• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.421-424
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• 2007

Two patients, one with glioblastoma multiforme [GM] in the right thalamus and the other with meningioma at the right frontal convexity, had suffered bilateral cortical blindness after transtentorial herniation. On one of those patients, bilateral cortical blindness had occurred due to acute obstructive hydrocephalus caused by GM and on the other patient, cortical blindness had developed after acute hemorrhage from meningioma. Bilateral occipital lobes of those patients showed signal change on the brain magnetic resonance image [MRI]. There were no ophthalmologic abnormalities on fundoscopy and ophthalmologic examination. After recovery of consciousness, cortical blindness was detected in both patients, and during gradual recovery period, visual function was slowly recovered. The pattern of visual evoked potential [VEP] at 7 weeks and 12 weeks after herniation was normalized gradually. Cortical blindness due to herniation was reversible, even though the high signals of bilateral visual cortex still existed on MRI 16 month later in case 2.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.6
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• pp.571-580
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• 2014

To address unsolved issues of change detection in animated choropleth maps, we proposed the concept of 'gross change detection' and performed an experiment that empirically verifies the incidence of change blindness stems from the 'magnitude of change (MOC)', spatial distribution in animated choropleth maps. We generated experimental materials using the change-characterization arrays and the global Moran's I. Participants had 108 cases of changing maps with time duration (1 to 3 sec) and had questions. The results showed that MOC and duration affect gross change detection, but the most interesting result from our experiment was that different spatial distributions between two adjacent choropleth maps may lead the map reader to under- or over-estimate the level of gross change in the map. It implies that we should consider spatial distribution of change when we design animated choropleth maps.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.4
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• pp.428-437
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• 1994

Optic nerve injury serious enough to result in blindness had been reported to occur in 3% of facial fractures. When blindness is immediate and complete, the prognosis for even partial recovery is poor. Progressive or incomplete visual loss may be ameliorated either by large dosage of steroid or by emergency optic nerve decompression, depending on the mechanism of injury, the degree of trauma to the optic canal, and the period of time that elapses between injury and medical intervention. We often miss initial assessment of visual function in management of facial fracture patients due to loss of consciousness, periorbital swelling and emergency situations. Delayed treatment of injuried optic nerve cause permanent blindness due to irreversible change of optic nerve. But by treating posttraumatic optic nerve injuries aggressively, usable vision can preserved in a number of patients. The following report concerns three who suffered visual loss due to optic nerve injury with no improvement after steroid therapy and/or optic nerve decompression surgery.

• Korean Journal of Cognitive Science
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• v.34 no.4
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• pp.259-275
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• 2023

The aim of this study was to investigate font change blindness based on text difficulty in the "Moving Window Task", as originally introduced by McConkie and Rayner(1975). During the reading process where the moving window was applied, different target words in terms of font style compared to the text were presented. As participants' gaze reached the position of the target word, the font of the target word was changed to match the text font. The font of the target word before the change was either sans-serif when the text font was serif, or serif when the text font was sans-serif. After completing the reading task, more than half of the participants(62.5%) reported not detecting the font change. Observation of eye movements at the target word positions revealed that when understanding the content within the text was difficult, there was an increase in the number of regressions, an extended gaze duration, and a reduction in saccade length. Specifically, the increase in the number of regressions was evident only when the text font was serif, in other words, when the font of the target word shifted from sans-serif to serif. These results suggest that sensory interference unrelated to content understanding is not easily detected during reading. However, the possibility of detection increases when comprehension of the content becomes challenging. Furthermore, this exceptional detection possibility implies that it may be higher when the text font is serif compared to when it is sans-serif.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.3
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• pp.202-208
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• 2019

In this study, an active element pattern (AEP) of a printed dipole was analyzed in 1D and 2D arrays. First, an AEP of the printed dipole was obtained using the simulation in the 2D infinite array. The scan blindness in the 2D array occurred in the E-plane direction at around ${\pm}36^{\circ}$; however, it was barely observed in the 1D array. To analyze the cause of the scan blindness in the 2D array, the dispersion properties of a unit cell was obtained and compared with the scan blindness by frequency change. The difference between the scan blindness of the 1D and 2D arrays was clarified using the comparison of the Q value in the unit cell in the 1D and 2D arrays. Then, the coupling of the electric field in the E-plane direction was observed when nine elements were separated between the two ports in a linearly arranged dipole structure. Finally, the printed dipole array was fabricated, and an AEP was measured for the $11{\times}1$ and $11{\times}3$ sub arrays. The proposed theory was verified using these observations and by comparison with the simulation results.

