• Journal of Korean society of Dental Hygiene
• /
• v.12 no.3
• /
• pp.513-520
• /
• 2012

Objectives : In this study, contact angle and shore D hardness were measured, and a shark fin test was conducted after selecting five addition silicon(Blu-Mousse, BM; EXABITE II, EX; PERFECT, PF; Regisil$^{(R)}$ Rigid, RE; Silagum$^{(R)}$, SI) in order to figure out the properties of elastomeric interocclusal recording materials and reduce errors at interocclusal recording. 8) Methods : A contact angle was measured using a contact angle analyzer. After placing a drop of liquid on the surface of the specimens of interocclusal recording materials, a contact angle was photographed with a CCD camera on the equipment. In terms of a shark fin test, interocclusal recording materials were mixed for the time proposed by the manufacturer and inserted into the split ring of the Shark fin device. Twenty (20) seconds exactly, a metal rod was removed to make the materials slowly absorbed. Once they hardened, fin height was measured with a caliper after separating molds and trimming the specimens. The shore D hardness was measured with a shore D hardness tester(Model HPDSD, Hans Schmidt & Co. Gmbh, Germany) in sixty (60) minutes after fabricating specimens. In each experiment, five specimens, mean and standard deviation were calculated. A one-way ANOVA test was performed at the p>0.05 level of significance. In terms of correlation among the tests, Pearson correlation coefficient was estimated. For multiple comparison, Scheffe's test was carried out. Results : A contact angle was the highest in EX with $99.23^{\circ}$ (p<0.05) while the result of the shark fin test was the longest in RE with 5.45mm. SI was the lowest (0.27mm) with statistical significance. Among the interocclusal recording materials, significant difference was observed in terms of means (p<0.05). The shore D hardness was the highest in SI with 31.0 while RE was significantly low with 16.4 (p<0.05). Among the materials, statistically significant difference was observed in terms of means when compared to the rest materials (RE), BM, RE and SI (PF and EX) and the remaining materials (BM and SI) (p<0.05). In terms of correlations among the tests, a negative correlation occurred between shore D hardness and shark fin test(r=-0.823, p=0.000). Conclusions : According to the study above, it is necessary to understand the properties of interocclusal recording materials and consider contact angle, shark fin test and properties of shore D hardness to select appropriate materials.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.36D no.10
• /
• pp.61-70
• /
• 1999

In this paper, we analyze several exposure time schedules to obtain uniform multiple hologram and measure the diffraction efficiencies of holograms stored in $LiNbO_3$:Fe(0.015wt%) crystal through experiments. The minimum angular selectivity and the intensity ration of two incident beams are investigated precisely by the high resolution system(minimum angle : $0.0028^{\circ}$). Considering initial recording time, total exposure time and time constants, the efficiency distribution(0.014 ${\pm}$ 0.005%) of 100 holograms is measured and the 330 analog images are recorded in the same place. Also, total 500 holograms are retrieved by spatial multiplexing.

• Child Health Nursing Research
• /
• v.15 no.3
• /
• pp.261-270
• /
• 2009

Purpose: The purpose of this study was to compare the result of one-way ANOVA with that of cross-correlation time series analysis in order to evaluate physiologic responses of premature infants to human voices. Methods: Four premature infants born prior to 32 weeks gestational age were included in the study. The Gould 4000TA Recording System recorded the preterm infant's heart and respiratory rate while they were listening to a pre-recorded voice recording. Each infant listened to both male and female voices (1 min each) at each testing session. Results: The results of both one-wayANOVA and cross-correlation time series analysis using heart and respiratory rate data were not consistent in some of premature infants. A cross-correlation time series analysis revealed that the responses of premature infant to vocal stimulation occurred at a varying number of seconds after the stimulus was presented and lasted for over 20-30 sec. Conclusion: The results indicate that a time series analysis can provide more detailed information on the rapidly changing physiologic status of premature infant to the auditory stimulus. In addition, the results provide an insight into an auditory responsitivity of premature infants to a naturally occurring sound, the human voice, in the neonatal intensive care unit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.71-77
• /
• 2002

The spectrum of impulse response signal which is obtained from an impulse hammer testing is used for frequency response function, nevertheless it has serious faults when the record length for the signal processing is not very long. The faults cannot be avoided with the conventional signal analyzer that is processing all the signals as if they are always periodic. The signals generated by the impact hammer are undoubtedly non-periodic because of the damping, and are acquired for limited recording time due to the memory as well as the computation performance of the signal analyzer. This paper will make clear the relation between the faults and the length of recording time, and propose the way for solving the faults.

• Journal of the Korea Convergence Society
• /
• v.8 no.1
• /
• pp.7-12
• /
• 2017

In this paper, we proposed an electronic attendance-absence recording system using a smartphone that does not require separate BLE(Bluetooth Low Energy) devices and infrastructure by using BLE advertisement technology of smartphone. The existing BLE-based electronic attendance-absence recording system requires a BEL device to be attached to each classroom for services and a separate technology to identify the devices attached to the classroom. Also, due to the interference with each other, sometimes an error occurred in the electronic connection. In this paper, we propose a system to solve the problems about time, place and cost, which is a disadvantage of the conventional Bluetooth beacon system. BLE advertising function of the smartphone that the user is using without BLE device, it is possible to construct infrastructure for electronic attendance-absence recording system. In order to evaluate the effectiveness of the proposed system, we designed the system structure and operation flow and constructed the system using the smart phone in actual used.

• Journal of Advanced Navigation Technology
• /
• v.17 no.2
• /
• pp.234-239
• /
• 2013

Learning a lesson about poor concentration and problems of the existing content, the system of language which could not be determined, Many teachers' assessment decision was made. As a result, voice recording based on the combination of ubiquitous technology and virtual reality technology, and install the projector in a classroom Through the learning content corresponding grade English student ID card attached RFID reader in each classroom, and students of RFID tags attached. In reality of the virtual three-dimensional image content foreigners and question-and-answer using the voice recording technology at the same time check the pronunciation and intonation level passes or level failure judged. Student education data to a central server system is configured to do so after saving to the DB through a feedback process, which provides information. Analysis of the issues that can have a common language content in the present study and Problem for voice recording technology to solve the problem and did not solve the existing language in the content level based classes.

• Korean Journal of Optics and Photonics
• /
• v.9 no.3
• /
• pp.199-204
• /
• 1998

To increase the storage density in hologram recording, a simple scheme to obtain rotational, angular and spatial multiplexing efficiently at the same time is proposed and experimented. Both rotational multiplexing and angular multiplexing are obtained by controlling the reference beam directly by use of a pair of wedge prisms, while spatial multiplexing is obtained by shifting the recording medium in the recording plane. It is possible to get both an acute-angle geometry, in which the angle between the signal and reference beams is less than 90$^{\circ}$, and a 90$^{\circ}$ geometry, in which the angle is approximately 90$^{\circ}$. In experiment, 180 holograms were multiplexed with an acute-angle geometry where a photopolymer was used for the recording medium, and 147 holograms with 90$^{\circ}$ geometry where a Fe-doped LiNbO$_3$ crystal was used. The proposed scheme makes it easy it easy to realize a practical holographic memory system by simplifying the control of three complex mechanical motions that are necessary for the three multiplexing techniques.

• Korean Journal of Optics and Photonics
• /
• v.14 no.6
• /
• pp.663-668
• /
• 2003

We studied a localized hologram recording method that can be used in a disk-shaped medium. In this method, the reference beam is focused by use of a cylindrical lens to get a thin spot in the medium, and then a hologram is recorded in that spot by illuminating the signal beam. Many localized holograms are multiplexed by shifting the medium by a distance more than the thin spot size of the reference beam. This method does not need recording-time scheduling for uniform diffraction efficiencies. We show that a minimal required thickness of the recording medium exists for a given spot size of the signal beam. We performed experiments for data storage and retrieval, and obtained a storage density of 20 bits/${\mu}{\textrm}{m}$$^2$ and a raw-bit error rate (RBER) of 2.5${\times}$10$^{-3}$ , when a 2 mm-thick Fe-doped LiNbO$_3$ crystal was used.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.254-260
• /
• 2019

Recently, a self-camera that generates and distributes a large amount of moving images has been rapidly increasing due to the appearance of SNS such as Facebook, Instagram, and Tweet using mobile. In particular, the amount of SNS connections using mobile phones is significantly increasing in terms of usage, number of connections, and usage time. However, the use of a self-recording system using a smartphone by itself is extremely limited not only in terms of usage but also in frequency of use. In addition, the conventional unattended recording system is a very expensive system that automatically records and tracks an object to be photographed using an infrared signal. Therefore, this paper developed a low cost unmanned recording system using mobile phone. The system consists of a commercial mobile camera, a servomotor for moving the camera from side to side, a microcontroller for controlling the motor, and a commercial wireless Bluetooth earset for video audio input. And it is an unmanned automation system using mobile, and anyone can record image by self image tracking.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.11a
• /
• pp.196-197
• /
• 2002