فیلترها/جستجو در نتایج    

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متن کامل


نویسندگان: 

MARCUCCI M.

اطلاعات دوره: 
  • سال: 

    1985
  • دوره: 

    17
  • شماره: 

    -
  • صفحات: 

    86-91
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    217
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

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

بازدید 217

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اطلاعات دوره: 
  • سال: 

    1392
  • دوره: 

    23
  • شماره: 

    4
  • صفحات: 

    418-429
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    828
  • دانلود: 

    215
چکیده: 

در بسیاری از فرآیندهای تولیدی و خدماتی، کیفیت محصول یا عملکرد فرآیند به کمک رابطه ای خطی یا غیرخطی، بین متغیر پاسخ و یک یا چند متغیر مستقل، بیان می گردد. به چنین روابطی در اصطلاح، پروفایل می گویند. متغیر پاسخ در رابطه پروفایل می تواند پیوسته یا گسسته باشد. تحقیقات نسبتا گسترده ای تا بحال در رابطه با متغیرهای پاسخ پیوسته انجام شده ولی متغیرهای پاسخ گسسته کمتر مورد توجه قرار گرفته است. در حالی که کاربردهای بالقوه ای وجود دارد که متغیر پاسخ با مدلهای رگرسیون لجستک رسته ای یا دودویی مدلسازی می شوند. متغیرهای پاسخ رسته ای کاربردهای متوعی به ویژه در صنعت خدمات دارند. در این مقاله ابتدا به منظور پایش پروفایل ها در فاز I، نمودارهای کنترل پیشنهادی برای پایش پروفایل هایی که دارای پاسخ چندرسته ای اسمی هستند توسعه داده شده اند. مدل مبنای پروفایل، رگرسیون لجستیک چندرسته ای اسمی در نظر گرفته شده است. عملکرد نمودارهای کنترل با استفاده از شبیه سازی و احتمال هشدار برای سناریوهای مختلف خارج از کنترل مقایسه شده اند.

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

بازدید 828

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نویسندگان: 

اطلاعات دوره: 
  • سال: 

    0
  • دوره: 

    8
  • شماره: 

    4
  • صفحات: 

    412-429
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    205
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

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

بازدید 205

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

    2018
  • دوره: 

    4
  • شماره: 

    2
  • صفحات: 

    15-25
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    218
  • دانلود: 

    0
چکیده: 

Background & Aim: Questionnaires are used mostly as a tool in medical research. Due to the different varieties of questionnaires, we may face different score Distributions. In many cases multiple linear regression assumptions are violated. Beta-binomial regression model has the high flexibility and compatibility with this situation. In previous studies there were no comparison between beta-binomial accuracy and other models to fitting quality of life data. So in this study, our aim is to compare the accuracy of models to prediction. Methods & Materials: In this cross-sectional study we collected the quality of life data from 511 healthy women in Qazvin, Iran. The data were used to compare accuracy of betabinomial model and with some other models. Since beta-binomial considers the discrete response variable, so it should be compared with other similar models which are mostly used such as Multinomial, dirichlet-Multinomial and ordinal regression models. The main method that we used in our study was cross-validation to determine the accuracy of different models. To compare the different aspects, vast variety of situations were made and considered. Results: Regarding to the accuracy of models that were obtained by cross-validation in different situations, beta-binomial model had better accuracy among all models. Conclusion: According to the results, we have concluded that beta-binomial model is more accurate in prediction and fitting to the quality of data than the other models. The main advantages of this model are its simplicity, more efficacy and accuracy than the similar models.

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

بازدید 218

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اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    24
  • شماره: 

    2
  • صفحات: 

    137-142
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    332
  • دانلود: 

    0
چکیده: 

In certain statistical process control applications, quality of a process or product can be characterized by a function commonly referred to as profile. Some of the potential applications of profile monitoring are cases where quality characteristic of interest is modelled using binary, Multinomial or ordinal variables. In this paper, profiles with Multinomial response are studied. For this purpose, Multinomial log it regression (MLR) is considered as the basis. Then, the MLR is converted to Poisson GLM with log link. Two methods including Multivariate exponentially weighted moving average (MEWMA) statistics, and Likelihood ratio test (LRT) statistics are proposed to monitor MLR profiles in phase II. Performances of these three methods are evaluated by average run length criterion (ARL). A case study from alloy fasteners manufacturing process is used to illustrate the implementation of the proposed approach. Results indicate satisfactory performance for the proposed method.

