• Title/Summary/Keyword: AD

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A Study of node Authentication in Ad-hoc Network using Java Card (자바 카드를 이용한 Ad-hoc망의 노드 인증에 관한 연구)

  • Lee, Cheol-Seung;Shin, Myeong-Sook;Lee, Joon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.902-905
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    • 2005
  • In this paper we challenge the mobile node Authentication using Java Card authentication protocol in Ad-hoc network environment. Ad-hoc network is a collection of wireless mobile nodes without the support of a stationary infrastructure. and DSR routing protocol, which is one of famous mobile ad-hoc rooting protocols, has the following network path problem. this paper is the security structure that defined in a mobile network and security and watches all kinds of password related technology related to the existing authentication system. It looks up weakness point on security with a problem on the design that uses Ad-hoc based structure and transmission hierarchical security back of a mobile network, and a server-client holds for user authentication of an application level all and all, and it provides one counterproposal. Java Card Authentication of mobile node can possibly be applied to the area of M-Commerce, Wireless Security, and Ubiquitous Computing and so on.

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Performance Analysis of TCP using DSR Routing Protocols in Ad-hoc Mobile Network (DSR 라우팅 프로토콜을 사용한 Ad-hoc 무선망에서의 TCP 성능 분석)

  • Park, Seung-Seob;Yuk, Dong-Cheol
    • The KIPS Transactions:PartC
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    • v.9C no.5
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    • pp.647-654
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    • 2002
  • Ad-hoc networks consist of a set of mobile hosts that communicate using wireless links, without the use of other supporting communication facilities (such as base stations, etc.). Therefore, the topology of an Ad-hoc network frequently changes due to the movement of mobile host, which nay lead to sudden packet loss. Recently, the large amount of research has focused on the routing protocols needed in such an environment. In this paper, TCP Reno, Sack, and Tahoe versions are analysed using DSR protocol which is the representative On-Demand routing protocol in Ad-hoc wireless network. As the result of this simulation, we know that TCP Reno relatively has higher throughput than that of Sack and Tahoe, and TCP Reno has more stable performance than that of TCP Tahoe and Sack, regardless of the speed of mobile node and the size of topology.

Mutual Perceptions among Clients, Agencies, and Consumers on the Evaluation of Ad Creativity: Extending Application of the Co-Orientation Model (광고 창의성 평가에 대한 광고주, 광고 제작자, 소비자 간의 상호인식 연구: 상호지향성 모델의 확장 적용)

  • Kim, Bong-Chul;Choi, Myung-Il;Lee, Jin-U
    • (The) Korean Journal of Advertising
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    • v.25 no.1
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    • pp.179-201
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    • 2014
  • This study explored mutual perceptions among clients, agencies, and consumers on the evaluation of ad creativity applying the co-orientation model. In order to investigate agreement, congruence, accuracy among three groups, they exposed to real commercials as stimuli and evaluated ad creativity of them in terms of four dimensions, such as originality, appropriateness, clarity, and relevance. Results indicated that agreement between agencies and consumers is relatively high, whereas one between clients and agencies is relatively low. Also, clients show relatively higher level of congruence, but agencies have relatively lower level of one. Accuracy between agencies' evaluation of ad creativity and clients' perception of agencies' view on ad creativity, and between consumers' evaluation of ad creativity and clients' perception of consumers' view on ad creativity would be relatively high. On the other hand, accuracy between clients' evaluation of ad creativity and agencies' perception of clients' view on ad creativity would be relatively low. Results showed that there is a need clients and agencies to consider on consumers' viewpoints on ad creativity.

Adipose-derived stem cells decolonize skin Staphylococcus aureus by enhancing phagocytic activity of peripheral blood mononuclear cells in the atopic rats

