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متن کامل


اطلاعات دوره: 
  • سال: 

    1401
  • دوره: 

    12
  • شماره: 

    47
  • صفحات: 

    7-32
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    185
  • دانلود: 

    39
چکیده: 

Nowadays, the fundamental role of having a purpose for life in physical and mental health has been confirmed. According to victor frankl, presence of a purpose in life gives life a meaning and increases resilience against pains and traumas. The importance of the purpose in life construct reveals the need for a reliable and valid tool to measure it. Crumbaugh and Maholick's purpose in life questionnaire is the first and one of the most applied tools for the assessment of life's purposefulness. The aim of this research is to determine the factor structure of purpose in life questionnaire. The questionnaire was administered on 206 students who were selected through random stratified sampling at Ferdowsi University of Mashhad. Exploratory factor analysis showed that there are two factors "comprehension" and "purpose" and this finding were confirmed by confirmatory factor analysis. Altogether results of this research showed factor validity of the purpose in life questionnaire with a two factor pattern

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نویسندگان: 

مهدی پور مصطفی

اطلاعات دوره: 
  • سال: 

    1403
  • دوره: 

    14
  • شماره: 

    4
  • صفحات: 

    49-67
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    0
  • دانلود: 

    0
چکیده: 

در این پژوهش، ساختار امواج یون-صوتی ضربه ای در یک پلاسمای غیرمغناطیسی شامل یون های گرم و الکترون هایی با توزیع کاپای منظم شده بررسی شده است. با به کار بردن روش اختلال کاهشی، معادلة غیرخطی کورته وگ- دوری برگرز (K-dVB) برای دینامیک امواج یون-صوتی ضربه ای تعیین شده است. در اینجا، اتلاف ایجاد شده به وسیلة چسبندگی سینماتیکی یون نیز در نظر گرفته شده است. جواب تحلیلی معادلة غیرخطی K-dVB به کمک روش تانژانت هایپربولیک تعیین شده است. علاوه براین، جزئیات شرایط انتشار موج ضربه ای به صورت نوسانی و یا یکنواخت نیز به صورت تحلیلی بررسی شده است. مشاهده می شود که اگر چسبندگی محیط پلاسما نسبتاً کوچک باشد، امواج ضربه ای نوسانی قابلیت انتشار در محیط پلاسمای مد نظر را خواهند داشت.  همچنین مشاهده می شود که الکترون هایی با توزیع کاپای منظم شده می توانند ساختار امواج ضربه ای را تصحیح کنند. به عبارت دیگر، هر دو موج ضربه ای با دامنة مثبت و منفی قابلیت انتشار در محیط پلاسمای حاضر را دارند. وابستگی ساختار موج ضربه ای به پارامترهای مربوط به توزیع الکترون ها (  و ) و ضریب چسبندگی یون ها نیز مورد بررسی قرار گرفته است. نتایج پژوهش حاضر می تواند در درک پدیده های الکتروستانیکی غیرخطی در پلاسماهای فضایی با الکترون های دارای توزیع کاپای منظم شده مفید باشند.

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اطلاعات دوره: 
  • سال: 

    2019
  • دوره: 

    5
تعامل: 
  • بازدید: 

    140
  • دانلود: 

    0
چکیده: 

COMMUNITY structure DETECTION IN SOCIAL NETWORKS HAS BECOME A BIG CHALLENGE. VARIOUS METHODS IN THE LITERATURE HAVE BEEN PRESENTED TO SOLVE THIS CHALLENGE. RECENTLY, SEVERAL METHODS HAVE ALSO BEEN PROPOSED TO SOLVE THIS CHALLENGE BASED ON A MAPPING-REDUCTION MODEL, IN WHICH DATA AND ALGORITHMS ARE DIVIDED BETWEEN DIFFERENT PROCESS NODES SO THAT THE COMPLEXITY OF TIME AND MEMORY OF COMMUNITY DETECTION IN LARGE SOCIAL NETWORKS IS REDUCED. IN THIS PAPER, A MAPPING-REDUCTION MODEL IS FIRST PROPOSED TO DETECT THE structure OF COMMUNITIES. THEN THE PROPOSED FRAMEWORK IS REWRITTEN ACCORDING TO A NEW MECHANISM CALLED Distributed CACHE MEMORY; Distributed CACHE MEMORY CAN STORE DIFFERENT VALUES ASSOCIATED WITH DIFFERENT KEYS AND, IF NECESSARY, PUT THEM AT DIFFERENT COMPUTATIONAL NODES. FINALLY, THE PROPOSED REWRITTEN FRAMEWORK HAS BEEN IMPLEMENTED USING SPARK TOOLS AND ITS IMPLEMENTATION RESULTS HAVE BEEN REPORTED ON SEVERAL MAJOR SOCIAL NETWORKS. THE PERFORMED EXPERIMENTS SHOW THE EFFECTIVENESS OF THE PROPOSED FRAMEWORK BY VARYING THE VALUES OF VARIOUS PARAMETERS.

