• Title/Summary/Keyword: Group Key

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A Study on Region-based Secure Multicast in Mobile Ad-hoc Network (Mobile Ad-hoc Network에서 영역기반 보안 멀티캐스트 기법 연구)

  • Yang, Hwanseok
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.12 no.3
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    • pp.75-85
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    • 2016
  • MANET is a network composed only mobile network having limited resources and has dynamic topology characteristics. Therefore, every mobile node acts as a route and delivers data by using multi-hop method. In particular, group communication such as multicast is desperately needed because of characteristics such as battery life of limited wireless bandwidth and mobile nodes. However, the multicast technique can have different efficient of data transmission according to configuring method of a virtual topology by the movement of the nodes and the performance of a multicast can be significantly degraded. In this paper, the region based security multicast technique is proposed in order to increase the efficiency of data transmission by maintaining an optimal path and enhance the security features in data transmission. The group management node that manages the state information of the member nodes after the whole network is separated to area for efficient management of multicast member nodes is used. Member node encrypts using member key for secure data transmission and the security features are strengthened by sending the data after encrypted using group key in group management node. The superiority of the proposed technique in this paper was confirmed through experiments.

Vitamin D3 and Beta-carotene Deficiency is Associated with Risk of Esophageal Squamous Cell Carcinoma - Results of a Case-control Study in China

  • Huang, Gui-Ling;Yang, Lei;Su, Ming;Wang, Shao-Kang;Yin, Hong;Wang, Jia-Sheng;Sun, Gui-Ju
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.819-823
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    • 2014
  • Objective: The aim was to evaluate roles of vitamin D3 (VD3) and beta-carotene (BC) in the development of esophageal squamous cell carcinoma (ESCC) in a high-risk area, Huai'an District, Huai'an City, China. Methods: 100 new ESCC diagnosed cases from 2007 to 2008 and 200 residency- age-, and sex-matched healthy controls were recruited. Data were collected from questionnaires, including a food frequency questionnaire (FFQ) to calculate the BC intake, and reversed phase high-performance liquid chromatography (RP-HPLC) was used to measure the serum concentrations of BC and VD3. Odds ratios (OR) and 95% confidence intervals (CI) were calculated in conditional logistic regression models. Results: The average dietary intake of BC was $3322.9{\mu}g$ (2032.4-5734.3) in the case group and $3626.8{\mu}g$ (1961.9-5827.9) in control group per capita per day with no significant difference by Wilcoxon test (p>0.05). However, the levels of VD3 and BC in the case group were significantly lower than in the control group (p<0.05). The OR values of the highest quartile and the lowest quartile of VD3 and BC in serum samples were both 0.13. Conclusion: Our results add to the evidence that high circulating levels of VD3 and BC are associated with a reduced risk of ESCC in this Chinese population.

Effects of different types of xanthophyll extracted from marigold on pigmentation of yellow-feathered chickens

  • Yu Wei;Kun Qin;Xu Qin;Fulong Song;Xiao Xu
    • Animal Bioscience
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    • v.36 no.12
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    • pp.1853-1859
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    • 2023
  • Objective: This study aimed to explore the effects of different types of xanthophyll extracted from marigold on the growth performance, skin color, and carcass pigmentation. Methods: A total of 192 healthy 60-day-old yellow-feathered broilers weighing an average of 1,279±81 g were randomly allocated to 4 groups, each with 6 replicates and 8 broilers. The 4 treatments were as follows: i) CON group, fed with basal diet; ii) LTN group, supplemented with lutein; iii) MDP group, supplemented with monohydroxyl pigment including dehydrated lutein, β-cryptoxanthin, and α-cryptoxanthin; iv) LTN+MDP group, supplemented with lutein and monohydroxyl pigment in proportion to 1:1. The supplementary content of LTN, MDP, and LTN+MDP was 2 g/kg. Skin color was measured after 7, 14, 21, and 28 days of feeding the dietary treatments. The breast, thigh, and abdominal fat of slaughtered chickens were stored in cold storage at 4℃ for 24 hours and then the meat color of lightness (L*), redness (a*), and yellowness (b*) values was determined. Results: The results showed that all treatments enhanced the yellow scores of subwing skin on day 14, 21, and 28 (p<0.05), and the mixture of lutein and monohydroxyl pigment promoted the yellow scores of shanks on day 14, 21, and 28 (p<0.05). The mixture of lutein and monohydroxyl pigment increased the yellow scores of beaks and all treatments enhanced the yellow of shanks on day 28 (p<0.05). In addition, all treatments improved the yellow (b*) values of breast and thigh muscle, moreover, the monohydroxyl pigment and the mixture of lutein and monohydroxyl pigment enhanced the values of redness (a*) and yellow (b*) of abdominal fat (p<0.05). Conclusion: In summary, different types of xanthophyll extracted from marigold significantly increased the yellow scores of skin color and the yellow (b*) values of carcass pigmentation. Especially, the mixture of lutein and monohydroxyl pigment was more efficient on skin color.

