• Korean Security Journal
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• no.61
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• pp.377-400
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• 2019

Photography is the most commonly used method of documenting the crime and incident scene as it helps maintaining chain of custody (COC) and prove integrity of the physical evidence. It can also capture phenomena as they are. However, digital images can be manipulated and lose their authenticity as admissible evidence. Thus only limited techniques can be used to enhance images, and one of them is Fourier transform. Fourier transform refers to transformation of images into frequency signals. Fast Fourier transform (FFT) is used in this study. In this experiment, we overlapped fingerprints with graph paper or other fingerprints and separated the fingerprints. Then we evaluated and compared quality of the separated fingerprints to the original fingerprints, and examined whether the two fingerprints can be identified as same fingerprints. In the case of the fingerprints on graph paper and general pattern-overlapping fingerprints, fingerprint ridges are enhanced. On the other hand, in case of separating complicated fingerprints such as core-to-core overlapping and delta-to-delta overlapping fingerprints, quality of fingerprints can be deteriorated. Quality of fingerprints is known to possibly bring negative effects on the credibility of examiners. The result of this study may be applicable to other areas using digital imaging enhancement technology.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.37-43
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• 2007

Purpose: Photogrammetry has been introduced as an alternative to direct measurement to obtain facial distances for a variety of anthropometric applications. The aim of this study is to establish morphological and functional value of an eye in Korean youths using specially designed computer software with digital photographic images. Methods: Authors measured anthropometry of an eye in Korean youths 1,449 individuals(622 males, 827 females) and analyzed stastically them. Results: The mean measurements are as follows. The diameter of cornea was $11.6{\pm}0.9mm$ in males and $11.3{\pm}0.9mm$ in females. The vertical dimension of palpebral fissure was $7.4{\pm}1.7mm$ in males and $8.2{\pm}1.6mm$ in females. The intercanthal width was $35.8{\pm}3.2mm$ in males and $34.4{\pm}2.9mm$ in females. The biocular width was $90.4{\pm}5.7mm$ in males and $87.4{\pm}5.3mm$ in females. The endocantion-superior margin of palpebral fissure distance was $12.7{\pm}1.4mm$ in males and $11.6{\pm}1.4mm$ in females. The horizontal dimension of palpebral fissure was $28.5{\pm}2.2mm$ in males and $27.4{\pm}1.9mm$ in females. The slant of palpebral fissure was $10.7{\pm}2.6^{\circ}$ in males and $11.3{\pm}3.0^{\circ}$ in females. The height of upper eyelid was $10.6{\pm}2.3mm$ in males and $10.7{\pm}2.3mm$ in females. The width of double fold was $2.0{\pm}0.7mm$ in males and $1.9{\pm}0.6mm$ in females. A double fold was seen in 21.9% of males and 44.9% of females. The most frequent shape of the double fold was type IV. The most common type of epicanthal fold was type III in both males and females. Conclusion: Photogrammetic measurement of large population using specially designed software could offer reliable data and these data could be useful reference for preoperative consultation, surgical planning and anthropometic study of eye.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.3
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• pp.180-188
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• 1999

The dynamic elastic properties of metal matrix composites were investigated by resonant ultrasound spectroscopy(RUS). The composites used in this study consisted of 2124 aluminum alloy reinforced with different concentrations of SiC particles. RUS can determine the nine independent elastic stiffness($C_{ij}$) for the orthorhombic symmetry on a small specimen simultaneously. The elastic constants were determined as a function of the volume fraction. A concept of effective aspect ratio. which combine the aspect ratio and the orientation of reinforcement. was used to calculate the initial moduli from Mori-Tanaka theory for the input of RUS minimization code. Young's moduli can be obtained from the measured stiffnesses. The results show that the elastic stiffness increases with increment of the particle content. The behavior of elastic stiffness indicates that the particle redistribution induced by the extrusion process enlarges the transversely isotropic symmetry as the fraction of reinforced particles increase. This relationship could be used for determination of the volume fractions of reinforcement as a potential tool of nondestructive material characterization.

• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.5-33
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• 2017

This study explored challenges and desires related to social relationships among adolescents with intellectual disabilities, using the photovoice method. Six adolescents with intellectual disabilities (M = 18.33 years) who are attending a general high school participated in 7 sessions of a photovoice program. They selected themes related to social relationships through group discussions and shared their photos related to the themes with other participants. Our study yielded 15 subthemes within 5 social relationships (peers, teachers, boyfriends/girlfriends, parents, persons whom I need) from adolescents with intellectual disabilities as follows: relationships with peers (feeling lonely and left out, being teased and bullied by peers, making efforts to fix damaged relationships with friends), relationships with teachers (feeling appreciated by teachers who understand me, lacking interactions with teachers, wanting teachers to show they care about my school life), relationships with boyfriends/girlfriends (wanting to have a boyfriend/girlfriend, feeling worried and fearful about having a boyfriend/girlfriend, trying to attract a boyfriend/girlfriend), relationships with parents (being thankful to parents for their unconditioned love, enjoying time with parents, feeling bad because of not being close to father), persons whom I need (persons who enjoy spending time with me, persons who help me, persons who never give up on me). This study provides implications for social work practice, such as training for improving peer relationships and coping with peer conflict, education for fostering healthy romantic relationships, training for promoting social skills of adolescents with intellectual disabilities, and education for increasing awareness of the social needs of students with intellectual disabilities among peers without disabilities, teachers, and social workers.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.189-194
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• 2019

Forest investigation is the basic data for forest preservation and forest resource development, and periodical data acquisition and management have been performed. However, most of the current forest investigations in Korea are surveys to grasp the current status of forests, and various applications have not been made as geospatial information. In this study, the unmanned aerial scanner was used to acquire and process data in the forest area and to present an efficient forest survey method through analysis of the results. Unmanned aerial scanners can extract ground below vegetation, effectively creating DEM for forest management. It can be used as geospatial information for forest investigation and management by generating accurate topographical data that is impossible in conventional photogrammetry. It can also be used to measure distances between power lines and vegetation or manage transmission lines in forest areas. The accurate vertical distance measurement for vegetation surveys can greatly improve the accuracy of labor measurement and work efficiency compared to conventional methods. In the future, the use of unmanned aerial scanners will improve the data acquisition efficiency in forest areas, and will contribute to improved accuracy and economic feasibility compared to conventional methods.

• Solar Energy
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• v.14 no.2
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• pp.75-90
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• 1994

Thermal energy transport in a two-dimensional horizontal and vertical channel with an isothermal rectangular beam attached to one adiabatic wall is investigated from the numerical solution of Navier-Stokes and energy equations. The solutions have been obtained for dimensionless aspect equations. The solutions have been obtained for dimensionless aspect ratios of beam, H/B=$0.25{sim}4$, Reynolds numbers, Re=$50{\sim}500$ and Grashof numbers, Gr=$0{\sim}5{\times}10^4$. The mean Nusselt number, $\overline{Nu}$ for horizontal and vertical channels shows same value at Gr=0 and increases as Gr increases and decreases as H/B increases at Re=100. $\overline{Nu}$ of vertical channel shows higher in $0.25{\leq}H/B<1.1$ and lower in $1.1{\leq}H/B{\leq}4.0$ than that of horizontal channel at $Gr=10^4$, Re=100. $\overline{Nu}$ of vertical channel shows higher in $0.25{\leq}H/B<1.1$ and lower in $1.1{\leq}H/B=1.0$ than that of horizontal channel at Re=100, $0<Gr{\leq}5{\times}10^4$. A comparison between the experimental and numerical results shows good agreement.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.10
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• pp.421-428
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• 2021