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نویسندگان: 

BEYGY H. | MEYBODI M.R.

اطلاعات دوره: 
  • سال: 

    2003
  • دوره: 

    1
  • شماره: 

    1
  • صفحات: 

    0-0
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    221
  • دانلود: 

    0
چکیده: 

A dictionary machine is a database of (key, record) pairs with a given set of operators. Typical operators include insert, delete, delete record with minimum key, delete record with maximum key, record with minimum key, record with maximum key, nearest record, predecessor, successor, rank, and count. The different implementations of dictionary machines for Distributed memory multiprocessor computers are reported in the literature. The stored chain, balanced cube, banyan heap are some examples. Binary search mesh is a concurrent data structure for dictionary machine for implementation of dictionary machines on the Distributed memory multiprocessor computers with mesh or hypercube topologies. The implementation of binary search mesh which is given in [24] has some problems: hole is created in the insert operation, properties of the binary search mesh are not preserved in delete operation, mesh is not balanced, and data structure has low throughput. In [4] the balanced binary search mesh has proposed which doesn"t create hole in the insert operator and preserve the binary search mesh in the delete operator. In this paper, we propose the complete binary search mesh, which solve problems in binary search mesh and balanced binary search mesh. In this data structure, the levels of mesh are filled in the increasing order, which improves the throughput of data structure. For implementation of this data structure on the mesh or hypercube, the machine logically consists of two different non-disjoint networks: broadcasting network for sending operators and sending network for sending the responses, which reduce the overall traffic of the network. Comparison of complete binary search mesh with other dictionary machines implemented on the Distributed memory multi processor computers with mesh topology shows that the complete binary search mesh has higher throughput.

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نویسنده: 

حیدری علیرضا

اطلاعات دوره: 
  • سال: 

    1394
  • دوره: 

    1
تعامل: 
  • بازدید: 

    457
  • دانلود: 

    1445
چکیده: 

لطفا برای مشاهده چکیده به متن کامل (PDF) مراجعه فرمایید.

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نویسندگان: 

KHOSHNIYAT H. | ABDIPOUR A. | MORADI G.

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    46
  • شماره: 

    2
  • صفحات: 

    47-52
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    214
  • دانلود: 

    0
چکیده: 

Modeling and simulation of communication circuits at high frequency are important challenges ahead in the design and construction of these circuits. Knowing the fact that the lumped element model is not valid at high frequency, Distributed analysis is presented based on active and passive transmission lines theory. In this paper, a lossy transmission line model of traveling wave switch (TWSW) is presented and fully Distributed analysis of this structure is also introduced. In the off state, the ordinary single pole single throw (SPST) switches operate as short or open circuit and return an observable part of the signal. To improve return loss in the off state, a non-uniform structure of SPST switches is proposed which is based on the artificial tapered transmission line produced by applying various controlling voltage at the gate. The analysis of ordinary and improved structure of SPST switches is performed and it is further compared with that of the semi-Distributed and fully Distributed methods. The results of simulation easily approve the improvement of matching in the off state.

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نویسندگان: 

Ghazi Nader Dina | Aghayari Reza

اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    53
  • شماره: 

    2
  • صفحات: 

    168-178
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    105
  • دانلود: 

    18
چکیده: 

Plastic hinge properties play a crucial role in predicting the nonlinear response of structural elements. The plastic hinge region of reinforced concrete normal beams has been previously studied experimentally and analytically. The main objective of this research is to evaluate the behavior of the plastic hinge region of reinforced concrete deep beams and its comparison with normal beams through finite element simulation. To do so, ten beams contain six deep beams, and four normal beams, under concentrated and uniformly Distributed loading, are investigated. Lengths in the plastic hinge region involving curvature localization, rebar yielding, and concrete crushing zones are studied. The results indicate that the curvature localization zone is not suitable for the prediction of plastic hinge length in reinforced concrete deep beams. Based on the results it can be stated that in simply supported normal beams the concrete crushing zone is focused on the middle span, but in simply supported deep beams by creating a compression strut between loading place and support, the concrete crushing zone spreads along the compression trajectory. The rebar yielding zone of simply supported beams increases as the loading type is changed from the concentrated load at the middle to the uniformly Distributed load.

