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The challenges we are faced with in localizing objects are the complex environments, such as tunnels, high-rise areas and underground parking lots. This paper develops a bionic vibration source localization device to estimate the direction of the object which is inspired by the unique and precise hunting localization mechanism of scorpions. The localization device uses the sensor array, which is patterned after the scorpions’ biological sensory structure, and imitates the coding mode of scorpions’ sensory neurons for determination of the prey (vibration source) bearing. To verify the effectiveness of the localization device, some experiments were performed through real collected vibration signals. The Average Estimated Error (AEE) and the Relative Estimated Error (REE) of the experimental results were calculated to be 3.64° ± 2.44° and −1.43° ± 4.14°, respectively. It indicates that the device has a good performance to estimate the bearings of vibration sources at different distances and azimuths. This bionic localization device lays the foundation for the development of locating the moving object in some special conditions.

Vibrations propagating through the soil into the building can not only be harmful to the building structure or cause its accelerated wear, but can also effect on the vibrational comfort in the rooms. They can also be annoying for residents and building users, and in extreme cases can lead to sleep disorders, headaches and neurotic conditions. Especially vibrations from the low frequency range from 5 to 25 Hz are undesirable, because there are resonance frequencies of human internal organs in this frequency range. The human perception of vibrations in buildings, despite many researches made in the past, despite standards and requirements in this area, is still a topic not fully understood mainly due to the subjective nature of the perception of vibrations by various people. It is widely known that the type of transport vibration source has an impact on human perception. Vibrations generated by above-ground sources are more felt on the upper floors as opposed to vibrations generated from the underground. In this paper three types of transport vibrations are analyzed on one chosen building located in Warsaw. Human perception of vibration is evaluated according to two methods: root mean squared (RMS) and vibration dose value (VDV).

Harvesting energy from ambient vibration sources is challenging due to its low characteristic amplitude and frequencies. In this purpose, this work presents a compact hybrid vibration converter based on electromagnetic and magnetoelectric principles working for a frequency bandwidth and under real vibration source properties. The combination of especially these two principles is mainly due to the fact that both converters can use the same changes of the magnetic field for energy harvesting. The converter was investigated using finite element analysis and validated experimentally. Results have shown that a frequency bandwidth up to 12 Hz with a characteristic resonant frequency at 24 Hz and a power density of 0.11mW/cm3 can be reached.

Operational transfer path analysis is applied in this study to identify the vibration source and its critical transfer path. A simple analytical five-degrees-of-freedom mechanical isolation system is first taken as an example to illustrate the analysis flow and to validate the accuracy of operational transfer path analysis. The acceleration amplitude spectrum of the receiver is used to prove the accuracy, and the path contribution of each path is used to identify the critical path. Operational transfer path analysis is then applied to the cab mount system of a heavy commercial vehicle to identify the vibration source and its critical transfer path. The vibration energy propagation capabilities from the four cab mounts to the driver’s seat are analyzed by operational transfer path analysis with the path contribution analysis, and the maximum vibration source is identified by the path operation contribution analysis. The analysis and evaluation method of the operational transfer path analysis introduced in this study can provide a research foundation and reference for vibration or noise source identification in mechanical systems.

Operators of hand tractors are exposed to high levels of hand transmitted vibration (HTV). This vibration, which can be both irksome and hazardous to human health, is imparted to the operator via his or her hands and arms. However, a standardized method for measuring HTV of hand tractors has yet to be defined. The aim of the study was to present an experimental method for the investigation of the biodynamic response and vibration transmissibility of the hand-arm system during the operation of a hand tractor in a stationary mode. Measurements were performed with ten subjects using three grip forces and three handle vibration levels to examine the influences of the hand pressure and frequency on hand transmitted vibration (HTV). The results indicate that the tightness of grip on the handle influences the vibration response of the hand-arm system, especially at frequencies between 20 and 100 Hz. The transmission of lower frequencies in the hand-arm system was relatively unattenuated. In comparison, attenuation was found to be quite marked for higher frequencies during the operation of the hand tractor. The vibration transmissibility to different parts of the hand-arm system decreased with the increase of the distance from the vibration source. The proposed methodology contributes to the collection of consistent data for the evaluation of operator vibration exposure and the ergonomics development of hand tractors.