Effects of quercetin and coated sodium butyrate dietary supplementation in diquat-challenged pullets

  • Zhou, Ning;Tian, Yong;Liu, Wenchao;Tu, Bingjiang;Gu, Tiantian;Xu, Wenwu;Zou, Kang;Lu, Lizhi
    • Animal Bioscience
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    • v.35 no.9
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    • pp.1434-1443
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    • 2022
  • Objective: This study was designed to investigate the hypothesis that dietary quercetin (QUE) and coated sodium butyrate (SB) supplementation alleviate oxidative stress in the small intestine of diquat (DIQ)-challenged pullets. Methods: A total of 200 13-week-old pullets were divided into four groups: the control group (CON), the DIQ group, the QUE group, and the coated SB group, and injected intraperitoneally with either saline (CON) or diquat (DIQ, QUE, and SB) to induce oxidative stress on day 0. Results: On the first day, the malondialdehyde and superoxide dismutase (SOD) concentrations in the SB group were significantly different from those in the DIQ and QUE groups (p<0.05), and dietary supplementation with SB increased serum glutathione peroxidase (GSH-PX) levels compared with the DIQ group (p<0.05). Quercetin and SB increased the levels of CLAUDIN-1 and zonula occludens-1 (ZO-1) in the jejunum. On the tenth day of treatment, QUE attenuated the decrease in GSH-PX levels compared to those of the CON group (p<0.05), while SB increased SOD, GSH-PX, and total antioxidant capacity levels compared to those of the DIQ group. Nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase-1 (HO-1) mRNA levels in the QUE and SB groups increased (p<0.05) and CLAUDIN-1 mRNA levels in the QUE and SB groups were upregulated compared to those in the DIQ group ileum tissue. Conclusion: Supplementation of QUE and SB demonstrated the ability to relieve oxidative stress in pullets post DIQ-injection with a time-dependent manner and QUE and SB may be potential antioxidant additives for relieving oxidative stress and protecting the intestinal barrier of pullets.

A need-awaring multi-agent approach to nomadic community computing for ad hoc need identification and group formation

  • Choi, Keun-Ho;Kwon, Oh-Byung
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2005.11a
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    • pp.183-192
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    • 2005
  • Recently, community computing has been proposed for group formation and group decision-making. However, legacy community computing systems do not support group need identification for ad hoc group formation, which would be one of key features of ubiquitous decision support systems and services. Hence, this paper aims to provide a multi-agent based methodology to enable nomadic community computing which supports ad hoc need identification and group formation. Focusing on supporting group decision-making of relatively small sized multiple individual in a community, the methodology copes with the following three characteristics: (1) ad hoc group formation, (2) context-aware group need identification, and (3) using mobile devices working in- and out-doors. NAMA-US, an RFID-based prototype system, has been developed to show the feasibility of the idea proposed in this paper.

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Biochemical Characterization of Exoribonuclease Encoded by SARS Coronavirus

  • Chen, Ping;Jiang, Miao;Hu, Tao;Liu, Qingzhen;Chen, Xiaojiang S.;Guo, Deyin
    • BMB Reports
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    • v.40 no.5
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    • pp.649-655
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    • 2007
  • The nsp14 protein is an exoribonuclease that is encoded by severe acute respiratory syndrome coronavirus (SARS-CoV). We have cloned and expressed the nsp14 protein in Escherichia coli, and characterized the nature and the role(s) of the metal ions in the reaction chemistry. The purified recombinant nsp14 protein digested a 5'-labeled RNA molecule, but failed to digest the RNA substrate that is modified with fluorescein group at the 3'-hydroxyl group, suggesting a 3'-to-5' exoribonuclease activity. The exoribonuclease activity requires $Mg^{2+}$ as a cofactor. Isothermal titration calorimetry (ITC) analysis indicated a two-metal binding mode for divalent cations by nsp14. Endogenous tryptophan fluorescence and circular dichroism (CD) spectra measurements showed that there was a structural change of nsp14 when binding with metal ions. We propose that the conformational change induced by metal ions may be a prerequisite for catalytic activity by correctly positioning the side chains of the residues located in the active site of the enzyme.

