• Sleep Medicine and Psychophysiology
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• v.6 no.1
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• pp.19-25
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• 1999

Sleep alters both breathing pattern and the ventilatory responses to external stimuli. These changes during sleep permit the development or aggravation of sleep-related hypoxemia in patients with respiratory disease and contribute to the pathogenesis of apneas in patients with the sleep apnea syndrome. Fundamental effects of sleep on the ventilatory control system are 1) removal of wakefulness input to the upper airway leading to the increase in upper airway resistance, 2) loss of wakefulness drive to the respiratory pump, 3) compromise of protective respiratory reflexes, and 4) additional sleep-induced compromise of ventilatory control initiated by reduced functional residual capacity on supine position assumed in sleep, decreased $CO_2$ production during sleep, and increased cerebral blood flow in especially rapid eye movement(REM) sleep. These effects resulted in periodic breathing during unsteady non-rapid eye movement(NREM) sleep even in normal subjects, regular but low ventilation during steady NREM sleep, and irregular breathing during REM sleep. Sleep-induced breathing instabilities are divided due primarily to transient increase in upper airway resistance and those that involve overshoots and undershoots in neural feedback mechanisms regulating the timing and/or amplitude of respiratory output. Following ventilatory overshoots, breathing stability will be maintained if excitatory short-term potentiation is the prevailing influence. On the other hand, apnea and hypopnea will occur if inhibitory mechanisms dominate following the ventilatory overshoot. These inhibitory mechanisms include 1) hypocapnia, 2) inhibitory effect from lung stretch, 3) baroreceptor stimulation, 4) upper airway mechanoreceptor reflexes, 5) central depression by hypoxia, and 6) central system inertia. While the respiratory control system functions well during wakefulness, the control of breathing is commonly disrupted during sleep. These changes in respiratory control resulting in breathing instability during sleep are related with the pathophysiologic mechanisms of obstructive and/or central apnea, and have the therapeutic implications for nocturnal hypoventilation in patients with chronic obstructive pulmonary disease or alveolar hypoventilation syndrome.

• Journal of Oral Medicine and Pain
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• v.41 no.2
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• pp.54-60
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• 2016

Purpose: Mandibular advancement devices (MAD) are used effectively and widely for the treatment of obstructive sleep apnea (OSA) and rapid-eye-movement (REM) dependency of the patients can affect the treatment outcome of OSA. The aim of this study was to compare treatment outcomes of MAD between REM-related and not-REM-related OSA patients. Methods: Fifty-six consecutive patients with OSA who received MAD therapy were evaluated using full night polysomnography before and after insertion of the MADs. The patients were divided into REM-related (REM apnea-hypopnea index [AHI] at least two times higher than their non-REM AHI) and not-REM-related (REM AHI less than two times higher than their non-REM AHI) OSA groups. Results: MAD is used for the treatment of OSA effectively. In respect of AHI, MAD therapy were effective both in REM-related OSA and not-REM-related OSA, but MAD therapy was more effective in not-REM-related OSA than REM-related OSA in overall sleep and non-REM sleep. $SpO_2$ saturations were improved after MAD therapy, but were not different between two groups. Epworth sleepiness scale scores were not improved after MAD therapy. Percentage of REM sleep was increased after MAD therapy but was not different between two groups. Conclusions: MAD therapy was more effective in not-REM-related OSA than REM-related OSA and REM dependency can be a predictive factor of treatment outcome of oral appliance for OSA patients.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.999-1011
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• 2021

In spatio-temporal fusion aiming at predicting images with both high spatial and temporal resolutionsfrom multi-sensor images, the radiometric inconsistency between input multi-sensor images may affect prediction performance. This study investigates the effect of radiometric correction, which compensate different spectral responses of multi-sensor satellite images, on the spatio-temporal fusion results. The effect of relative radiometric correction of input images was quantitatively analyzed through the case studies using Sentinel-2, PlanetScope, and RapidEye images obtained from two croplands. Prediction performance was improved when radiometrically corrected multi-sensor images were used asinput. In particular, the improvement in prediction performance wassubstantial when the correlation between input images was relatively low. Prediction performance could be improved by transforming multi-sensor images with different spectral responses into images with similar spectral responses and high correlation. These results indicate that radiometric correction is required to improve prediction performance in spatio-temporal fusion of multi-sensor satellite images with low correlation.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.63-71
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• 2021