This study investigated the localization ability of an impulse vibration source outside the body in two-dimensional space. We tested whether humans can recognize the direction or distance of an impulse vibration source when using their hand to detect spatiotemporal vibrotactile information provided by the propagated vibrational wave from the source. Specifically, we had users put their hands on a silicone rubber sheet in several postures. We asked users to indicate the position of the vibration source when a location on the sheet was indented. Experimental results suggested that the direction of the impact vibration source can be recognized to some extent, although recognition accuracy depends on hand posture and the position of the vibration source. The best results were achieved when the fingers and palm were grounded and a vibration source was presented around the middle fingertip, and the directional recognition error in this case was 6 degree. In contrast, results suggest it is difficult to accurately recognize the distance of the vibration. The results of this study suggest a new possibility for directional display where vibrotactile actuators are embedded at a distance from the user's hand.

Machine-induced vibrations and their control represent, for several reasons, a crucial design issue for buildings, and especially for industrial facilities. A special attention is required, at the early design stage, for the structural and dynamic performance assessment of the load-bearing members, given that they should be optimally withstand potentially severe machinery operations. To this aim, however, the knowledge of the input vibration source is crucial. This paper investigates a case-study eyewear factory built in Italy during 2019 and characterized by various non-isolated computer numerical control (CNC) vertical machinery centers mounted on the inter-story floor. Accordingly, the structure started to suffer for pronounced resonance issues. Following the past experience, this paper reports on the efficiency of a coupled experimental-numerical method for generalized predictive and characterization studies. The advantage is that the machinery features are derived from on-site experiments on the equipment, as well as on the floor. The experimental outcomes are then assessed and integrated with the support of Finite Element (FE) numerical simulations, to explore the resonance performance of the floor. The predictability of marked resonance issues is thus analyzed, with respect to the reference performance indicators.

When the combat platform is running on the road at a constant speed, it will have different vibration responses due to the different speed and road roughness. Road excitation is the main vibration source of the vibration system of the combat platform. Obtaining accurate road information is the key to analyze and evaluate the impact of the combat platform system on the road. In this paper, based on the fitting expression of road power spectral density recommended by GB/T7031-2005 and Simulink simulation software, the simulation model of combat platform is established when it is moving, and then the time-domain response of 1/2 combat platform system dynamics model under road random excitation is analyzed. The influence of road roughness and running speed on the vibration response of platform body is analyzed. It provides a theoretical basis for the design and structure optimization of combat platform.

With the rapid development of urbanization and industrialization in modern society, the large-scale integrated hub must meet the seamless connection of various modes of transportation, thus the railway undepassing the airport terminal has become the main choice for engineering construction scheme. When the train under passes the airport, the vibration due to the wheel-rail excitation will affect the airport office area, commercial area and passenger waiting room in the terminal. With consideration of vibration source system, transmission process and vibration receiving body, this paper established the vehicle-track coupled model and the tunnel-soil-surface building integrated coupled model respectively to analyze the vibration characteristics of railway underpassing airport terminal as well as the effect of the corresponding vibration isolation measures.

The paper aims to summarize a modern approach to design of new or optimization of the existing vibration technologies, respectively. The optimization method consists of several necessary phases, which need to take place with utmost precision. In the first phase, a study of the current state of the solved problem is carried out along with analysis of the used bulk material performed as a measurement of mechanical-physical properties. Furthermore, a model of a new structural solution is designed and subjected to a number of simulation experiments using the DEM method. The parameters obtained from the performed simulations are used for manufacturing the vibration separator prototype including the design of a suitable vibration source. Operational tests of the vibration separator are carried out followed by putting the technology into operation.

