• 정보와 통신
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• 제24권11호
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• pp.14-24
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• 2007

최근 네트워크 공격 기술이 날로 발전함에 따라 각 시스템에서 노출된 취약성이 패치되기 전에 네트워크 환경을 위협하는 zero-day 공격이 최대 이슈로 등장하고 있다. 본 고에서는 zero-day 위협에 대응하기 위해서, 활발하게 진행되고 있는 탐지 시그니처 자동 생성 기술에 대한 최근 연구 동향에 대해 소개하고, 이러한 기존 연구 및 기술들의 단점을 보완하기 위해 개발되고 있는 하드웨어 기반 고성능, 시그니처 자동 생성 시스템을 포괄하는 네트워크 보안 지능화 기술을 소개한다. 그리고 생성된 탐지 시그니처를 타 보안 솔루션들과 공유하기 위한 운영 프레임워크를 제안하고, 생성된 시그니처를 공유하기 위해 사용하는 시그니처 생성 교환프로토콜과 메시지 교환 형식을 정의한다. 이러한 지능화대응 기술을 활용함으로써 zero-day 공격에 대해 초기에 탐지하고 신속하게 대응하여 네트워크 인프라를 보호하는 효과를 기대할 수 있다. 또한, 체계적인 보안 정책 관리를 통하여 향후 발생할 네트워크 위협 공격들에 대해서도 빠르게 대응할 수 있도록 하여 국가적인 차원에서의 효과적인 방어체계를 구축하는데 기여할 것이다.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1206-1213
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• 2006

자기 전파하는 웜들의 속도가 사람이 대응하는 속도 보다 매우 빠르기 때문에 zero-day 웜들을 봉쇄하기 위해서는 웜 시그니쳐의 빠른 검출과 자동생성이 필수적이다. 본 논문에서는 웜 공격에 대응 할 수 있는 시그니쳐 자동생성 방법을 제안하고, 제안한 방법의 프로토타입을 구현하여 DHT 기반 네트워크에 적용하여 웜 시그니쳐를 생성함으로써 제안한 방법의 유효성을 보이도록 한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.585-588
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• 2016

IoT System의 특성상 IoT Device(혹은 Sensor)는 우리의 일상생활에 쉽게 노출(또는 장착)되어있고, IoT Device에 대한 직접적인 물리적 접근이 쉬우므로, 이로 인한 물리적 보안이 매우 취약하다. 본 연구에서는 IoT System의 ARMv7 Thumb Architecture 대상으로 직접적인 로컬 시스템 취약성을 공격하여 IoT System 속으로 침투하는 Zero-Day Attack을 구현하였다.

• Asian Journal of Atmospheric Environment
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• 제9권4호
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• pp.259-271
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• 2015

This study conducted analyses on biogenic volatile organic compounds (BVOC) emission sources contributing to urban ozone ($O_3$) concentration in Osaka Prefecture, Japan in summer 2010 by using the Weather Research and Forecasting model (WRF) version 3.5.1 and the Community Multiscale Air Quality model (CMAQ) version 5.0.1. This prefecture is characterized by highly urbanized area with small forest area. The contributions of source regions surrounding Osaka were estimated by comparing the baseline case and zero-out cases for BVOC emissions from each source region. The zero-out emission runs showed that the BVOC emissions substantially contributed to urban $O_3$ concentration in Osaka (10.3 ppb: 15.9% of mean daily maximum 1-h $O_3$ concentration) with day-by-day variations of contributing source regions, which were qualitatively explained by backward trajectory analyses. Although $O_3$ concentrations were especially high on 23 July and 2 August 2010, the contribution of BVOC on 23 July (35.4 ppb: 25.6% of daily maximum $O_3$) was much larger than that on 2 August (20.9 ppb: 14.2% of daily maximum $O_3$). To investigate this difference, additional zero-out cases for anthropogenic VOC (AVOC) emissions from Osaka and for VOC emissions on the target days were performed. On 23 July, the urban $O_3$ concentration in Osaka was dominantly increased by the transport from the northwestern region outside Osaka with large contribution of $O_3$ that was produced through BVOC reactions by the day before and was retained over the nocturnal boundary layer. On 2 August, the concentration was dominantly increased by the local photochemical production inside Osaka under weak wind condition with the particularly large contribution of AVOC emitted from Osaka on the day.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.595-598
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• 2014

