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اطلاعات دوره: 
  • سال: 

    1403
  • دوره: 

    54
  • شماره: 

    1
  • صفحات: 

    121-131
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    42
  • دانلود: 

    11
چکیده: 

We address the Throughput maximization problem for downlink transmission in DF-relay-assisted cognitive radio networks (CRNs) based on simultaneous wireless information and power transfer (SWIPT) capability. In this envisioned network, multiple-input multiple-output (MIMO) relay and secondary user (SU) equipment are designed to handle both radio frequency (RF) signal energy harvesting and SWIPT functional tasks. Additionally, the cognitive base station (CBS) communicates with the SU only via the MIMO relay. Based on the considered network model, several combined constraints of the main problem complicate the solution. Therefore, in this paper, we apply heuristic guidelines within the convex optimization framework to handle this complexity. First, consider the problem of maximizing Throughput on both sides of the relay separately. Second, each side progresses to solve the complex problem optimally by adopting strategies for solving sub-problems. Finally, these optimal solutions are synthesized by proposing a heuristic iterative power allocation algorithm that satisfies the combinatorial constraints with short convergence times. The performance of the optimal proposed algorithm (OPA) is evaluated against benchmark algorithms via numerical results on optimality, convergence time, constraints’ compliance, and imperfect channel state information (CSI) on the CBS-PU link.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 42

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نویسندگان: 

Mehrabi Arefe | Emadi Mohammad Javad

اطلاعات دوره: 
  • سال: 

    2022
  • دوره: 

    54
  • شماره: 

    1
  • صفحات: 

    3-14
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    33
  • دانلود: 

    0
چکیده: 

In this paper, an Unmanned Aerial Vehicle (UAV) assisted cooperative communication system is studied, wherein a source transmits information to the destination through an energy harvesting decode-and-forward UAV. It is assumed that the UAV can freely move in between the source-destination pair to set up line of sight communications with both nodes. Since the battery of the UAV may be limited, it can harvest energy from the received signal by power splitting technique to be able to perfectly transmit data to the destination. Therefore, we study Throughput maximization problem for multiple time slots data transmission through the cooperative energy harvesting UAV.  To maximize the Throughput, optimal power allocation at the source and the UAV and power splitting ratio at the UAV are studied over each time slot in presence of energy-causality constraints at the UAV. Finally, numerical results are presented to analyze the spectral and energy efficiency of the proposed system, and effects of optimal power allocations and power splitting ratio.  The results indicate that by utilizing optimal resource allocations at the source and the UAV, and utilizing Simultaneous Wireless Information and Power Transfer (SWIPT), significant Throughput improvement is achieved compared to those without optimal resource allocation or SWIPT. All of static UAV scenarios (i.e., the maximum Throughput between the source and the destination) increases, while there is no need to increase the battery capacity of the UAV.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    1
  • شماره: 

    1
  • صفحات: 

    129-144
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    200
  • دانلود: 

    0
چکیده: 

شناسایی و حذف گلوگاه های توان عملیاتی، ابزاری کلیدی برای افزایش توان عملیاتی و بهره وری در سیستم های تولید است. با این حال، به دلیل پیچیدگی و پویای کارخانه، حذف گلوگاه های توان عملیاتی یک چالش بزرگ تلقی می شود. پژوهشگران سعی کرده اند ابزارهایی را برای کمک به شناسایی و حذف این گلوگاه ها توسعه دهند. از لحاظ تاریخی، تلاش های تحقیقاتی بر توسعه رویکردهای مدل سازی برای شناسایی گلوگاه ها در سیستم های تولید متمرکز شده اند. با این حال، با ظهور دیجیتالی سازی صنعتی و هوش مصنوعی، محققان راه های مختلفی را بررسی کردند که در آن ها می توان از هوش مصنوعی برای از بین بردن گلوگاه ها استفاده نمود. در این پژوهش نقش هوش مصنوعی در شناسایی و حذف گلوگاه ها بیان شده و تلاشهای صورت گرفته در زمینه گلوگاه های توان عملیاتی به چهار دسته (1) شناسایی، (2) تشخیص، (3) پیش بینی و (4) تجویز طبقه بندی می شوند. همچنین توصیه های عملی و جهت گیری پژوهش های آینده ارائه شده است که می تواند به بهبود استفاده عملی و نظری هوش مصنوعی در صنایع کمک نماید.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 200

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مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
نویسندگان: 

اطلاعات دوره: 
  • سال: 

    2019
  • دوره: 

    55
  • شماره: 

    -
  • صفحات: 

    0-0
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    56
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 56

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نویسندگان: 

ABAGYAN R. | TOTROV M.

