• Journal of IKEEE
• /
• v.24 no.2
• /
• pp.604-609
• /
• 2020

We investigated the influence of rapid thermal annealing on aluminum nitride (AlN) thin film Schottky barrier diodes (SBDs) manufactured structures deposited on a 4H-silicon carbide (SiC) wafer using radio frequency sputtering. The Ni/AlN/4H-SiC devices annealed at 400℃ exhibited Schottky barrier diode (SBDs) properties with an on/off current ratio that was approximately 10 times higher than that of the as-deposited device structures and the devices annealed at 600℃ as measured at room temperature. Auger electron spectroscopy (AES) measurements revealed that atomic oxygen concentrations in the annealed AlN devices at 400℃, is ascribed to the improvement in on/off ratio and the reduction of on-resistance. Additionally, we investigated the electrical characteristics of the AlN/SiC SBD structures depending on the frequency variation of sound waves.

• The Journal of the Acoustical Society of Korea
• /
• v.33 no.2
• /
• pp.102-110
• /
• 2014

The effect of a bonding layer on the performance of a quarter-wave (${\lambda}/4$) mode PVDF ultrasound transducer having not only a piezoelectric layer but also a non-piezoelectric layer between two electrodes was analyzed. The equivalent circuit of a transmission line model by Kikuchi et al.[Sound of IEICE, 55-A, 331-338 (1981)] was introduced for the analysis. The validity of the model was confirmed by comparison with a KLM model for three postulated adhesion cases of a $80{\mu}m$ thick piezoelectric PVDF film to a copper (Cu) backer. The pulse-echo responses of five PVDF transducers, each fabricated with a different thickness ($5{\mu}m{\sim}20{\mu}m$) of the bonding layer, were measured and the results were compared with those by simulation. The two results were in good agreement with each other and it was noted that the effect of the bonding layer on the performance of the transducer could be analyzed by the Kikuchi model. In detail, the $20{\mu}m$ bonding layer decreased the center frequency and the bandwidth by about 19.7 % and 25.0 %, respectively, and increased the insertion loss by 57.2 %.

• The Journal of the Acoustical Society of Korea
• /
• v.39 no.6
• /
• pp.576-584
• /
• 2020

In order to obtain basic information for using polyvinyl alcohol (PVA) gel as a tissue mimicking phantom for temperature visualization, the temperature change characteristics due to the focused ultrasound were examined for different concentration of PVA. To obtain the basic acoustic characteristics, the speed of sound, the attenuation coefficient, and the density depending on the PVA concentration were measured, and the thermodynamic characteristics, such as thermal conductivity and heat capacity, were measured. The range of temperature rising in the vicinity of the focal point due to the focused ultrasound was observed using a thermochromic film that changes color at 30 degree or more, and the discolored area was obtained by image processing of the recorded image. As the concentration of PVA increases in the given range of 2 wt% ~ 16 wt%, the area that rises above 30 degree inside the gel increases linearly. It is confirmed that the discolored area increases as the power applied to the focused ultrasonic transducer increases. These results showed good agreement with the simulation results using the finite element method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.284-286
• /
• 2021

With the continuous development of the Internet and digital, platforms are emerging to store large amounts of media data and provide customized services to individuals through online. Companies that provide these services recommend movies that suit their personal tastes to promote media consumption. Each company is doing a lot of research on various algorithms to recommend media that users prefer. Movies are divided into genres such as action, melodrama, horror, and drama, and the film's audio (music, sound effect, voice) is an important production element that makes up the film. In this research, based on movie trailers, we extract audio for each genre, check the commonalities of audio for each genre, distinguish movie genres through supervised learning of artificial intelligence, and propose a utilization method for generating metadata in the future.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.14 no.10
• /
• pp.1007-1014
• /
• 2004

This paper presents a study of low frequencies volume velocity vibration control of a smart panel in order to reduce sound transmission. A distributed piezoelectric quadratically shaped polyvinylidene fluoride (PVDF) polymer film is used as a uniform force actuator and an array of $4\;{\times}\;4$ accelerometer is used as a volume velocity sensor for the implementation of a single-input single-output control system. The theoretical and experimental study of sensor-.actuator frequency response function shows that this sensor-actuator arrangement provides a required strictly positive real frequency response function below about 900 Hz. Direct velocity feedback could therefore be implemented with a limited gain which gives reductions of about 15 dB in vibration level and about 8 dB in acoustic power level at the (1,1) mode of the smart panel. It has been also shown that the shaping error of PVDF actuator could limit the stability and performance of the control system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.368-373
• /
• 2003

This paper presents a study of low frequencies volume velocity vibration control of a smart panel in order to reduce sound transmission. A distributed piezoelectric quadratically shaped polyvinylidene fluoride (PVDF) polymer film is used as a uniform force actuator and an array of 4$\times$4 accelerometer is used as a volume velocity sensor for the implementation of a single-input single-output con rot system. The theoretical and experimental study of sensor-actuator frequency response function sho vs that this sensor-actuator arrangement provides a required strictly positive real frequency response function below about 900Hz. Direct velocity feedback could therefore be implemented with a limited gain which gives reductions of about 15㏈ in vibration level and about 8 ㏈ in acoustic power level at the (1, 1) mode of the smart Panel. It has been also shown that the shaping error of PVDF actuator could limit he stability and performance of the control system.

