• Title/Summary/Keyword: Sound Speed

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Seismic reflection imaging of a Warm Core Ring south of Hokkaido (훗카이도 남부 Warm Core Ring의 탄성파 반사법 영상화)

  • Yamashita, Mikiya;Yokota, Kanako;Fukao, Yoshio;Kodaira, Shuichi;Miura, Seiichi;Katsumata, Katsuro
    • Geophysics and Geophysical Exploration
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    • v.14 no.1
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    • pp.18-24
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    • 2011
  • A multi-channel seismic reflection (MCS) survey was conducted in 2009 to explore the deep crustal structure of the Pacific Plate south of Hokkaido. The survey line happened to traverse a 250-km-wide Warm Core Ring (WCR), a current eddy that had been generated by the Kuroshio Extension. We attempted to use these MCS data to delineate the WCR fine structure. The survey line consists of two profiles: one with a shot interval of 200m and the other with a shot interval of 50 m. Records from the denser shot point line show much higher background noise than the records from the sparser shot point line. We identified the origin of this noise as acoustic reverberations between the sea surface, seafloor and subsurface discontinuities, from previous shots. Results showed that a prestack migration technique could enhance the signal buried in this background noise efficiently, if the sound speed information acquired from concurrent temperature measurements is available. The WCR is acoustically an assemblage of concave reflectors dipping inward, with steeper slopes (${\sim}2^{\circ}$) on th ocean side and gentler slopes (${\sim}1^{\circ}$) on the coastal side. Within the WCR, we recognised a 30-km-wide lens-shaped structure with reflectors on the perimeter.

Timing Agency in Digital Comics : Focused on Multimedia Comics (전자만화의 타이밍 에이전시 : 멀티미디어와 혼합된 만화를 중심으로)

  • Yoh, Mi-Ju
    • Cartoon and Animation Studies
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    • s.27
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    • pp.79-97
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    • 2012
  • Comic book readers have respectively different reading speed and this means that time in comics is translated by readers' view. The authors arrange panels and gutters to control time, but time recognition in comics depends on the readers and generally it is the readers' role. On the contrary, the phenomenon having occurred by infinite canvas varied the authority of timing. Infinite canvas can give the comic book authors more authority of controlling timing than the readers by intervening in readers' relative time as an agents and transforming their fictive time into absolute time. Following to the concept of "Agency" in games, agency is the power which satisfies the players by reemergence of their intentions. Since some of digital comics absorbed the properties of other media such as animation and sound, we can see that the reader's timing agency is shifted to the author's timing agency. The purpose of this study is to analyse this phenomenon and to remind that agency motivated by the balance between material constraints and formal constraints becomes a condition of readability of digital comics but excessive timing constraints given to the readers causes a decrease of the readers' timing agency. This also can be a considerable matter when we produce digital comics.

Fabrication and Characterization of Aluminum Honeycomb Panel (경량 알루미늄 허니콤 판재의 제작 및 특성 평가)

  • Kim, Kee Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.666-671
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    • 2018
  • A honeycomb panel is a plate made by attaching two surface plateson eitherside of a honeycomb core. The honeycomb plate hasexcellent specific strength and energy absorption and is suitable for use in regions where good impact resistance is required. Recently, with the increasing the need for a lightweight design to facilitate transportation, numerous studies have been conducted using aluminum honeycomb plates as body materials for vehicles such as automobiles and high-speed trains. In addition, honeycomb plates have excellent sound deadening properties, as well as excellent heat insulation and durability. Savings in weight using lightweight materials such as aluminum alloy for honeycomb panel's skin can lead to increase fuel economy and reduction in air pollution. In this study, in order to improve the design technology of the honeycomb plate material, the manufacturing technology of the aluminum honeycomb core and honeycomb plate material and various mechanical properties of the honeycomb plate were evaluated. From the results, it was found that the design of the manufacturing process of the aluminum honeycomb plate, as well as itsproduction and characteristics, were improved. The resulting excellent energy absorption capability of the honeycomb plate was due to the repetitive core buckling, indicating that the higher the compressive strength, the higher the strength per bonded area.

The Effect of The Index of Indoor Environment on The Productivity (실내환경지수가 생산성에 미치는 영향)

  • Kim, Myung-Ho;Lee, Ye-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.615-621
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    • 2018
  • To enhance the energy saving and comfort of indoors, this study performed a stimulation of sound fluctuation, color temperature, and aroma. The experiment with EEG, HRV, and Vibra images was conducted in an environmental test room with a temperature of $25[^{\circ}C]$, relative humidity of 50[RH%], air current speed of 0.002[m/s], and illuminance of 1000[lux]. The stimulation experiment set up different sensory stimulation conditions, such as before exposure, single-sensory stimulation of fluctuation a=1.106 jazz music, single-sensory stimulation of RED color lighting, single-sensory stimulation of scent aroma, and multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma. After the multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting and scent aroma, the capacity for work and attention were increased, and the stress index and fatigue degree were decreased. In addition, multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma were effective in maintaining a stable heart and health. In addition, the Vibra image appeared to decrease tension/anxiety and stress. The multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma help increase the Neuro-energy more than that by no exposure and single-sensory stimulation.