اطلاعات دوره: 
  • سال: 

    2001
  • دوره: 

    5
  • شماره: 

    -
  • صفحات: 

    375-382
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    167
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 167

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 1 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
نویسندگان: 

JAFAR TAFRESHI LEILA | YAGHMAEE FARZIN

اطلاعات دوره: 
  • سال: 

    2016
  • دوره: 

    4
  • شماره: 

    3
  • صفحات: 

    167-173
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    375
  • دانلود: 

    0
چکیده: 

Data mining and knowledge discovery are important technologies for business and research. Despite their benefits in various areas such as marketing, business and medical analysis, the use of data mining techniques can also result in new threats to privacy and information security. Therefore, a new class of data mining methods called privacy preserving data mining (PPDM) has been developed. The aim of researches in this field is to develop techniques those could be applied to databases without violating the privacy of individuals. In this work we introduce a new approach to preserve sensitive information in databases with both numerical and categorical attributes using fuzzy logic. We map a database into a new one that conceals private information while preserving mining benefits. In our proposed method, we use fuzzy membership functions (MFs) such as Gaussian, P-shaped, Sigmoid, S-shaped and Z-shaped for private data. Then we cluster modified datasets by Expectation maximization (EM) algorithm. Our experimental results show that using fuzzy logic for preserving data privacy guarantees valid data clustering results while protecting sensitive information. The accuracy of the clustering algorithm using fuzzy data is approximately equivalent to original data and is better than the state of the art methods in this field.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 375

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مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
اطلاعات دوره: 
  • سال: 

    2024
  • دوره: 

    10
تعامل: 
  • بازدید: 

    30
  • دانلود: 

    0
چکیده: 

In social networks groups play a crucial role and making decisions based on majority consensus. Which influencer nodes should we select if our goal is to broadcast a subject in a target group and increase the number of active nodes in this group? Here, we study a new influence maximization (IM) problem that focuses on individuals in a target group who are activated by some relevant topic or information. Target Group Influence maximization (TGIM) aims to select k influencer nodes in such a way that the number of activated nodes in the target group is maximized. In this paper, we study TGIM and focus on activating the majority of nodes in the target group. We propose an algorithm named Reinforcement Learning for Target Group (RLTG) based on the analysis of the influence of nodes on the target group. The algorithm uses the reinforcement learning approach to learn the optimal path from each target node to some candidate influencers. The experimental results indicate that the recommended approach outperforms known methods.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 30

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نویسنده: 

Shirvani Shiri Fateme | GHOLAMI ALI

اطلاعات دوره: 
  • سال: 

    2016
  • دوره: 

    34
تعامل: 
  • بازدید: 

    161
  • دانلود: 

    0
چکیده: 

MANY EFFORTS ARE ACCOMPLISHED BY GEOPHYSICISTS TO MATCH ZERO-PHASE SYNTHETICS DERIVED FROM WELL LOGS AND SEISMIC SECTIONS CREATED THROUGH PROCESSING STAGES, BUT THE RESULTS OF THEIR COMPARISON ALWAYS SHOW US DIFFERENT DISCONTINUITIES THAT RETURN TO THE PHASE MISMATCHES. BASED ON FIELD MEASUREMENTS AND PHYSICAL LAWS WE CAN DO DETERMINISTIC CORRECTIONS. NO NSTATIONARY (OR TIME-VARYING) PHASES ARE IDENTIFIED BY APPLYING STATISTICAL ANALYSIS OF DATA. CONSTANT PHASE ROTATIONS BY KURTOSIS maximization IS A KIND OF STATISTICAL METHOD THAT CAN REVEAL THE PHASE OF A SEISMIC WAVELET. IT IS POWERFUL ENOUGH TO DETECT NO NSTATIONARY PHASE CHANGES AND TO BE USED IN HIGH-RESOLUTION SEISMIC DATA PROCESSING AND INTERPRETATION. FOR PHASE ESTIMATION, WE USE A MOVING WINDOW TECHNIQUE BY MAXIMIZING THE KURTOSIS OF EACH WINDOW. THE ESTIMATED PHASES ARE THEN USED FOR ZEROING THE PHASE OF THE SEISMIC WAVELET.

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 161

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نویسندگان: 

ZUBAIR HASAN

اطلاعات دوره: 
  • سال: 

    2002
  • دوره: 

    19
  • شماره: 

    3
  • صفحات: 

    95-118
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    135
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 135

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عنوان: 
نویسندگان: 

نشریه: 

اطلاعات دوره: 
  • سال: 

    1400
  • دوره: 

    47
  • شماره: 

    -
  • صفحات: 

    -
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    23
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

شاخص‌های تعامل:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

بازدید 23

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 1 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
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