• Korea Journal of Hospital Management
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• v.7 no.1
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• pp.88-104
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• 2002

According to the change of mandatory referral system in July 1, 2000, the effect to the medical utilization of outpatient clinic and medical income in ophthalmology of tertiary care medical institute, S Hospital in Seoul was evaluated for 6 months before(1999. 12$\sim$2000. 5) and after(2000. 12$\sim$2001. 5). The results were as follows: 1. The number of outpatients was reduced by 16.6%. The number of patient with blindness low vision, retina, glaucoma increased and that of patient with accommodation refractive error, cataract decreased. 2. The number of cataract patients was reduced by 36.6%. The major location of patient's address was changed to nearer to the hospital. The number of cataract surgery reduced in 4.1%, the waiting time reduced in 42.2%, however surgery time increased in 20.2% and number of postoperative complications increased in 11.4%. 3. The income of outpatient clinic and cataract surgery reduced. Among items of outpatient clinic income, the most increased was ocular examination and the most reduced was injection and drugs. Among items of cataract surgery income, the most increased was operation fee and the most decreased was doctor's fee. In conclusion, for the patient, due to the lowered density of outpatient population more space was provided to the patients with more severe disease entity such as blindness' low vision, retina and glaucoma. For the hospital, the need for the expansion of ophthalmology was not found, however that for creation of the special clinics dealing with more severe disease entity was found. Due to reduced income and increased need of financial investment for the equipment and manpower for the more severe disease entity, the ophthalmology of tertiary care medical institute is faced with financial disaster. It is strongly suggested that the cost of medical practice of more severe disease entity be raised to achieve the success after change of mandatory referral system in ophthalmology.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.87-92
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• 2022

In this paper, a study was conducted on the design of an array element that can be applied to the AESA radar for seeker. An antenna for application to AESA radar should choose an optimal radiation element to be applied to an array antenna in order to secure electronical beam steering characteristics, and consider beam steering characteristics when designing. In particular, in order to satisfy the wide-angle beam steering characteristics, the wide-angle impedance matching technique should be used to minimize the scan blindness region that may occur during wide-angle steering. As such, securing the stability of system operation is becoming an important design consideration for AESA radar. In this paper, WAIM is applied to the end of the radiation element to improve the characteristics of the radiation element applied to the AESA radar antenna device, and the change in the performance of the active reflection coefficient, which is a stable operation index of the system, is reviewed. The final performance result verified the validity of the proposed method by mathematically synthesizing the simulation data.

• Journal of the Korean Society of Safety
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• v.7 no.3
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• pp.60-65
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• 1992

As many industrial workers have been involved with computer terminal tasks, for example, monitor ing, inspection, or computer da4a entry etc., concerns for difficulty evaluation of computer terminal tasks are Increased. This study provides that eyeblink can be used as a means of difficulty evaluation of a computer terminal lask. Four subjects without color blindness are asked to perform the monitoring task of the binary choice type under five levels of task difficulty. In each task, eyeblink rates and eyeblink interval times were measured from the subjects. The results show that the eyeblink rate does decrease with an Increase in task difficulty. In addition, it was found that both eyeblink interval time and eyeblink Interval time variation increased with an increase in task difficulty. It was concluded that the change of eyeblink rate, eyeblink interval time and eyeblink interval time and eyeblink interval time variation could be regarded as a generalized response to the imposition of task difficulty.

• 대한예방의학회:학술대회논문집
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• 1994.02b
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• pp.293-296
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• 1994

At the conclusion of a double-blinded, randomized clinical trial of propranolol hydrochloride, but before un blinding, the patients and clinic personnel were asked to guess the treatment group assignment of each patient. While 79.9% of the patients receiving propranolol correctly Identified their treatment group assignment, 57.2% of the patients receiving placebo incorrectly guessed that they were aiso in the propranolol group. No specific mechanism was identified to explain why more patients receiving propranolol were better able to guess' their group assignment. Clinic physicians correctly identified the group assignment of 69.9% of the patients receiving propranolol and 68.8% of the patients receiving placebo. Clinic coordinators correctly identified the group assignment of 67.1% of the patients receiving propranolol and 70.6% of the patients receiving placebo. For clinic personnel, heart rate level and heart rate change seem to be the mechanisms employed to Identify their patients' treatment assignment.

• Korean Journal of Health Psychology
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• v.16 no.3
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• pp.557-575
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• 2011

This study tried to examine the characteristics of attention deficits in patients with Obstructive Sleep Apenea(OSA) with different age levels, and to examine which indices of polysomnograms might be related to the indices of attention deficits in OSAs. Two age-level groups and a normal control group were subjected to two computerized attention tests, including a continuous performance test(CPT) and a change blindness task(CBT). In addition, the three groups were subjected to a Polysomnography to extract several sub-indicators of polysomnogram, and an Epworth Sleepiness Scale which measures subjective sleepiness. As results, the OSAs showed significantly more omission and commission errors in CPT, and they showed lower accuracy in CBT compared to the normal group. The results of a correlational analysis showed that attention deficits in OSA are significantly correlated with arterial oxygen saturation among sub-indicators of polysomnograms. In conclusion, OSAs seems to be less attentive, having difficulties in response inhibition, and having deficiencies in noticing important environmental changes. Age seems to make these deficiencies even worse. Especially, the relationship between attention deficiency and hypoxia which could cause irreversible cerebrum damage has an implication in cognitive impairment prevention through early treatment.