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A method of determining levels of transport noise in the passenger sections of a railway car is offered, which will provide the necessary comfort level on noise. It is suggested to conduct classification of passenger sections of a car depending on the noise level., Предлагается методика определения уровней транспортного шума в пассажирских помещениях вагона, которые обеспечат необходимую комфортабельность (по шуму). Предлагается проводить классификацию пассажирских помещений вагона в зависимости от уровня шума., Пропонується методика визначення рівнів транспортного шуму в пасажирських приміщеннях вагона, які забезпечать необхідну комфортабельність (по шуму). Пропонується здійснювати класифікацію пасажирських приміщень вагона залежно від досягнутого рівня шума.

This paper reports the micromachining techniques for fabricating edge-suspended RF/microwave passive components, which are proposed to deliver enhanced performance without sacrificing their mechanical strength and reliability. The fabrication incorporates ICP-DRIE dry etching and TMAH anisotropic etching techniques, which are both CMOS compatible. The edge-suspended structures were realized by a TMAH solution consisting of 5 wt\% TMAH, 1.6 wt\% Si and 0.5 wt\% (NH4)(2)S2O8. This solution offers effective etching of silicon along the {100} and {110} planes, while having negligible etching on aluminum and {111} planes. The layout requirement for achieving edge-suspended passive components is also outlined on the basis of the analysis of the anisotropic etching along different crystal orientations. Using the techniques described here, high performance spiral inductors and coplanar waveguides (CPW) with significantly reduced loss are demonstrated. For a three-tum 4.5 nH inductor, a 70\% increase (from 6.8 to 11.7) in maximum Q-factor and a 57\% increase (from 9.1 GHz to 14.3 GHz) in self-resonance frequency are obtained with an 11 mum suspended edge in 25 mum wide lines compared to the conventional inductors without being micromachined. A 50 Omega edge-suspended CPW exhibits a reduction in insertion loss, from 2.4 dB mm(-1) in a conventional CPW to 0.4 dB mm(-1) at 39 GHz.

Polycrystalline silicon (poly-Si) thin film transistor (TFT) technology is very suitable for driving an active matrix LCD (AMLCD) panel as the driver circuit, and the panel can be integrated on the same substrate. This allows the entire display system to be thin and makes the concepts of `TV on wall' and `sheet computer' possible. However, the large variation of threshold voltage of poly-Si TFT across the wafer makes it difficult to obtain analogue amplifiers with constant gain and phase margin. In this paper, an analogue data driver for the poly-Si TFT AMLCD is proposed. An operational amplifier with a gate bias-voltage generation circuit for this analogue data driver, with characteristics independent of variations in threshold voltage, will be presented. In Hspice simulation, with threshold voltage varying from 2.5 V to 4.5 V, gain variations of the proposed amplifier were reduced from +/-10 dB to +/-0.2 dB and phase margin variations were reduced from 10degrees to 0.37degrees compared with typical operational amplifier design. This enables the analogue data driver for AMLCD to be implemented in poly-Si TFT technology.

A 9-month study of four relocatable school buildings, each retro-fitted with small reverse cycle air conditioners (ACs), was conducted to investigate their effectiveness in heating and cooling the classrooms. A comparison with data from previous studies found the energy used by the ACs for heating these temporary classrooms was only 19–20% of the energy used by individual gas heaters installed in permanent classrooms. When equipment efficiencies were considered, the AC units supplied 20–27% less energy to heat the classrooms. The possible reasons for this reduction in supplied energy are explored in this paper. CO2 emissions for the AC units in heating mode, however, were calculated to be 16% greater than for individual gas heaters. The AC units were also used for cooling and on an average the total annual energy consumption for heating and cooling was found to be 11.6 kWh m−2. Responses to a small survey of staff and students about the use and operation of the conditioners are presented. Their responses were more favourable than the predictions of comfort levels in the classrooms using the Predicted Mean Vote–Predicted Percentage of Dissatisfaction (PMV–PPD) model, which indicated “uncomfortable” conditions on average summer days at 3:00 p.m. and average winter days at 10:00 a.m. Background noise levels in the classrooms with the air conditioners in use were above the recommended maximum design level of 45 dB(A); levels of up to 65 dB(A) were measured.

