نتایج جستجو برای: noise measurement

تعداد نتایج: 620940  

احمدی, سعید, لطفی, معصومه, منصوری, نبی الله, منظم, محمدرضا,

Introduction: Using diesel generators is necessary for activities like welding in construction sites and it is often accompanied with noise pollution. The aim of this study was to evaluate noise pollution induced by diesel generators in construction activities in one of the districts of Tehran city.   Material and Method: In this descriptive study, 14 construction sites were selected for th...

ژورنال: علوم زمین 2018
Hamid Reza Siahkoohi Hanieh Mardomi Mir Sattar Meshinchi Asl

Magnetotellurics is an exploration method which is based on measurement of natural electric and magnetic fields of the Earth and is increasingly used in geological applications, petroleum industry, geothermal sources detection and crust and lithosphere studies. In this work, discrete wavelet transform of magnetotelluric signals was performed. Discrete wavelet transform decomposes signals into c...

Journal: :iranian journal of public health 0
dian darina indah daruis norazmira wati awang baba md. deros ahmad rashdan ismail

background: sound produced by the passing traffic contributes to noise pollution. noise pollution affects the residents of both city and suburban areas. the noise produced does not only disturb the community living nearby the main road during the day but becomes worse during the night. the purpose of the study is to perform noise level measurement and subjective evaluation on the noise produced...

آزادی, نمامعلی , ساقی, محمد حسین , صادقی, شهرام ,

Background: One of the critical unit in each hospital is intensive care unit (ICU). The United States’ Environmental Protection Agency (EPA) recommends to control the noise level of this unit in order to not exceed 45 decibels (dBA) during the day and 35 dBA at night. In this study, our goal was to evaluate the noise level at adult and neonatal ICUs at some Sanandaj’s hospitals, Iran. Methods:...

2015
Zhifei Zhang

The report surveys the evolution of image denoising techniques from the perspectives of detection, measurement, and removal. Since noise detection and measurement are intrinsically the same, we focus on the discussion of noise measurement and noise removal techniques. For noise measurement approaches, we survey filter-based, block-based, and wavelet-based, as well as other important achievement...

Journal: :jundishapur journal of health sciences 0
sahar geravandi department of nursing, tehran medical sciences branch, islamic azad university, tehran, ir iran afshin takdastan environmental technologies research center, department of environmental health engineering, health faculty, ahvaz jundishapur university of medical sciences, ahvaz, ir iran elahe zallaghi department of environmental, khouzestan sciences and research, islamic azad university, ahvaz, ir iran mehdi vousoghi niri department of environmental health engineering, health faculty, ahvaz jundishapur university of medical sciences, ahvaz, ir iran mohammad javad mohammadi department of environmental health engineering, health faculty, ahvaz jundishapur university of medical sciences, ahvaz, ir iran; department of environmental health engineering, health faculty, ahvaz jundishapur university of medical sciences, ahvaz, ir iran. tel: +98-9355439707 hamed saki department of environmental health engineering, health faculty, ahvaz jundishapur university of medical sciences, ahvaz, ir iran

conclusions according to the results of this study, with increasing load of traffic, there is an increasing need for proper consideration plans to control noise pollution and prevent its effects. results according to the research findings, the equivalent sound pressure levels in all stations were 76.28 ± 3.12 db (mean ± sd). according to sound measurements and the survey questionnaire, noise po...

In this paper, a novel method based on a combination of Extended Kalman Filter (EKF) with Self-adaptive Differential Evolution (SaDE) algorithm to estimate rotor position, speed and machine states for a Permanent Magnet Synchronous Motor (PMSM) is proposed. In the proposed method, as a first step SaDE algorithm is used to tune the noise covariance matrices of state noise and measurement noise i...

H. Shahbazi S. Mirzaei Y. Norouzi,

Instantaneous Frequency Measurement (IFM) devices are the essential parts of anyESM, ELINT, and RWR receiver. Analog IFMs have been used for several decades. However, thesedevices are bulky, complex and expensive. Nowadays, there is a great interest in developing a wideband, high dynamic range, and accurate Digital IFMs. One Digital IFM that has suitably reached allthese requirements is mono-bi...

Journal: :تحقیقات نظام سلامت 0
نگار جعفری دانشجوی کارشناسی ارشد، کمیته تحقیقات دانشجویی، مهندسی بهداشت محیط، مرکز تحقیقات محیط زیست، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران بیژن بینا استاد، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران سهیلا مرتضایی کارشناسی ارشد، مهندسی بهداشت حرفه ای، کارشناس آزمایشگاه گروه بهداشت حرفه ای، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران افشین ابراهیمی استادیار، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران علی عبداله نژاد دانشجوی کارشناسی ارشد، کمیته تحقیقات دانشجویی، مهندسی بهداشت محیط، مرکز تحقیقات محیط زیست، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران

background: to prevent the adverse health effects of noise pollution and to achieve the recommended standards, assessment of noise levels in the cities is essential. the aim of this study was to evaluate noise pollution levels (npls) in isfahan, iran and compare them with recommended standard values. materials and methods: a total number of 19 measurement points were selected from most congeste...

M. H. Haji Mirsaeidi, Sh. Mohammad Nejad,

In this paper altitude measurement from water surface using laser beam is presented. Research data indicate that the reflection of infrared waves from water surface is about zero and it is less than 2% for visible radiations. Phase-shift and heterodyne technique was used for the measurement, and the laser beam ( mW p nm 10 , 700 = = l ) was modulated by a sine wave having a fixed frequency....

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید