A Model and Vibrational Analysis of a Dolphin’s Acoustic System

Author(s):  
Alec Dryden ◽  
Brianna Huhmann ◽  
Oscar Martin-Garcia ◽  
Shawn Duan

Abstract In this paper, a vibrational model of a dolphin’s acoustic system is presented. The working mechanism encompasses the dolphin’s lungs and nasal passage which hosts air pockets, the phonic lips, anterior and posterior bursae, the melon, lower jaw, and the brain. However, this study’s components of interest were the phonic lips, anterior bursa, and the surrounding muscle tissues. The phonic lips were modeled as rigid plates, surrounding muscles were modeled as springs, and the bursa was modeled as a damper. The chosen mechanical elements produced an underdamped system. There were two cases considered: a system in which the dolphin produces one click and a system in which the dolphin produces a series of clicks, called a click train. The former case is produced when the posterior phonic lip quickly and suddenly impacts the anterior phonic lip. Therefore, this was modeled as an impulse input. The latter case is produced when the posterior and anterior lip periodically engage one another. This was modeled as a sawtooth input. Using commercial computer software, a total of four different scenarios were considered, a healthy dolphin scenario and sick dolphin scenario for each input type.

2012 ◽  
Vol 203 ◽  
pp. 500-503 ◽  
Author(s):  
Yun Dian Zhang ◽  
Long Shen Han

Ultrasonic deicing is a new method of deicing. This paper analyzed and designed a kind of ultrasonic deicing acoustic system, then simulated it with the ANSYS, which is a kind of finite element simulation computer software used to do finite element simulation work. The results indicate that the frequency and mechanical properties of the acoustic system meet the expectant demand.


Author(s):  
Leo Barish

Although most of the wool used today consists of fine, unmedullated down-type fibers, a great deal of coarse wool is used for carpets, tweeds, industrial fabrics, etc. Besides the obvious diameter difference, coarse wool fibers are often medullated.Medullation may be easily observed using bright field light microscopy. Fig. 1A shows a typical fine diameter nonmedullated wool fiber, Fig. IB illustrates a coarse fiber with a large medulla. The opacity of the medulla is due to the inability of the mounting media to penetrate to the center of the fiber leaving air pockets. Fig. 1C shows an even thicker fiber with a very large medulla and with very thin skin. This type of wool is called “Kemp”, is shed annually or more often, and corresponds to guard hair in fur-bearing animals.


Author(s):  
G.Y. Fan ◽  
J.M. Cowley

In recent developments, the ASU HB5 has been modified so that the timing, positioning, and scanning of the finely focused electron probe can be entirely controlled by a host computer. This made the asynchronized handshake possible between the HB5 STEM and the image processing system which consists of host computer (PDP 11/34), DeAnza image processor (IP 5000) which is interfaced with a low-light level TV camera, array processor (AP 400) and various peripheral devices. This greatly facilitates the pattern recognition technique initiated by Monosmith and Cowley. Software called NANHB5 is under development which, instead of employing a set of photo-diodes to detect strong spots on a TV screen, uses various software techniques including on-line fast Fourier transform (FFT) to recognize patterns of greater complexity, taking advantage of the sophistication of our image processing system and the flexibility of computer software.


Author(s):  
F.A. Ponce ◽  
H. Hikashi

The determination of the atomic positions from HRTEM micrographs is only possible if the optical parameters are known to a certain accuracy, and reliable through-focus series are available to match the experimental images with calculated images of possible atomic models. The main limitation in interpreting images at the atomic level is the knowledge of the optical parameters such as beam alignment, astigmatism correction and defocus value. Under ordinary conditions, the uncertainty in these values is sufficiently large to prevent the accurate determination of the atomic positions. Therefore, in order to achieve the resolution power of the microscope (under 0.2nm) it is necessary to take extraordinary measures. The use of on line computers has been proposed [e.g.: 2-5] and used with certain amount of success.We have built a system that can perform operations in the range of one frame stored and analyzed per second. A schematic diagram of the system is shown in figure 1. A JEOL 4000EX microscope equipped with an external computer interface is directly linked to a SUN-3 computer. All electrical parameters in the microscope can be changed via this interface by the use of a set of commands. The image is received from a video camera. A commercial image processor improves the signal-to-noise ratio by recursively averaging with a time constant, usually set at 0.25 sec. The computer software is based on a multi-window system and is entirely mouse-driven. All operations can be performed by clicking the mouse on the appropiate windows and buttons. This capability leads to extreme friendliness, ease of operation, and high operator speeds. Image analysis can be done in various ways. Here, we have measured the image contrast and used it to optimize certain parameters. The system is designed to have instant access to: (a) x- and y- alignment coils, (b) x- and y- astigmatism correction coils, and (c) objective lens current. The algorithm is shown in figure 2. Figure 3 shows an example taken from a thin CdTe crystal. The image contrast is displayed for changing objective lens current (defocus value). The display is calibrated in angstroms. Images are stored on the disk and are accessible by clicking the data points in the graph. Some of the frame-store images are displayed in Fig. 4.


1997 ◽  
Vol 6 (3) ◽  
pp. 57-65 ◽  
Author(s):  
Lisa A. Wood ◽  
Joan L. Rankin ◽  
David R. Beukelman

Word prompt programs are computer software programs or program features that are used in addition to basic word processing. These programs provide word lists from which a user selects a desired word and inserts it into a line of text. This software is used to support individuals with severe speech, physical, and learning disabilities. This tutorial describes the features of a variety of word prompt programs and reviews the current literature on the use of these programs by people with oral and written language needs. In addition, a matrix that identifies the features contained in eight sample word prompt programs is provided. The descriptions of features and the matrix are designed to assist speech-language pathologists and teachers in evaluating and selecting word prompt programs to support their clients' oral and written communication.


Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Michael J. Egnoto ◽  
Darrin J. Griffin

Abstract. Background: Identifying precursors that will aid in the discovery of individuals who may harm themselves or others has long been a focus of scholarly research. Aim: This work set out to determine if it is possible to use the legacy tokens of active shooters and notes left from individuals who completed suicide to uncover signals that foreshadow their behavior. Method: A total of 25 suicide notes and 21 legacy tokens were compared with a sample of over 20,000 student writings for a preliminary computer-assisted text analysis to determine what differences can be coded with existing computer software to better identify students who may commit self-harm or harm to others. Results: The results support that text analysis techniques with the Linguistic Inquiry and Word Count (LIWC) tool are effective for identifying suicidal or homicidal writings as distinct from each other and from a variety of student writings in an automated fashion. Conclusion: Findings indicate support for automated identification of writings that were associated with harm to self, harm to others, and various other student writing products. This work begins to uncover the viability or larger scale, low cost methods of automatic detection for individuals suffering from harmful ideation.


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