Friction and Wear Behavior of Ultra-Thin TiN Film during Sliding Wear against Alumina and Hardened Steel (마모 상대재 변화에 따른 TiN 극박막의 마찰 및 마모거동)

  • Song, Myeong-Hun;Lee, Jae-Gap;Kim, Yong-Seok
    • Korean Journal of Materials Research
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    • v.10 no.1
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    • pp.62-68
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    • 2000
  • Ultra thin TiN films (50∼700nm thickness) were deposited on AISI 304 stainless steel substrates using a reactive DC magnetron sputtering deposition process to investigate their wear and friction properties. Dry sliding wear tests of the films were carried out against hardened steel and alumina counterparts using a pin-on-disk type wear tester at room temperature. Variation of friction coefficient was measured as a function of film thickness, load, sliding speed and roughness of the substrate. Worn surfaces of the film were examined by a scanning electron microscope. Wear resistance of the TiN film increased with the increase of the film thickness. The TiN film showed relatively high wear resistance in spite of its ultra thin thickness when it is mated by the steel counterpart, while it showed poor wear resistance with the alumina counterpart. The good wear resistance with the steel counterpart was explained by the formation of oxide layers on the film surface and sound interface character between the ultra thin film and the substrate.

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A Mobile Newspaper Application Interface to Enhance Information Accessibility of the Visually Impaired (시각장애인의 정보 접근성 향상을 위한 모바일 신문 어플리케이션 인터페이스)

  • Lee, Seung Hwan;Hong, Seong Ho;Ko, Seung Hee;Choi, Hee Yeon;Hwang, Sung Soo
    • Journal of the HCI Society of Korea
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    • v.11 no.3
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    • pp.5-12
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    • 2016
  • The number of visually-impaired people using a smartphone is currently increasing with the help Text-to-Speech(TTS). TTS converts text data in a mobile application into sound data, and it only allows sequential search. For this reason, the location of buttons and contents inside an application should be determined carefully. However, little attention has been made on TTS service environment during the development of mobile newspaper application. This makes visually-impaired people difficult to use these applications. Furthermore, a mobile application interface which also reflects the desire of the low vision is necessary. Therefore, this paper presents a mobile newspaper interface which considers the accessibility and the desire of various visually impaired people. To this end, the proposed interface locates buttons with the consideration of TTS service environment and provides search functionality. The proposed interface also enables visually impaired people to use the application smoothly by filtering out the words that are pronounced improperly and providing the proper explanation for every button. Finally, several functionalities such as increasing font size and color reversal are implemented for the low vision. Simulation results show that the proposed interface achieves better performance than other applications in terms of search speed and usability.

Determination of Combustion Propagation Velocity of Thermite Reaction Mixture Using Continuous VOD Measurement System (연속적 폭굉속도 측정 시스템을 이용한 테르밋 반응 혼합물의 연소전파속도 측정에 관한 연구)

  • Kim, Min-Seong;Kang, Hyeong-Min;Jeong, Sang-Sun;Jeong, Yun-Yeong;Park, Hoon;Cho, Sang-Ho
    • Explosives and Blasting
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    • v.33 no.3
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    • pp.21-28
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    • 2015
  • The objective of this study is to develop a method for monitoring continuously the combustion propagation behavior of commercial thermite reaction mixtures using conventional continuous VOD (velocity of detonation) system. In order to monitor the combustion front propagation with elapsed time during thermite reaction, the VOD system employs two types of commercial VOD probes and one self-made probe: VOD PROBEROD-OS, VOD PROBEROD-HS and VOD PROBEROD-ES, respectively. Among the probes, the only self made VOD PROBEROD-ES successfully demonstrates the velocity of combustion propagation (VOC) with elapsed time. It was found that VOC of the thermite reaction mixture inside a steel tube has been reached around 200m/s within 100mm distance from the ignition and dramatically increased up to about twice the speed of sound in the range between 100mm and 300mm distance. Finally the VOC reached up to around 800m/s. This results imply that it is necessary to use over 300mm long cartridge of thermite reaction mixture in order to achieve normal VOC of the mixture.