Purpose: The aim of this study was to assess the artefacts of 12 fixed orthodontic appliances in magnetic resonance images obtained using 1.5-T and 3-T scanners, and to evaluate different imaging sequences designed to suppress metal artefacts. Materials and Methods: In vitro, study casts of 1 adult with normal occlusion were used. Twelve orthodontic appliances were attached to the study casts and scanned. Turbo spin echo (TSE), TSE with high readout bandwidth, and TSE with view angle tilting and slice encoding for metal artefact correction were used to suppress metal artefacts. Artefacts were measured. In vivo, 6 appliances were scanned: 1) conventional stainless-steel brackets; 2) nickelfree brackets; 3) titanium brackets; 4) a Herbst appliance; 5) a fixed retainer; and 6) a rapid maxillary expander. The maxilla, mandible, nasopharynx, tongue, temporomandibular joints, and cranial base/eye globes were assessed. Scores of 0, 1, 2, and 3 indicated no artefacts and minor, moderate, and major artefacts, respectively. Results: In vitro, titanium brackets and the fixed retainer created minor artefacts. In vivo, titanium brackets caused minor artefacts. Conventional stainless-steel and nickel free brackets, the fixed retainer, and the rapid maxillary expander caused major artefacts in the maxilla and mandible. Conventional stainless-steel and nickel-free brackets caused major artefacts in the eye globe (3-T). TSE with high readout bandwidth reduced image artefacts in both scanners. Conclusion: Titanium brackets, the Herbst appliance, and the fixed retainer caused minor artefacts in images of neurocranial structures(1.5-T and 3-T) when using TSE with high readout bandwidth.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.1
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• pp.18-35
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• 1999

Coptidis Rhizoma, Fraxini Cortex, Jinpisan(秦皮散) have been as eye washes of inflammatory eye disease in the oriental medicine. Especially Jinpisan(秦皮散) has been used for the disease which is similar to Peudomonas aeruginisa keratitis. This research was attempted to investigate the effect of Coptidis Rhizoma, Fraxini Cortex, Jinpisan(秦皮散), on Peudoronas aeruginisa keratitis. Pseudomonas aeruginosa keratitis causes a deep rapid intense ulceration which often leads to perforation of the cornea within 48 hours. In this research, we induced keratits in the rabbits by inoculating Pesudomonas aeruginosa(9027) and observed the effect on the keratitis and the irritation against the external eye. Also we mesured the minimum inhibitory consentration(MIC) of Coptidis Rhizoma, Fraxini Cortex, Jinpisan(秦皮散) by agar diliution method and the anti-bacterial activites by disk method. The tested bacteria were as follows : a) Pseudomonas aeruginosa (9027), b) Streptococcus pneumoniae(6303), c) Staphylococcus epidermidis(12228), d) Staphylococcus aureus(6538P). The results were as follows ; 1. The groups which were applied eye washes of Fraxini Cortex, Jinpisan reavealed a significant effect, but the group applied eye wash of Coptidis Rhizoma reveaded no effect on Pseudomonas aeruginosa keratitis. 2. Applying eye washes of Coptidis Rhizoma, Fraxini Cortex, Jinisan revealed an irritation against external eyes. 3. Coptidis Rhizoma showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylucoccus aureus by agar diliution method 4. Coptidis Rhizoma showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by disk method. 5. Fraxini Cortex showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by agar diliution method 6. Fraxini Cortex showed an anti-bacterial activity on Pseudomonas aeruginosa, Sireptococcus pneumoniae, Staphylococcus epidermidis, Staphy1ococcus aureus by disk method. 7. Jinpisan showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by agar diliution method. 8. Jinpisan showed an anti-bacterial activity on Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus epidermidis, Staphylococcus aureus by disk method. According to the above results, Fraxini Cortex, Jinpisan(秦皮散) are recognized to have an effective treatment on the Pesudomonas aeruginosa keratitis, so this experiment is thought to be a basic ingredient in proving the effect of Fraxini Cortex, Jinpisan which is applied many in documents and clinical medicine. In the comparison of anti-bacterial activity and results of treatment on the Pesudomonas aeruginosa keratitis, Jinpisan(秦皮散) was more effective than Coptidis Rhizoma, Fraxini Cortex.

• Journal of the Ergonomics Society of Korea
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• v.36 no.4
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• pp.293-303
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• 2017

Objective: This study aims to evaluate visual discomfort and visual fatigue caused by watching HMD and smartphones by conducting both subjective and objective measure. Background: With the rapid development of mobile Head-Mounted Display (HMD), the problem of visual discomfort and visual fatigue caused by watching Virtual Reality (VR) contents became a crucial concern for consumers and manufacturers, especially given that the casing of mobile HMD keeps the phone at a specified distance from the lenses that is close to the eyes. Method: Two smartphones were chosen for a preliminary study: LG G5 and Galaxy S7. As for a main study, iPhone 6S and Galaxy S7 were used. After being exposed to the selected clips, participants were asked to answer Simulator Sickness Questionnaire (SSQ) and went through optometric tests that measure tear break-up time, spherical equivalent, and contrast sensitivity. Results: The subjective assessments indicate that HMD causes more visual discomfort compared to watching a smartphone. Furthermore, the experimental result confirms that watching a HMD causes more eye dryness compared to smartphones. Conclusion: The result of the study compared visual discomfort and visual fatigue of two different displays, HMD and smartphone, and confirmed that watching HMD causes more visual discomfort and visual fatigue. Application: Ultimately, this study could help manufacturers understand the strengths and weaknesses of different display forms, providing guidance for an effective application of HMD.

• Korean Journal of Poultry Science
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• v.19 no.1
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• pp.17-25
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• 1992

The efficacy of B$_1$l live vaccine which is used successfully in chicken was examined against Newcastle disease in quails. A total of 480 male quails were divided into 4 groups, of which 3 groups were vaccinated via drinking water, eye instillation and spraying method and the remaining was employed as a nonvaccinated control group. At 3 weeks after the first vaccination a part of quails in each group was revaccinated. Efficacy of the vaccine was evaluated by the antibody responses and the protection rates after challenge with a virulent NDV. Vaccination of quails with $B_1$ NDV at 10 days of age resulted in beneficial effect compared to nonvaccinated group regardness of vaccination methods adopted although general protection rates were considerably low. Twice vaccination gave higher protection than once vaccination. Hemagglutination inhibition antibody responeses were significantly higher in groups of quails vaccinated by spray and eye instillation method than by drinking water administration. Antibody responses were marked at 2 weeks onward and until 5 to 7 weeks after vaccination. Antibody responses were rapid and marked after second vaccination. However, antibody level did not last longer than 5 to 7 weeks postvaccination. Vaccine caused no adverse effect on quails in terms of growth'rate, body temperature or clinical signs.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.143-146
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• 2007

Due to the expansion of cities and the increasing number of large-scale and complex public spaces, there is an increase in public signage. Moreover, the information described on these signs tends to be diverse and complicated. Complex signs that contain multiple destinations or other information must be considered to determine not only the proper size, color, etc. but also the most effective arrangement of design elements. In the previous research, the cognitive utility of complex public signs was estimated using computer simulation software. In the current research, we focused on the objective estimation of the effectiveness of the results obtained in the previous research utilizing an eye mark recording system. Two cognitive engineering experiments clarified five points for improvement in the usability of complex signs, as follows: 1) Parallel construction of characters and pictograms is more efficient. 2) Grouping elements result in rapid recognition of information chunks. 3) Visual characters and pictograms are effective, along with proper density of information. 4) Specific arrangement of sign arrows is effective. 5) Figures on signs influence the sequence of information searches.

• Culinary science and hospitality research
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• v.14 no.3
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• pp.16-30
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• 2008

Rapid change of surroundings has been influencing the work environment for cooks, making it more convenient; however, there are still many difficulties to improve. Especially, cooks are exposed to lots of occupational diseases due to tension and pressure as well as noise, high temperature and humidity in their work place. This study examines cooks' operational exhaustion caused by cooking operation and cooking circumstances. The analyzed result shows the job fatigue related to the general features of the cooks(such as charged cooking part, types of engaged business, class of position, cooking career, and working hours). For example, pains on the neck, back, arms and wrist are mostly affected by the charged cooking parts. Effects related to the types of engaged business, backaches usually occurred in Catering, pains in shoulder from serving at hotels and eye-tiredness from meal serving. As for working hours, most of backaches occurred from over 13-hour-work, and pains in shoulder and eye-tiredness under 8-hour-work. Pains in legs, tiredness, and the change of weight do not have any relations withthe general features of the cooks statistically(p>0.05).

• Journal of Dairy Science and Biotechnology
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• v.29 no.2
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• pp.43-49
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• 2011

The increasing number of analytes in concern and the alarming health and environmental consequences have required effective means of monitoring for safety control. Biosensors offer advantages as alternatives to conventional analytical methods because of their inherent specificity, simplicity, and quick response. Colorimetric biosensor, one of biosensor group, is one of the easiest and the most convenient methods because detection can be done using naked eye. Recently, a novel method for rapid detection and read-out of specific immunoassays with naked eye using polydiacetylene (PDA) was developed. Polydiacetylene has recently been in the limelight as a transducing materials because of its special features that allow optical transduction of sensory signals and inherent simplicity and ease of use in supramolecular chemistry. Various forms of PDA are used as a sensor platform for detection of various biological analytes such as viruses, DNA, proteins, bacteria and hazardous molecules.