Turkish Journal of Electrical Engineering and Computer Sciences最新文献_第10页

A novel adaptive hysteresis DC-DC buck converter for portable devices 一种便携式自适应迟滞DC-DC降压变换器

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1809-45

S. Park, Ju Sang Lee, Sang-Dae Yu

引用次数: 1

HyBiX: A novel encoding bitmap index for space- and time-efficient query processing HyBiX:一种新颖的编码位图索引，用于节省空间和时间的查询处理

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1807-277

Naphat Keawpiba, L. Preechaveerakul, S. Vanichayobon

{"title":"HyBiX: A novel encoding bitmap index for space- and time-efficient query processing","authors":"Naphat Keawpiba, L. Preechaveerakul, S. Vanichayobon","doi":"10.3906/ELK-1807-277","DOIUrl":"https://doi.org/10.3906/ELK-1807-277","url":null,"abstract":"A bitmap-based index is an effective and efficient indexing method for answering selective queries in a read- only environment. It offers improved query execution time by applying low-cost Boolean operators on the index directly, before accessing raw data. A drawback of the bitmap index is that index size increases with the cardinality of indexed attributes, which additionally has an impact on a query execution time. This impact is related to an increase of query execution time due to the scanning of bitmap vectors to answer the queries. In this paper, we propose a new encoding bitmap index, called the HyBiX bitmap index. The HyBiX bitmap index was experimentally compared to existing encoding bitmap indexes in terms of space requirement, query execution time, and space and time trade-off for equality and range queries. As experimental results, the HyBiX bitmap index can reduce space requirements with high cardinality attributes with satisfactory execution times for both equality and range queries. The performance of the HyBiX bitmap index provides the second-best results for equality queries and the first-best for range queries in terms of space and time trade-off.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"44 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88126056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Probabilistic small-signal stability analysis of power system with solar farm integration 太阳能电站一体化电力系统的概率小信号稳定性分析

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1804-228

Samundra Gurung, S. Naetiladdanon, A. Sangswang

{"title":"Probabilistic small-signal stability analysis of power system with solar farm integration","authors":"Samundra Gurung, S. Naetiladdanon, A. Sangswang","doi":"10.3906/ELK-1804-228","DOIUrl":"https://doi.org/10.3906/ELK-1804-228","url":null,"abstract":"Currently, large-scale solar farms are being rapidly integrated in electrical grids all over the world. However, the photovoltaic (PV) output power is highly intermittent in nature and can also be correlated with other solar farms located at different places. Moreover, the increasing PV penetration also results in large solar forecast error and its impact on power system stability should be estimated. The effects of these quantities on small-signal stability are difficult to quantify using deterministic techniques but can be conveniently estimated using probabilistic methods. For this purpose, the authors have developed a method of probabilistic analysis based on combined cumulant and Gram– Charlier expansion technique. The output from the proposed method provides the probability density function and cumulative density function of the real part of the critical eigenvalue, from which information concerning the stability of low-frequency oscillatory dynamics can be inferred. The proposed method gives accurate results in less computation time compared to conventional techniques. The test system is a large modified IEEE 16-machine, 68-bus system, which is a benchmark system to study low-frequency oscillatory dynamics in power systems. The results show that the PV power fluctuation has the potential to cause oscillatory instability. Furthermore, the system is more prone to small-signal instability when the PV farms are correlated as well as when large PV forecast error exists.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"50 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82688691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Automated elimination of EOG artifacts in sleep EEG using regression method 用回归方法自动消除睡眠脑电图中的眼电信号伪影

