• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.27-28
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• 1989

In conventional line scan angiography, flow signal has been enhanced by the time_of_flight effect while the signal from stationary tissues has been suppressed by the saturation rf pulse followed by spoiling gradients. Due to the inhomogeneous rf field and the tissue dependent T1 relaxation time, however, stationary tissues can not be suppressed completely or uniformly, and the remnant stationary signal deteriorates the resultant angiogram. Here, the complete cancellation of stationary tissues is made possible by the spectral analysis of a series of repetitive line images of the same slice. The Fourier transformation of a set of line images results in the spectrum images, where stationary tissues are collected into the dc component while arteries are included in harmonic components because of the variation of the flow velocity and the resultant flow signal in arteries according to the cardiac cycle. The summation of harmonic components excluding the dc component results in the angiogram of arteries with the complete cancellation of stationary tissues.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.1
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• pp.25-29
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• 2016

Background: The most important reason for pre-operative administration of medication is to reduce anxiety. Alleviation of fear and anxiety about surgery enables patients to remain comfortable during treatment. Dexmedetomidine (DEX) is a fast-acting drug that is used as a premedication in different circumstances because it has sedative and anti-anxiolytic effects, and stable hemodynamics. It also has the advantage of intranasal administration. The aim of this study was to investigate the effects and hemodynamic stability of DEX by retrospectively analyzing cases in which DEX was administered nasally as a premedication. Methods: Ten patients treated at Dankook University Dental Hospital, recruited between February and April 2015, received intranasal delivery of $2{\mu}g/kg$ DEX, 30 minutes prior to general anesthesia. Anesthesia records of anxiety, blood pressure, respiration, pulse, estimated arterial oxygen saturation ($SpO_2$), and partial pressure, or maximum concentration, of carbon dioxide ($ETCO_2$) were analyzed. Results: Administration of DEX prior to a general anesthetic effectively relieved anxiety. Respiratory depression, the most severe adverse effect of other sedatives, was not observed. Hemodynamic stability under general anesthesia was maintained during treatment and a reduction in emergence delirium was observed upon completion of treatment. Conclusions: Premedication administration of DEX is safe for pediatric patients undergoing dental treatment under general anesthesia.

• Speech Sciences
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• v.14 no.3
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• pp.127-137
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• 2007

The aim of this study is to examine the influence of vocal training on internal respiration in order to develop an efficient method of singing phonation. Five males trained singers (age:$25.0{\pm}1.4years$, career:$6.8{\pm}1.1\;years$) and five female trained singers (age:$22.0{\pm}1.0years$, career:$5.8{\pm}1.2\;years$) participated in this study. $SaO_2$(Oxi Hemoglobin saturation) was measured by Oxy-Pulse meter while $P_ACO_2$ (Pressure Alveolar $CO_2$) was measured by Quick et $CO_2$ before and after 2-minute, 4-minute and 6-minute vocal training. Result showed that $SaO_2$ was within a normal range after vocal training but $P_ACO_2$ came out lower than the normal range (36-40mmHg) after vocal training which led to Hypocapnia. This caused the singers to experience some headache and dizziness.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.5
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• pp.273-283
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• 2013

The traditional medical equipments are devices used by medical professionals but not used in public environment. Common people, however, require light-weight medical devices to make healthcare for themselves nowadays. Those medical devices are used to monitor personal health status such as blood pulse, blood pressure, diabetes. Also, some of them are operated in mobile environment called u-healthcare. This paper implements a portable healthcare system composed of $SpO_2$(Saturation of Partial Pressure Oxygen) sensors and a gateway for detecting hypoxemia during people's leasure activity such as climbing or hiking. The $SpO_2$ sensor is designed as watch style to support dynamic exercise and the gateway is designed as necklace style to support the elderly. The result of a performance evaluation shows that the performance of the $SpO_2$ sensor using reflection technology is not lower than that of a clairvoyant styled $SpO_2$ sensor.

• The Korean Journal of Pain
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• v.6 no.1
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• pp.109-116
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• 1993

In March of l992, We performed two intentional total spinal blocks for the relief of pain. This was for 2 cases of post-traumatic cervical syndrome whose various symptoms were chronically unresponsive to the usual conservative treatments. We regularly checked the blood pressure, pulse rate, oxygen saturation and observed clinically the changes of respiration, consciousness, lid and light reflexes during the total spinal block. Pain relief was evaluated by using the Visual Analog Scale which is designed to measure the subjective intensity of pain. The results were as follows; 1) The effectiveness of total spinal block was 60% in case 1, 40% in case 2. 2) We observed two complications from the procedure. Firstly during the block, these were transient periods of hypotension. Following the block, accidental procedures related direct neural trauma resulted in anterior chest wall pain. In conclusion we believe that total spinal block is a satisfactory and reliable method for the treatment of post-traumatic cervical syndrome.

• Current Optics and Photonics
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• v.3 no.2
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• pp.143-149
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• 2019

Shape ellipticity dependence of the exciton fine energy levels in CdTe and CdSe nanocrystal quantum dots were compared theoretically by considering the crystal structure and the Coulomb interaction of an electron and a hole. While quantum dot ellipticity changes from an oblate to prolate quantum dot via spherical shape, both the fine energy levels and the dipole moment in wurtzite structure of a CdSe quantum dot change linearly for ellipticity. In contrast, CdTe quantum dots were found to show a level crossing between the bright and dark exciton states with a significant change of the dipole moment due to the cubic structure. Shape ellipticity dependence of the optical nonlinearities in CdTe and CdSe nanocrystal quantum dots was also calculated by using semiconductor Bloch equations. For a spherical shape quantum dot, only $1^L$ dominates the optical nonlinearities in a CdSe quantum dot, but both $1^U$ and $0^U$ contribute in a CdTe quantum dot. As excitation pulse area becomes strong (${\sim}{\pi}$), the optical nonlinearities of both CdSe and CdTe quantum dots are mainly governed by absorption saturation. However, in the case of a prolate CdTe quantum dot, the real part of the nonlinear refractive index becomes relatively significant.

