• 한국통신학회논문지
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• 제32권5A호
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• pp.402-408
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• 2007

센서 네트워크는 무선 채널의 근본적인 보안상의 취약점 이외에도 센서 노드 자체의 하드웨어적인 제약 사항을 가진다. 따라서 보안성을 보장해 주기 위해 기존의 무선통신 네트워크와는 다른 접근이 필요하다. 즉 인증 방법의 경량화를 통해서 저 사양의 센서 노드에서 동작 가능하고 보안체계 작동 시에 네트워크의 성능을 유지 할 수 있도록 해야 한다. 본 논문에서는 이러한 센서 네트워크가 가지는 특징들을 고려하여 네트워크 성능과 보안성 사이에서의 절충점을 만족시킬 수 있는 데이터 origin인증 방법에 대해 논의하였다. 이것은 각 센서 노드들이 클러스터 헤드와 스타 토폴로지 형태로 연결된 센서 네트워크에서 메시지에 특수한 인증코드의 첨부로 네트워크 성능은 유지하면서 주고받는 메시지의 origin인증을 가능하게 하는 challenge-response 방식의 인증방식이다. 이때 사용되는 특수한 코드는 질의코드와 응답코드의 순서쌍이 오직 하나만 존재하는 특징을 가진 유일순차코드로서, 본 논문에서는 이를 생성하는 방법과 생성된 코드의 인증 적용 방법에 대해서 설명하고 공격에 대한 안전성에 대해서 논의 한다.

• 한국어병학회지
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• 제29권1호
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• pp.13-23
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• 2016

Lectins play significant roles in the innate immune responses through binding to pathogen-associated molecular patterns (PAMPs) on the surfaces of microorganisms. In the present study, tissue distribution and expression analysis of olive flounder lectins were performed after viral hemorrhagic septicemia virus (VHSV) challenge. Fish egg lectin and serum lectin were found to be predominantly expressed in the gills and liver, these results indicate that the transcript expression of olive flounder lectins is concentrated in immune-related tissues. Following a VHSV challenge, an overall increase in the transcript levels of the genes was observed and the expression patterns were distinctly divided into early and later responses during VHSV infection. In conclusion, olive flounder lectins are specifically expressed in immune-related organs and induced in both the immediate and long-lasting immune responses to VHSV in the olive flounder. These results indicate that lectins may be play important roles in the host defense mechanism and involved in the innate and adaptive immune response to viruses in fish.

• Computers and Concrete
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• 제20권3호
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• pp.351-360
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• 2017

This paper presents an efficient membrane finite element for the cyclic inelastic response analysis of RC structures under complex plane stress states including shear. The model strikes a balance between accuracy and numerical efficiency to meet the challenge of shear wall simulations in earthquake engineering practice. The concrete material model at the integration points of the finite element is based on damage plasticity with two damage parameters. All reinforcing bars with the same orientation are represented by an embedded orthotropic steel layer based on uniaxial stress-strain relation, so that the dowel and bond-slip effect of the reinforcing steel are presently neglected in the interest of computational efficiency. The model is validated with significant experimental results of the cyclic response of RC panels with uniform stress states.

• 대한수의학회지
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• 제26권1호
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• pp.149-156
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• 1986

An experiment was carried out to measure the cellular immune response in the animals by sensitizing the animals with 2, 4-dinitrochlorobenzene(DNCB). The fowls could be sensitized with primary application of DNCB. The sensitizing and challenge dose was standardized. Heterophils were prominent in the early inflammatory response in the superficial and deep dermal regions with scattering of eosinophils. The histological response in the fowls was characteristic of a delayed hypersensitivity reaction.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권3호
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• pp.356-364
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• 2015

The transmission performance of TSV considering the effect of electronic-thermal coupling is an new challenge in three dimension integrated circuit. This paper presents the thermal equivalent circuit (TEC) model of the TSV, and discussed the thermal equivalent parameters for TSV. Si layer is equivalent to transmission line according to its thermal characteristic. Thermal transient response (TTR) of TSV considering electronic-thermal coupling effects are proposed, iteration flow electronic-thermal coupling for TSV is analyzed. Furthermore, the influences of TTR are investigated with the non-coupling and considering coupling for TSV. Finally, the relationship among temperature, thickness of $SiO_2$, radius of via and frequency of excitation source are addressed, which are verified by the simulation.