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نویسندگان: 

Gharehkhani a. | Abbaspour Sani E.

اطلاعات دوره: 
  • سال: 

    2018
  • دوره: 

    31
  • شماره: 

    2 (TRANSACTIONS B: Applications)
  • صفحات: 

    315-321
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    201
  • دانلود: 

    0
چکیده: 

In this paper, using only 32 MEMS switches, a new design for 6 bit DMTL phase shifter is proposed. The reduction in number of switches in ordinary 6 bit phase shifter from 63 to 32 is due to combination of one 5. 625 degree for least significant bit and 11. 25 degree for the rest of the switches. In new proposed method, the die size and loss of the CPW line reduced by decreasing the number of the switches. Analytical and finite element simulation with HFSS and COMSOL software, is used for considering the performance of the proposed structure. The results showed that, maximum return loss of phase shifter and mean RMS phase error are-10. 5 dB and1. 4o, respectively. Although two different micro switches are used but the pull in voltages are identical. The final configuration size is 1. 5 × 18. 5 mm2, and surface micromachining process is suggested for the phase shifter manufacturing.

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اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    11
  • شماره: 

    2
  • صفحات: 

    61-74
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    159
  • دانلود: 

    27
چکیده: 

ABSTRACTDuring the last century, ports of Persian Gulf become the most important storage, refining and transportation of crude oil, oil derivation, petrochemical products and also, business activities. Nowadays, due to functional diversity between ports, the impact of port activities on the development of urban spaces will be different, and this issue leads to structural differences of port cities. The purpose of this research is to identify the key variables affecting the relations and spatial structure of port-city in Dubai as the most thriving and successful port-city in the Persian Gulf. This research is based on deductive reasoning and carried out by analysis of cross effects with secondary data (results of other prominent articles) and also primary data (questionnaire). sampling method is based on purposive sampling and Micmac software was used to analyze the data. Output of Micmac software shows the position of the instability of the system. Therefore, the position of each variables in the conceptual model can be categorized to driver, linkage, dependent, and autonomous factors. The research findings indicate 4 variables (like as “income, cost and investmnets in port-city”) can be introduced as a driver factor, 5 variables (like as “advanced multimodal transportation in the port”) can be introduced as a linkage factor, 6 variables (like as “quality of living environment and desirable city”) can be introduced as a dependent factor, 3 variables (like as “environmental protection and sustainable development of the city-port”) can be introduced as an autonomous factor. The rapid development of Dubai can be explained by the purposeful distribution of revenues from trade and tourismExtended AbstractIntroductionDuring the last century, ports of Persian Gulf become the most important storage, refining and transportation of crude oil, oil derivation, petrochemical products and also, business activities. The global increase in oil demand since the 1950s led to the creation of discovery of new oil wells and large industrial areas. With the construction of new oil or gas facilities in the port areas, increasing oil revenues contributed to the countries of the Persian Gulf region and form a new geographical relationship between ports and coastal cities which had an impact on the spatial structure and relation of them. Nowadays, due to functional diversity between ports, the impact of port activities on the development of urban spaces will be different, and this issue leads to structural differences of port cities. In the 1950s, Containerization (container loading technology) was based in some of the world's ports and created a huge transformation in the shipping industry, which had a significant impact on the development of ports. Although the ports of the Persian Gulf have made a significant contribution to the economic growth and physical development of other ports in the world, but few researches have been done on the variables and factors affecting the development of the spatial structure of the important ports of the Persian Gulf. This region, due to its unique geographical location, has always been considered as a most important corridor in the field of economic and transportation throughout history. Some of the most important energy and commercial ports in this region are: Dubai, Manama, Kuwait, Dammam, Doha, Bushehr, Bandar-Abbas and Assaluyeh. In this regard, the purpose of this research is to identify the key variables affecting the relations and spatial structure of port-city in Dubai as the most thriving and successful port-city in the Persian Gulf. MethodologyThis research is based on deductive reasoning and carried out by analysis of cross effects with secondary data (results of other prominent articles) and also primary data (questionnaire). The method used in this research is quantitative and the sampling method is based on purposive sampling. the variables affecting the spatial structure of port-city relations were identified in the form of a review of 31 prominent articles. 