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

بازدید 332

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نویسندگان: 

مقیم بیگی میثم

اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    16
  • شماره: 

    2
  • صفحات: 

    449-468
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    164
  • دانلود: 

    48
چکیده: 

در این مقاله یک مدل رگرسیون لوژستیک چند جمله ای نیمه پارامتری برای رده بندی پیکربندی های برچسب دار معرفی شده است. در مدل رگرسیونی متغیر تبینی تابع هسته ای است که با استفاده از معیار توان-واگرایی به دست آمده است. همچنین متغیر پاسخ به صورت رسته ای بوده و رده هر پیکربندی را نشان می دهد. این مدل رگرسیونی نیمه پارامتری بر اساس فواصل تعریف شده در فضای شکل معرفی شده و به همین دلیل میزان رده بندی درست اشکال با استفاده از این روش در مقایسه با روش های پیشین بهبود یافته است. عملکرد این مدل در قالب یک مطالعه شبیه سازی مورد بررسی قرار گرفته است. در انتها نیز کاربردی از این روش در رده بندی دو مجموعه داده واقعی به نمایش گذاشته شد. همچنین روش ارائه شده در این مقاله با روش های معرفی شده در نوشتگان مقایسه گردید که نشان از عملکرد مناسب این روش در رده بندی پیکربندی ها دارد.

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

بازدید 164

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 48 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
نویسندگان: 

KAMRAD B. | RITCHKEN P.

اطلاعات دوره: 
  • سال: 

    1991
  • دوره: 

    37
  • شماره: 

    12
  • صفحات: 

    1640-1653
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    79
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

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

بازدید 79

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
اطلاعات دوره: 
  • سال: 

    1401
  • دوره: 

    52
  • شماره: 

    4
  • صفحات: 

    269-280
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    139
  • دانلود: 

    12
چکیده: 

One of the obvious reasons for most disorders in network service provisioning is network path congestion. Congestion avoidance in today's networks is too costly and sometimes impossible. With the introduction of SDN, centralizing the equipment's control plane has become possible. This paper presents an enhanced method named ESV-DBRA to avoid congestion in multi-tenant SDN networks. At first, ESV-DBRA monitors the traffic load and delay of all network paths for each tenant individually. Then, by merging the parameters obtained from the monitoring, the Service Level Agreements (SLA), and a novel proposed cost function, it calculates the cost of the network paths per tenant. As a result, traffic for each tenant is routed through the path/paths at the lowest possible cost from the tenant's perspective. Next, the bandwidth quotas will be calculated and assigned to the tenants over their optimal routes. Afterward, whenever congestion is likely to occur in a path, ESV-DBRA automatically changes the route or bandwidth of the tenants' traffic related to this path to avoid congestion. Related algorithms are also proposed.Eventually, simulations show that the proposed method effectively increases bandwidth utilization by 10.76%.

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

بازدید 139

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesدانلود 12 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesاستناد 0 مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resourcesمرجع 0
اطلاعات دوره: 
  • سال: 

    2024
  • دوره: 

    12
  • شماره: 

    1
  • صفحات: 

    71-84
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    5
  • دانلود: 

    0
چکیده: 

Organic agriculture is one of the sustainable farming systems that emphasizes economic, social, and environmental aspects to achieve sustainability targets. This study aims to identify the economic, social, and environmental factors affecting organic product production from the perspective of experts and 150 farmers in Jiroft County. The results revealed that low government financial support for organic farmers (average rating of 3.8133) is the most effective factor, while lack of adequate marketability (average rating of 2.6733) is the least effective factor among the barriers to achieving organic agriculture. from the farmers' perspective. According to experts, organic farming serves as a tool for improving public health conditions, (average rank of 11.66), which it is determined as the most effective factor. However, it does not significantly contribute to self-sufficiency in agricultural production, with an average rank of 6.07, being the least influential factor among the factors affecting organic farming. Among the average ranks of the components of influential factors in organic farming (educational, economic, social-managerial indicators), the lowest ranking is the government's financial support for organic farmers (average rank of 3.13), making it the most influential. Whereas, the lack of suitable marketability with an average rank of 2.67 is the least influential factor among the factors affecting organic farming. Furthermore, the results show that holding promotional and educational classes has a positive and significant impact on the acceptance of organic cultivation, as following the recommendations of promoters and having the necessary education can increase production and reduce costs.

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

بازدید 5

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اطلاعات دوره: 
  • سال: 

    1400
  • دوره: 

    51
  • شماره: 

    4
  • صفحات: 

    431-441
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    149
  • دانلود: 

    24
چکیده: 

Different types of contact, including contact between node pairs, any-contact of nodes, and contacts of the entire network, are used to characterize social relations in mobile social networks. Different modes of routing, from the point of view of message delivery semantics, encompass unicasting, multicasting, any-casting, and broadcasting. Studies have shown that using probability Distribution functions of contact data, which is mainly assumed to be homogeneous for nodes, improves the performance of these networks. However, there exists an important challenge in studies on Distributions. A lot of works apply the Distribution of one type of contact to other types. Hence in routing applications, it causes to use of the Distribution of one type of contact for any mode of routing. This study provides a complete solution to model each type of homogeneous contact data Distribution and to use them in different modes of routing. We propose a routing algorithm that uses this new model. Results show that our solution improves the average latency of comparing methods Epidemic, TCCB, and DR about 3.5-times, 30%, and 45%, respectively. It achieves a delivery rate of about 5% and 6%, and average latency about 6% and 8% better than that of DR and TCCB, respectively.

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

بازدید 149

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