• 한국통신학회논문지
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• 제32권12B호
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• pp.750-757
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• 2007

본 논문에서는 SIP 기반의 VoIP 망에서 발생할 수 있는 스팸 위협에 대해 분석하고 이를 차단하기 위해 UA와 프락시 서버 간에 인증 및 SDP를 암호화할 수 있는 키 교환 기법을 제안한다. 기존 HTTP 다이제스트 인증은 호 설정 시 마다 사용자 인증을 위해 매 번 challenge 값을 전송해야 하므로 많은 메시지 교환 과정이 요구되고 SDP에 대한 기밀성도 제공하지 않는다. 제안 기법은 본 논문에서 분석한 스팸 위협을 차단하기 위해 등록 과정 에서 세션 마스터 키 및 초기 nonce를 교환하고 이 키를 인증 키 및 암호화 키로 유도해 사용하므로 호 설정 시 challenge 값 전송에 따른 메시지 교환 과정과 S/MIME 또는 TLS 적용 시 발생하는 오버헤드를 줄일 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권4호
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• pp.541-551
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• 2012

The effects of dietary additives and holding time on resistance and resilience of broiler chickens to Clostridium perfringens challenge were investigated by offering four dietary treatments. These were a negative control (basal), a positive control (Zn-bacitracin) and two dietary additives, mannanoligosaccharides (MOS), and acidifier. Two holding times included (a) immediate access to feed and water post hatch (FED) and (b) access to both feed and water 48 h post hatch (HELD). Chicks fed Zn-bacitracin had no intestinal lesions attributed to necrotic enteritis (NE), whereas chicks fed both MOS or acidifier showed signs of NE related lesions. All dietary treatments were effective in reducing the numbers of C. perfringens in the ileum post challenge. The FED chicks had heavier body weight and numerically lower mortality. The FED chicks also showed stronger immune responses to NE challenge, showing enhanced (p<0.05) proliferation of T-cells. Early feeding of the MOS supplemented diet increased (p<0.05) IL-6 production. The relative bursa weight of the FED chicks was heavier at d 21 (p<0.05). All the additives increased the relative spleen weight of the HELD chicks at d 14 (p<0.05). The FED chicks had increased villus height and reduced crypt depth, and hence an increased villus/crypt ratio, especially in the jejunum at d 14 (p<0.05). The same was true for the HELD chicks given dietary additives (p<0.05). It may be concluded that the chicks with early access to dietary additives showed enhanced immune response and gut development, under C. perfringens challenge. The findings of this study shed light on managerial and nutritional strategies that could be used to prevent NE in the broiler industry without the use of in-feed antibiotics.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.501-509
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• 2021

The aim of this was evaluate the efficacy of lysozyme on growth performance, nutrient digestibility, excreta microflora population, and blood profiles of weanling pigs under Escherichia coli (E. coli) challenge. A total of 30 piglets weaned at 25 days, 7.46 kg body weight, were assigned to three dietary treatments, composed of five replications, two piglets per replication, for 7 days. The dietary treatment groups were negative control (NC; without antibiotics and lysozyme), positive control (PC; NC + antibiotics), lysozyme (NC + 0.1% lysozyme). All piglets were challenged orally with 6 ml suspension, containing E. coli K88 (2 × 10⁹ CFU/mL). Dietary supplementation with lysozyme and PC resulted in no significant differences in average daily gain and gain to feed efficiency. Weanling pigs fed with E. coli challenge with lysozyme and PC treatments had significantly enhanced nutrient retentions of dry matter and energy (p < 0.05); however, there was a tendency to increase nitrogen digestibility. Furthermore, dietary inclusion of lysozyme and antibiotics treatment groups had a beneficial effect on excreta, ileal, and cecal of the fecal microbial population as decreased E. coli (p < 0.05) counts, without effects on lactobacillus counts. A significant effect were observed on a white blood cells, epinephrine and cortisol concentrations were reduced in piglets fed diets containing E. coli challenge with lysozyme and antibiotics supplementation comparison with the NC group. Therefore, the present data indicate that lysozyme in diet could ameliorate the experimental stress response induced by E. coli in piglets by decreasing intestinal E. coli, white blood cells and stress hormones and improving nutrient digestibility.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1189-1195
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• 2008