Noise levels in the NUH-60 (Black Hawk) Aeromed Flight Simulator located at the U.S. Army Aeromedical Research Laboratory were measured. Noise levels were adjusted using a nine-position control set by the simulator operator. The simulator operator's manual stated that noise levels should not exceed 85 dBA. Measurements were made at five noise level settings at the pilot and copilot stations. Results showed that the A-weighted sound level of the flight simulator at Noise Level Setting 1 was 81.8 dBA while levels at Settings 3, 5, %, and 9 exceeded the 85 dBA noise exposure limit. In addition, the octave-band frequency spectrum of the simulator noise at Setting 9 differed appreciably from the spectrum of an actual UH-6OA aircraft. These differences were particularly large (exceeding 20 dB) in the upper frequencies in the speech range and should be considered before similar research involving communication or speech intelligibility is conducted. It is noted that noise hazard signs are posted appropriately at the entrance to the USAARL NUH-60 flight simulator in accordance with MIL-STD-1474D "Noise Limits". Hearing protective devices should be used in the simulator when operated at noise levels above the lowest noise level setting.

"At the request of the Hawaii Department of Business and Economic Development (DBED), ERCE undertook a limited information search and literature review to identify methodologies, criteria, case studies and governmental policies regarding determination of potential impact level thresholds near geothermal power plant developments (or similar facilities). Information regarding standards and criteria used in Hawaii was gathered, as well as projects and processes from elsewhere in the United States. Following consultation with DBED staff, ERCE prepared a brief scope of work. Principal tasks included internal discussions with other ERCE staff regarding potential sources of the desired information; contacts with knowledgable individuals outside the firm; and review of holdings of the University of California libraries related to topics of interest. The work to date cannot be considered complete. The topic is broad and interdisciplinary. However, we believe that the research has identifIed some useful information for discussion, as well as sources for further review. The information which follows is organized into five major topics: 1) air quality; 2) sound levels; 3) alternative project mitigation strategies; 4) recommended actions; and 5) references likely to contain applicable information regarding these issues. Environmental issues associated with geothermal development can span the entire spectrum of topics, including potential impacts to biological and cultural resources, visual impacts, increased traffic, interference with existing or proposed land uses, changes in sound levels, light & glare, water quality/quantity issues, and air quality changes. For this particular geothermal development, the key issues appear to be impacts to air quality, sound levels, human health and safety issues associated with those physical changes, and related interference with residential "quality of life." We have therefore focused our review on air quality and sound level considerations

The purpose of this study is to investigate and evaluate adaptive tracking filters for shipboard gun fire control systems that must defend against evasive targets. Several design concepts are compared using both tracking error and predicted position error as performance measures. The effects of target evasion, sensor measurement noise level, modeling uncertainties, and length of the measurement interval are investigated, and the trade-offs between performance and algorithm complexity are discussed.

U.S. Army Human Engineering Laboratory (HEL) Standard S-1-63C (September 1972) was the first design standard for noise in which all previous conflicts between U.S. Army medical guidelines and materiel design criteria were resolved. Its lineal descendent, MIL-STD-1474(MI) (March 1973), was the first design standard for noise in which all Army review activities concurred. This report treats the historical background of Army noise standards, the bases for the noise-limit provisions of MIL-STD-1474(MI), and considerations underlying the specified noise measurement procedures. Appendixes credit the many personnel involved, and an extensive list of references is provided.

This report is one of a series describing the research program undertaken by the Aerospace Medical Research Laboratory to develop procedures for predicting community noise exposure resulting from aircraft operations. This report outlines the acoustic measurement test conditions, the acoustic data reduction and interpretation procedures, and the type of aircraft performance information needed to obtain a noise data file for predicting the noise produced by aircraft operations. The procedures result in the descriptions of the noise of an aircraft in terms of the effective perceived noise level, the sound exposure level and several other noise measures. Level flight measurements and static engine noise tests are described, and are applicable to conventional fixed wing aircraft and helicopters., See also report dated Nov 74, ADA004822.