The density of high-rise building is increasing over recent years in urban city. Construction activities, particularly piling processes, D-wall excavation, are paid attention due to ground borne vibrations. The impact of construction-induced vibrations on existing buildings is discussed in the past and so on. However, the impact of some special source such as grab shocking the Metro Line 3 (Hanoi) hasnot beenmentioned in literature. This paper evaluates the potential effect of ground vibrations induced by grab shock on sensitive existing buildings through field experiences, alsothe analytical closed-form formulation of construction-induced vibrations on existing building in Hanoi is proposed. This formulation is applied to investigate the construction-induced vibrations on existing building in Metro Line 3 project. This application is useful to control the grab drop length as well as the distance of existing building to vibration source.

Different researches have been conducted in order to make the interpretation of tissues belonging to different individuals carrying different characteristics. These investigations are generally based on vibration signals. In the studies in the literature, the vibration signals that usually appear in the vocal cords during speech are examined. However, there is no study on vibration signals recorded by applying any vibration source. The investigation of the frequency characteristics of the vibration source which has a fixed frequency on the tissues is of great importance both for the information about the tissue and the investigation of the related diseases. In this study, it is aimed to design the user interface to measure the vibration signals taken from certain distances to the vibration source applying vibration at a constant frequency to the living tissues determined on the human face and to analyze these vibration signals. The first part of the equipment consists of a motor and a drive part that provides vibration. Another part consists of accelerometer sensors and drives in MEMs structure which enable the detection of vibrations at certain points of the face region. The control of the hardware is carried out with a microcontroller-based module. With the help of this designed device, it is thought that vibration signals from living tissues can help soft and hardness interpretation of related tissues and body conductivity interpretation of related tissues can be done in future studies.

In this study we propose a novel method for drone surveillance that can simultaneously analyze time-frequency responses in all pixels of a high-frame-rate video. The propellers of flying drones rotate at hundreds of Hz and their principal vibration frequency components are much higher than those of their background objects. To separate the pixels around a drone's propellers from its background, we utilize these time-series features for vibration source localization with pixel-level short-time Fourier transform (STFT). We verify the relationship between the number of taps in the STFT computation and the performance of our algorithm, including the execution time and the localization accuracy, by conducting experiments under various conditions, such as degraded appearance, weather, and defocused blur. The robustness of the proposed algorithm is also verified by localizing a flying multi-copter in real-time in an outdoor scenario.

Traditional researches concerning the damping mechanisms of materials are limited to the phases and structures of materials, ignore the damping-related characteristics of the vibration source and of the materials themselves, and thus have great one-sidedness. This paper combines vibration science and material science on the basis of the models of mechanical vibration. Based on summarizing existing damping mechanisms, it proposes three mechanisms of damping: wave-type, particle-type and molecular force-type. By considering the macroscopic morphology of materials and the structures of molecules composing materials, it provides a guideline for preparing damping materials and studying their performance. Drawing on various research results, it also presents some inference based on available theories, creates a new perspective for researching damping mechanisms, and thus it is of high reference value for future research.

Monitoring the underground pipeline to prevent the illegal intrusion is a quite important work for civil infrastructure security management. The distributed fiber optic sensing technology nowadays has been widely used in the monitoring. Meanwhile, it also suffers from a relatively high false alarm rate. To tackle the difficult problem of false alarms, the paper develops a short range lateral positioning method of vibration source based on ultra-weak fiber Bragg grating vibration sensing array. Two parallel fiber optic cables are required to be deployed at the both sides of the pipeline. The positioning algorithm establishes a least square misfit function between the predicted and observed travel time difference based on the double-cable data. By systematically searching through the possible lateral distance in a selected range, an optimal distance can be identified according to the minimal misfit value. The tests on synthetic and field data validate the effectiveness of the proposed method.

The vibration prediction model of the key vibration source points of a vehicle platform is studied. Starting from the analysis of the factors affecting the vibration response and the correlation analysis, the key factors affecting the vibration response of the same vehicle structure are sorted out. The vibration prediction model of the key vibration source points is established by using neural network, and using the measured data to verify the accuracy of the vibration prediction model of the cabin section I, cabin II and cabin III of the platform. The results show that in the frequency range of 1∼500Hz, the maximum error of root mean square of cabin I is 2.75dB, that of cabin II is 2.3dB, and that of cabin II is 2.97dB.