최근의 사이버 공격은 보안패치가 발표되기 이전의 보안취약점을 악용하는 제로 데이(Zero Day) 공격, 웹 사이트를 대상으로 한 공격이 주를 이루고 있다. 이러한 공격은 소프트웨어 자체에 내장된 보안취약점을 이용하는 것이 대부분으로, 특히나 소스코드의 보안취약점을 이용한 사이버 공격은 보안장비로는 대응이 어려운 특성을 가진다. 따라서 이러한 공격을 예방하기 위해 소프트웨어를 구현하는 단계에서부터 보안취약점을 배제 시켜야한다. 본 논문에서는 구현단계에서부터 보안위협을 해소하는 Secure Coding 가이드 지원 도구를 설계하고자 한다.

• 상하수도학회지
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• 제27권5호
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• pp.581-590
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• 2013

A research was performed for zero discharge system of waste water which is produced from energy recovery process of waste and biomass. Leachate and all kinds of waste water should be separated and integrated into three categories in addition to converting existing leachate treatment facility into waste water treatment facility as well as introducing a management system of reverse osmosis membrane facility and bioreactor landfill. Following these conditions to better water treatment process, it was likely to produce over 3,000 tons of low-grade recycling water and 2,000 tons of high-grade recycling water per day when zero discharge system of waste water is applied starting from 2016. Economical efficiency was also surveyed in total treatment fee. Present system costs 18,129 million won per year, and suggested zero discharge system would cost 15,789 million won per year.

• 대한한방소아과학회지
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• 제15권2호
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• pp.31-41
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• 2001

We studied 100 neonates to enter a Dongguk University Oriental Hospital Postpartum Care Center, during 9 months from February 10. 2001 to November 4. 2001. The conclusion is following. 1. Newborn sex ratio was 1.70. 2. Delivery method : Normal vaginal delivery was 66 and cesarean section was 34. 3. Gestation age : Premature infants less than 37 weeks were 2 term infants from 37 to 41 weeks were 98 and post-term infants 42 or more weeks were zero. 4. Period between birth and admission : First to fifth day was 66 sixth to tenth day was 32 and eleventh or more day was 2. 5. Period of admission : 1 to 7 days were 8. 8 to 14 days were 65. 15 to 21 days were 23. and 22 to 28 days were 4. 6. Weight : Birth weight less than 2500g was 3. 2500 to 3999g was 92. and 4000g or more was 5. 7. Height : Zero week after birth the average height was 48.8cm, one week after birth was 50.0cm, two weeks after birth was 51.8cm, three weeks after birth was 53.2cm, four weeks after birth was 54.5cm. 8. Head circumference : Zero week after birth the average head circumference was 34.6cm, one week after birth was 35.3cm, two weeks after birth was 35.7cm, three weeks after birth was 36.3cm, four weeks after birth was 36.8cm. 9. Chest circumference : Zero week after birth the average chest circumference was 33.2cm, one week after birth was 33.5cm, two weeks after birth was 34.4cm, three weeks after birth was 35.1cm, four weeks after birth was 36.6cm. 10. Feeding : There was not breast feeding, artificial feeding was 8, and mixing feeding was 92. 11. Jaundice : Physiologic jaundice was 10, pathologic jaundice was 1.