The High Efficiency Image File Format (HEIF) is an MPEG-developed image format that utilizes the video codec H.265 to store still screens in a single image format. The iPhone has been using HEIF since 2017, and Android devices such as the Galaxy S10 have also supported the format since 2019. The format can provide images with good compression rates, but it has a complex internal structure and lacks significant compatibility between devices and software, making it not popular to replace commonly used JPEG (or JPG) files. However, despite the fact that many devices are already using HEIF, digital forensics research regarding it is lacking. This means that we can be exposed to the risk of missing potential evidence due to insufficient understanding of the information contained inside the file during digital forensics investigations. Therefore, in this paper, we analyze the HEIF formatted photo file taken on the iPhone and the motion photo file taken on the Galaxy to find out the information and features contained inside the file. We also investigate whether or not the software we tested support HEIF and present the requirement of forensic tools to analyze HEIF.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.160-167
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• 2021

The purpose of this study was to investigate the prevalence and characteristics of pre-eruptive intracoronal radiolucencies (PEIR) from panoramic radiographs in Korean children and adolescents. This study examined panoramic radiographs of 3,000 patients aged between 5 and 14 years old who visited ten dental hospitals in Korea. The age and gender of the patients, the tooth type, the number of intracoronal radiolucent lesions, and the location and size of the lesions were recorded. The overall prevalence of patients with PEIR was 2.5%. The difference in the presence of PEIR between both genders was not significant. Within each tooth type, the mandibular first molar showed highest prevalence of PEIR (29.6%). The central part of the crown was the most frequently observed location of PEIR (56.8%). The size of the PEIR lesions was mostly limited to less than one-third of the thickness of coronal dentin.

• 기호학연구
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• no.57
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• pp.59-90
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• 2018

This paper examines the discussions related to image and signification through the theories of Roland Barthes. We have already been able to see through the studies of Semiotics and Anne H?nault that the denotation is distinguished from the connotation in the linguistic dimension. Through the analysis of the advertising image of Barthes, we have seen that the syntagmatic relationship can make the sense of the image objective. From this study, we also emphasized that it is possible to subjectively interpret images that deviate from the syntagmatic relationship. In addition, we examined the concepts of Studium and Punctum by Barthes. With this we have found that the definition of a personal meaning to objects has a theoretically clear position. Finally, we have been able to understand the concept of 'le sens obtus' through the article ${\ll}$ Le troisi?me sens ${\gg}$. The notion of 'sens obtus' makes it possible to realize that the objective and clear sense of object is not the one chosen primarily from the subject. By facing an object such as an image to be interpreted, the subject is placed in a situation where he is not compelled to choose a meaning but rather he chooses one of the possible senses. This makes it clear that the semantic levels provided by semiotic theories are limited to the analytic dimension.

• (The) Research of the performance art and culture
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• no.18
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• pp.379-412
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• 2009

According to "Jinjak-yigwe(進爵儀軌)", a special banquet was held at Yungyungdang(演慶堂, a kind of royal theatre) to celebrate the 40th birthday of Queen Soonwon(純元王后) in 1828. This banquet is famous for the presentation of nineteen new Jungjae(呈才) repertoires that the Crown Prince Hyomyung(孝明) created. In order to explore the theoretical basis for the reproduction and presentation of Yungyungdang(演慶堂) Jinjak(進爵, a type of royal banquets), in this article, the imagination and experience of the presentation of Yungyungdang Jinjak are pursued, while focussing on audience's reception. In Yungyungdang Jinjak, King Soonjo(純祖), Queen Soonwon and the prince were the special audience; they participated in the procedure of Ye(禮, etiquette of ceremony) and also were considered as the characters of certain repertoire of Jungjae. Hyomyung arranged the spectacles from the myths of Taoist gods and immortal hermits, as well as historic episodes of the past emperors' elegant tastes of music. These mythic and historic images lead the audience toward the imagination and experience on the transcendental world. Hyomyung, managing the administration as the representative of King Soonjo, tried to show absolute royal authority through the splendid performances of Yungyungdang Jinjak, so as to overcome the politicaly difficult situation. He set up the sacred world for his father King Soonjo, distinct from the secular ordinary world, and emphasized his position as the bridge between the two sides. He expressed his filial duty through the devotion of performing arts to display absolute royal authority.