• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.457-460
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• 2002

The image quality of three-dimensional (3D) images has been widely investigated by the qualitative analysis method. A need remains for an objective and quantitative method to assess the image quality of 3D volume-rendered images. The purpose of this study was to evaluate the quantitative accuracy of distance measurements on 3D volume-rendered images of a dry human skull by using multi-detector computed tomography (MDCT). A radiologist measured five times the twenty-one direct measurement line items composed among twelve reference points on the skull surface with a digital vernier caliper. The water filled skull specimen was scanned with a MDCT according to the section thicknesses of 1.25, 2.50, 3.75, and 5.00 mm for helical (high quality; pitch 3:1) scan mode. MDCT data were reconstructed with its acquisition section thickness and with 1.25 mm section thickness for all scans. An observer also measured seven times the corresponding items on 3D volume-rendered images with measuring tools provided by volumetric analysis software. The quantitative accuracy of distance measurements on the 3D volume-rendered images was statistically evaluated (p-value < 0.05) by comparatively analyzing these measurements with the direct distance measurements. The accuracy of distance measurements on the 3D volume-rendered MDCT images acquired with 1.25, 2.50, 3,75 and 5.00 mm section thickness and reconstructed with its section thickness were 48%, 33%, 23%, and 14%, respectively. Meanwhile, there were insignificant statistical differences in accuracy of distance measurements among 3D volume-rendered images reconstructed with 1.25 mm section thickness for the each acquisition section thickness. MDCT images acquired with thick section thickness and reconstructed with thin section thickness in helical scan mode should be effectively used in medical planning of 3D volume-rendered images. The quantitative analysis of distance measurement may be a useful tool for evaluating the quantitative accuracy and the defining optimal parameters of 3D volume-rendered CT images.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.697-702
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• 2005

The aim of this study was to divide vocalizations of laying hens (Hy-Line Brown) into general vocalizations (GVs), heat stress-related vocalization (HSV), and cold stress-related vocalizations (CSVs) and to determine if they are classified by the discriminant function analysis method. Thirty laying hens, 65-wk-old, were recorded using digital video recorders 2 times from 10:00 to 14:00 h in each thermal environment (thermoneutral: $22.0{\pm}1.8^{\circ}C$, too hot: $32.0{\pm}2.0^{\circ}C$, too cold: $8.0{\pm}1.9^{\circ}C)$ after a 7 day acclimation period. When the laying hens were not recorded, they were kept in thermoneutral conditions. The GVs, HSV, and CSVs were divided based on the shapes of spectrums and spectrograms. The GVs, HSV, and CSVs were identified as 5, 1, and 3 types, respectively. Pitch, intensity, duration, formant 1, formant 2, formant 3, and formant 4 among the thermal environment-related vocalizations were significantly different (P<0.001). The discrimination rate determined by discriminant function analysis was 86.2%. These results suggest that HSV and CSVs are present and may be used as an indicator of the thermal environment.

• Clinics in Shoulder and Elbow
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• v.17 no.1
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• pp.25-30
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• 2014

Background: Normal elbow joint kinematics has been widely studied in cadaver, whilst in vivo study, especially of the forearm, is rare. Our study analyses, in vivo, the kinematics of normal forearm and of malunited forearm using a three-dimensional computerized simulation system. Methods: We examined 8 patients with malunited Monteggia fracture and 4 controls with normal elbow joint. The ulna and radius were reconstructed from CT data placing the forearm in three different positions; full pronation, neutral, and full supination using computer bone models. We analyzed the axis of rotation 3-dimentionally based on the axes during forearm rotation from full pronation to full supination. Results: Axis of rotation of normal forearm was pitch line, with a mean range of 2 mm, from full pronation to full supination, connecting the radial head center proximally and ulnar fovea distally. In normal forearm, the mean range was 1.32 mm at the proximal radioulnar joint and 1.51 mm at the distal radioulnar joint. However in Monteggia fracture patients, this range changed to 7.65 mm at proximal and 4.99 mm at distal radoulnar joint. Conclusions: During forearm rotation, the axis of rotation was constant in normal elbow joint but unstable in malunited Monteggia fracture patients as seen with radial head instability. Therefore, consideration should be given not only to correcting deformity but also to restoring AOR by 3D kinematics analysis before surgical treatment of such fractures.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.343-349
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• 2004

Electroglottograph(EGG) is a signal recorded from the vocal cord vibration by measuring electrical impedance across the vocal folds through the neck skin. The purpose of this study was to develop EGG system and to evaluate possibility for the application on speech analysis and laryngeal disease diagnosis. EGG system was composed of two pairs of ring electrodes, tuned amplifier, phase sensitive detector, low pass filter, and auto-gain controller. It was designed to extract electric impedance after detecting by amplitude modulation method with 2.7MHz carrier signal. Extracted signals were transmitted through line-in of PC sound card, sampled and quantized. Closed Quotient(CQ), Speed Quotient(SQ), Speed Index(SI), fundamental frequency of vocal cord vibration(F0), pitch variability of vocal fold vibration (Jitter), and peak-to-peak amplitude variability of vocal fold vibration(Shimmer) were analyzed as EGG parameters. Experimental results were as follows: the faster vocal fold vibration, the higher values in CQ parameter and the lower values in SQ and SI parameters. EGG and speech signals had the same fundamental frequency. CQ, SQ, and SI were significantly different between normal subjects and patients with laryngeal cancer. These results suggest that it is possible to implement portable EGG system to monitor the function of vocal cord and to test functional changes of the glottis.