A method is set forth for predicting the acoustically induced structural vibration in transport category aircraft. Charts are presented which correlate third-octave random noise and vibration levels at various confidence levels, for the frequency range of 50 to 2500 Hertz. The prediction charts are based on measured data from modern transport aircraft and are presented for the normal direction, ground operation, and a reference structural mass and rigidity. Shell-type structure (fuselage, pods, fairings) and box-type structure (wing, horizontal/vertical stabilizer) are treated separately. Means are provided for predicting lateral and tangential vibration, vibration in pressurized cruise flight, and for correcting for changes in structural mass and rigidity. Application of the method to a hypothetical airplane design case is illustrated in an example., Appendix to rept. no. LG74ER0120.

The Air Force community noise prediction model (NOISEMAP) is used to describe the aircraft noise exposure around airbases and thereby aid airbase planners to minimize exposure and prevent community encroachment which could limit mission effectiveness of the installation. This report documents two computer programs (OMEGA 10 and OMEGA 11) which were developed to prepare aircraft flight and ground runup noise data for input to NOISEMAP. OMEGA 10 is for flight operations and OMEGA 11 is for aircraft ground runups. All routines in each program are documented at a level useful to a programmer working with the code or a reader interested in a general overview of what happens within a specific subroutine. Both programs input normalized, reference aircraft noise data; i.e., data at a standard reference distance from the aircraft, for several fixed engine power settings, a reference airspeed and standard day meteorological conditions. Both programs operate on these normalized, reference data in accordance with user-defined, non-reference conditions to derive single-event noise data for 22 distances (200 to 25,000 feet) in a variety of physical and psycho-acoustic metrics. These outputs are in formats ready for input to NOISEMAP. (Author), See also Rept. no. AMRL-TR-73-107 dated Aug 75, AD-A017 741.

The automatic loudspeaker control (ALC) senses ambient noise levels in a given space and automatically adjusts the loudspeaker output serving that space. This eliminates hazardous loudspeaker outputs in confined spaces and, more importantly, assures unimpaired reception of vital information. In addition to covering the design approach, system description, and planned system deployment, this report also provides a listing of ALC documents available from NOSC and appendices of the primary technical data and evaluations for the ALC.

This report presents the results obtained during the second quarter of the Communications-Electronics Intra-System Electromagnetic Interference Measurement Techniques and Instrumentation Project. The period covered was 21 Sep. 1979 to Dec 1979. The major efforts in the second quarter consisted of completing the IEMCAP feasibility study and developing a broadband measurement system for conducting EMC measurements. (Author)

This report establishes criteria and performance guidelines desirable in environmental noise monitors that are achievable through state-of-the-art technology. To assess this technology, the performances of 10 available units were evaluated based on the following points: (1) Data reduction methods and analytic results; (2) Dynamic range; (3) Impulse response; (4) Environmental considerations (temperature extremes and wind); (5) Shock resistance; (6) Ease of operation; and (7) Likelihood of errors in operation. Favorable and unfavorable features discovered during the investigation of these units are discussed, as well as desirable features found to be absent in all of the units. Based on the study and the conclusions, the operating characteristics of an ideal unit are recommended.

This is the second part of a program concerning noise certification for V/STOL and helicopter aircraft. Aspects considered were: an engineering calculation procedure which validly and reliably reflects annoyance to helicopter operations; estimates of noise exposure levels which could be compatible with human activities in areas surrounding heliports; noise exposure modeling for helicopter noise; certification measurement approaches for helicopter noise certification. The basics of the program involved human response evaluations of conventional takeoff and landing (CTOL) aircraft noise, simulations of helicopter noise emphasizing 'slap' or pulsating noise effects, and recordings of a wide variety of helicopter operations., See also report dated Nov 75, AD-A018 036.