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1809-180

M. Dursun, Seral Özşen, S. Günes, B. Akdemir, Ş. Yosunkaya

{"title":"Automated elimination of EOG artifacts in sleep EEG using regression method","authors":"M. Dursun, Seral Özşen, S. Günes, B. Akdemir, Ş. Yosunkaya","doi":"10.3906/ELK-1809-180","DOIUrl":"https://doi.org/10.3906/ELK-1809-180","url":null,"abstract":"Sleep electroencephalogram (EEG) signal is an important clinical tool for automatic sleep staging process. Sleep EEG signal is effected by artifacts and other biological signal sources, such as electrooculogram (EOG) and electromyogram (EMG), and since it is effected, its clinical utility reduces. Therefore, eliminating EOG artifacts from sleep EEG signal is a major challenge for automatic sleep staging. We have studied the effects of EOG signals on sleep EEG and tried to remove them from the EEG signals by using regression method. The EEG and EOG recordings of seven subjects were obtained from the Sleep Research Laboratory of Meram Medicine Faculty of Necmettin Erbakan University. A dataset consisting of 58 h and 6941 epochs was used in the research. Then, in order to see the consequences of this process, we classified pure sleep EEG and artifact-eliminated EEG signals with artificial neural networks (ANN). The results showed that elimination of EOG artifacts raised the classification accuracy on each subject at a range of 1%– 1.5%. However, this increase was obtained for a single parameter. This can be regarded as an important improvement if the whole system is considered. However, different artifact elimination strategies combined with different classification methods for another sleep EEG artifact may give higher accuracy differences between original and purified signals.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"133 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81827007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A novel hybrid teaching-learning-based optimization algorithm for the classification of data by using extreme learning machines 一种基于极端学习机的混合式数据分类优化算法

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1802-40

E. Sevinç, Tansel Dökeroglu

引用次数: 17

Understanding attribute and social circle correlation in social networks 理解社交网络中的属性和社交圈关联

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1806-91

P. Nerurkar, M. Chandane, S. Bhirud

{"title":"Understanding attribute and social circle correlation in social networks","authors":"P. Nerurkar, M. Chandane, S. Bhirud","doi":"10.3906/ELK-1806-91","DOIUrl":"https://doi.org/10.3906/ELK-1806-91","url":null,"abstract":"Social circles, groups, lists, etc. are functionalities that allow users of online social network (OSN) platforms to manually organize their social media contacts. However, this facility provided by OSNs has not received appreciation from users due to the tedious nature of the task of organizing the ones that are only contacted periodically. In view of the numerous benefits of this functionality, it may be advantageous to investigate measures that lead to enhancements in its efficacy by allowing for automatic creation of customized groups of users (social circles, groups, lists, etc). The field of study for this purpose, i.e. creating coarse-grained descriptions from data, consists of two families of techniques, community discovery and clustering. These approaches are infeasible for the purpose of automation of social circle creation as they fail on social networks. A reason for this failure could be lack of knowledge of the global structure of the social network or the sparsity that exists in data from social networking websites. As individuals do in real life, OSN clients dependably attempt to broaden their groups of contacts in order to fulfill different social demands. This means that ‘homophily’ would exist among OSN users and prove useful in the task of social circle detection. Based on this intuition, the current inquiry is focused on understanding ‘homophily’ and its role in the process of social circle formation. Extensive experiments are performed on egocentric networks (ego is user, alters are friends) extracted from prominent OSNs like Facebook, Twitter, and Google+. The results of these experiments are used to propose a unified framework: feature extraction for social circles discovery (FESC). FESC detects social circles by jointly modeling ego-net topology and attributes of alters. The performance of FESC is compared with standard benchmark frameworks using metrics like edit distance, modularity, and running time to highlight its efficacy.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"24 3 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89641260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A new computer-controlled platform for ADC-based true random number generator and its applications 一种基于adc的真随机数发生器计算机控制平台及其应用

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1806-167

Selçuk Coskun, I. Pehlivan, Akif Akgül, Bi̇lal Gürevi̇n

{"title":"A new computer-controlled platform for ADC-based true random number generator and its applications","authors":"Selçuk Coskun, I. Pehlivan, Akif Akgül, Bi̇lal Gürevi̇n","doi":"10.3906/ELK-1806-167","DOIUrl":"https://doi.org/10.3906/ELK-1806-167","url":null,"abstract":"The basis of encryption techniques is random number generators (RNGs). The application areas of cryptology are increasing in number due to continuously developing technology, so the need for RNGs is increasing rapidly, too. RNGs can be divided into two categories as pseudorandom number generator (PRNGs) and true random number generator (TRNGs). TRNGs are systems that use unpredictable and uncontrollable entropy sources and generate random numbers. During the design of TRNGs, while analog signals belonging to the used entropy sources are being converted to digital data, generally comparators, flip-flops, Schmitt triggers, and ADCs are used. In this study, a computer-controlled new and flexible platform to find the most appropriate system parameters in ADC-based TRNG designs is designed and realized. As a sample application with this new platform, six different TRNGs that use three different outputs of Zhongtang, which is a continuous time chaotic system, as an entropy source are designed. Random number series generated with the six designed TRNGs are put through the NIST800–22 test, which has the internationally highest standards, and they pass all tests. With the help of the new platform designed, ADC-based high-quality TRNGs can be developed fast and also without the need for expertise. The platform has been designed to decide which entropy source and parameter are better by comparing them before complex embedded TRNG designs. In addition, this platform can be used for educational purposes to explain how to work an ADC-based TRNG. That is why it can be utilized as an experiment set in engineering education, as well.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"39 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89723707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

