• Title/Summary/Keyword: sound track

Search Result 83, Processing Time 0.023 seconds

A Study on Elementary School Teachers' Understanding of, Certainty in, and Familiarity with Wave Concepts in Textbook and Teacher's Guidebook (교과서와 교사용 지도서에 제시된 소리의 성질 단원의 파동개념에 대한 초등 교사들의 이해도, 확신도와 친숙도 분석)

  • Jeong, Jaehun;Lee, Jiwon;Kim, Jung Bog
    • Journal of Korean Elementary Science Education
    • /
    • v.35 no.4
    • /
    • pp.389-405
    • /
    • 2016
  • The purpose of this study was to analyze elementary school teachers' understanding, certainty, and familiarity with 13 key concepts of wave physics that are presented in textbook and teacher's guidebook. 123 elementary school teachers answered concept tests and questionnaires. In the results to these tests and questionnaires, teachers demonstrated a high level of understanding and high certainty in understanding with regard to the concepts of sound generation, effect of medium on wave, timbre, wavelength, and trough and crest of wave. For the topics of sound velocity, wave reflection and wave transmission, teachers demonstrated a high level of understanding but low certainty in understanding. With regard to sound propagation, teachers demonstrated a low level of understanding and an improperly high certainty in that low understanding. Teachers lacked knowledge, i.e., displayed a low level of understanding and low certainty in sound strength, sound frequency, constructive interference and destructive interference. In constructive and destructive interference, the teachers also displayed a low level of familiarity. We analyzed the differences in teacher's understanding, certainty, and familiarity according to teacher demographics defined by the teacher's gender, teaching experience with concepts of sound, career, curriculum track while in high school, and major in university. There were no significant differences in understanding, certainty, or familiarity as defined by gender, teaching experience, and career. However, these displays of knowledge were affected by the teacher's curriculum track in high school and their major. These results suggest that the teacher's understanding of, familiarity with, and certainty in wave physics concepts are more influenced by their learning experience than by their teaching experience. Therefore, we suggest additional learning opportunities for teachers (such as teacher training programs) in order to improve teacher knowledge and correct teacher misconceptions in wave physics.

Analysis of Interior Noise of KTX in Tunnel with Concreted Track (콘크리트 궤도 터널 내 KTX 차량의 실내소음 특성 분석)

  • Kim, Jae-Chul;Lee, Chan-Woo
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.17 no.11
    • /
    • pp.1037-1042
    • /
    • 2007
  • KTX trains show a high interior noise level in tunnel with concreted track at 300 km/h. Generally, the concreted track has higher sound emissions compared with ballasted track due to the reduced absorption and the major sources of interior noise for KTX are known as the aerodynamic noise and rolling noise. Therefore, It is necessary to find out noise source and noise components to affect interior noise in tunnel with concreted track. In this study, we measure the noise and vibration inside KTX in tunnel in order to find the cause of the interior noise of KTX. The analysis results show that the interior noise of KTX in tunnel with concreted track is increased sharply by a low frequency below 80 Hz. We know that the low frequency noise inside KTX in tunnel with concreted track is generated at the natural frequency of carbody by aerodynamic noise outside gangway and rolling noise. In order to reduce the noise level at 80 Hz, modification of mud-flap length between carbodys is suggested and the effect of noise reduction is examined in tunnel with concreted track.

Application of Speech Recognition with Closed Caption for Content-Based Video Segmentations

  • Son, Jong-Mok;Bae, Keun-Sung
    • Speech Sciences
    • /
    • v.12 no.1
    • /
    • pp.135-142
    • /
    • 2005
  • An important aspect of video indexing is the ability to segment video into meaningful segments, i.e., content-based video segmentation. Since the audio signal in the sound track is synchronized with image sequences in the video program, a speech signal in the sound track can be used to segment video into meaningful segments. In this paper, we propose a new approach to content-based video segmentation. This approach uses closed caption to construct a recognition network for speech recognition. Accurate time information for video segmentation is then obtained from the speech recognition process. For the video segmentation experiment for TV news programs, we made 56 video summaries successfully from 57 TV news stories. It demonstrates that the proposed scheme is very promising for content-based video segmentation.

