• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권7호
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• pp.2548-2567
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• 2015

Recently, there has been a clear trend towards the application of ad hoc networking technology in civil aviation communication systems, giving birth to a new research field, namely, aeronautical ad hoc networks (AANETs). An AANET is a special type of ad hoc wireless network with a significantly larger scale and distinct characteristics of its mobile nodes. Thus, there is an urgent need to develop a simulator to facilitate the research in these networks. In this paper, we present a network simulator, Aero-Sim, for AANETs. Aero-Sim, which is based on the freely distributed NS-2 simulator, enables detailed packet-level simulations of protocols at the MAC, link, network, transport, and application layers by composing simulations with existing modules and protocols in NS-2. Moreover, Aero-Sim supports three-dimensional network deployment. Through several case studies using realistic China domestic air traffic, we show that the proposed simulator can be used to simulate AANETs and can reproduce the real world with high fidelity.

• 융합보안논문지
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• 제11권6호
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• pp.37-44
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• 2011

VANET(Vechicular Ad-hoc Network)은 지능형 차량들로 이루어진 애드혹 네트워크 환경으로서 최근 들어 그 연구가 활발하게 진행되고 있는 분야이다. VANET은 원활한 교통 소통, 사고 방지 등 여러 가지 편리한 기능들을 제공하지만 그 기반을 애드혹 네트워크에 두고 있기 때문에 애드혹 망에서 발생하는 보안 문제를 가지고 있고 또한 그 환경적 특성에 따라 추가적인 보안 요구 사항이 존재한다. 본 논문에서는 오류수정부호(Error Correcting Code)의 생성행렬을 사용하여 부호화된 인증서를 생성하고 이를 기반으로 차량의 익명성과 비연결성을 제공하는 V2I(Vehicular to Interface) 인증 프로토콜을 제안한다. 또한 기존 방식에서 차량 등록 및 인증 서버(KDC)의 차량 비밀 키 관리에 대한 오버헤드 문제를 해결하게 되었다.

• 천문학회보
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• 제42권2호
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• pp.55.5-56
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• 2017

Galaxy dynamics probes weak gravity at accelerations below the de Sitter scale of acceleration adS = cH, where c is the velocity of light and H is the Hubble parameter. Low and high redshift galaxies hereby offer a novel probe of weak gravity in an evolving cosmology, satisfying H(z) = H0(1 + A(6z + 12z^2 +12z^3+ 6z^4+ (6/5)z^5)/(1 + z) with baryonic matter content A sans tension to H0 in surveys of the Local Universe. Galaxy rotation curves show anomalous galaxy dynamics in weak gravity aN < adS across a transition radius r beyond about 5 kpc for galaxy mass of 1e11 solar mass. where aN is the Newtonian acceleration based on baryonic matter content. We identify this behavior with a holographic origin of inertia from entanglement entropy, that introduces a C0 onset across aN=adS with asymptotic behavior described by a Milgrom parameter satisfying a0=omega/(2pi), where omega=sqrt(1-q)H is a fundamental eigenfrequency of the cosmological horizon. Extending an earlier confrontation with data covering 0.003 < aN/adS < 1 at redshift z about zero in Lellie et al. (2016), the modest anomalous behavior in the Genzel et al. sample at redshifts 0.854 < z <2.282 is found to be mostly due to clustering 0.36 < aN/adS < 1 close to the C0 onset to weak gravity and an increase of up to 65% in a0.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2011년도 추계학술발표회
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• pp.31-45
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• 2011

The amyloid ${\beta}$-peptide ($A{\beta}$), which originates from the proteolytic cleavage of amyloid precursor protein (APP), plays a central role in the pathogenesis of Alzheimer's disease (AD). Mounting evidence indicates that different species of $A{\beta}$, such as $A{\beta}$ oligomers and fibrils, may contribute to AD pathogenesis via distinct mechanisms at different stages of the disease. Importantly, elevation and accumulation of soluble $A{\beta}$ oligomers closely correlate with cognitive decline and/or disease progression in animal models of AD. In agreement with these studies, oligomers of $A{\beta}$ have been shown to directly affect synaptic plasticity, a neuronal process that is known to be essential for memory formation. Our previous studies showed that $A{\beta}$ induces the breakdown of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a phospholipid that regulates key aspects of neuronal function. PI(4,5)P2 breakdown was found to be a key step toward synaptic and memory dysfunction in a mouse model of AD. To this end, we seek to identify small molecules that could elevate the levels of PI(4,5)P2 and subsequently block $A{\beta}$ oligomer-induced breakdown of PI(4,5)P2 and synaptic dysfunction.. We found that (20S)Rg3, an active triterpene glycoside from heat-processed ginseng, serves as an agonist for phosphatidylinositol 4-kinase IIalpha (PI4KIIalpha), which is a lipid kinase that mediates a rate-limiting step in PI(4,5)P2 synthesis. Consequently, (20S)Rg3 stimulates PI(4,5)P2 synthesis by directly stimulating the activity of PI4KIIalpha. Interestingly, treatment of a mouse model of AD with (20S)Rg3 leads to reversal of memory deficits. Our data suggest that the PI(4,5)P2-promoting effects of (20S)Rg3 may help mitigate the cognitive symptoms associated with AD.

