• Title/Summary/Keyword: P2P networks

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Architectural Analysis of Type-2 Interval pRBF Neural Networks Using Space Search Evolutionary Algorithm (공간탐색 진화알고리즘을 이용한 Interval Type-2 pRBF 뉴럴 네트워크의 구조적 해석)

  • Oh, Sung-Kwun;Kim, Wook-Dong;Park, Ho-Sung;Lee, Young-Il
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.1
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    • pp.12-18
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    • 2011
  • In this paper, we proposed Interval Type-2 polynomial Radial Basis Function Neural Networks. In the receptive filed of hidden layer, Interval Type-2 fuzzy set is used. The characteristic of Interval Type-2 fuzzy set has Footprint Of Uncertainly(FOU), which denotes a certain level of robustness in the presence of un-known information when compared with the type-1 fuzzy set. In order to improve the performance of proposed model, we used the linear polynomial function as connection weight of network. The parameters such as center values of receptive field, constant deviation, and connection weight between hidden layer and output layer are optimized by Conjugate Gradient Method(CGM) and Space Search Evolutionary Algorithm(SSEA). The proposed model is applied to gas furnace dataset and its result are compared with those reported in the previous studies.

Cortical Thickness of Resting State Networks in the Brain of Male Patients with Alcohol Dependence (남성 알코올 의존 환자 대뇌의 휴지기 네트워크별 피질 두께)

  • Lee, Jun-Ki;Kim, Siekyeong
    • Korean Journal of Biological Psychiatry
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    • v.24 no.2
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    • pp.68-74
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    • 2017
  • Objectives It is well known that problem drinking is associated with alterations of brain structures and functions. Brain functions related to alcohol consumption can be determined by the resting state functional connectivity in various resting state networks (RSNs). This study aims to ascertain the alcohol effect on the structures forming predetermined RSNs by assessing their cortical thickness. Methods Twenty-six abstinent male patients with alcohol dependence and the same number of age-matched healthy control were recruited from an inpatient mental hospital and community. All participants underwent a 3T MRI scan. Averaged cortical thickness of areas constituting 7 RSNs were determined by using FreeSurfer with Yeo atlas derived from cortical parcellation estimated by intrinsic functional connectivity. Results There were significant group differences of mean cortical thicknesses (Cohen's d, corrected p) in ventral attention (1.01, < 0.01), dorsal attention (0.93, 0.01), somatomotor (0.90, 0.01), and visual (0.88, 0.02) networks. We could not find significant group differences in the default mode network. There were also significant group differences of gray matter volumes corrected by head size across the all networks. However, there were no group differences of surface area in each network. Conclusions There are differences in degree and pattern of structural recovery after abstinence across areas forming RSNs. Considering the previous observation that group differences of functional connectivity were significant only in networks related to task-positive networks such as dorsal attention and cognitive control networks, we can explain recovery pattern of cognition and emotion related to the default mode network and the mechanisms for craving and relapse associated with task-positive networks.

Comparative phylogenetic relationship between wild and cultivated Prunus yedoensis Matsum. (Rosaceae) with regard to Taquet's collection (Taquet 신부의 왕벚나무: 엽록체 염기서열을 통한 야생 왕벚나무와 재배 왕벚나무의 계통학적 비교)

  • Cho, Myong-Suk;Kim, Chan-Soo;Kim, Seon-Hee;Kim, Seung-Chul
    • Korean Journal of Plant Taxonomy
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    • v.46 no.2
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    • pp.247-255
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    • 2016
  • As an attempt to determine the identity of the old trees of flowering cherries planted in the yard of the Catholic Archdiocese of Daegu, we conducted comparative phylogenetic analyses between wild and cultivated Prunus yedoensis Matsum. We generated the phylogeny (MP) and haplotype network (TCS) of 25 individuals, including wild P. yedoensis, from Jeju Island, cultivated P. ${\times}$yedoensis 'Somei-yoshino' from Korea and Japan, and P. spachiana f. ascendens (Makino) Kitam. from Jeju Island and Japan based on highly informative sequences of two cpDNA regions (rpl16 gene and trnS-trnG intergenic spacer). The wild and cultivated P. yedoensis were distinguished from each other in both the phylogeny and haplotype networks, and the old flowering cherry trees in Daegu had a cpDNA haplotype identical to that of the cultivated P. ${\times}$yedoensis 'Someiyoshino'. Compared to the cultivated P. ${\times}$yedoensis 'Somei-yoshino', wild P. yedoensis appears to have greater haplotype diversity, presumably originating from the genetic diversity of P. spachiana f. ascendens that functioned as a maternal parent in the hybrid origin of wild P. yedoensis. A future detailed study requires extensive sampling of P. spachiana f. ascendens from Japan and Korea to determine their precise phylogenetic relationships relative to wild and cultivated P. yedoensis. We concluded that the old flowering cherry trees planted in the yard of the Catholic Archdiocese of Daegu are highly likely to be of cultivated origin rather than wild types from Jeju Island, as previously speculated.