A study was conducted with 48 weaned barrows ($28{\pm}3d$, $8.45{\pm}0.14kg$) to determine the effect of Achyranthes bidentata polysaccharide (ABPS) supplementation on pig performance, immunological, adrenal and somatotropic responses following Escherichia coli lipopolysaccharide (LPS) challenge. The experiment was a $2{\times}2$ factorial design; the main factors included diet (supplementation with 0 or 500 mg/kg ABPS) and immunological challenge (LPS or saline). On d 14 and 21 of the trial, pigs were given an intraperitoneal injection with either $100{\mu}g/kg$ BW of LPS or an equivalent amount of sterile saline. Blood samples were obtained 3 h after injection for analysis of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), prostaglandin $E_2$ ($PGE_2$), cortisol, growth hormone (GH), insulin-like growth factor (IGF)-I and immunoglobulin G (IgG). On d 2 after LPS challenge, peripheral blood lymphocyte proliferation (PBLP) was measured. LPS administration decreased average daily feed intake (ADFI) (p<0.05), had a tendency to decrease average daily gain (ADG) (p<0.10) during both the first and second challenge periods and increased (p<0.05) feed:gain ratio only during the first challenge period. ABPS tended to improve ADG (p<0.10) during the first challenge period, and improved ADG (p<0.05) and tended to improve ADFI (p<0.10) during the second challenge period. ABPS did not affect feed:gain ratio. An interaction (p<0.05) between LPS challenge and diet was observed for the plasma concentrations of TNF-${\alpha}$, $PGE_2$ and cortisol after both LPS challenges such that, among LPS-treated pigs, pigs fed the ABPS diet were lower for these indices than those receiving the control diet. In contrast, pigs fed the ABPS diet had higher IGF-I (p<0.05) compared with those fed the control diet. No effect of diet, LPS challenge or both on GH and IgG was observed after both LPS administrations. LPS challenge increased PBLP when these cells were incubated with $8{\mu}g/ml$ of LPS during both the challenge periods, and did likewise when incubated with $8{\mu}g/ml$ of concanavalin A only after the first challenge. ABPS had no effect on PBLP. These data demonstrate that ABPS alters the release of pro-inflammatory cytokines following an immunological challenge, which might enable pigs to achieve better performance.

• Tuberculosis and Respiratory Diseases
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• 제43권2호
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• pp.182-189
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• 1996

연구목적 : 기관지 천식은 기도의 염증반응, 기관지 과민 반응의 증가및 가역적인 기도의 수축을 특징으로 하는 질환으로, 기관지 염증반응의 단계중에서도 호산구등의 염증세포들이 혈관벽을 통과한후 염증 부위로의 이동 및 활성화에 관여하는 RANTES의 농도를 특이 항원으로 유발후 측정하여 기관지 천식의 병인과의 관계를 알아보고자 하였다. 대상 및 방법 : 1994년 3월부터 1995년 3월까지 전북대학교 병원 내과에 내원한 환자중 알레르기 피부시험과 비특이적 기관지유발 시험에서 양성반응을 보인 아토피성 기관지 천식 환자 16명과 정상 대조군 8명을 대상으로 RANTES를 측정하였다. 결과 : 1) 특이 항원 기관지 유발 검사 전 혈청내 RANTES농도는, 조기 천식반응군이 57740pg/ml, 이중 천식반응환자군이 54430pg/ml으로 정상 대조군의 31087pg/ml에 비해 기관지 천식 환자군에서 유의있게 증가하였으나(P<0.05), 조기 천식환자군에 비해 이중 천식환자군에서 유의한 증가는 볼수 없었다. 2) 기관지 천식환자에서 특이 항원 유발후 30분, 2시간 8시간후에 측정한 RANTES농도는 조기 천식반응군이 각각 51508, 51288, 그리고 52264pg/ml으로 유발전에 비해 유의있는 관찰할수 없었으며, 이중 천식환자군역시 각각 51723, 50110, 그리고 55674pg/ml으로 유발전에 비해 유의있는 변화는 관찰할수 없었다. 결론 : 아토피성 기관지 천식 환자의 병인에 RANTES 농도의 증가가 중요한 역할을 하며, 특히 천식의 만성 염증성 변화에 깊히 관여한다고 생각된다.