{"title":"An upper bound on the throughput for myopic policy in multi-channel opportunistic access","authors":"Saber Salehkaleybar, Seyyed Arash Majd, Mohammadreza Pakravan","doi":"10.1109/ISTEL.2010.5733993","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5733993","url":null,"abstract":"We study myopic sensing policy for an opportunistic communication system in which the states of channels evolve as independent Markov chains. A Secondary User (SU) takes one channel to sense and access in each time slot by myopic sensing policy. In the myopic policy, SU ignores the impact of the current action on the future decisions and tries to maximize the expected immediate reward. We propose an upper bound on the throughput achieved by the myopic sensing policy for general case in which channels have different Markov models. In particular, the proposed bound is compared with the Zhao et. al's upper bound (UZhao) for the channels with identical models. We prove that there are conditions in which the proposed bound is tighter than UZhao bound. Besides, the throughput obtained from the simulation is compared with the proposed bound. The results demonstrate that the bound is tight and close to the simulation results.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117158202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Performance evaluation of server virtualization in data center applications","authors":"M. Ahmadi, D. Maleki","doi":"10.1109/ISTEL.2010.5734102","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734102","url":null,"abstract":"One of the important targets in new generation data centers is minimizing the cost through efficient use of available resources. Virtualization is a new technology that provides an opportunity for extension of independent virtual resources based on available physical systems. This paper evaluates performance of virtualized versus non-virtualized servers in data center applications. We have presented a tile based evaluation based on heterogeneous workloads to compare several key parameters and demonstrate effectiveness of virtualization techniques. Moreover, we have evaluated the virtualized server models using V-Motion techniques and maximum sever consolidation. Results of evaluation for different criteria confirm that server virtualization technique has high throughput and CPU usage as well as good performance with noticeable agility. Experimental results which are obtained through our prototype model demonstrate that server virtualization can significantly reduces resource consumption while improves system performance. Obtained results certify that server virtualization can be a strategic decision for saving the investment, increasing service performance and creating new virtual environments.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127099581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improved rate controlled reliable transport protocol (IRCRT) for wireless sensors networks","authors":"F. Akbari, M. Yaghmaee","doi":"10.1109/ISTEL.2010.5734072","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734072","url":null,"abstract":"IRCRT is an end-to-end reliable transport protocol that acts according to RCRT, but improved its rate allocation unit. In this protocol, nodes can go in OFF state, and when a node is OFF, sink does not allocate any rate to it, so other nodes can use better from the channel capacity. In addition, when any part of network becomes congested, this protocol only decreases the rate of nodes that are in the congested part, not all nodes. This improvement also increases channel utilization. We simulate this protocol on NS.2 on LINUX and compare it with RCRT. Simulation results show that IRCRT acts better than RCRT in sent and received packets, and fairness, too.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127118780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A structural rule-based stemmer for Persian","authors":"Elahe Rahimtoroghi, H. Faili, A. Shakery","doi":"10.1109/ISTEL.2010.5734090","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734090","url":null,"abstract":"This paper presents a new stemmer for Persian language. We used a structural approach for stemming which uses the structure of words and morphological rules of the language to recognize the stem of each word. We composed 33 rules to describe a structural rule-based stemmer. The rules are written based on the morphology of Persian language and its word derivation structure. For evaluation, we used our stemmer in an information retrieval system. The results demonstrated that by enhancing the system with this stemmer, the information retrieval system's precision increases, by the factor of 4.78% and the indexing file size decreases by the factor of 6%.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125858992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Azghani, A. Aghagolzadeh, S. Ghaemi, M. Kouzehgar
{"title":"Intelligent modified mean shift tracking using genetic algorithm","authors":"M. Azghani, A. Aghagolzadeh, S. Ghaemi, M. Kouzehgar","doi":"10.1109/ISTEL.2010.5734133","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734133","url":null,"abstract":"Object Tracking using mean shift algorithm has gained much attention in recent years due to its simplicity. In this paper, we present a modified mean shift tracking method using genetic algorithm. First, a background elimination method is used to eliminate the effects of the background on the target model. The mean shift procedure is applied only for one iteration to give a good approximate region of the target. In the next step, the genetic algorithm is used as a local search tool to exactly identify the target in a small window around the position obtained from the mean shift algorithm. The simulation results prove that the proposed method outperforms the traditional mean shift algorithm in finding the precise location of the target at the expense of slightly more complexity.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"40 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122811601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. D. Kashani, M. R. Hedayati Rad, M. R. Hedayati Rad, M. Mahzoun