  • PDF

A Study on "A Midsummer Night's Palace" Using VR Sound Engineering Technology

  • Seok, MooHyun;Kim, HyungGi
    • International Journal of Contents
    • /
    • v.16 no.4
    • /
    • pp.68-77
    • /
    • 2020
  • VR (Virtual Reality) contents make the audience perceive virtual space as real through the virtual Z axis which creates a space that could not be created in 2D due to the space between the eyes of the audience. This visual change has led to the need for technological changes to sound and sound sources inserted into VR contents. However, studies to increase immersion in VR contents are still more focused on scientific and visual fields. This is because composing and producing VR sounds require professional views in two areas: sound-based engineering and computer-based interactive sound engineering. Sound-based engineering is difficult to reflect changes in user interaction or time and space by directing the sound effects, script sound, and background music according to the storyboard organized by the director. However, it has the advantage of producing the sound effects, script sound, and background music in one track and not having to go through the coding phase. Computer-based interactive sound engineering, on the other hand, is produced in different files, including the sound effects, script sound, and background music. It can increase immersion by reflecting user interaction or time and space, but it can also suffer from noise cancelling and sound collisions. Therefore in this study, the following methods were devised and utilized to produce sound for VR contents called "A Midsummer Night" so as to take advantage of each sound-making technology. First, the storyboard is analyzed according to the user's interaction. It is to analyze sound effects, script sound, and background music which is required according to user interaction. Second, the sounds are classified and analyzed as 'simultaneous sound' and 'individual sound'. Thirdly, work on interaction coding for sound effects, script sound, and background music that were produced from the simultaneous sound and individual time sound categories is done. Then, the contents are completed by applying the sound to the video. By going through the process, sound quality inhibitors such as noise cancelling can be removed while allowing sound production that fits to user interaction and time and space.

A Study on the Effects of the Train Gust induced by High speed train at 350km/h on the Simple Vertical Surfaces Parallel to the Track (고속열차 350km/h 주행시 열차풍이 방음벽 등 궤도에 수직평행한 선로변 구축물에 미치는 영향에 관한 연구)

  • Kim, Jae-Bok;Nam, Sung-Won;Ko, Tae-Hwan
    • Proceedings of the KSR Conference
    • /
    • 2007.11a
    • /
    • pp.529-544
    • /
    • 2007
  • After rapid running is begun in domestic, problem by the train gust that was not considered at existent train running appeared. If the High-Speed railway business speed rises by 350km/h in the future, is going to become more big problem. This study conducts an experiment that measure in local about KTX train beside Gyeong-Bu High speed railroad track about aerodynamics effect that happen by passage of train and analyzed. In case KTX II runs with the 350km/h speed, forecasted effect that get in the simple vertical surfaces parallel to tracks according to distance from rail center. Compared construction size with structural analysis in case do not consider with case that consider the train gust about sound proof walls representatively. As a result, proposed wind load standard that apply at sound proof walls design.

  • PDF

Bottom Loss Variation of Low-Frequency Sound Wave in the Yellow Sea (황해에서 저주파 음파의 해저손실 변동)

  • Kim, Bong-Chae
    • Ocean and Polar Research
    • /
    • v.29 no.2
    • /
    • pp.113-121
    • /
    • 2007
  • The sound wave in the sea propagates under the effect of water depth, sound speed structure, sea surface roughness, bottom roughness, and acoustic properties of bottom sediment. In shallow water, the bottom sediments are distributed very variously with place and the sound speed structure varying with time and space. In order to investigate the seasonal propagation characteristics of low-frequency sound wave in the Yellow Sea, propagation experiments were conducted along a track in the middle part of the Yellow Sea in spring, summer, and autumn. In this paper we consider seasonal variations of the sound speed profile and propagation loss based on the measurement results. Also we quantitatively investigate variation of bottom loss by dividing the propagation loss into three components: spreading loss, absorption loss, and bottom loss. As a result, the propagation losses measured in summer were larger than the losses in spring and autumn, and the propagation losses measured in autumn were smaller than the losses in spring. The spreading loss and the absorption loss did not show seasonal variations, but the bottom loss showed seasonal variations. So it was thought that the seasonal variation of the propagation loss was due to the seasonal change of the bottom loss and the seasonal variation of the bottom loss was due to the change of the sound speed profile by season.

