نتایج جستجو برای: ratio of valley floor width to valley height vf

تعداد نتایج: 22181690  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند 1388

a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

Journal: :Physical review. B, Condensed matter 1989
Ping Jiang

Resonant tunneling of double-barrier quantum wells (DBQW's) affected by interface roughness has been investigated. Our results show that interface roughness induces oscillation resonant structure around the principal resonant peak. EA'ects of interface roughness on the resonant bias voltage, peak-to-valley current ratio, and the width of the principal resonant peak are also investigated. Temper...

2017
A. Kasprak F. J. Magilligan K. H. Nislow N. P. Snyder A. KASPRAK F. J. MAGILLIGAN K. H. NISLOW N. P. SNYDER

In‐channel large woody debris (LWD) promotes quality aquatic habitat through sediment sorting, pool scouring and in‐stream nutrient retention and transport. LWD recruitment occurs by numerous ecological and geomorphic mechanisms including channel migration, mass wasting and natural tree fall, yet LWD sourcing on the watershed scale remains poorly constrained.We developed a rapid and spatially e...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی خواجه نصیرالدین طوسی - دانشکده مهندسی برق و کامپیوتر 1391

power transformers are important equipments in power systems. thus there is a large number of researches devoted of power transformers. however, there is still a demand for future investigations, especially in the field of diagnosis of transformer failures. in order to fulfill the demand, the first part reports a study case in which four main types of failures on the active part are investigate...

2014
DAVID R. BRIDGLAND D. R. Bridgland

In his writings John Lubbock expounded views on the understanding of past climates, prehistoric faunas, early humans, and the evolution of landscape and river systems. His contributions on some of these related topics are scarcely remembered, despite comparison with modern thinking showing them frequently to have been prescient. He visited the Somme valley, observing river terrace gravels and P...

2000
Parviz Parto Keyue M. Smedley

A new passive Power Factor Corrector (PFC) based on Valley Fill (VF) is proposed for an off-line Flyback converter. By adding an extra winding which is magnetically coupled to the Flyback transformer and electrically coupled to the VF, higher Power Factor (PF) and lower Total Harmonic Distortion (THD) can be achieved. The proposed circuit uses a high frequency inductor, low voltage capacitors t...

2006
J. Bruce H. Shyu Kerry Sieh Jean-Philippe Avouac Wen-Shan Chen Yue-Gau Chen

[1] The Longitudinal Valley fault is a key element in the active tectonics of Taiwan. It is the principal structure accommodating convergence across one of the two active sutures of the Taiwan orogeny. To understand more precisely its role in the suturing process, we analyzed fluvial terraces along the Hsiukuluan River, which cuts across the Coastal Range in eastern Taiwan in the fault’s hangin...

Journal: :پژوهش های جغرافیای طبیعی 0
الهه شفیعی سید احمد علوی نصیر نادری میقان

introduction tectonic of binaloud mountain ranges is controled by thrust faults system and folds related to these faults. parts of this mountain ranges and neyshabour plain is as study area in north eastern iran and between latitudes 36° 11´ 00 to 36° 30´ 00 and longitudes 58° 35´ 00 to 59° 00´ 00. in this paper we first study morphometric indices in this area then analyze drainages and allovia...

2013
Jon D. Pelletier

[1] In this article, a method for drainage network extraction from high-resolution digital elevation models (DEMs; e.g., those derived from airborne laser swath mapping) is presented, which requires just two user-defined parameters and is capable of handling discontinuous valley networks. The accuracy and robustness of the method are illustrated using synthetic valley networks that mimic the co...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - دانشکده جغرافیا 1392

the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so...

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