25 experts (who had comprehensive knowledge and information about the development process of the city-port of Dubai) participated to determine the effectiveness or influence of variables. Finally, the output of data analysis was done by the Micmac software. Results and discussionOutput of Micmac software shows the position of the variables in the diagram that it indicates their status in the system and their role in the dynamics and changes of the system. The method of distribution and dispersion of the variables in the spatial structure of port-city relations indicates the instability of the system. Therefore, based on the output of the system, the position of each variables in the conceptual model can be identified in five categories (driver, linkage, dependent, autonomous and regulatory variables). According to the results, some variables such as “the changes in the strategic positions” and “geopolitics of port-city”, “the modification of the management method” and “regional planning of the ports”, “the promotion of local governance in the relations between port-city” and “the way of national and international management of ports have been introduced as driver variables. On the other hand, five variables consist of “advanced multimodal transportation in the port” and “income, cost and investment in the port-city”, “the contrast and physical integration of the port - city space”, “the development of various industrial and production activities in the ports and their local hinterland” and “their qualities Financial and commercial policies of ports” have been introduced as linkage variables. Findings of research also shows that some variables consist of “quality of living environment and desirable city”, “quantity and quality of transit corridors (rail, road and air) to hinterland”, “construction and launching the new port (sea port or dry port)”, “terminal facilities and infrastructure and warehousing”, “conflict or convergence between the city and the port” and “increase in population growth rate and migration to the port - city” categorized as dependent variables. Three variables including “cultural and historical background of ports”, “use of cheaper energy, Less-polluted, clean and renewable energies in the city-port” and “environmental protection and sustainable development of the city-port” categorized as autonomous variables. Finally, a variable with the title of “improvement in management and information technology and development in loading, unloading and storage of commodities” have been introduced as regulatory variables. The findings of this research have a remarkable similarity with other researches carried out in the field of city-port relation and clearly emphasize the direct impact of the "investment in port-city" in the development of them. For example, Grossmann (2008) emphasized that city-port of Hamburg has become one of the largest ports in Northern Europe during the last few decades due to huge domestic and foreign investment. ConclusionThis research carried out in order to introduce and explain the key variables affecting the development of the spatial structure of the port-city of Dubai. On this basis, 21 variables have been extracted by systematic reviews of prominent articles. In the following, 25 experts were selected with the purposive sampling method. Among the 21 variables extracted, 4 variables (like as “geopolitics of port-city”) introduced as a driver factor, 5 variables (like as “advanced multimodal transportation in the port”) introduced as a linkage factor, 6 variables (like as “quality of living environment and desirable city”) introduced as a dependent factor, 3 variables (like as “environmental protection and sustainable development of the city-port”) introduced as an autonomous factor. The rapid development of Dubai can be explained by the purposeful distribution of revenues from trade and tourism. A part of these revenues has been directed towards investment in important transportation infrastructures such as airports and ports of this city. These strategies have a wide impact on improving the economic growth of the city and the development of the port in order to adapt with the global trade and advanced technologies. FundingThere is no funding support. Authors’ ContributionAuthors contributed equally to the conceptualization and writing of the article. All of the authors approved the content of the manuscript and agreed on all aspects of the work declaration of competing interest none. Conflict of InterestAuthors declared no conflict of interest. Acknowledgments We are grateful to all the scientific consultants of this paper.

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نویسندگان: 

HASANLOO MAHMOUD | MOVAGHAR ALI

اطلاعات دوره: 
  • سال: 

    2012
  • دوره: 

    3
  • شماره: 

    3
  • صفحات: 

    19-34
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    371
  • دانلود: 

    0
چکیده: 

The IP Lookup Process is a key bottleneck in routing due to the increase in routing table size, increasing traffic and migration to IPv6 addresses. The IP address lookup involves computation of the Longest Prefix Matching (LPM), which existing solutions such as BSD Radix Tries, scale poorly when traffic in the router increases or when employed for IPv6 address lookups. In this paper, we describe a high performance parallel IP lookup mechanism based on Distributed memory organization that uses P processor for solving LPM problem. Since multiple processors are used, the number of prefixes to be compared for each processor has been reduced. In other words each processor needs to find LPM for a specific IP address among N/P of prefixes. In order to reduce the number of memory access in each processor which is a major bottleneck in IP lookup process, we use ISCB-Tree data structure for the sake of storing the forwarding table in each processor. ISCB-Tree is a B-Tree like data structure that reduces the height of prefix tree and logarithmic growing manner with the increasing number of prefixes. By the using of this data structure the number of memory access reduces sharply.

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