  • Lee, Jaehee;Park, Leejin;Kim, Hyeyoung;Rho, Bong-il;Han, Rafael Taeho;Kim, Sewon;Kim, Hee Jin;Na, Heung Sik;Back, Seung Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.4
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    • pp.287-295
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    • 2022
  • Staphylococcus aureus (S. aureus) is known to induce apoptosis of host immune cells and impair phagocytic clearance, thereby being pivotal in the pathogenesis of atopic dermatitis (AD). Adipose-derived stem cells (ASCs) exert therapeutic effects against inflammatory and immune diseases. In the present study, we investigated whether systemic administration of ASCs restores the phagocytic activity of peripheral blood mononuclear cells (PBMCs) and decolonizes cutaneous S. aureus under AD conditions. AD was induced by injecting capsaicin into neonatal rat pups. ASCs were extracted from the subcutaneous adipose tissues of naïve rats and administered to AD rats once a week for a month. Systemic administration of ASCs ameliorated AD-like symptoms, such as dermatitis scores, serum IgE, IFN-γ+/IL-4+ cell ratio, and skin colonization by S. aureus in AD rats. Increased FasL mRNA and annexin V+/7-AAD+ cells in the PBMCs obtained from AD rats were drastically reversed when co-cultured with ASCs. In contrast, both PBMCs and CD163+ cells bearing fluorescent zymosan particles significantly increased in AD rats treated with ASCs. Additionally, the administration of ASCs led to an increase in the mRNA levels of antimicrobial peptides, such as cathelicidin and β-defensin, in the skin of AD rats. Our results demonstrate that systemic administration of ASCs led to decolonization of S. aureus by attenuating apoptosis of immune cells in addition to restoring phagocytic activity. This contributes to the improvement of skin conditions in AD rats. Therefore, administration of ASCs may be helpful in the treatment of patients with intractable AD.

Comparison of Dietary Behavior between Atopic Dermatitis Patients and Controls in Elementary School Students Living in the Sung-nam Area (성남시 소재 초등학교 저학년에서 아토피 피부염 환자군과 대조군의 식생활 비교)

  • Shin, You-Kyung;Kim, Myung-Hee;Chung, Ja-Yong
    • Journal of the Korean Society of Food Culture
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    • v.23 no.5
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    • pp.655-661
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    • 2008
  • The prevalence of atopic dermatitis (AD) in children has increased dramatically in recent years. Although AD has genetic determinants, this rapid increase is most likely due to changes in environmental influences--for example, dietary changes. The purpose of this case-control study was to assess the relationship between the risk of developing AD and dietary factors, including eating habits, food intake, and the consumption of various functional foods in children at ages of 7 or 8 years. 143 AD patients and 335 healthy children participated in this study. A mini-dietary assessment was utilized to evaluate the food intake and dietary patterns of the children, and other information, including demographic and socioeconomic characteristics, eating habits, and the frequency of functional food use was collected using a questionnaire. The results demonstrated that, among the demographic and socioeconomic factors assessed in this study, female gender, mother's employment, and the family history of AD significantly increased the risk of AD. However, no differences in dietary habits and specific food intake between AD patients and healthy controls were identified. On the other hand, the frequencies of taking multivitamin supplements, Spirulina, or gamma-linoleic acid were significantly higher in AD patients than in the controls. These data indicate that alterations in eating habits and the intake of certain foods may not be a critical cause associated with the risk of AD in school-age children, and caution should be taken in recommending food elimination diets for the purpose of preventing AD. Further studies are required in order to determine whether the intake of specific nutrients could contribute to the increase or prevention of the development of AD in school-age children.

Analysis of Asian Dust Events in Korea between 1997 and 2005

  • Choi, Soon-Ho;Choi, Yongjoo;Ghim, Young Sung
    • Asian Journal of Atmospheric Environment
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    • v.7 no.2
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    • pp.114-119
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    • 2013
  • The characteristics of Asian dust (AD) in Korea between 1997 and 2005 were investigated, focusing on peak 1-hour $PM_{10}$ concentrations during AD events at seven cities over the Korean Peninsula. The frequency of AD events decreased from Seoul to Busan, indicating the major pathway of AD in Korea was from northwest to southeast. AD events were most frequent in 2001 while peak concentrations during AD events were much higher in 2002. Recent works show that the trajectories from northerly directions increased during the 2000s and later (Chun, 2009; Kim, 2008). In this work, the fraction of trajectories from the northwest was the largest on the whole, although trajectories from each direction varied by city and year. It is presumed that high concentrations of $PM_{10}$ during AD events are generally associated with trajectories from the northwest rather than from the source region.