Bladder volume is an important and useful indicator to accurately diagnosis urinary diseases. Using the mechanical probe with single vibration source to estimate bladder volume is low-priced and portable. It also contains fast computation speed and low requirements to operators. However, the bladder volume estimated by this kind of probe will be influenced by improper scanning positions. To address this problem, we propose two localization approaches. One is based on geometry method, which has fast computation speed and high accuracy. The other one is based on neural network method, which contains high robustness and stable experiment results. After applying these two approaches to the standard phantom environment and human environment, we get a conclusion that the proposed approaches can effectively decrease the bladder volume estimation error caused by improper scanning positions.

The objectives of this article were to review the literature on endodontic procedures published in various journals during the last two decades. The various obturation techniques, viz. single -cone technique, multiple-cone technique, chemo-plasticized gutta-percha, thermo-plasticized injectable gutta-percha, obturation using pastes, and SPAD/resorcinol formaldehyde, have been described and compared. The various methods used for qualitative and quantitative evaluation of micro-leakage, viz. micro-computed tomography, radiography, CT scans, cone-beam computed tomography, scanning electron microscope, fluid filtration method, dye penetration test, and bacterial leakage technique, have been described and studied by various researchers. The consultation with endodontic experts indicates that substantial improvements can be recommended on obturation procedure, and also, a few modifications may be required in obturation devices from productivity as well as ergonomics point of view. A total of 250 research papers and patents (19 Nos) have been shortlisted for conducting literature survey. The shortlisted paper was classified into various categories, viz. root canal obturation techniques (63 Nos), micro-leakage evaluation techniques (80 Nos), and root canal obturation sealing ability (75 Nos), root canal obturator design (36 Nos), and root canal geometrical parameters (25 Nos). The following statements are deduced from the above literature survey: (1) End outcome of the comparison of the various techniques revealed that warm vertical condensation is the best technique. (2) Consultation with the experts revealed that there is a need of obturator device which combines heat and vibration source. (3) The fluid filtration is the best technique as compared to other experimental techniques. Micro-computed tomography is the best qualitative and nondestructive technique. (4) There is a need for the development of an analytical model which can quantify the root canal obturation.

Preservation of historical buildings is a main challenge in civil engineering field. One of the main concerns in this regard is metro induced vibration received by historical structures. There is a need to evaluate effectiveness of vibration mitigation measures in preservation of monumental buildings. The most widely used method of reducing metro vibrations is changes in the structure of the vibration source (not sufficiently investigated in the literature). In response to this need, effectiveness of track stiffness reduction in mitigation of vibration was investigated in this research. Comprehensive field tests were conducted in the Iranian metro lines. The track stiffness as well as the induced vibrations were measured. It was shown that track stiffness has noticeable role in the track levels of vibration, and in turn in metro vibration reduction. The amounts of vibration reduction were derived as a function of track stiffness reduction.

This study proposes a concept of vision-based vibration source localization that can extract objects vibrating at hundreds of Hz with pixel-level accuracy using images captured at an undersampled frame rate that is much lower than the vibration frequency. We discuss how to determine the minimum frame rate of undersampled images so that different vibration frequencies, including DC background components, are separable when the vibration frequencies are larger than the Nyquist frame rate of the images. By executing short-time Fourier transforms for brightness signals at all pixels, we demonstrate the performance of vibration source localization using undersampled images when observing flying multicopters with propellers rotating at hundreds of Hz.

This paper focuses on the experimental vibration analysis of the small-scale unmanned helicopter and the methods to weaken the influence for control design. The vibration source of the small-scale helicopter and the evaluation criteria are introduced. The influence of the main blades dynamic balance on vibration is analyzed and the way to decrease is presented; based on frequency domain analysis technology, the influence of the main rotor speed is well-analyzed and the method to optimize the rotor speed is proposed. The experimental results show that the analysis and the methods are effective and suitable for vibration reduction.

