• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.241-248
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• 2016

Objectives: The purpose of the study is to evaluate the dental website usability in Korea. The dental website included dental university hospital, network dental hospital and dental office. Methods: The study was carried out by three age groups including twenties, thirties, and forties. Each group consisted of ten customers and evaluated twelve websites of dental hospitals. Each was assigned to four hospitals and three tasks including easiness of online reservation, preventive information, and treatment information. They filled out the self-administered questionnaire. The questionnaire included the easiness of on-line reservation, satisfaction on the quality and quantity of preventive informations, satisfaction on the quality and quantity of treatment informations, predictiveness on the sub-menu, usefulness of site map, information on the main page of web site, usefulness of decision on visit to dentistry, and revisit intention. Results: The easiness of on-line reservation was the highest in the private dental office, and university dental hospital and network dental hospitals followed in conducting task(1). The anticipated value and measurement on the usefulness of web site were the lowest in network dental hospitals and the time interval between two values was 57 seconds. This discrepancy showed the largest difference. The satisfaction on treatment information in task(3) was higher than that of the satisfaction on preventive information in task (2). The revisit intention was the highest in dental university hospitals. Conclusions: This study showed the comparison in usefulness of web site of university dental hospitals, network dental hospitals and private dental office. The web site focused on the treatment information rather than preventive information. This study suggested that the most important function of dental web site would be the preventive information that was mainly operated by the role of dental hygienists rather than treatment information in the future.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.85-92
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• 2016

PURPOSE: A good, valid, and feasible tool for evaluating sit to stand (STS) is needed to help clinicians quantify the STS ability of stroke patients and people with balance disorders. The purpose of this study was to evaluate the concurrent validity of the Nintendo Wii Balance Board (WBB) and a force plate during STS and gait. METHODS: Seventeen healthy adults performed five trials of STS and gait on the WBB placed on the force plate. The force plate and the WBB were compared in regard to center of pressure (COP) and ground reaction force (GRF) data that were collected simultaneously. The variables used for analysis were time (s), integral summation (%), COP path length (mm), COP x range, and COP y range, all of which were measured for both tasks. Counter (%), peak (%), and rebound (%) were analyzed for STS, and $1^{st}$ peak (%), min peak (%), and 2nd peak (%) were analyzed for gait. The concurrent validity was analyzed using an intraclass correlation coefficient (ICC) and a standard error of measurement (SEM) with a 95% confidence interval. RESULTS: The concurrent validity of the WBB for STS ranged from fair to good (ICC=.701~.994, SEM=.029~3.815). The concurrent validity for gait was good (ICC=.869 ~.989, SEM=.007~2.052) aside from path length and x and y ranges of COP (ICC=-.150~.371, SEM=3.635~4.142). CONCLUSION: The GRF of the WBB has a good validity for STS and gait analysis. The WBB is remarkably portable, easy to use, and convenient for clinically assessing STS and gait.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.58-68
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• 2015

Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p<0.05). Time interval for recovery from decreased serum Ca to its normal range (>9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis ($R^2$ = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.309-316
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• 2010

In this study, a digital particle holographic system and its application to channel-flow measurements were investigated. A double-exposure hologram recording system that is capable of recording digital holograms in a short time interval was developed. A correlation coefficient method was used to determine the focal plane of particles. The Wiener filter was used to remove noises and improve image quality. Two-threshold and image segmentation methods were used for binary image transformation. The cross-correlation method was used for particle pairing. The developed system was employed to study channel flow fields, and the axial velocities of channel flow were measured. The measurement errors are acceptable, and this proves the feasibility of using the digital particle holographic system as a good tool for flow-field measurements.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.919-926
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• 2023

To analyze the cause of the destruction of thin, carbon-backed lithium fluoride targets during a measurement of the fusion of ⁷Li and ¹⁷O, we estimate theoretically the lifetimes of carbon and LiF films due to sputtering, thermal evaporation, and lattice damage and compare them with the lifetime observed in the experiment. Sputtering yields and thermal evaporation rates in carbon and LiF films are too low to play significant roles in the destruction of the targets. We estimate the lifetime of the target due to lattice damage of the carbon backing and the LiF film using a previously reported model. In the experiment, elastically scattered target and beam ions were detected by surface silicon barrier (SSB) detectors so that the product of the beam flux and the target density could be monitored during the experiment. The areas of the targets exposed to different beam intensities and fluences were degraded and then perforated, forming holes with a diameter around the beam spot size. Overall, the target thickness tends to decrease linearly as a function of the beam fluence. However, the thickness also exhibits an increasing interval after SSB counts per beam ion decreases linearly, extending the target lifetime. The lifetime of thin LiF film as determined by lattice damage is calculated for the first time using a lattice damage model, and the calculated lifetime agrees well with the observed target lifetime during the experiment. In experiments using a thin LiF target to induce nuclear reactions, this study suggests methods to predict the lifetime of the LiF film and arrange the experimental plan for maximum efficiency.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.519-526
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• 2013

ECG signal has the feature that is repeated in a cycle of P, Q, R, S, and T waves and is sampled at a high sampling frequency in general. By using the feature of periodic ECG signals, maximizing compression efficiency while minimizing the loss of important information for diagnosis is required. However, the periodic characteristics of such amplitude and period is not constant by measuring time and patients. Even though measured at the same time, the patient's characteristics display different periodic intervals. In this paper, an adaptive multi-level coding is provided by coding adaptively the dominant and non-dominant signal interval of the ECG signal. The proposed method can maximize the compression efficiency by using a multi-level code that applies different compression ratios considering information loss associated with the dominant signal intervals and non-dominant signal intervals. For the case of long time measurement, this method has a merit of maximizing compression ratio compared with existing compression methods that do not use the periodicity of the ECG signal and for the lossless compression coding of non-dominant signal intervals, the method has an advantage that can be stored without loss of information. The effectiveness of the ECG signal compression is proved throughout the experiment on ECG signal of MIT-BIH arrhythmia database.