• 한국토양비료학회지
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• 제39권6호
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• pp.409-414
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• 2006

황산화 미생물인 Genus Thiobacillus 중 몇 종류의 탈질균은 여러 종류의 황 화합물($S^{2-}$, So, $S_2O{_3}^{2-}$, $S_4O{_6}^{2-}$, $SO{_3}^{2-}$)을 황산염이온으로 산화시키면서 동시에 질산성질소를 질소 가스 형태로 전환시킨다. 이는 독립영양 미생물이므로 외부 탄소원이 필요치 않으며, C/N비가 낮은 폐수에 에탄올 대신 값이 싼 황 입자의 투입으로 경제적이며 효과적인 탈질화를 유도할 수 있다. 후탈질시 인위적인 유기물의 투입대신 값 싼 황입자를 사용하여 질소를 제거하며, 처리효율이 안정적이고, 운전이 쉬워, 최근 이 공정은 세계적으로 많이 연구되고 있다. 그러나 탈질시 알칼리도가 파괴되어 특히 알칼리도가 낮은 폐수의 경우 고농도 탈질시 pH가 떨어져 탈질이 더 이상 진행되지 않으며, 고농도의 질산성질소를 처리할 경우 부산물로서 고농도의 황산염이온이 생성된다는 부수적인 단점을 안고 있다. 본 연구에서는 MCR로부터 독립영양 미생물을 분리 characterization 및 미생물 동정을 하였다. MCR내에는 주로 Paracoccus denitrificans and Paracoccus versutus (formerly Thiobacillus versutus)가 주종을 이루었으며 이들 미생물들은 유기물도 에너지원으로 이용할 수 있는 facultative autotrophic denitrifier이었다. 이들 미생물을 탈질에 이용할 시 유기물이 있는 조건에서도 성장하기 때문에 유입 폐수 내 유기물 농도에 영향을 받지 않고 또는 인위적으로 소량의 유기물을 넣어 독립영양탈질과 종속영양탈질을 동시에 일어날 수 있도록 함으로서 독립영양탈질의 단점인 높은 황산염이온 생성 및 알칼리도 파괴를 막을 수 있을 것으로 사료된다.

• 한국정보통신학회논문지
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• 제17권2호
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• pp.495-502
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• 2013

MANET(Mobile Ad-hoc Network)에서는 에너지 효율을 높이기 위한 다양한 클러스터링 기법과 라우팅 알고리즘이 연구되고 있다. 일반적으로 무선 Ad-hoc 네트워크에서는 LEACH와 같은 클러스터 기반의 동적 라우팅 알고리즘이 많이 사용된다. 본 논문에서는 클러스터내의 각 노드가 가지는 속성을 고려하여 클러스터를 생성하고 노드를 관리하는 ATICC(Adaptive Time Interval Clustering Control) 알고리즘 기법을 제안한다. 제안한 ATICC은 노드의 속성 중의 하나인 잔여에너지 값으로 노드의 에너지 레벨을 분류한다. 그리고 분류된 에너지 레벨에 대응하는 시간차 컨트롤 기법을 이용하여 클러스터링 과정을 수행하거나 노드들을 관리한다. 특히 제안한 ATICC 알고리즘은 MANET에서 클러스터의 생성, 재생성, 진입 노드 및 이탈 노드의 검출과 관리를 통해 노드의 에너지 관리 효율을 향상시키고 클러스터의 Lifetime을 증가시키는 결과를 보여주었다.

• 대한한방소아과학회지
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• 제29권1호
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• pp.27-43
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• 2015

Objectives The purpose of this study was to investigate the effects of AI on AD induced by DNCB in mice. AI has antiallergic property that is useful in treating allergy-related-diseases, such as asthma, anaphylactic shock, acute bronchitis and skin diseases, skin pruritus from gastrointestinal diseases. However, AI has not been studied intensively yet regarding anti-inflammatory effect on AD. Therefore, this study was conducted on 2,4-dinitrochlorobezene (DNCB)-induced mice to investigate effects of AI in AD. Methods In the experiment, we divided mice into four groups: a normal group (NOR), a control group (CON), an AI spread group (AI spread), and an AI spread and feeding group (AI spread & feeding). Then examined the changes in the body weight, weights of spleen and ear, thickness of dorsum skin and ear skin, clinical aspects on dorsum skin, historical assessments, proliferation of splenocytes in vitro and in vivo, and cytokine (TNF-${\alpha}$, IL-10). Results From the experiment, the ear weight of AI spread & feeding group was significantly dropped and the ear thickness of both AI spread and AI spread & feeding were decreased significantly. Dorsum skin thickness was also decreased significantly in both AI spread and AI spread & feeding group. Also, AI treatment improved the symptoms of AD, such as coloration, erythema and desquamation and had a better effect on AI spread & feeding group. In histopathological observation, thickened epidermis, hyperkeratosis, pigmentation, hypergranulosis, parakeratosis were diminished as well in both AI spread and AI spread & feeding group. In vitro, we could observe when AI was increased as proliferation rate of splenocytes were increased, too. Conclusions In conclusion, these data suggest that AI can decrease symptoms of AD and show AI can be useful herbal therapy for AD.