Summary JSC Bashneftegeofizika, the largest domestic oilfield services company with more than 85 years of history, is a group of high-tech companies that specialize in performing a wide range of geophysical research to develop and operate oil and gas fields. Due to the wide spread of the idea of import substitution, Bashneftegeofizika JSC set itself the task of creating a domestic source of excitation of a seismic vibration signal, which by its characteristics will not be inferior to foreign analogues. Technical capabilities of our company allowed us to develop and launch our own vibrating installations “Batyr”. The tests performed showed the results corresponding to the task in hand.

Compressors are an essential component in Gasco's plants that transfer enormous energy to process fluids in the form of pressure and velocity. Conventional process and piping design are based on consistent / steady operating parameters and at times designers overlook the possibilities of sudden changes in process parameters. Operating conditions are sometimes altered as part of capacity/performance enhancements. These changes result in difference between design and operating conditions of the compressor which can also impact associated piping systems. In one of Gasco's plants, abnormal vibrations upstream of anti-surge valve piping at Expander-Compressor, were observed. Sustained vibrations are a threat to critical inline instruments and mechanical components thereby posing integrity risk and potential Loss of Process Containment (LOPC). LOPC can have significant impact not only to process, personal and environment safety but could also lead to production loss with impact on business and reputation. This paper addresses the study carried out to identify the root cause of vibration, and the remedial measures recommended and implemented to mitigate the risks due to piping system vibration. An exhaustive multi-discipline investigation was carried out comprising of site visits, data collection, detailed review of existing documentation, as-built conditions and current operating parameters. Process and control system review did not indicate any abnormalities. In addition, piping vibration induced due to compressor or anti-surge valve operation was ruled out as cause based on design review of anti-surge valve and expander compressor/turbine. Piping system review concluded that inadequate pipe supporting was the primary reason for piping vibration. Comprehensive Stress Analysis (static and dynamic) was conducted to determine the modifications required to mitigate vibrations. The stress analysis accounted for actual operating cases in addition to the design conditions. Based on stress / vibration analysis, pipe support modifications were proposed to make the piping system adequately rigid and minimize vibration. This resulted in increase of system's natural frequency while ensuring that the stresses are within permissible limits. Proposed modifications were designed for implementation without the need for shutdown. Post implementation, piping Vibration were reduced drastically and were found to be within acceptable limits specified in Energy Institute guidelines. This has resulted in increased personnel safety, reduced environmental and operating risks, reduced downtime and failures, and preservation of company assets and reputation. Due to the criticality of the process / equipment and non-availability of near term shut-down window, the main challenge in this exercise was to provide modification solutions which can be implemented while the compressor / plant is online. Innovative approach to design of support system utilizing in-house expertise, and continuous support during implementation are key takeaways from this project.

To assess the vibration influence of punching machine to surrounding buildings, a field test is carried out in a certain mold punching company. After analyzing the intensity of vibration source, Z vibration level (VLZ) and other indicators, the vibration comfort of the buildings is evaluated according to the requirement of standards. Their results show that the operation of the punching machine causes the vertical vibrations in second and third floors for a three-story lightweight steel construction which is 75 m far from the punch machine to be out of limits while the ground floor not. And then they make the staff of these floors uncomfortable. It is indicated that the influence of punching machine to the light steel structure building should be taken into consideration the location, and if necessary, countermeasures should be taken to reduce such effects.

The context of the paper is the need across many industries for prediction and simulation of vibro-acoustic response of assembled structures. One of the main areas of difficulty is to know the excitation forces. The blocked force method allows vibration sources to be characterised independently using conventional measurements similar to those used in Transfer Path Analysis (TPA). A major advantage is that the blocked force data remains valid when for example the same vibration source is attached to different receiver structures. It is shown how measured blocked forces can be validated using an ‘on board validation‘ procedure. Progress in the standardisation of the blocked force method is also described. The question is then considered of how this blocked force data can be fed into vibro-acoustic models to provide realistic excitation and response prediction. It is shown that a substucturing step is needed in which the passive properties of the source and receiver structures are combined. Examples are presented to demonstrate that this substructuring step can be a source of significant error and ways of minimising the errors are discussed.