A Seamless Handoff Method Using Multiple Gateway in Hybrid Ad-hoc Networks (하이브리드 Ad-hoc 네트워크에서 다중 게이트웨이를 이용한 끊김없는 핸드오프 기법)

  • Cho, Seong-Min;Park, Sung-Han
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.1059-1062
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    • 2005
  • A hybrid ad-hoc network consists of a wired network and a mobile ad-hoc network connected by the internet gateway. To provide seamless service for internet user in hybrid ad-hoc network, an efficient internet gateway selection technique and a fast handover technique are needed. In this paper, we propose a seamless handoff technique for providing mobility of mobile hosts in hybrid ad-hoc networks. The proposed technique improves general handoff performance by an internet gateway re-registration algorithm for ad-hoc networks. Moreover, it reduces handoff processing time in the range of certain region by using mobility management agent (MMA) and also the packet loss when handoff occurs out of the range of MMA by tunneling technique.

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Epigenetic modification is linked to Alzheimer's disease: is it a maker or a marker?

  • Lee, Jung-Hee;Ryu, Hoon
    • BMB Reports
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    • v.43 no.10
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    • pp.649-655
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    • 2010
  • Alzheimer's disease (AD) is the most common age-dependent neurodegenerative disorder and shows progressive memory loss and cognitive decline. Intraneuronal filaments composed of aggregated hyperphosphorylated tau protein, called neurofibrillary tangles, along with extracellular accumulations of amyloid $\beta$ protein (A$\beta$), called senile plaques, are known to be the neuropathological hallmarks of AD. In light of recent studies, epigenetic modification has emerged as one of the pathogenic mechanisms of AD. Epigenetic changes encompass an array of molecular modifications to both DNA and chromatin, including transcription factors and cofactors. In this review, we summarize how DNA methylation and changes to DNA chromatin packaging by post-translational histone modification are involved in AD. In addition, we describe the role of SIRTs, histone deacetylases, and the effect of SIRT-modulating drugs on AD. Lastly, we discuss how amyloid precursor protein (APP) intracellular domain (AICD) regulates neuronal transcription. Our understanding of the epigenomes and transcriptomes of AD may warrant future identification of novel biological markers and beneficial therapeutic targets for AD.

Data and Control Signal Transmission Energy Conserving Routing in Wireless Ad-hoc Networks (Ad-hoc 네트워크에서 데이터와 제어신호 전송 에너지 소비를 고려하는 라우팅)

  • 김영남;박숙영;송지원;이주영;이상규
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04a
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    • pp.190-192
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    • 2002
  • 무선 통신 기술의 발달과 함께 응급상황이나 전시와 같이 필요에 의해 임의의 장소에 형성되어 사용되어질 수 있는 네트워크의 필요성이 커지면서 Ad-hoc 네트워크에 관한 여러 가지 연구가 진행되고 있다. Ad-Hoc 네트워크에서는 기존의 유선 네트워크 망에서와는 달리휴대용 기기들만으로 네트워크 망이 형성이 되어있고 이때 휴대용 기기들은 대부분 배터리를 에너지원으로 사용한다. 무한대의 에너지를 갖고 있다고 볼 수 있었던 종전의 유선 네트워크에서와는 단리 배터리를 에너지원으로 사용하는 Ad-Hoc 네트워크에서는 효율적인 에너지 자원 관리가 중요한 이슈가 된다. 이에 관련된 연구의 하나로 Chang과 Tassiulas는 [1]에서 시스템 활동시간 증가에 초점을 두고 Ad-Hoc 네트워크상의 라우팅 경로를 재조정해 줌으로써 시스템의 활동 시간을 늘이는 라우팅 방법을 제안하였다. 그러나, 그들의 방법에서는 단지 데이터 전송에 사용되는 에너지의 양만을 고려한 모델로, 에어신호의 전송 에너지 사용은 고려하지 않았다. 본 논문에서는 Ad-hoc 네트워크의 라우팅에 데이터 전송 뿐만 아니라 제어신호의 전송 에너지 사용을 함께 고려한 라우팅 방법을 소개한다.

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Performance analysis of Mobile Hosts based on On-Demand Ad-Hoc Networks (On-Demand Ad-Hoc망에서의 이동 호스트의 성능분석)

  • 하윤식;송창안;김동일
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.213-217
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    • 2003
  • An Ad-Hoc networks is a set of wireless mobile host which forms temporary networks without any concentrated controls or any helps of standard support services. Mobile host' routers are operated by their mobile hosts without fixed routers, therefore, the original routing protocol algorithm are not effective. There are two major Protocols in Ad-Hoc Network. A Table-Driven algorithm and an On-Demand, but the latter is presented more effective. We try to compare and analyze the performances of each protocol's host in this thesis.

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