• 대한지역사회영양학회지
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• 제17권3호
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• pp.271-279
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• 2012

The prevalence of atopic dermatitis (AD) has increased recently all over the world. Several studies worldwide reported growth retardation associated with AD, but few studies were reported in Korea. Therefore, the objective of this study was to identity the differences in growth and nutrient intakes between Korean children with and without AD. The participants were 71 AD children and age, gender-matched 81 control children aged 10 to 36 months. Demographic information was gathered by questionnaires. Height and weight were measured at clinic and health centers. Height and weight for age, and weight for height were converted as deviation in Z scores using World Health Organization Standard. A 24 hour dietary recall method was performed to estimate nutrient intakes. A higher percentage of AD children had insufficient energy and intakes of calcium, phosphorus, iron, zinc and vitamin B2, defined as intakes lower than 75% of the Dietary Reference Intakes for Korean, compared to the control group (P < 0.001, P < 0.001, P = 0.003, P = 0.001, P = 0.014, P = 0.001, respectively). The percentages of children with height and weight for age Z score below than-1 (stunted) were significantly higher in the AD group (P < 0.001 and P < 0.001, respectively). Multiple food restriction, defined as ${\geq}$ 3 food elimination, was associated with insufficient energy and intakes of calcium, phosphorus, iron, zinc, vitamins A and B2. In conclusion, children with AD need regular nutrient assessment and education about alternative food choices to avoid r food elimination in order to prevent growth retardation or inadequate nutrient intakes. Further longitudinal studies for growth and nutrient intakes should be performed to understand the patterns of growth in children with AD.

• 약학회지
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• 제56권2호
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• pp.92-98
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• 2012

This study was conducted to determine if YJ-1, a novel herbal complex from a mixture of six oriental herbs (Hydnocarpi Semen, Sesami Semen, Dictamni Radicis Cortex, Momordicae Semen, Xanthii Fructus, and Sophorae Radix), has therapeutic properties for the treatment of atopic dermatitis (AD). Using AD like symptom-induced NC/Nga mice by 1-chloro 2,4-dinitrobenzene (DNCB), the effectiveness of YJ-1 on AD was evaluated. Elidel cream$^{(R)}$ (1% pimecrolimus) was used as a control. Dermal application of YJ-1 reduced major clinical signs of AD such as erythema, pruritus, lichenification, edema/escoriations, and dryness. Interestingly, YJ-1 more improved AD-related symptoms including decrease of spleen weight, IL-4, and IgE level in the serum as well as reduction of scratching counts and clinical skin severity in the NC/Nga AD mouse model. Especially, treatment of YJ-1 at 20% in NC/Nga mice more effected than Elidel cream. These results suggest that the ointment of YJ-1 may enhance the process of AD healing by alleviating allergic reaction and has potential for therapeutic reagent for the treatment of AD.

• 한국환경과학회지
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• 제16권4호
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• pp.399-407
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• 2007

The characteristics of meteorological conditions relevant to Asian dust (AD) outbreaks and their occurrence frequencies were analyzed in four source regions (R1 to R4) during spring months (March to May) of 1995-2002. Moreover, the concentration variations of AD (e.g., $PM_{10}$) observed in Korea were investigated during the study period. In the relationship between AD outbreaks and three meteorological parameters (i.e., air temperature, wind speed, and aridity), the largest AD outbreaks in April (${\sim}250$ observations) mostly occurred in R2 when air temperature ranging from 10.0 to $15^{\circ}C$ and surface wind speed from 7 to $9m\;s^{-1}$ were recorded. Moreover, the aridity ($\geq4$) in April was significantly high in R2 with the maximum frequency of AD outbreaks (i.e., 206 observations). On the other hand, the number (percentage) of days belonging to AD events observed in five Korean cities were found to be 116 (44%), 121 (46%), and 26 days (10%) in March, April, and May, respectively. The mean $PM_{10}$ concentrations were found to range from 150 to 220, 150 to 200, and 95 to $120{\mu}g\;m^{-3}$ in March, April, and May, respectively. Consequently, this implied that the AD events in Korea were found to be gradually frequent in early spring and to be affected from the large AD outbreaks observed in the source regions.