{"title":"Reliability analysis of the auto-tracked FSO communication links","authors":"F. D. Kashani, M. R. Hedayati Rad, M. R. Hedayati Rad, M. Mahzoun","doi":"10.1109/ISTEL.2010.5734069","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734069","url":null,"abstract":"The effects of auto-tracking subsystems on the bit-error-rate (BER) and reliability of free-space optical (FSO) communication links are investigated. Based on Gaussian beam formula on the receiver plane and considering the atmosphere losses due to absorption, scattering and atmospheric turbulence numerical values for Power In Bucket (PIB), Signal to Noise Ratio (SNR) and BER are calculated. Using above mentioned values, the role of auto-track subsystems on link reliability improvement is described. The results are illustrated by graphs obtained by calculation and simulation.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122856029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Outage analysis of equal-gain combiner over shadowed-rice fading channels","authors":"H. Samimi","doi":"10.1109/ISTEL.2010.5734041","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734041","url":null,"abstract":"Land mobile satellite (LMS) channels can be modelled accurately by the shadowed-Rice (SR) fading model. Recently, an approximate SR model is proposed by the author for LMS channels. Compared with the existing models, the proposed model is analytically tractable and makes it possible to approximate very accurately the probability density function (PDF) of the SR random variable (RV) by a finite weighted sum of Rice PDFs. In this paper and relying on the proposed model, the statistics of the sum of independent SR RVs is studied. While this problem is well understood for common fading models such as the Rayleigh, Rice, and Nakagami, a minor attention has been devoted to the SR case. In this paper, the PDF and the Cumulative distribution function (CDF) of the sum of independent SR RVs are derived in the form of infinite, convergent series using well-known Beaulieu series approach. In this regard, the coefficients of the Beaulieu series are calculated for the case of SR fading channels in analytical, closed-form expressions, and hence, the CDF and the PDF of the sum of independent SR RVs are derived. The derived statistics are used to analyze the performance analysis of equal-gain combining (EGC) diversity receiver operating over independent SR fading channels and novel closed-form expression for the outage probability is developed.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128396069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Overlapped ontology partitioning based on semantic similarity measures","authors":"Kobra Etminani, Amin Rezaeian Delui, Mahmoud Naghibzadeh","doi":"10.1109/ISTEL.2010.5734169","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734169","url":null,"abstract":"Today, public awareness about the benefits of using ontologies in information processing and the semantic web has increased. Since ontologies are useful in various applications, many large ontologies have been developed so far. But various areas like publication, maintenance, validation, processing, and security policies need further research. One way to better tackle these areas is to partition large ontologies into sub partitions. In this paper, we present a new method to partition large ontologies. For the proposed method, three steps are required: (1) transforming an ontology to a weighted graph, (2) partitioning the graph with an algorithm which recognizes the most important concepts, and (3) making sub-ontologies from results of the partitioning. Here, semantic distance measures are used to produce semantic graph, and using overlapped partitioning algorithms on the graph, a set of meaningful ontology partitions which can cause less communications in distributed reasoning is made. The proposed method shows better performance comparing with the previous partitioning method.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124188491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Farzaneh Seyed Mostafaei, Nahid Amani, P. Hajipour
{"title":"Proposing a new QoS/SLA management model by regulatory authority","authors":"Farzaneh Seyed Mostafaei, Nahid Amani, P. Hajipour","doi":"10.1109/ISTEL.2010.5734078","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734078","url":null,"abstract":"According to ITU database about telecommunication regulatory bodies, regulators were responsible to monitor the quality of services in about 84% countries across the world in 2005; furthermore, regulators assigned the quality borders in about 76% of countries. In this paper we use metamodeling strategy to analyze and model the required processes for QoS/SLA management system. This model is developed based on regulatory requirements for the sake of monitoring operators. Inevitably regulatory monitoring methods and policies are different in each counties regarding to their customers and industrial infrastructures; however, the important points achieved from their experiences are similar and applicable in our modeling. In this design the prominent elements from regulatory side are being considered with special focus on the customer assessments. Interfering customer's opinions in our proposed model is the most important part which defines the most critical regulatory responsibility. By this means regulator can be informed about the customers' desires and market's potentials; also, it helps comparing and ranking between service providers. In brief, analyzing customers' ideas helps the regulator to better policy making and performing.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"474 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121766902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hoda S. Ayatollahi Tabatabaii, M. Khansari, H. Rabiee
{"title":"On the effect of random network coding in GIA-based P2P live video streaming systems","authors":"Hoda S. Ayatollahi Tabatabaii, M. Khansari, H. Rabiee","doi":"10.1109/ISTEL.2010.5734105","DOIUrl":"https://doi.org/10.1109/ISTEL.2010.5734105","url":null,"abstract":"Recently it has been shown that network coding can highly improve the network throughput in the communication systems and specifically increase the downloading performance in P2P networks. This paper presents a new live streaming system for GIA-based P2P networks. In the proposed system the traditional GIA protocol is improved for an efficient use in multimedia applications. We introduce a new mesh-pull layered video streaming framework for GIA-based systems and employ random network coding to improve the network performance. Random network coding algorithm enables each peer to send a single encoded video chunk instead of multiple video blocks toward the destination node and save its downloading and uploading bandwidths to a great extent. Comparison of our new GIA-based live streaming system with the traditional GIA demonstrates that this system can achieve a significant improvement in total end-to-end delay, network throughput and redundancy of bandwidth usage.","PeriodicalId":306663,"journal":{"name":"2010 5th International Symposium on Telecommunications","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133932954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}