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.275-285
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• 1997

We have investigated Pi 2 pulsations which were observed both on ground magnetometer array and by satellites. On November 9th in 1994, Pi 2 pulsations appeared globally on the 190/210 magnetometer chain and Hermanus station when two satellites(EXOS-D and ETS-VI) were located near the magnetic meridian of the 210 array. The local time of measurements covers from morning(LT=8.47hr) to afternoon(LT=20.3hr) and the bandwidth of peak frequency is found relatively small. The signals of the electric field are highly coherent with ground-based observations with the out of phase oscillations. However, the magnetic field measurement on the ETS-VI in the outer magnetosphere(L=6.60) shows no signature of Pi 2 pulsations over the same time interval and the correlation with any of the ground-based stations is found to be very weak, even through both satellites and magnetometer chain are located close to each other in local time. We suggest that this event may be a direct evidence of Pi 2 pulsations as virtual resonant modes which are localized in the plasmasphere(Lee 1996). The results show that the cavity mode oscillations can occur in the inner magnetosphere with less spectral noise compared to the outer magnetospheric case.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.17-25
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• 1991

This study was undertaken to find the effect of radiation therapy on the healing ability of surgical wounds and on this basis, to find the proper time interval between the radiation therapy and surgery. Two hundred and fifty-two mice were used and a single dose of 2000 cGy was given in each instances to the hind limb of mice. Incisional wounds were produced after varying intervals in the previously irradiated areas and then they were followed up at regular intervals by the measurement of tensile strength. The wounds which received surgery immediately, 1 or 2 weeks after irradiation revealed marked delay and the wounds which received surgery 12, 16 or 20 weeks after irradiation demonstrated slight delay in wound healing in terms of tensile strength measurement. But the wounds which received irradiation 4 or 8 weeks before surgery did not differ much in the wound healing process from that of the control group. Histopathologic studies of the wounds demonstrated epithelization in most instances as quickly as in the control wounds. The appearance of fibroblasts and collagen fibers has delayed momently and appeared to have close correlation with the tensile strength healing curves.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.439-448
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• 2001

This paper considers the acoustical characteristics of the closing click sounds of the mechanical valves employed in an implantable biventricular assist device (BYAD) and their re1evance to the Physical states of the valved. Bj rk Shiley Convexo Concave tilting disk valve was chosen for the study and acoustic measurement was made for the BYAD operated in a mock circulatory system as well as implanted in an animal (sheep). In the BYAD operated in the mock circulatory system. three different states of the valve were examined, ie. normal. mechanically damaged. pseudo-thrombus attached. Microphone measurement for the BVAD implanted in the animal was carried out for five days at a regular time interval from one day after implantation. Characteristic spectrum of the sound from the valve was estimated using Multiple Signal Classification (MUSIC) in which the optimal order was determined according to Bayesian Information Criterion (BIC) . It was observed that the mechanical damage of the valve resulted in changes of the structure of the acoustic spectrum. In contrast. the thrombus formed on the valve did not change much the basic structure of the spectrum but brought about altering the spectral Peak frequencies and energies. Maximum spectral Peak (MSP) with the greatest energy was seen at 2 kHz for the normal valve and it was shifted to 3 kHz for the calve attaching the Pseudo-thrombus. Unlike the normal valve, strong spectral Peak appeared around 7 kHz in the sound from the valve mechanically damaged. In the case of the BYAD implanted in the animal. as the thrombus grew, acoustic energy was reduced relatively more in the low frequency components (〈 2 kHz) and the frequencies of the 1st, 2nd and 3rd MSP were increased little. The thrombus formation would result in reduction in both the variability of the 1st, 2nd and 3rd MSP and the value of the BIC optimal order.

• Journal of Environmental Impact Assessment
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• v.28 no.1
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• pp.35-48
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• 2019

Long term flow measurement and water quality analysis data need to determine the target and allowable load for each basin in Total Water Pollution Load Management System (TWPLMS). The Load Duration Curve (LDC) is analyzed the relationship between flow data and water quality, and evaluates the pollutant load characterization by flow conditions. LDC of Kyeongancheon is created by the Flow Duration Curve (FDC) that was analyzed 8-day interval measured flow data from 2006 to 2015 and numeric water quality target in Kyeongancheon. As a result of this study, it is necessary to manage the point source pollutant because the numeric water quality target is not satisfied in the low flows. Also the numeric water quality target has been exceed for four months from March to June of the year and continuous and systematic watershed management is required to satisfy the numeric water quality target.