• Composites Research
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• v.34 no.5
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• pp.290-295
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• 2021

The application of lightweight structural composites to automobiles as a solution in line with global fuel economy regulations to curb global warming is recognized as a megatrend. This study was conducted to provide a technical approach that can respond to the issue of replacing parts that require conductive properties to maximize the application of thermoplastic carbon fiber reinforced plastics (CFRPs), which are advantageous in terms of repair, disposal and recycling. By utilizing the properties of the low-viscosity polymerizable oligomer matrix, it was possible to prepare a thermoplastic CFRP exhibiting excellent impregnation properties while uniformly mixing the conductive filler. Various carbon-based conductive fillers such as carbon black, carbon nanotubes, graphene nanoplatelets, graphite, and pitch-based carbon fibers were filled up to the maximum content, and electrical and thermal conductive properties of the fabricated composites were compared and studied. It was confirmed that the maximum incorporation of filler was the most important factor to control the conductive properties of the composites rather than the type or shape of the conductive carbon filler. Experimental results were observed in which it might be advantageous to apply a one-dimensional conductive carbon filler to improve electrical conductivity, whereas it might be advantageous to apply a two-dimensional conductive carbon filler to improve thermal conductivity. The results of this study can provide potential insight into the optimization of structural design for controlling the conductive properties of thermoplastic CFRPs.

• Cartoon and Animation Studies
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• s.36
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• pp.469-491
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• 2014

Webtoon has developed the method that makes it possible to express sound visually. Also we can also hear sound in webtoon through the development of web technology. It is natural that we analyze the sound that we can hear, but we can also analyze the sound that we can not hear. This study is based on 'dual code' in cognitive psychology. Cartoonists can make visual expression on the basis of auditive impression and memory, and readers can recall the sound through the process of memory and memory-retrieval. This study analyzes both audible sound and inaudable sound. Concise analysis owes the method to film sound theory. Three main factor, Volume, pitch, and tone are recognized by frequency in acoustics. On the other hand they are expressed by the thickness and site of line and image of sound source. The visual expression of in screen sound and off screen sound is related to the frame of comics. Generally the outside of frame means off sound, but some off sound is in the frame. In addition, horror comics use much sound for the effect of genre like horror film. When analyzing comics sound using this kinds of the method film sound analysis, we can find that webtoon has developed creative expression method comparing with simple ones of early comics. Especially arranging frames and expressing sound following and vertical moving are new ones in webtoon. Also types and arrangement of frame has been varied. BGM is the first in using audible sound and recently BGM composed mixing sound effect is being used. In addition, the program which makes it possible for readers to hear sound according to scroll moving. Especially horror genre raise the genre effects using this technology. Various methods of visualizing sound are being created, and the change shows that webtoon could be the model of convergence in contents.

• (The) Research of the performance art and culture
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• no.36
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• pp.415-440
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• 2018

On September 23, 2015, the Ministry of Education announced the 2015 revision of educational curriculum which aimed at 'cultivating creative talents' based on the Article 23, Section 2 of the Elementary and Secondary Education Law. As a result, music curriculum have also been partially revised, which seems to maintain the 2009 revision of music curriculum. Although Jeongganbo 井間譜 is already exposed in the music curriculum for the third and forth grades of elementary school, the learning content about how to read Jeongganbo and how to express the pitch and length of sound including the origin of its name and the background of its invention are dealt with specifically in the fifth and sixth grades. Jeongganbo is known as the oldest mensural notation in the Orient created by King Sejong of the Joseon Dynasty in the middle of the $15^{th}$ century, and it was used for the first time in Sejong sillok akbo 世宗實錄樂譜 (Scores in the Annals of King Sejong), the oldest musical score still in existence. However, in the music textbooks as well as the most of specialized books related to the Korean traditional music, it is uncritically accepted without providing clear grounds that Sejong invented Jeongganbo himself. If so, it is necessary to investigate on which grounds it is claimed that Sejong invented Jeongganbo. This paper first examined the grounds of the proposition that "Sejong invented Jeongganbo," which is introduced in the music textbooks for the fifth and sixth grades of elementary school, by separating it into Sejong's creation of Sinak 新樂 (new music), Sejo's invention of Jeongganbo and Sejong's invention of Hangeul. Next, this paper examined how the subject of the invention of Jeongganbo has been described in the textbooks for the fifth and sixth grades in elementary school based on the 2009 revision of music curriculum, and suggested the direction of a desirable music education by pointing out the related problems. According to historical records and circumstances such as Sejong's creation of Sinak, Sejo's invention of Jeongganbo with 16 Jeonggan (square) in one vertical line, Sejong's invention of Hangeul and so on, it seems to be the most reasonable that Sejong is the subject of the invention of Jeongganbo as of now. However, the attitude of the musical academy to accept and educate the unclear thing as if it is a fact does not seem desirable. Therefore, I suggest that it should be described "Jeongganbo was invented in the period of Sejong" or "it is supposed that Jeongganbo was invented by Sejong" rather than presenting "Sejong made Jeongganbo" or "created" until revealing the clear evidence about the subject of Jeongganbo.