An analysis is made of the noise reduction potential for the business jet aircraft fleet registered in the United States as of 1975. Noise characteristics of each aircraft are defined at various thrust levels and noise reductions achievable for different design options are determined. Costs and performance penalties are assessed for each option in order to evaluate the consequences of lowering present FAR 36 Appendix C noise levels. With current technology, the exhaust noise of all engines can be reduced significantly with multi-element nozzles, but the addition of a lined ejector provides little additional noise reduction at greatly increased weight and performance penalties. Acoustic liners in exhaust ducts reduce fan or core noise for some engines but inlet liners have little value. Equipping aircraft with new engines achieves major noise reductions but is technically and economically reasonable for only about twenty percent of existing business jet aircraft. To assess noise reductions, a single number criterion is proposed, based on the effective perceived noise level contour that circumscribes a two square-mile area. Also it is recommended that takeoff noise be measured at 2.5 nautical miles from brake release.

Noise increases the interference between colours and conflicting colour names. The interference increases with the time spent in the noise. This could be due to the overarousal produced by the noise, or to the perceptual isolation which the noise also produces. (Author)

The report presents a computer program which automates a vibration prediction method. Inputs to the program are estimates of fluctuating pressure levels in third-octave bands. These may be either sound pressure levels from the engines or the levels of aerodynamic flow turbulence. In addition, for new aircraft with structures which differ appreciably from contemporary transport designs, values of parameters which characterize the mass and rigidity of the new structure may be input to the program. Results are printed in tables of third-octave band accelerations, and optionally they may be plotted in graphical form. It is intended that this technical memorandum be used in conjunction with AFFDL-TR-74-74, Appendix I, as a quick and efficient prediction method for acoustically induced vibration in transport aircraft., See also report dated Sep 74, AD-A004 215.

This study provides results that contribute to establishment of airport noise levels that are compatible with residential living activities. Community noise simulation systems were placed in the homes of twenty-four families that were not impacted by actual airport noise. Four different airport noise conditions were simulated. Three conditions involved day flights of 150 aircraft with average Noise Exposure Forecast (NEF) values of 36.9, 32.5, and 26.9. The fourth condition added 18 night flights (10:00 PM to 7:00 AM) which resulted in a mean NEF of 32.9. Interference with daily living activities and annoyance responses to the four conditions were obtained. Some of the results and conclusions are presented.

The Aircraft Sound Description System (ASDS) is a method of describing aircraft noise. It has been established as the basic FAA technique for predicting community noise exposure caused by aircraft operations. This report (in four volumes) is a description of the manual and computer techniques for applying ASDS as well as a current set of noise exposure contours. This volume presents in tabular form a set of 239 ASDS noise exposure contours covering 51 different aircraft types. A description of the data tables and a statement of conditions and assumptions in developing the data are presented. The other volumes in the set are: Volume I, 'Overview,' Volume 2, 'Manual Application Procedures,' and Volume 4, 'Computer Application Procedures'. This document contains updated versions of the tables published in Report FAA-EQ-74-2, Volume 3, dated March 1974., Supersedes report dated Mar 74, AD-786 614. See also report dated Mar 74, AD-786 613.

Evaluation of noise generated by manually operated data processing machines was made. Noise levels were measured and a noise profile was constructed. No hazardous levels were measured, but there was interference with verbal communications. Techniques for noise reduction are presented.

Noise levels generated by T-37 aircraft were measured at Mather AFB CA while simulating various ground operations and during a flyover. These data were collected to assist in the evaluation of the impact of a proposed T-37 mission on base activities. Noise was recorded inside and outside selected buildings on base which were thought to be affected by these operations. Maximum levels encountered at each building are presented. Measured noise levels indicate little or no impact on base activities from noise generated during operation of T-37 aircraft. Where appropriate, recommendations for minimizing noise and suggestions for additional evaluations are made.

Calculation procedures to describe airplane noise during takeoff and approach have been programmed for batch operation on a large digital computer. Three routines are included. The first normalizes far-field noise spectra to reference conditions and then determines spectra at various distances from the airplane, for airport elevations between sea level and 6000 feet and ambient temperatures between 30F and 100F. Overall sound pressure levels, A-weighted noise levels, perceived noise levels, and effective perceived noise levels are calculated. The second routine uses aerodynamic and engine thrust data to produce takeoff and approach flight path description. Volume 4 describes the computer program and gives instructions for its operation., See also Volume 3, AD-A012 373 and Volume 5, AD-A012 375.