• The Journal of the Korea Contents Association
• /
• v.17 no.1
• /
• pp.634-661
• /
• 2017

This study examines the procedure of successful novel adaptation. It is well known from precedent studies that narrative structure of novels should change forms to suit the media characteristics of films. But, the changing forms of narrative structure is not a sufficient condition of successful novel adaptation, but a necessary condition. A successful adaptation could be completed with filmic expressions on the presented narrative structure. The core of filmic expression is cinematic language which means the composition and array of image and sound. The novel, Kirishma Thing deals with everyday life of high school students and it consists of six stories which are narrated by one student each in first person point of view. The film, Kirishma Thing implemented a different strategy. It reveals the same events several times to show many characters over in each person's point of view in the first half. In the second half, all the characters gathers at the rooftop of the school to have an unilinear narrative structure over one event. This film utilize all kinds of cinematic language to achieve these structures including the widescreen aspect ratio which exposes as many characters as possible in one shot, picture composition which shows the same event in a different point of view, contrast in lighting and music which differentiates and empowers the last sequence of the film.

• Journal of Industrial Convergence
• /
• v.21 no.3
• /
• pp.189-194
• /
• 2023

Recently, various studies on flexible electronic devices have been performed. In this study, the potential of Ag nanowires was evaluated as a material to replace the ITO transparent conductive film. Ag nanomaterials were formed on the glass by a novel brush coating method and an argon plasma evaporation method based on atmospheric pressure plasma. First, the Ag solution is coated on the glass with a brush, and the remaining solvent is removed with atmospheric plasma. During this process of solvent evaporation, a sound is generated by the reaction between the atmospheric plasma and the solvent. Therefore, the remaining amount of the solvent can be confirmed. In order to observe optical properties and electrical results such as reflectance, transmittance, and absorbance according to the number of coatings of the film, the results were analyzed by coating up to 5 times. For the purpose of investigating the interaction of light with Ag nanowires, reflectance and transmittance were measured while changing the wavelength of light from 200 nm to 800 nm. In the case of absorbance, the trend of increasing light absorption of the Ag nanowires according to the coating was clearly confirmed. The electrical properties showed a great change from the time of coating more than 4 times, and in particular, the resistance value was lower than kΩ/cm2 when the coating was applied 5 times. Based on these optical and electrical results, we plan to verify the possibility of a transparent conductive film by applying it to electronic devices in the future.

• Science of Emotion and Sensibility
• /
• v.23 no.4
• /
• pp.105-116
• /
• 2020

The purpose of this study is to progress the limitations and disadvantages of existing safety clothing by applying high technology to current safety clothing that is produced and distributed only with fluorescent fabrics and retroreflective materials. Therefore, the industrial suspender-type safety belt and engineering technology are introduced, designed, and fabricated to help save a life in an emergency. First, the suspender-type safety belt to be developed is designed to emit light by LED attached to the film, and the body of the belt-wearer is recognized from a distance through retroreflection from the flashing LED. It aims to support people's safety by preventing accidents during roadside work, rescue activities, and sports activities at night. Second, with the development of advanced devices when the user is in an unconscious state due to distress or falls into an unconscious state due to distress or accident, the tilt sensor of the control unit attached to the belt automatically detects the angle of the human body and generates light and sound. It is intended to further enhance the utilization by mounting a sensing and signaling device that generates a distress signal and shaping it in the form of a belt attached to a vest that can be easily detached from the outside of the garment. When the wearer falls due to an accident, the tilt sensor of this belt detects the angle change and then the controller generates a high-frequency sound and repeated LED blinking signals at the same time. In the case of conventional safety vests, it is almost impossible to detect that the person is wearing a vest when there is no ambient light, but in case of the safety belts in this study, the sound and light signals of the safety belt enable us to find the wearer within 100 meters even when there is no ambient light.

• Cartoon and Animation Studies
• /
• s.47
• /
• pp.125-148
• /
• 2017

This paper analyzes Korean aesthetic characteristics of Korean independent animation, which is closely related to artistic and social characteristics, by searching Korean independent animation image for the winner of "Indie AniFest", the only independent animation film festival in Korea. And social communication methods. There are three ways in which Korean Independence Animation shows the way of speaking through award-winning works. The first is a method of expressing feelings, impulses, and desires in a formative way, and a direct and sensuous image as in sign language or sound. In the second method of speaking differently with images, in the third method, It makes the voice of the fringe through the real world of the story sound as a story of reality. Animation is a medium that 'originalizes and communicates meaning' as an image, and has implemented and constructed a new way of speaking, which is different from existing social voices. Nevertheless, it is not easy to find a research that approaches animation from the viewpoint of social and political speech through images. Therefore, this paper is necessary for the balanced development of animation. In addition, this study can contribute to re - examining Korean independent animation from an academic point of view and to discover and evaluate fair value from a wider perspective.