A Study on the Effect of Accident-Proneness Prospect by Health Conditions in Children (유아의 건강도에 따른 사고경향예지도에 관한 연구)

  • 방주영
    • Korean Journal of Health Education and Promotion
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    • v.13 no.1
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    • pp.90-116
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    • 1996
  • The purpose of this study is to provide basic data for the children so as to avoid any accidents and to improve their health through a sound and safe living environment with safety education established through more systematic methods. For the study, the methods used include the questionnaires for collecting data which are distributed among 273 children from 3 to 6 years old. They live in three districts of Seoul (Kangnam and Kangbuk), Kyeonggido (Munsan and Ilsan) and Incheon. The children's general characteristics are investigated and the relationship between the accident-proneness prospects and their results are analyzed assuming that children's health is expected to have an effect on their safety. The findings of the study are as follows: 1. The accident-proneness prospect (for the living safety) has significant difference in sleeping habits and physically weak conditions(p<0.05). 2. The accident-proneness prospect (for the traffic safety) has no significant difference in accordance with the children's health condition. 3. Children's reasoning power has no significant difference in accordance with their health condition. 4. Children's movement speed non-significantly differs in accordance with their health condition. 5. Children's movement stability has a significant difference in accordance with their health conditions such as history of mild disease(p<0.05) and physical work capacity(p<0.05). 6. Children's attention power has no significant difference in accordance with their health condition. 7. Children's characteristic activities show a significant difference in accordance with their health history of mild disease(p<0.05). mental health(p<0.05). eating habits(p<0.05) and others (i.e. auditory abnormality and skin desease)(p<0.05). 8. General assessment of the APP test has no significant difference in accordance with their health condition. 9. The health conditions are a significant difference in the history of mild disease in accordance with sex(p<0.05) and whole family members(p<0.001). Also there are shown significant differences. in accordance with sex(p<0.05). in physical work capacity(p<0.05). Eye sight, blood circulation and skin condition show significant differences in accordance with residence(p<0.05) and whole family members(p<0.01). and the condition of eating habits appeared significant in accordance with age(p<0.05). Also, sleeping habits and physically weak conditions shows significant differences in accordance with age(p<0.001) and housing pattern(p<0.01), and others (i.e. auditory abnormality and skin desease) show significant differences in accordance with residence (p<0.001).

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Microleakage and Anticariogenic Effect of S-PRG Filler-containing Pit and Fissure Sealant (S-PRG filler를 함유한 치면열구전색제의 미세누출 및 항우식효과)

  • Shin, Seungwoo;Kim, Jongsoo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.40 no.4
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    • pp.247-252
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    • 2013
  • Pit and fissure sealant prevents biofilm accumulation, plays a role in forming a barrier to acidic substance made by the bacteria. The Surface reaction-type pre-reacted glass ionomerI(S-PRG) filler was developed in 1999. S-PRG filler releases fluoride continuously and does not decompose under wet conditions. The aim of this study was to test the microleakage and anticariogenic effect to adjacent enamel of S-PRG filler-containing pit and fissure sealant. Sound premolars and molars were used in this study. A S-PRG filler-containing pit and fissure sealant, Beautisealant$^{(R)}$(Shofu, Japan) was used for this experiment, the composite resin sealant Concise$^{(R)}$(3M ESPE, USA) was used as control. For the microleakage test, all teeth surface were double coated with finger nail varnish, with the exception of a 1.0 mm window around the restoration margins. The teeth were immersed in 2% methylene blue solution for 24 hours and then rinsed in tap water. For the anticariogenic effect evaluation, all tooth were immersed in artificial carious solution for 9 days and rinsed with tap water. Each tooth was embedded in orthodontic acrylic rein and subsequently sectioned longitudinally in a bucco-lingual direction with a low-speed diamond saw. The cut sections were examined using a stereomicroscope. Differences in microleakage between the two groups were not different significantly. But the S-PRG filler-containing pit and fissure sealant showed higher anticariogenic effect than that of flowable resin sealant.

Investigation of the Noise Reduction in the Hollow Cylinder Structure (중공 원통형 구조물의 전달소음 감소 방안 연구)

  • Lee, Sang-Won;Lee, Jong-Kil;Jo, Chi-Yong
    • 대한공업교육학회지
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    • v.36 no.1
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    • pp.115-130
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    • 2011
  • When the hollow cylinder structure moves in underwater with high speed structural can be propagated from the end of the structure to the front side. This noise can reduce the sensitivity of the conformal array which installed in the surface of the cylinder. To reduce this noise propagation it is suggested to install two self-reduction rings at the surrounding of the cylinder which is 500mm in diameter and 840mm in length. The places of the two noise reduction rings are 120mm and 240mm point from the end of the structure. Two noise reduction rings reduced 10.1 % of maximum stress. When outside noise frequency applied to the structure from the 4kZ to 6kHz, 20dB noise reduction was calculated using 6 order polynomial equation. When outside noise frequency also applied to the structure with 200Hz, 500Hz, 900Hz, maximum sound pressure level point moved to the end of the structure. Most conformal sensors are fabricated at the front side of the structure. Based on the simulation results proposed two rings can be reduced noise propagation from the tail of the structure effectively.