In this paper, we study the train-induced vibration recorded by seismographs during our experiment in May 2004 in Yanzhou, Shandong Province by means of Source-Scanning Algorithm (SSA). The result shows that there are 3 distinct nest-shaped fine structures made by the movement of train during three very short periods. We get three vibration source images by piecewise separation. The images show that the train is heading forward from NW to SE when passing through this district. The example convinces us that the source of train can be dealt with as a lot of separate little vibration sources by means of some suitable pretreatment. It also shows the potentials of SSA in dealing with the data lacking seismic phases like this.

In this paper we present a novel approach of realizing a safe, simple, and inexpensive sensor applicable to pigmented lesions detection. The approach is based on temporal tracking of back-reflected secondary speckle patterns generated while illuminating the affected area with a laser and applying periodic pressure to the surface via a controlled vibration source. When applied to pigmented lesions, the technique is superior to visual examination in avoiding many false positives and resultant unnecessary biopsies. Applying a series of different vibration frequencies at the examined tissue and analyzing the 2-D time varying speckle patterns in response to the applied periodic pressure creates a unique signature for each and different pigmented lesion. Analyzing these signatures is the first step toward detection of malignant melanoma. In this paper we present preliminary experiments that show the validity of the developed sensor for the classification of pigmented lesions.

Signals from skin-mounted accelerometers may contain measurement error when compared to those obtained from bone-mounted sensors. While this error may be minimized through various techniques, additional error may arise as a result of accelerometer removal from the skin and subsequent replacement. The purpose of this experiment was to determine if skin-mounted accelerometer signals remain similar before and after sensor replacement when sensors are stimulated within a consistent vibration environment. The spines of five porcine and five human cadavers were vibrated non-invasively and the resulting response measured using accelerometers glued to the skin overlying the vertebrae of interest (T-9 in porcine cadavers, L2-L4 in human cadavers). Accelerometers were removed, then replaced, to their perceived original positions. Accelerometer signals showed high repeatability within an original placement, however, once replaced, pre- and post-replacement signals were statistically dissimilar in all cadavers tested. Specifically, the similarity of pre- and post-replacement signals was poor for different skin types (porcine and human) and did not improve with accelerometer proximity to the vibration source. From these data, we conclude that accelerometers adhered to the skin overtop spinous processes are able to obtain highly repeatable signals for a given placement, however, signals change significantly after sensor replacement. When skin-mounted accelerometers are used in gait and other studies, investigators should consider performing test/re-test analyses to ensure that sensor data are not affected if sensor replacement is required by design or by accident.

Near field authentication is of great importance for a range of applications, and has attracted many research efforts in the past decades. Several approaches have been developed and demonstrated their feasibility. The state-of-art works, however, still have much room to improve their automation and usability. First, user assistance is required in most existing approaches, which will be easily observed and imitated by attackers. Second, the authentications of several works heavily depend on special hardware, e.g., Server or high resolution screen, which greatly restricts their application scenarios. In this paper, we present a near field authentication system Tooth that needs little human assistance and is compatible with most smart phones. ToAuth is based on the key insight that the acceleration traces are similar for a pair of smart phones when they are contacting physically and vibrating. The random vibration patterns are sufficiently uncertain to provide high entropy to generate a pair of cryptographic keys yet are inimitable for a third party who does not get in touch with the vibration source. ToAuth leverages the keys to make authentication for smart phones. We implement ToAuth on Android platform and evaluate its performance under various scenarios. Extensive experiments demonstrate ToAuth could achieve around 90% success rate in stable environment, and prevent attacks depended on vibration noise.