GS28 Protects Neuronal Cell Death Induced by Hydrogen Peroxide under Glutathione-Depleted Condition

  • Lee, Hwa-Ok;Byun, Yu-Jeong;Cho, Kyung-Ok;Kim, Seong-Yun;Lee, Seong-Beom;Kim, Ho-Shik;Kwon, Oh-Joo;Jeong, Seong-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.3
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    • pp.149-156
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    • 2011
  • Golgi SNAP receptor complex 1 (GS28) has been implicated in vesicular transport between intra-Golgi networks and between endoplasmic reticulum (ER) and Golgi. Additional role(s) of GS28 within cells have not been well characterized. We observed decreased expression of GS28 in rat ischemic hippocampus. In this study, we examined the role of GS28 and its molecular mechanisms in neuronal (SK-N-SH) cell death induced by hydrogen peroxide ($H_2O_2$). GS28 siRNA-transfected cells treated with $H_2O_2$ showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, which corresponded to an increase of intracellular reactive oxygen species (ROS) in the cells. Pretreatment of GS28 siRNA-transfected cells with p38 chemical inhibitor significantly inhibited cytotoxicity; we also observed that p38 was activated in the cells by immunoblot analysis. We confirmed the role of p38 MAPK in cotransfected cells with GS28 siRNA and p38 siRNA in the cell viability assay, flow cytometry, and immunoblot. Involvement of apoptotic or autophagic processes in the cells was not shown in the cell viability, flow cytometry, and immunoblot analyses. However, pretreatment of the cells with necrostatin-1 completely inhibited $H_2O_2$-induced cytotoxicity, ROS generation, and p38 activation, indicating that the cell death is necroptotic. Collectively these data imply that $H_2O_2$ induces necroptotic cell death in the GS28 siRNA-transfected cells and that the necroptotic signals are mediated by sequential activations in RIP1/p38/ROS. Taken together, these results indicate that GS28 has a protective role in $H_2O_2$-induced necroptosis via inhibition of p38 MAPK in GSH-depleted neuronal cells.

Phase Switching Mechanism for WiFi-based Long Distance Networks in Industrial Real-Time Applications

  • Wang, Jintao;Jin, Xi;Zeng, Peng;Wang, Zhaowei;Wan, Ming
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.1
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    • pp.78-101
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    • 2017
  • High-quality industrial control is critical to ensuring production quality, reducing production costs, improving management levels and stabilizing equipment and long-term operations. WiFi-based Long Distance (WiLD) networks have been used as remote industrial control networks. Real-time performance is essential to industrial control. However, the original mechanism of WiLD networks does not minimize end-to-end delay and restricts improvement of real-time performance. In this paper, we propose two algorithms to obtain the transmitting/receiving phase cycle length for each node such that real time constraints can be satisfied and phase switching overhead can be minimized. The first algorithm is based on the branch and bound method, which identifies an optimal solution. The second is a fast heuristic algorithm. The experimental results show that the execution time of the algorithm based on branch and bound is less than that of the heuristic algorithm when the network is complex and that the performance of the heuristic algorithm is close to the optimal solution.

Radionuclides of Ground waters in Busan (부산지역 지하수의 방사성물질 특성)

  • Jeon, Dae-Young
    • Journal of Soil and Groundwater Environment
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    • v.14 no.5
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    • pp.51-61
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    • 2009
  • This study was performed to research the characteristic of radionuclides of 80 groundwater monitoring networks in Busan. According to the research, average concentration of Uranium was $4.33\;{\mu}g/L$, maximum concentration of Uranium was $171.55\;{\mu}g/L$ among the 80 sampling sites. One sample exceeded the Proposal standard of drinking water in USA in Uranium ($30\;{\mu}g/L$) and four samples exceeded the recommendatory value of WHO about Uranium ($15\;{\mu}g/L$). Radon and gross-$\alpha$ concentration of all samples were far less than the Proposal standard of drinking water in USA. In this study average concentration of radionuclides in underground water wasn't too high, but needed to control the concentration of them to prevent exposure to the people. And it needs to be taken measures in some sites with high concentration of Uranium by closing the pipe line or etc through more studies.

