• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.1
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• pp.28-37
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• 2006

Purpose: Evaluation of vocal cord vibration is very important in cases of voice disorders. There are several equipments for examining the vocal fold vibration such as laryngeal stroboscope, ultra high-speed digital imaging system, and videokymograph. Among these, laryngeal stroboscope is the most popular equipment because of easy to examine the laryngeal pathology. However, current laryngo-stroboscopes are too bulky to move and relatively expensive. The purpose of this research is to develope a portable laryngeal stroboscope of equivalent performance with the current equipments. Methods and Materials: Recently developed high luminescent white LEDs(light emitting diodes) are placed at the head of the endoscope as light sources for the CCD image sensor which is also placed at the head with imaging lens. This arrangement eliminates the bulky light source like expensive halogen or xenon lamps as well as the optical light guiding cables. The LEDs are controlled to flash in phase with the voice frequency of the examinee. The CCD captures these strobo images and converts them into video signals for examinations. Results: There was no functional differences between preexisting stroboscope and the newly developed stroboscope of this study. LED light sources and microprocessor based control circuits of the stroboscope enabled the development of flicker-less, hand-held, portable and battery-operating stroboscope. Conclusion: The developed stroboscope is cost-effective, small-sized, easy to use and very easy desirable to bring and to use in any place.

• The monthly packaging world
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• s.258
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• pp.96-99
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• 2014

• The monthly packaging world
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• s.252
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• pp.50-55
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• 2014

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.7-13
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• 2006

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.26 no.2
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• pp.91-93
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• 2015

Substantial confusion exists regarding the nomenclature of benign vocal fold lesions (BVFL), because there were no pathologically diagnostic findings and deep understanding of pathogenesis in the past. There is no consensus on specific labels for BVFL, nor are the most commonly used terms defined. There is a need for a defined nomenclature for the purpose of improving communication among clinicians and with patients. Furthermore, precise definitions of BVFL will facilitate clinical research of voice disorders and may lead to a better understanding of outcomes for BVFL treatment. Laryngoscope, stroboscope, voice evaluation are used to diagnose BVFL. The objective of this review article was to develop a new paradigm of BVFL nomenclature using patient's history, stroboscope, voice therapy results, and operative findings. Furthermore, precise definitions of BVFL will facilitate clinical research of voice disorders and may lead to a better understanding of outcomes for BVFL treatment.

• Korean Association for Visual Culture
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• v.19
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• pp.189-221
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• 2012

This thesis investigates the development of optical instruments in the 19th century, before the birth of the cinema, and the principle of the perception of moving images. For this purpose it traces the development stages of the optical instruments which demonstrated 'illusion of movement' from 1820s when the 'persistence of vision' had begun to be researched by scientists. Then, it examines the theory of the 'persistence of vision' or 'afterimage effect' known as the principle in the perception of illusion of movement produced from moving images. The optical instruments in the 19th century that presented the illusion of movement began with the Thaumatrope (double-sided picture disc), and appeared from the Phenakistiscope/Stroboscope (revolving disc), the Zoetrope (revolving drum) and the Praxinoscope (mirror-reflexive revolving drum), and in 1892 the Projection-Praxinoscope presented firstly the moving pictures (animation) on the screen. According to the research of psychology and physiology in the early 20th century it has been recognized that the 'afterimage effect' theory is not sufficient to explain the perception of illusion of movement from the moving images which is closely related to the particularity of the visual perception system of the human eyes. Since then, the Phi-phenomenon suggested 1912 by the Gestalt psychologist, Max Wertheimer (1880-1943), is regarded as the most persuasive theory until now, although it is still imperfect.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.811-815
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• 1990

This paper describes the method on image acquisition and image processing in the turning process. The formation of discontinuous chips during high-speed oblique cutting without lubricant was observed by means of video camera recorder and stroboscope. The image processing technique for chip flow is described and the results are presented for variable feeds. It is concluded that experimental values of chip flow angle are similar to theoretical values of Stabler's rule.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.495-499
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• 2000

Auditory system is separated to Outer Ear, Middle Ear and Inner Ear, Middle Ear plays an important role as the sound transfer on amplitude. With analysing of Middle Ear, we can understand disease and compare unformal auditory systems. However, the investigation of mechanical modeling and analysis have been reported in a few paper. In this paper, a three dimensional Eardrum model of human ear was developed and analysed applying the general purpose Finite-Element program (Nastran). Vibration patterns of the eardrum obtained from FEM analysis are in agreements with the experimental results using stroboscope.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.26-32
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• 2007

Objective and Background: Laryngeal stroboscope is an useful equipment in evaluation of vocal cord vibration and in early detection of mucosal lesion including invasive cancer of the vocal cord. Recently Lee et al. (2006) developed portable stroboscope using voice as synchronization signal. It has been frequently impaired ability to synchronize the flashes even in normal female. Authors tried to investigate various methods including vibration pick-up, microphone, laryngeal microphone, and contact microphone for development of simple and accurate method like electroglottograph signal. The purpose of this study was to estimate wheher the vibration pick-up is available and is consistent with the signal of EGG. Subjects and Methods: Authors compared the signals between EGG and noncontact method such as voice, contact methods including vibration pick-up, laryngeal microphone, and contact microphone in normal twenty adults (male 10 and female 10). The number of peak in one cycle was compared with the number of the peak in EGG, and the percent of phase difference in the peak was compared with EGG Also, authors tried to investigate which site of vibration pick-up was most effective for synchronization of stobo flashes. Three site including anterior neck below the cricoid cartilage, thyroid ala, and suprahyoid region were analysed. Results: Among various methods for synchronization of strobo flashes, vibration pick-up was most effective method in peak detection. And anterior neck below cricoid cartilage was the most available site of the vibration pick-up. Conclusion: Authors suggest that vibration pick-up is most available and effective method for synchronization of strobo flashes.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.9-14
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• 2005

An experimental investigation has been carried out to reveal the atomization process of the diesel fuel spray. The spray injected through a single hole nozzle was taken by a camera on the opposite side of a stroboscope for macroscopic observation or a nanolite for microscopic observation. The effect of nozzle aspect ratio was analyzed with disintegration phenomena of the diesel spray. Based on the enlarged spray photograph, atomization process was observed in detail and further the spray cone angle was measured under various ambient pressures. The result shows that atomization of diesel spray in early stage of injection is mainly progressed in the vicinity of spray periphery region except the region close to the nozzle exit and spray head region. The spray cone angle is nearly constant under the pressurized condition, while it decreases with elapsing time under the atmospheric condition.