The complex vibration source identification of structure in the vibration analysis and control is an important aspect that people pay more attention. First, the complex vibration system of structure is divided to several related subsystem each other in the paper. The model of subsystem-input/single-output system is established. The correlations between inputs and the model after average process in multi subsystem-input system are developed. The value changes of correlated input matrix and the affecting to the output in various relevant condition of subsystem-inputs are analyzed. According to coherence analysis, the method to estimate the contribution of inputs to the output is obtained. And the accuracies of method are verified by simulation. Finally, the vibration data are given by an automobile test. After the data analysis, the usefulness of new method provided in the paper is verified.

Studies have shown that applying a vibration of certain frequencies and intensities on the tooth can accelerate tooth movement, thus shorten orthodontic treatment duration. The optimal frequency may be related to the natural frequency of the tooth-periodontal ligament(PDL)-bone complex (TPBC), therefore we designed a vibrating device which can measure the natural frequency of the TPBC, and produce vibration load with customized frequencies and intensities. This device consists of four parts, vibration source, vibration frequency modulator, vibration amplitude modulator, natural frequency measurement module. To optimize the vibrator's design, specifically structure and natural frequency, static analysis and modal analysis were both made. The application method of the vibrator is also introduced. The designed vibrator can customize vibration load and obtain the natural frequency of TPBC, and it will be used for experiments to obtain the relation between the optimal frequency and the natural frequency of TPBC.

For the prediction and control of vibration and structure-borne noise generated by various kinds of machinery and equipment installed in buildings, it is necessary to know the vibromotive force of the machinery. It seems to be necessary to standardize the method for determination of vibromotive force. This method should not only have sufficient accuracy, but also be simple as much as possible and applicable to the field measurements. In order to be fullfilled these requirements, we have put the main point on the development of substitution method, and basic studies on the important subjects of this method were carried out. In this paper, the important results are described.

By analysis on all kinds of the vibration source and noise mechanism, this paper points out the vibration and noise harm, cause and source of the hydraulic hoist hydraulic system. Further more it puts forward to effective and specific measures to reduce the vibration and noise of the hydraulic hoist hydraulic system which can also be widely applied to vibration and noise control of other hydraulic system. Keywords-Hydraulic system; Vibration; Noise; Control measures

Prediction of ground vibration amplitudes and their comparison with legislative values is a frequent engineering task. Different methods for prediction of ground vibration amplitudes exist: (1) Empirical methods are widely used in practice (as shown later in this chapter) and are based on available attenuation relationships of measured ground vibration amplitudes with distance from the source. Problem with their use is that the existing attenuation relationships may not be available and if they are then complementary data about ground condition and vibrating source to which they apply may not be specified so that it is difficult to assess their relevance to a problem at hand. (2) Simplified analyses can always be used but they require knowledge of properties of vibration source and of ground conditions, which may not be available in part or in total. (3) Numerical analyses are expected to provide accurate solutions of the problem but they require the use of proprietary software (e.g. listed in http://www.ggsd.com), expertise in its use and frequently detailed ground properties. Lack of expertise and/or detailed ground properties affect the accuracy of the results of numerical methods. (4) Small and full scale testing is most convincing method for assessment of future ground vibration amplitudes but requires the use of a specialist laboratory or field instruments and the expertise. Therefore, the testing is not so frequently used in practice.

For the most common rotating machinery problems, vibration analysis is usually a straightforward procedure. The primary vibration source is often estimated by using only vibration amplitude and frequency data. However, with the high cost of today’s machinery and the even larger investment in plant processes, an “estimate” of the machinery problem is not good enough. In order to increase the accuracy of vibration analysis decision making, other measurement parameters must be used. This paper will present some of the lesser used techniques by way of machinery case histories.

An integrated reception‐plate inverse‐force method for vibration power and force transmitted from a mounted vibration source measurement has been prototyped and evaluated. The tests developed data to aid in understanding the repeatability and reproducibility of the method, which is necessary as these methods are integrated into industrial noise control design applications. The reception plate has many advantages such as mounting structure mobility matching, simple source‐receiver dynamics and inexpensive reproducible test setups. The inverse force method has the advantage estimating of the blocked force characterization in situ. Implementing the inverse method on a reception plate allows the use of a common set of accelerometers measurements. The accelerometers measurements are processed for plate flexural response to estimate input power using reception plate methods and transfer mobility measurements for the blocked force characterization method. The goal of this work is to development of an industrial engineering‐tolerance cost‐effective, vibration source characterization method for the specification of acceptable source levels of equipment.

