نتایج جستجو برای: data variability

تعداد نتایج: 2535942  

Journal: :آب و خاک 0
فرخ اسدزاده منوچهر گرجی علیرضا واعظی سلمان میرزایی

introduction: field plots are widely used in studies related to the measurements of soil loss and modeling of erosion processes. research efforts are needed to investigate factors affecting the data quality of plots. spatial scale or size of plots is one of these factors which directly affects measuring runoff and soil loss by means of field plots. the effect of plot size on measured runoff or ...

Journal: :تحقیقات جغرافیایی 0
زهره مریانجی گروه جغرافیای طبیعی دانشگاه اصفهان علی اکبر سبزی پرور دانشگاه بوعلی همدان سعید موحدی گروه جغرافیای طبیعی دانشگاه اصفهان سید ابوالفضل مسعودیان گروه جغرافیای طبیعی دانشگاه اصفهان سعید موحدی گروه جغرافیای طبیعی دانشگاه اصفهان حسین عساکره گروه جغرافیا دانشگاه زنجان علی اکبر سبزی پرور

abstract one of the most variability of atmospheric parameter is precipitation, which changes seasonally. it is important to understand exact characteristic of rainfall seasonal variable. therefore, it is unavoidable to study rainfall season in hamedan province, because hameden is one of the important centers of agriculture in iran. in this research, the seasonal variability of rainfall is cons...

Extended abstract 1- Introduction Soil salinity is one of the most important desertification parameters in many parts of the world. Thus, preparing soil salinity maps in macro scales is necessary. Water and soil salinity as one of the contributing parameters in desertification, cause soil and vegetation degradation. Soil salinization represents many negative effects on the earth systems such ...

Reliable characterization of subsurface soil in urban areas is a major concern in geotechnical and geological engineering projects. In this regard, this research deals with development of a 3D geological engineering model on Mashhad City soil using Sequential Gaussian Simulation (SGS) approach. The intense variability of soil in the study area has sometimes caused serious problems in civil engi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تهران - دانشکده علوم اداری و مدیریت بازرگانی 1380

در ادراه امور سازمان نیز از تکنولوژی data base در دو زمینه مشخص یعنی بصورت سیستم های عملیاتی و سیستم های اطلاعاتی میتوان استفاده کرد. در شرایط کنونی وجود موانع متعدد از قبیل فرهنگ غالب در سازمان های بزرگ و طرز تلقی مدیران دیوان سالار از یکطرف و تازه گی و پیچیده بودن فنون مربوط به سیتم های data base فقدان دانش، تجربه و تخصص کافی برای بهره گیری کامل از آن از طرف دیگر، برنامه ریزی و اقدام برای ایج...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و زبانهای خارجی 1390

abstract the current study set out to address the issue as to whether the implementation of portfolio assessment would give rise to iranian pre-intermediate efl learner autonomy. participants comprised 60 female in pre-intermediate level within the age range of 16-28.they were selected from among 90 language learners based on their scores on language proficiency test -key english test. then, t...

Journal: :CoRR 2017
Elyas Sabeti Anders Høst-Madsen

Heart rate variability (HRV) is a vital measure of the autonomic nervous system functionality and a key indicator of cardiovascular condition. This paper proposes a novel method, called pattern tree which is an extension of Willem’s context tree to real-valued data, to investigate HRV via an atypicality framework. In a previous paper atypicality was developed as method for mining and discovery ...

2010
Abraham Otero Xosé Antón Vila-Sobrino Francisco Palacios Ortega Francisco J. Coves

This paper presents a new algorithm for the detection of Obstructive Sleep Apnea (OSA) from a single electrocardiogram lead. It is based on the alterations that OSA patients present in the LF and HF bands of the heart rate variability power spectrum. The algorithm calculates the power of the spectrum in two bands that roughly corresponding with the LF and HF bands. Then the ratio between the po...

Journal: :Expert Syst. Appl. 2008
Samjin Choi Zhongwei Jiang

This paper describes a long-term cardiorespiratory sensor system, which is supposed to be used for monitoring sleep condition at home environment. This system consists of belt sensor probe, data acquisition and communication devices, and the data processing algorithms. New wearable sensor probe with a couple of conductive fabric sheets material and a PVDF film material is developed. To obtain c...

2003
P. van Geert M. van Dijk

In accordance with dynamic systems theory, we assume that variability is an important developmental phenomenon. However, the standard methodological toolkit of the developmental psychologist offers few instruments for the study of variability. In this article we will present several new methods that are especially useful for visualizing and describing intra-individual variability in individual ...

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