• Geophysics and Geophysical Exploration
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• v.16 no.3
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• pp.171-179
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• 2013

An automated ultrasonic velocity measurement system adopting pulse-echo-overlap (PEO) method has been constructed, which is known to be a precise and versatile method. It has been applied to velocity measurements for 5 kinds of engineering plastic cores and compared to first arrival picking (FAP) method. Because it needs multiple reflected waves and waves travel at least 4 times longer than FAP, PEO has basic restriction on sample length measurable. Velocities measured by PEO showed slightly lower than that by FAP, which comes from damping and diffusive characteristics of the samples as the wave travels longer distance in PEO. PEO, however, can measure velocities automatically by cross-correlating the first echo to the second or third echo, so that it can exclude the operator-oriented errors. Once measurable, PEO shows essentially higher repeatability and reproducibility than FAP. PEO system can diminish random noises by stacking multiple measurements. If it changes the experimental conditions such as temperature, saturation and so forth, the automated PEO system in this study can be applied to monitoring the velocity changes with respect to the parameter changes.

• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.3-13
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• 2001

It has been known that nonlinear characteristics of sorption affect the transport behavior of water soluble pollutants in soils. However detailed experimental studies have not been performed to verify the effect of non-linearity of adsorption isotherm on transport of chemicals in porous media. In this research, the distortion of breakthrough curves of a cationic surfactant (cetylpyridinium chloride, CPC) in a engineered stainless steel column packed with glass beads were investigated. Glass beads with about 110 $\mu\textrm{m}$diameter coated with a thin n-decane film were used as the media providing the sorption surface for CPC. The CPC adsorption isotherm on the surface of n-decane from aqueous solution was a typical Langmuir type. The breakthrough curve of CPC using step Input showed a late breakthrough on the front side and early breakthrough on the back side accordance to the shape of the isotherm. The retardation factor of CPC was found to be a strong function of the input concentration, which also a manifestation of the non-linearity of the isotherm. The retardation factors for the CPC with step input agreed with those of pulse input that the maximum concentrations are controlled to be the same as the step input concentrations. This results support the validity of the unproven field practices of using hydrogeotracers with non-linear adsorption isotherms to determine the hydrogeological parameters, e.g., NAPL saturation, air-water or NAPL-water interfacial areas.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.489-497
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• 2002

The purpose of this study was to compare the clinical sedation effect of chloral hydrate and hydroxyzine combination with and without nitrous oxide/oxygen inhalation when young children were sedated for dental treatment. The uncooperative 20 children aged, 21 to 47 months of age(ASA Class I), participated in the study. The author examined 20 children(male 12, female 8). Each patient was assigned to receive chloral hydrate(50mg/kg) and hydroxyzine(25mg). Next appointment, each patient was assigned to receive $N_2O-O_2$, choral hydrate and hydroxyzine. Sleep, crying, movement, and overall behavior response were evaluated, and the sedative effects were evaluated by Houpt's rating scale. Pulse rate and peripheral oxygen saturation were also measured for monitoring the sedated patients during treatment period by pulse oximeter. The result were as follows : 1. In the evaluation of sleep scores, crying scores, and movement scores, chloral $hydrate/hydroxyzine/N_2O-O_2$ combination group was significantly rated high(p<0.05). 2. In the evaluation of overall behavior scores, chloral hydrate/hydroxyzine/$N_2O-O_2$ combination group was significantly rated high(p<0.05). 3. In the evaluation of overall behavior evaluation scores(by Houpt), 93.3% in chloral $hydrate/hydroxyzine/N_2O-O_2$ combination group and 63.3% in chloral hydrate/hydroxyzine combination group were rated "good" or "very good". 4. There was no adverse side effect(i.e. respiratory depression) in both group.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.262-269
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• 2005

The purpose of this study was to compare the efficacy and complications of two oral sedative regimens, chloral hydrate (60mg/kg)/hydroxyzine(25mg) versus midazolam(1mg/kg)/meperidine(1mg/kg) for the sedation of pediatric dental patients. Fifteen patients(mean age 36.2months, range 24-47months), ASA Class I or II, who needed at least two restorative dental procedures were selected in this double-blind, randomized study. All subjects were randomly assigned to receive either chloral hydrate/hydroxyzine or midazolam/meperidine and 50% $N_2O/O_2$ was administered at each appointment. Behavior assessment(sleep, movement, crying, overall behavior) was made using Houpt Sedation Rating Scale and physiologic parameters(pulse rate, oxygen saturation) were monitored using pulse oximeter. The incidence of hypoxia($SpO_2$ 90% or less, at least 10s duration) and vomiting was recorded. Patients sedated with chloral hydrate/hydroxyzine showed significantly better overall behavior score than patients sedated with midazolam/meperidine. There was no clinically significant difference in the incidence of hypoxia and vomiting. It was concluded that oral administration of chloral hydrate/hydroxyzine is more effective than midazolam/meperidine for the sedation of pediatric dental patients.