (Effect of Bambusae Caulis in Liquamen manufactured by Different Production Process and Silk Worm Powder on Blood Sugar in db/db Mice)

  • 장경선;정동주;최찬헌;오영준
    • 동의생리병리학회지
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    • 제17권5호
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    • pp.1217-1223
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    • 2003
  • This study was carried out to understand the effects of Bambusae Caulis in Liquamen manufactured by different production process mixed with Silk Worm Powder on blood sugar in the db/db mice. Refined Bambusae Caulis in Liquamen D(L-BCL.D and H-BCL.D) manufactured by low or high temperature production process and original Bambusae Caulis in Liquamen producted by Hanlim pham Co. (BCL) and Silk Worm Powder were used. The effects of L-BCL.D+Silk Worm Powder, H-BCL.D+Silk Worm Powdr and BCl+SWP were observed in terms of blood sugar, creatinine, BUN, GPT in db/db mice. The amount of glucose was significantly decreased (P < 0.01) in the expremental groups compared with the control. The amount of Creatinine did not show any differences among four groups. The amount of blood urea nitrogen observed significant decrease in the case of BCL group. The amount of GPT did not show any differences among four groups.