Calculation procedures to describe airplane noise during takeoff and approach have been programmed for batch operation on a large digital computer. Three routines are included. The first normalizes far-field noise spectra to reference conditions and then determines spectra at various distances from the airplane, for airport elevations between sea level and 6000 feet and ambient temperatures between 30F and 100F. Overall sound pressure levels, A-weighted noise levels, perceived noise levels, and effective perceived noise levels are calculated. The second routine uses aerodynamic and engine thrust data to produce takeoff and approach flight path description. Volume 5 describes the computer program and give instructions for its operation., See also Volume 4, AD-A012 374.

In recent years, noise from construction sites has been an increasing problem for the Corps of Engineers. This report introduces noise as a problem, how it affects man, and Army requirements for the prevention of excessive noise. With this background, sample specifications are prepared to control construction-site noise and the means established to monitor compliance. Finally, information is given on state and local noise regulations and on noise-mitigation techniques.

The objective for this noise study was to reduce the noise levels within the S-280 Shelter to an NC-55, using eight combinations of duct configurations with single and double environmental conditioning unit combinations operating in the high cooling mode. The second purpose of this noise study is to provide the project office with a series of alternate duct configurations to meet the requirements for different types of shelter arrangements.

As a means of determining the accuracy and reliability of engineering calculation procedures that could be utilized as a basis for noise certification of V/STOL commercial aircraft, 36 persons made annoyance judgments to 34 noise signals presented at 5 different levels. The signals included recordings of conventional jet aircraft operations, turboprop and reciprocating engine powered commercial aircraft, helicopter flybys, and simulations of V/STOL operations. Both relative annoyance and absolute acceptability judgments were obtained.

The stern-aspect radiated noise of the cycloidal-propeller-powered vessel Seacon was measured and compared with that of several conventionally powered array tow-ships used by the Navy. The radiated noise spectra of the Seacon ranged from 150 to 133 dB re 1 microns Pa/m-Hz over the frequency range 100 to 500 Hz for low-thrust conditions and 153 to 133 dB microns Pa/m-Hz over the same frequency range at full thrust (5.6 knots). The low-thrust conditions were characterized by a more pronounced line structure. For the high-thrust conditions the cavitation-noise background masked most of the lines. Above 150 Hz these levels are equivalent to those of other vessels for which no special quieting efforts have been made. Below 150 Hz the noise spectra of the Seacon continued to increase at about 6 dB per octave, whereas that of the other vessels typically remained constant or peaked and declined. This continued rise is attributed to the Seacon's cycloidal propulsion system. Vessels for which special quieting efforts had been made were 10 to 20 dB quieter. Because of its special maneuvering capabilities the Seacon and vessels like it should be considered first when choosing platforms where station-keeping ability and slow-speed maneuvering are important. The propulsion system of the M/V Acadian Navigator was apparently the most effective in reducing noise, and this type of vessel is recommended for array towing.

This report considers the effectiveness of current noise regulations in Appendix F of FAR Part 36, examines the potential effectiveness of future technology to achieve further noise reduction, and evaluates a number of new concepts for noise certification procedures for propeller-driven small aircraft. The latter were based, in part, on results of a flight test program carried out with Cessna Aircraft Company, to evaluate the utility of takeoff noise tests and the possible use of sound exposure level as a suitable metric for noise certification of the subject aircraft. The study indicates that existing regulations have been effective in stimulating development of quieter propellers for the existing fleet of propeller-driven small aircraft. However, it does not appear economically feasible to achieve more noise reduction in most of this fleet using existing technology with the possible exceptions of some of the two-engine aircraft. However, application of future noise reduction technology, primarily for quieter propellers, should allow a reduction in current noise limits by about 6 dB and should reduce levels of the noisiest aircraft in the current fleet by as much as 10 dB. A takeoff test is appropriate for all propeller aircraft except those equipped with cruise-optimized fixed-pitch propellers. For this test, the current level flyover test appears to represent the noisiest operating condition.