Case Study of Cooperative Learning Simulating Turn-Key System in Design Class for Environmental Engineering (턴키 제도를 모사한 환경공학 설계과목의 협동학습 적용사례)

  • Kim, Geon-Ha;Oh, Ju-Won;Lee, Hack-Soo
    • Journal of Engineering Education Research
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    • v.9 no.4
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    • pp.5-9
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    • 2006
  • In this research, a case study for cooperative learning practiced in a design class for environmental engineering was presented. Designing a treatment facility for urban diffuse pollution was a main problem given to the participants. Turn-key system for civil works were simulated throughout class works. Twenty five students were grouped into four virtual companies and assigned own position from chairperson to workers. Each group competed throughout establishing design concept regarding order, expense calculation, process distribution, actual calculation. Best design with lowest bidding won the first place. For evaluating class effectiveness, one student from each group were monitored thorough semester. Participants were improved for their understanding about company establishment, turn-key system management, awareness about personal management, and presentation skills. Tension of the class was effectively elevated as well.

Key Management Framework based on Double Hash Chain for Secure Smart Grid Environments (안전한 스마트 그리드 환경을 위한 이중 해쉬 체인 기반 키 관리 프레임워크)

  • Lee, Young-Seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.9
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    • pp.2063-2072
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    • 2013
  • Smart Grid is the next-generation intelligent power grid that maximizes energy efficiency with the convergence of IT technologies and the existing power grid. It enables consumers to check power rates in real time for active power consumption. It also enables suppliers to measure their expected power generation load, which stabilizes the operation of the power system. However, there are high possibility that various kinds of security threats such as data exposure, data theft, and privacy invasion may occur in interactive communication with intelligent devices. Therefore, to establish a secure environment for responding to such security threat with the smart grid, the key management technique, which is the core of the development of a security mechanism, is required. Using a hash chain, this paper suggests a group key management mechanism that is efficiently applicable to the smart grid environment with its hierarchical structure, and analyzes the security and efficiency of the suggested group key management framework.

Significance of Thrombocytosis in Clinicopathologic Characteristics and Prognosis of Gastric Cancer

  • Li, Fang-Xuan;Wei, Li-Juan;Zhang, Huan;Li, Shi-Xia;Liu, Jun-Tian
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6511-6517
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    • 2014
  • Purpose: We aimed to study the relationship between thrombocytosis and clinical features of gastric cancerfocussing on platelet counts and gastric cancer progression through different TNM stages. Methods: According to the normal range of platelet count in our institution, 1,596 patients were divided to two groups: a thrombocytosis group (120 patients, > $400{\times}1000/{\mu}L$) and a control group (1,476 patients, ${\leq}400{\times}1000/{\mu}L$). Results: The incidence of thrombocytosis was 7.5%. Higher platelet counts were observed in patients with older age, larger tumor size, deeper invasion, lymph node metastasis, distant metastasis and advanced TNM stage. In multivariate logistic regression, tumor size, depth of tumor invasion, lymph node metastasis and TNM stage were independent risk factors for thrombocytosis of gastric cancer patients. On prognostic analysis, age, tumor size, tumor location, histologic type, depth of tumor invasion, lymph node metastasis, distant metastasis and TNM stage and platelet count were important factors. Tumor size, invasion depth, lymph node metastasis, TNM stage and the platelet count were independent prognostic factors. Conclusion: Thrombocytosis is associated with clinical features of gastric cancer patients and correlates with a poor prognosis.

Teen Based Secure Group Communication Scheme for Wireless Sensor Networks (무선 센서네트워크를 위한 TEEN 기반의 안전한 그룹통신 기법)

  • Seo, Il-Soo
    • Convergence Security Journal
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    • v.9 no.2
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    • pp.71-78
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    • 2009
  • It is very difficult to apply previous security protocols to WSNs(Wireless Sensor Networks) directly because WNSs have resource constrained characteristics such as a low computing ability, power, and a low communication band width. In order to overcome the problem, we proposes a secure group communication scheme applicable to WSNs. The proposed scheme is a combined form of the TEEN(Threshold sensitive Energy Efficient sensor Network protocol) clustering based hierarchical routing protocol and security mechanism, and we assume that WSNs are composed of sensor nodes, cluster headers, and base stations. We use both private key and public key cryptographic algorithms to achieve an enhanced security and an efficient key management. In addition, communications among sensor nodes, cluster headers, and base stations are accomplished by a hierarchical tree architecture to reduce power consumption. Therefore, the proposed scheme in this paper is well suited for WSNs since our design can provide not only a more enhanced security but also a lower power consumption in communications.

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