• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.213-218
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• 2010

Objective : Pituitary apoplexy (PA) is described as a clinical syndrome characterized by sudden headache, vomiting, visual impairment, and meningismus caused by rapid enlargement of a pituitary adenoma, We retrospectively analyzed the clinical presentation and surgical outcome in PA presenting with cranial neuropathy. Methods : Twelve cases (33%) of PA were retrospectively reviewed among 359 patients diagnosed with pituitary adenoma, The study included 6 males and 6 females, Mean age of patients was 49,0 years, with a range of 16 to 74 years, Follow-up duration ranged from 3 to 20 months, with an average of 12 months, All patients were submitted to surgery, using the transsphenoidal approach (TSA). Results : Symptoms included abrupt headache (11/12), decreased visual acuity (12/12), visual field defect (11/12), and cranial nerve palsy of the third (5/12) and sixth (2/12) Mean height of the mass was 29.0 mm (range 15-46) Duration between the ictus and operation ranged from 1 to 15 days (mean 7.0) The symptom duration before operation and the recovery period of cranial neuropathy correlated significantly (p = 0.0286) TSA resulted in improvement of decreased visual acuity in 91.6%, visual field defect in 54.5%, and cranial neuropathy in 100% at 3 months after surgery. Conclusion : PA is a rare event, complicating 3.3% in our series, Even in blindness following pituitary apoplexy cases, improvement of cranial neuropathy is possible if adequate management is initiated in time, Surgical decompression must be considered as soon as possible in cases with severe visual impairment or cranial neuropathy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.71-76
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• 2017

Visual perception is part of a field of study that examines the analysis and recognition of objects. There have been numerous studies on this topic, including research on the physiological and cognitive aspects of the visual system. Visual perception theory was established through such research efforts and the potential for its application in each field is being investigated. Mobile displays are a representative example of media in the new age. Therefore, this study is based on the understanding that research on visual perception must stress the importance of useful visual cognition. This study used displays to conduct legibility tests based on illumination intensity and contrast ratio. Two conditions relevant to legibility were tested 1) illumination intensity environment and 2) two luminance conditions proposed as measures to improve readability in existing mobile displays. The results of this study were analysed to determine the degree of legibility based on illumination intensity and contrast ratio, and measures for improving legibility were proposed.

• Korean Journal of Optics and Photonics
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• v.24 no.5
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• pp.217-223
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• 2013

White light MTF(Modulation Transter Function)s of biconvex trial lenses from 10 to 20 diopter (D) were represented as a function of angular frequency and visual acuity, and then they were compared with AIM(Aerial Image Modulation) curves. All of the biconvex trial lenses evaluated in on-axis mode had MTF performance that could resolve Landolt's ring up to visual acuity 2.0. However, in a half field angle of five degrees, the trial lens of 10 diopters was able to resolve Landolt's ring up to visual acuity 0.9, and that of 20 diopter only up to visual acuity 0.8. This means that the trial lenses in the case of a half field angle of five degrees do not have sufficient resolution to measure visual acuity by 1.0.

• The Journal of Internal Korean Medicine
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• v.42 no.5
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• pp.1045-1053
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• 2021

Objectives: This study investigated the effectiveness of acupuncture and herbal medicine (Gami-banhabakchulchunma-tang) for post-stroke visual impairment. Methods: A 79-year-old male with headache, dizziness, visual field defects, and blurred vision caused by a posterior cerebral infarction was treated with acupuncture and Gami-banhabakchulchunma-tang for three months. We used the Numerical Rating Scale (NRS) for each symptom and measured the patient's eye-movement range. Results: Following treatment, the NRS score for headache decreased from 5 to 0, and for dizziness and blurred vision, it decreased from 5 to 1. The NRS score for visual field defects decreased from 5 to 2. The range of the patient's left and right eye movements both improved, and no adverse side effects were observed during the admission period. Conclusions: Korean medical treatment with acupuncture and herbal medicine (Gami-banhabakchulchunma-tang) could effectively treat post-stoke visual impairment.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.2
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• pp.74-85
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• 1996

The objective of this study is to investigate the influence of viewing aspects based on formal aesthetics and psychophysica approaches of the MAISAN provincial park for landscape management. Two methods are applied in this study. First, according to the field study with map the quantitative analyses of the viewshed area, visual section and scenery types were achieved, herein the visual landscape characteristics is found. Second, based upon visual preference evaluation of the relationships between the viewing aspects and visual preference scores to landscape slides were measured by questionnaires. The main conclusions obtained by the research are as follows. Visual area of MAISAN has a quite wide viewshed though itself is surrounded. The preference for the visual terminal were change by its characteristics to the visual corridors, view points, viewing types and viewing distance. Especially, the regression analysis between visual preference and viewing distance indicated Y=-3.20X\sup 2\+18.64X+20.64. In this case, viewing distance 794m from O\sub p\ is more important point for visual experience. The viewing types B·C and famous view A obtained a high visual preference score. A visual terminus are viewed along an entire RouteA, so revealed by its evolving spatial containment as to exact the full potential of its changing perspectives. Also we conducted the degree of visual influence by the shade in visual area at MAISAN and clarified viewing vantage Route and point in LSH being necessary for landscape preservation.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.237-245
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• 2010