This report provides a description of the assumptions, methodologies and techniques employed in arriving at estimated sound levels for many of the aircraft included in FAA Advisory Circular AC-36-3B. AC 36-3B was published to provide the public and the aviation community with comparative sound level information for aircraft currently in use. Detailed noise estimation data sheets are provided for 78 aircraft types. A table showing the difference between EPNL and dB(A) for selected jet aircraft is also provided. (Author)

Taxiing noise measurements were performed at Atlanta Airport from December 10 to December 19, 1973. The measurement series included passby noise measurements of taxiing planes and ambient noise samples from the terminal roof and inside the terminal building. The primary purpose of these measurements was to determine whether changes in noise level result from shutting off some engines during taxiing for fuel conservation and air pollution reduction. After analysis of the noise data from this test series it was concluded that although the noise levels of individual planes on the taxiways were reduced by engine shutoff, the noise environment of the air terminal building was unaffected, because of the large distances from taxiways involved. (Modified author abstract)

The Aircraft Sound Description System (ASDS) is a method of describing aircraft noise. It has been established as the basic FAA technique for predicting community noise exposure caused by aircraft operations. This report (in four volumes) contains a description of the manual and computer techniques for applying ASDS as well as a current set of noise exposure contours. In this volume, a general introduction to the application procedures is presented. The material in subsequent volumes is described, and the required data preparation and basic methodology used in performing an ASDS application are presented. (Modified author abstract), See also Volume 2, AD-786 613 and report dated Mar 73, AD-758 588.

The Aircraft Sound Description System (ASDS) is a method of describing aircraft noise. It has been established as the basic FAA technique for predicting community noise exposure caused by aircraft operations. This report (in four volumes) is a description of the manual and computer techniques for applying ASDS as well as a current set of noise exposure contours. This volume presents computer application procedures for ASDS. A computer program package that implements the ASDS methodology is described. The package consists of a three program sequence which performs an ASDS analysis for a given scenario, and two data reduction programs which assist in analyzing the noise exposure data produced by the analysis sequence. Instructions for preparing the required input data and running the programs are presented with illustrative examples, and the various outputs produced by the programs are described. (Modified author abstract), See also Volume 3, AD-786 614 and report dated Mar 73, AD-758 588.

The Aircraft Sound Description System (ASDS) is a method of describing aircraft noise. It has been established as the basic FAA technique for predicting community noise exposure caused by aircraft operations. This report (in four volumes) is a description of the manual and computer techniques for applying ASDS as well as a current set of noise exposure contours. This volume presents the manual procedure for developing an Aircraft Sound Description System (ASDS) application in a step-by-step fashion. This procedure develops the aircraft noise exposure values and the 'Situation Index.' Data forms and pictorial layouts are used to illustrate the procedure. A sample application is presented to explain the details of each step. (Author), See also Volume 1, AD-786 612, Volume 3, AD-786 614 and report dated Mar 73, AD-758 588.

The efforts in this phase of the 'Aircraft Noise Definition' project was comprised of processing and analysis of existing acoustic and performance data and preparing acoustic and performance (based on average engine) graphical and computer presentations for two JT3D turbofan-powered DC-8s, one with short and one with long fan ducts; two DC-9s, one with JT8D-7 and one with JT8D-9 engines; and the DC-10-10 and DC-10-40 aircraft. The acoustic data included reference-day EPNL and peak A-weighted sound level curves with empirically developed curves for adjusting the noise levels to temperatures from 30F to 100F with the relative humidity held constant at 70 percent. The performance data include provisions for a temperature variation from 30F to 100F and runway altitude from sea level to 6000 feet. Data accuracy is described in terms of assignable confidence limits.

Excessive noise is a form of environmental pollution. The continual increase in the community noise level during the past two decades indicates a future noise problem comparable to the current air pollution problem of our large industrial centers. Trees and other forms of vegetation are known to have some effect on the transmission of sound but precise information on their use as noise screens is rather meager. In this study, we attempted to derive accurate, useful information for the above purpose, and to add to knowledge about outdoor sound propagation. Actual plantings of trees and shrubs in the form of shelterbelts and windbreaks on the Nebraska plains, and screen plantings of shrub-tree combinations within the city were studied.