One embodiment of the present invention provides a system that mitigates the effects of multiple vibration sources on a set of hard disk drives (HDDs) within a computer system. During operation, the system identifies a target HDD in the set of HDDs, wherein the performance of the target HDD is affected by mechanical vibrations. The system also identifies one or more primary vibration sources from the multiple vibration sources that affect the performance of the target HDD. Next, for each of the primary vibration sources, the system measures a first time-domain signal associated with the operation of the primary vibration source using a first vibration transducer associated with the primary vibration source. The system also measures a second time-domain signal associated with the target HDD using a second vibration transducer associated with the target HDD. Next, for each of the primary vibration sources, the system then computes a cross-power-spectral-density (CPSD) between the first and the second time-domain signals. The system then selectively mitigates the primary vibration sources based on the CPSDs between the primary vibration sources and the target HDD.

Vibration noise control is of great significance to submarines. Vibration and noise source analysis methods that are commonly used only analyze the sources of vibration and noise, but sources contributions of submarine equipments are not calculated quantitatively. The basic model of blind source separation (BSS) and an improved fixed-point algorithm based on independent component analysis (ICA) are introduced, and the performance of BSS is improved by means of clustering evaluation. A new method to calculate the source contributions quantitatively based on the improved algorithm and priori information is proposed. The performances of BSS methods based on different separation criteria are compared in the simulations, and the result of sources contributions is analyzed. The new method is applied in quantitative calculation of vibration source contributions of a scaled submarine model, and the comparative result shows that it has high calculation accuracy. The conclusions provide a reliable evidence for the active control of vibration noise.

Diagnosing operation of an impulse piping line in an industrial process is provided. A vibration source transmits a vibration signal through the piping and a vibration signal receiver receives the vibration signal. The operation of the impulse piping line is diagnosed, such as failure or impending failures, based upon the received vibration signal.

A vibration source driving device that realizes various vibration functions on portable telephones. The vibration source driving device includes a sound source for generating musical tone signals in response to music data. A vibration source to generate vibration, a driver to drive the vibration and a control circuit are further included such that the vibration source may be driven in synchronization with the rhythm signal within the music data.

A vibration isolation device for isolating a vibration source from a carried member, includes: a carrier for carrying the carried member; a housing positioned on the vibration source, and formed with an accommodating space; a cover for sealing an open end of the housing; a base mounted in the accommodating space, and extended through the cover to be connected to the carrier; a plurality of connecting members mounted in the accommodating space and around the base, wherein each of the connecting members is connected to the base and the cover; and a plurality of actuators provided in the connecting members respectively, for changing vibration of the connecting members and the base when the vibration source vibrates, so as to minimize vibration of the carrier, thereby achieving the effect of isolating vertical and horizontal vibrations.

A vibration isolator (10) with an adjustable response. A vibration isolator for isolating a vibration source from a support structure includes a base (14) in engagement with the support structure and two supports (16) connected to the base. At least one of the supports is slidably connected to the base. A flexible member (18) having a generally elongate shape and an elongate length is supported by the two supports. The flexible member is attachable to the vibration source. Each support slidably engages the flexible member such that the flexible member can move relative to each support with the support that is slidably connected to the base being moveable along the elongate length of the flexible member. The vibration isolator preferably further comprises means (42) for moving the slidably connected supports along the elongate length of the flexible member. The means for moving the slidably connected supports may be selected from a rotating shaft system, a piezoelectric actuator system, a hydraulic system, a system of racks on a common pinion, a cam bearing system, mechanical linkage systems, or mechanical cable systems. The moving means may be automated to respond to vibration occurring in the system in order to optimize the vibration isolation of the vibration isolator.