A novel accuracy assessment model for video stabilization approaches based on background motion 一种新的基于背景运动的视频稳像精度评估模型

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1810-68

Md. Alamgir Hossain, Tien-Dung Nguyen, E. Huh

引用次数: 0

TAPU: Test and pick up-based k-connectivity restoration algorithm for wireless sensor networks TAPU:基于测试和拾取的无线传感器网络k-连通性恢复算法

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1801-49

V. Akram, O. Dagdeviren

{"title":"TAPU: Test and pick up-based k-connectivity restoration algorithm for wireless sensor networks","authors":"V. Akram, O. Dagdeviren","doi":"10.3906/ELK-1801-49","DOIUrl":"https://doi.org/10.3906/ELK-1801-49","url":null,"abstract":"A k-connected wireless sensor network remains connected if any k-1 arbitrary nodes stop working. The aim of movement-assisted k -connectivity restoration is to preserve the k -connectivity of a network by moving the nodes to the necessary positions after possible failures in nodes. This paper proposes an algorithm named TAPU for k-connectivity restoration that guarantees the optimal movement cost. Our algorithm improves the time and space complexities of the previous approach (MCCR) in both best and worst cases. In the proposed algorithm, the nodes are classified into safe and unsafe groups. Failures of safe nodes do not change the k value of the network while failures of unsafe nodes reduce the k value. After an unsafe node’s failure, the shortest path tree of the failed node is generated. Each node moves to its parent location in the tree starting from a safe node with the minimum moving cost to the root. TAPU has been implemented on simulation and testbed environments including Kobuki robots and Iris nodes. The measurements show that TAPU finds the optimum movement up to 79.5% faster with 50% lower memory usage than MCCR and with up to 59% lower cost than the greedy algorithms.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"41 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79206455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Speech enhancement using adaptive thresholding based on gamma distribution of Teager energy operated intrinsic mode functions 基于Teager能量分布的自适应阈值语音增强

IF 1.1 4区计算机科学

Turkish Journal of Electrical Engineering and Computer Sciences Pub Date : 2019-04-01 DOI: 10.3906/ELK-1804-18

Özkan Arslan, E. Z. Engin

{"title":"Speech enhancement using adaptive thresholding based on gamma distribution of Teager energy operated intrinsic mode functions","authors":"Özkan Arslan, E. Z. Engin","doi":"10.3906/ELK-1804-18","DOIUrl":"https://doi.org/10.3906/ELK-1804-18","url":null,"abstract":"This paper introduces a new speech enhancement algorithm based on the adaptive threshold of intrinsic mode functions (IMFs) of noisy signal frames extracted by empirical mode decomposition. Adaptive threshold values are estimated by using the gamma statistical model of Teager energy operated IMFs of noisy speech and estimated noise based on symmetric Kullback–Leibler divergence. The enhanced speech signal is obtained by a semisoft thresholding function, which is utilized by threshold IMF coefficients of noisy speech. The method is tested on the NOIZEUS speech database and the proposed method is compared with wavelet-shrinkage and EMD-shrinkage methods in terms of segmental SNR improvement (SegSNR), weighted spectral slope (WSS), and perceptual evaluation of speech quality (PESQ). Experimental results show that the proposed method provides a higher SegSNR improvement in dB, lower WSS distance, and higher PESQ scores than wavelet-shrinkage and EMD-shrinkage methods. The proposed method shows better performance than traditional threshold-based speech enhancement approaches from high to low SNR levels.","PeriodicalId":49410,"journal":{"name":"Turkish Journal of Electrical Engineering and Computer Sciences","volume":"104 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80583870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2