• Asian-Australasian Journal of Animal Sciences
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• 제22권11호
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• pp.1540-1546
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• 2009

One hundred and forty-four piglets with an average birth weight of 1,672${\pm}$13.4 g were used to evaluate different feeding strategies for piglets reared from birth on a dummy sow. A 3${\times}$2 factorial experiment compared three nursing frequencies (1, 3 or 6 h intervals) and two feeding regimes (milk only, or milk combined with access to creep feed and water). The piglets which were nursed at one hour intervals had the lightest body weights at all days, and the poorest combined milk and creep feed dry matter conversion efficiency to piglet body weight gain in the second week. Piglets which were nursed at 3 h intervals had the heaviest body weight at day 15 and 22, but those nursed at 6 h intervals achieved similar body weight by days 29 (milk withdrawal) and 36. Piglets offered creep feed were observed to wean themselves before cessation of milk availability, and the timing of this self-weaning depended on the nursing frequency. The piglets nursed at one hour intervals weaned themselves between day 22 and day 29, those nursed at 3 h intervals weaned themselves between day 15 and day 22, whilst those nursed at 6 h intervals weaned themselves between day 8 and day 15. The piglets which were nursed at 6 h intervals had the highest total dry matter intake in weeks 3 and 4 when fed with milk, creep feed and water but not when fed milk only. They consequently had the poorest dry matter conversion efficiency in the fourth week and overall when fed with milk, creep feed and water, but not when fed milk only. It is concluded that the optimal management routine under these conditions is a 3 h nursing cycle with provision of supplementary creep feed and water.

• Journal of Veterinary Science
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• 제24권1호
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• pp.14.1-14.15
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• 2023

Background: The management of feline hindlimb full-thickness skin defects is challenging. On the other hand, the use of a semitendinosus (ST) myocutaneous flap for their coverage has not been reported. Objectives: To describe the ST flap and compare it with second intention healing for managing hindlimb full-thickness skin defects. Methods: In 12 purpose-bred laboratory domestic short-haired cats, two wounds were made on each tibia. The wounds in group A (n = 12) were covered with ST flaps, and those in group B (n = 12) were left to heal by second intention. In both groups, clinical assessment scoring and planimetry were performed between one-30 d postoperatively. Computed tomography-angiography (CTA) was performed on days zero, 10, and 30, and histological examinations were performed on days zero and 14 and at 6 and 12 mon postoperatively. Results: Statistically significant differences in the clinical assessment scores were observed between groups A and B on days 14 (p = 0.046) and 21 (p = 0.016). On the other hand, the time for complete healing was similar in the two groups. CTA revealed significant differences in the muscle width (day 0 compared to days 10 and 30 [p = 0.001, p = 0.026, respectively], and days 10 to 30 [p = 0.022]), ST muscle density, and the caliber of the distal caudal femoral artery and vein (day 0 compared to day 10 [p < 0.001], and days 10 to 30 [p < 0.001]). Histologically significant differences in inflammation, degeneration, edema, neovascularization, and fibrosis were observed on day 14 compared to zero and 6 mon, but no differences were found between the time interval of 6 and 12 mon. Conclusions: An ST flap can be used effectively to manage hindlimb full-thickness skin defects.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.575-579
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• 2000

First lactation records of 683 Murrah buffaloes maintained at NDRI, Karnal which were progeny of 84 sires used for comparing the heritability estimates of age at first calving, first lactation milk yield and first service period under single and multiple trait models using restricted maximum likelihood (REML) method of estimation under an individual animal model. The results indicated that the heritability estimates may vary under single and multiple trait models depending upon the magnitude of genetic and environmental correlation among the traits being considered. Therefore, a single or multiple trait model is recommended for estimation of variance components depending upon the goal of breeding programme. However, there may not be any advantage of considering a trait with zero or near zero heritability and having no or very low genetic correlation with other traits in the model. Lower heritability estimates of part lactation yield (120-day milk yield) implied that there may not be any advantage of considering this trait in place of actual 305-day milk yield, whereas, comparable heritability estimates of predicted 305-day milk yield suggested that it could be used for sire evaluation to reduce the cost of milk recording under field conditions.