The purpose of this study was to evaluate the effect of Korean red ginseng (KRG) on ocular blood flow in patients with glaucoma. In a prospective, randomized, placebo-controlled, double-masked crossover trial, 36 patients with open-angle glaucoma were consecutively recruited. Subjects were randomly assigned into two groups. Group A received 1.5 g KRG, administered orally three times daily for 12 weeks, followed by a wash-out period of 8 weeks and 12 weeks of placebo treatment (identical capsules filled with 1.5 g corn starch). Group B underwent the same regimen, but took the placebo first and then KRG. Blood pressure, heart rate, and intraocular pressure were measured at baseline and at the end of each phase of the study. Visual field examination and ocular blood flow measurements by the Heidelberg Retina Flowmeter were performed at baseline and at the end of each phase of the study. Changes in blood pressure, heart rate, intraocular pressure, visual field indices, and retinal peripapillary blood flow were evaluated. Blood pressure, heart rate, intraocular pressure, and visual field indices did not change after placebo or KRG treatment. After KRG treatment, retinal peripapillary blood flow in the temporal peripapillary region significantly improved (p=0.005). No significant changes were found in retinal peripapillary blood flow in either the rim region or the nasal peripapillary region (p=0.051 and 0.278, respectively). KRG ingestion appears to improve retinal peripapillary blood flow in patients with open-angle glaucoma. These results imply that KRG ingestion might be helpful for glaucoma management.

• ETRI Journal
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• v.36 no.2
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• pp.253-263
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• 2014

In the near future, traditional narrow and fixed viewpoint video services will be replaced by high-quality panorama video services. This paper proposes a visual-attention-aware progressive region of interest (RoI) trick mode streaming service (VA-PRTS) that prioritizes video data to transmit according to the visual attention and transmits prioritized video data progressively. VA-PRTS enables the receiver to speed up the time to display without degrading the perceptual quality. For the proposed VA-PRTS, this paper defines a cutoff visual attention metric algorithm to determine the quality of the encoded video slice based on the capability of visual attention and the progressive streaming method based on the priority of RoI video data. Compared to conventional methods, VA-PRTS increases the bitrate saving by over 57% and decreases the interactive delay by over 66%, while maintaining a level of perceptual video quality. The experiment results show that the proposed VA-PRTS improves the quality of the viewer experience for interactive panoramic video streaming services. The development results show that the VA-PRTS has highly practical real-field feasibility.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1245-1254
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• 2011

This paper proposes a target tracking algorithm for wheeled mobile robots using in various fields. For the stable tracking, we apply a vision system to a mobile robot which can extract targets through image processing algorithms. Furthermore, this paper presents an algorithm to position the mobile robot at the desired location from the target by estimating its relative position and attitude. We show the problem in the tracking method using the Position-Based Visual Servo(PBVS) control, and propose a tracking method, which can achieve the stable tracking performance by combining the PBVS control with Image-Based Visual Servo(IBVS) control. When the target is located around the outskirt of the camera image, the target can disappear from the field of view. Thus the proposed algorithm combines the control inputs with of the hyperbolic form the switching function to solve this problem. Through both simulations and experiments for the mobile robot we have confirmed that the proposed visual servo control method is able to enhance the stability compared to of the method using only either PBVS or IBVS control method.

• Journal of Biomedical Engineering Research
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• v.14 no.1
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• pp.63-72
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• 1993

In this paper, the effect of background grey levels on the visual perception of target image displayed on CRT monitor has been investigated. The purpose of this study is to investigate the efficacy of CRT monitor as a display medium of image Information especially in medical imaging field. Tllree sets of experiments have been performed in this study : the first was to measure the luminance response of CRT monitor and to find the best fitting equation, and the second was the psychophysical experiment measuring the threshold grey level differences between the target image and the background required for visual discrimination (or various background grey levels, and the third was to develop a visual model that is predictable of the threshold grey level difference measured in the psychophysical experiment. The result of psycophysical experiment shows that the visual perception performance is significantly degraded in the range of grey levels lower than 50, which is turned out due to she low luminance change of CRT monitor in this range while human eye has been adapted lo relatively bright ambient illumination. And it Is also shown in the simulation study using the developed visual model that the dominant factor degrading the visual performance is the reflected light from the monitor surface by ambient light in general illumination condition.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.70-77
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• 2017

Dynamic visual acuity is used as an important factor to measure athletic performance in sports field. A study on visual acuity testing system using non-see head mounted display (NST-HMD) was conducted recently. However, the NST-HMD has a problem that the sense of space felt by the subject differs from the actual environment. This is because the view is blocked so that it is only implemented in a virtual space. This paper proposes a dynamic visual acuity testing system using optical see through head mounted display (OST-HMD). To do this, OST-HMD and NST-HMD comparative tests were conducted using existing K-D (King-Devick) charts. Experiments were performed on 30 subjects and their visual acuity was measured and analyzed by parametric statistics and one-sample T-test. The results of the study demonstrate the effectiveness of the proposed OST-HMD. This study is expected to use the visual inspection and training equipment of OST-HMD.