Preventing ID Mapping Attacks on DHT Networks through Non-Voluntary Node Locating (비 자율적 노드 위치 결정을 통한 DHT 네트워크 ID 매핑 공격 방지)

  • Lee, Cheolho;Choi, Kyunghee;Chung, Kihyun;Kim, Jongmyung;Yun, Youngtae
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.4
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    • pp.695-707
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    • 2013
  • DHT(Distributed Hash Table) networks such as Kademlia are vulnerable to the ID mapping attack caused by the voluntary DHT mapping structure where the location of a node is solely determined by itself on the network topology. This causes security problems such as eclipse, DRDoS and botnet C&C on DHT networks. To prevent ID mapping attacks, we propose a non-voluntary DHT mapping scheme and perform analysis on NAT compatibility, attack resistance, and network dynamicity. Analysis results show that our approach may have an equivalent level of attack resistance comparing with other defense mechanisms and overcome their limitations including NAT compatibility and network dynamicity.

A Study on Performance Diagnostic of Smart UAV Gas Turbine Engine using Neural Network (신경회로망을 이용한 스마트 무인기용 가스터빈 엔진의 성능진단에 관한 연구)

  • Kong Chang-Duk;Ki Ja-Young;Lee Chang-Ho;Lee Seoung-Hyeon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2006.05a
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    • pp.213-217
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    • 2006
  • An intelligent performance diagnostic program using the Neural Network was proposed for PW206C turboshaft engine. It was selected as a power plant for the tilt rotor type Smart UAV (Unmanned Aerial Vehicle) which has been developed by KARI (Korea Aerospace Research Institute). For teaming the NN, a BPN with one hidden, one input and one output layer was used. The input layer had seven neurons of variations of measurement parameters such as SHP, MF, P2, T2, P4, T4 and T5, and the output layer used 6 neurons of degradation ratios of flow capacities and efficiencies for compressor, compressor turbine and power turbine. Database for network teaming and test was constructed using a gas turbine performance simulation program. From application results for diagnostics of the PW206C turboshaft engine using the learned networks, it was confirmed that the proposed diagnostics algorithm could detect well the single fault types such as compressor fouling and compressor turbine erosion.

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Design of Optimized pRBFNNs-based Face Recognition Algorithm Using Two-dimensional Image and ASM Algorithm (최적 pRBFNNs 패턴분류기 기반 2차원 영상과 ASM 알고리즘을 이용한 얼굴인식 알고리즘 설계)

  • Oh, Sung-Kwun;Ma, Chang-Min;Yoo, Sung-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.6
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    • pp.749-754
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    • 2011
  • In this study, we propose the design of optimized pRBFNNs-based face recognition system using two-dimensional Image and ASM algorithm. usually the existing 2 dimensional face recognition methods have the effects of the scale change of the image, position variation or the backgrounds of an image. In this paper, the face region information obtained from the detected face region is used for the compensation of these defects. In this paper, we use a CCD camera to obtain a picture frame directly. By using histogram equalization method, we can partially enhance the distorted image influenced by natural as well as artificial illumination. AdaBoost algorithm is used for the detection of face image between face and non-face image area. We can butt up personal profile by extracting the both face contour and shape using ASM(Active Shape Model) and then reduce dimension of image data using PCA. The proposed pRBFNNs consists of three functional modules such as the condition part, the conclusion part, and the inference part. In the condition part of fuzzy rules, input space is partitioned with Fuzzy C-Means clustering. In the conclusion part of rules, the connection weight of RBFNNs is represented as three kinds of polynomials such as constant, linear, and quadratic. The essential design parameters (including learning rate, momentum coefficient and fuzzification coefficient) of the networks are optimized by means of Differential Evolution. The proposed pRBFNNs are applied to real-time face image database and then demonstrated from viewpoint of the output performance and recognition rate.

Delay Guaranteed Bandwidth-Efficient Multicast Routing in Wireless Multi-hop Networks (다중 홉 무선 네트�p에서 지연을 고려한 멀티케스트 루팅)

  • Sohn, Hee-Seok;Lee, Chae Y.
    • Journal of the Korean Operations Research and Management Science Society
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    • v.41 no.2
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    • pp.53-65
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    • 2016
  • Static wireless multi-hop networks, such as wireless mesh networks and wireless sensor networks have proliferated in recent years because of they are easy to deploy and have low installation cost. Two key measures are used to evaluate the performance of a multicast tree algorithm or protocol : end-to-end delay and the number of transmissions. End-to-end delay is the most important measure in terms of QoS because it affects the total throughput in wireless networks. Delay is similar to the hop count or path length from the source to each destination and is directly related to packet success ratio. In wireless networks, each node uses the air medium to transmit data, and thus, bandwidth consumption is related to the number of transmission nodes. A network has many transmitting nodes, which will cause many collisions and queues because of congestion. In this paper, we optimize two metrics through a guaranteed delay scheme. We provide an integer linear programming formulation to minimize the number of transmissions with a guaranteed hop count and preprocessing to solve the aforementioned problem. We extend this scheme not only with the guaranteed minimum hop count, but also with one or more guaranteed delay bounds to compromise two key metrics. We also provide an explanation of the proposed heuristic algorithm and show its performance and results.