Prediction of The Rail way Track's Vibration Behavior and Corresponding Experimental Verification (철도궤도의 동적특성 예측 및 실험적 검증 연구)

  • Park, Hee-Jun;Kim, Kwan-Ju;Kim, Jea-Chul;Lee, Chan-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.11a
    • /
    • pp.883-888
    • /
    • 2004
  • One of commercial rapid transits produces peculiar booming sound when passing through the slab-track tunnel. In order to analyze that tympanic membrane-pressing noise systematically, typical source-transfer path-response analysis was carried out. Considering the octave band of booming noise, work scope was confined to structure-borne noise analysis, especially the dynamic behaviour of railway tracks. Experimental modal analysis of railway tracks, composed of rail, rubber pad, sleeper, ballast, and ground were performed. The results shows that transversal bending modes of the rail are suspicious for the cause of the low band booming noise. Finite element analysis are made use of to match preceding experimental results, and plausible dynamic properties of track components are produced.

  • PDF

Remote Sound Extraction Using Laser Doppler Interferometer (레이저 도플러 간섭계를 이용한 원거리 소리 추출)

  • Hwang, Jeong-hwan
    • Korean Journal of Optics and Photonics
    • /
    • v.32 no.3
    • /
    • pp.108-113
    • /
    • 2021
  • We propose and experimentally demonstrate a method of remote sound extraction using laser Doppler interferometry. The output frequency of a laser Doppler interferometer changes to be the same as the frequency of the acoustic wave from than object vibrated by the sound due to the Doppler effect. Based on this phenomenon, we measure the vibrational frequency of a remote target affected by a sound wave in real time, via laser Doppler interferometry. We track the peak frequency of the interferometer's output via appropriate signal processing, which confirms that the characteristics of the so detected wave are the same as that of the original sound source. We also confirm that the same method can retrieve the sound waves not only from remote sources of single tones, but from those of any sound.

Noise Prediction and Design of Soundproof Facilities for the High Speed Train (고속열차(TGV) 주행시 연변에서의 소음예측 및 방음시설설계)

  • ;J. P. Clairbois
    • Journal of KSNVE
    • /
    • v.9 no.6
    • /
    • pp.1106-1115
    • /
    • 1999
  • This paper sums up the study of the soundproof facilities (noise barriers) to be placed on the test track section within the Seoul-Pusan H.S.T. project. The objective of this study is to determine optimum design of soundproof including height, length, location, sound absorbing materials for test track(chonan-taejon). This paper shows the model to design the shape and materials of noise barrier for high speed trains(TGV, ICE, ect). The design of soundproof facilities is to be conducted by MITHRA for the prediction of noise impact of the TGV and for optimising noise barriers in order to reduce the noise generated by high speed trains. A number of computer simulations are carried out in order to determine the specification of noise barrier on test track.

  • PDF

The Variability Analysis of the Kinematic Variables of the Lower Extremities During AK(above-knee) Amputee Gait (대퇴절단 환자의 보행 시 양하지의 운동학적 변인에 대한 variability 분석)

  • Seo, Uk-hyeon;Ryu, Ji-seon
    • Korean Journal of Applied Biomechanics
    • /
    • v.15 no.4
    • /
    • pp.131-142
    • /
    • 2005
  • This study was investigated the stability of the AK amputee gait through analysing the variability on kinematic variables between the sound leg and the prosthetic limb. The one male, AK amputee who could walk for himself with his prosthetic limb was participated in this study. Six cameras of the MCU 240 and the QTM(Qualisys Track Manager) software were used for data collecting in this study. The relative angle of both segments was the difference between the absolute angle of the distal segment and the absolute angle of the proximal segment. The coupling angles between the prosthetic limb and the sound leg were caculated on the thigh Flexion/Extension in relative to the shank Flexion/Extension and the shank Flexion/Extension n relative to the foot Flexion/Extension. In order to evaluate the variability of segment and joint angle, C.V. was used, and to evaluate the variability for coupling angles, the Relative motion calculated by vector coding method of the continuous methods was used. As stated, the gait pattern of the prosthetic limb was almost similar gait pattern of the sound leg, but the prosthetic limb showed that the gait pattern of the sound leg and the prosthetic limb were not stable against the sound leg.