• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.1-7
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• 2010

To find an appropriate illuminance range for the disability glare caused by the road lighting system installed on guardrails, the influence of the disability glare was evaluated in comparison with the road lighting system of a streetlight. To test the disability glare, an indoor laboratory was constructed and a variation of luminance contrast threshold was evaluated. As a result, when the retinal illuminance was increased and glare sources existed within the narrow visual field, the luminance contrast threshold was increased. Although the road lighting luminaire was installed as low as the height of the guardrail on the road, when out of sight, the influence of the disability glare was small in comparison with the conventional road lighting system such as a streetlight.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.35-41
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• 2017

We propose a novel multi-photodiode array (MPDA) based retinal implant IC with on/off stimulation strategy for a visual prosthesis with improved spatial resolution. An active pixel sensor combined with a comparator enables generation of biphasic current pulses when light intensity meets a threshold condition. The threshold is tuned by changing the discharging time of the active pixel sensor for various light intensity environments. A prototype of the 30-channel retinal implant IC was fabricated with a unit pixel area of $0.021mm^2$, and the stimulus level up to $354{\mu}A$ was measured with the threshold ranging from 400 lx to 13120 lx.

• Journal of Korean Medicine Rehabilitation
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• v.24 no.2
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• pp.131-140
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• 2014

Objectives This study was aimed at comparing clinical effectiveness among trigger point treatment, Self-exercise treatment, trigger point - self-exercise cooperative treatment for neck pain caused by traffic accidents. Methods 63 patients with neck pain by traffic accidents were divided into 3 groups. Different types of treatments were carried out for each groups ; group A with trigger point, group B with self-exercise, group C with trigger point and self-exercise cooperative treatment. 3 groups were also treated with general acupuncture and herb-medicine treatment. Pain threshold, visual analogue scale (VAS), and neck disability index (NDI) were checked on a daily basis. SPSS ver. 18.0 for Windows was used for analysis of data. The effectiveness of treatment of each groups were verified by using paired test and one-way repeated-measures ANOVA test, and the comparison of VAS, NDI and pain threshold were demonstrated by independent samples t-test. Results 3 groups all showed significant difference in pain threshold, VAS and NDI after 8 days later. Group C showed more improvement in pain threshold, VAS and NDI than shown in group A and B. In the first period (from pre-treatment to 4th day treatment) group C showed significant difference in NDI and pain threshold but not in VAS as compared to group A and B. In the second period (from 4th treatment to 8th day treatment), Group C showed significant difference in pain threshold, VAS and NDI as compared to group A and B. Conclusions Trigger point - self-exercise cooperative treatment is proved to be more helpful to improve the unstability and reduce neck pain than trigger point treatment or self-exercise treatment only, therefore eventually leading to better satisfaction for patients with neck pain.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7C
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• pp.671-680
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• 2009

The diagnostic medical images(CT, MRI) in PACS require large storage and long transmission time. A simple and cheap way of overcoming these limitations is to increase the compression ratio. However, this requires a clinical validation for accurate diagnostic applications. The aim of this paper is to improve the compression efficiency of lossless JPEG2000 for diagnostic CT images by performing a visual-Iossless threshold filtering in high frequency subband. A proposed method, based on 5/3 reversible DWT, provides different subband-threshold values according to the compression ratio and gives the high subjective quality to reconstructed diagnostic CT images.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.181-190
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• 2011

Objectives: The purpose of this study is to investigate the clinical effects of heating-conduction acupuncture therapy on anterior talofibular ligament injury induced by acute and chronic ankle sprain. Methods: From April 19, 2010 to May 30, 2011 the 79 outpatients who had admitted to department of oriental rehabilitation medicine, Dae-Jeon oriental medical hospital, Dae-Jeon university with ankle sprain were performed heating-conduction acupuncture therapy on anterior taIofibular ligament injury. To evaluate the efficiency of heating-conduction acupuncture therapy, pain threshold with pressure algometer and visual analogue scale(VAS) were applied before treatment and after 1st, 2nd treatment. Results: 1. The pain threshold and VAS score showed significant improvement on acute subacute, chronic anterior talofibular ligament injury group. 2. The difference in pain threshold and VAS score between acute, subacute, chronic phase group was not significant. Conclusions: Heating-conduction acupuncture therapy has clinical effects of pan reduction on patient with anterior talofibular ligament injury.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.59-64
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• 2016

Background: This study was to investigate the effect of cervical HVLA technique and mulligan MWM technique on patients with lateral epicondylitis. Methods: 36 participants were randomly allocated to the two groups; group I involved high velocity low amplitude (HVLA) cervical mobilization technique, mulligan mobilizations with movement (MWM) technique (n=18). group II mulligan MWM (n=18). Patient attended for three times a week for six weeks. Results: The change of visual analogue scale (VAS) was statistically and significantly decreased in both of the group I and the group II. The change of patients rated tennis elbow evaluation (PRTEE) was statistically and significantly decreased in both of the group I and the group II. The change of pressure pain threshold (PPT) was statistically and significantly increased in both of the group I and the group II. Nevertheless, There is no statistical differences between group I and group II. Conclusion: After experiment, pressure pain threshold and visual analogue scale, patients rated tennis elbow evaluation were improved in both group. But Cervical HVLA group does not showed the change better than mulligan MWM group.

• International Journal of Contents
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• v.7 no.2
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• pp.59-63
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• 2011

The aim of our study was to evaluate the immediate effects of an 830-nm Aluminium gallium arsenide (GaAlAs) laser, by examining the changes, in pressure-pain threshold (PPT) and tenderness at 3 kg of the myofascial trigger point (MTrP) of the upper trapezius muscle in visual display terminal (VDT) workers in comparison with placebo treatment. Thirty VDT workers (13 males, 17 females) with complaints of upper trapezius muscle were recruited. All participants were given either active GaAlAs laser (830 nm wavelength, 450 mW, 9 J at point) or placebo GaAlAs laser, according to the double-blinded and placebo-controlled trial. Both active and placebo low-level laser therapy (LLLT) treatments showed no significant effect on PPT and tenderness at 3 kg. These results suggest that a higher dosage may be necessary to produce immediate effects when applying LLLT to the MTrP of relatively large muscles such as the upper trapezius muscle.

• Physical Therapy Rehabilitation Science
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• v.3 no.2
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• pp.142-147
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• 2014

Objective: This study aims to investigate high energy and low energy extracorporeal shockwave therapy (ESWT) and which one is more effective for shoulder pain. Design: Single blind randomized controlled trial. Methods: Fifty two subjects with upper trapezius (UT) trigger point (TrP) participated in this study. They were allocated to high energy (n=26) and low energy group (n=26). This study applies ESWT and investigates the changes of pressure pain threshold (PPT) and visual analogue scale (VAS). The high and low energy groups received focused piezo electric type ESWT 4 Hz, 1,000 pulses and 0.351 and $0.092mJ/mm^2$ respectively. Outcome measures of PPT and pain was measured by algometer and pain VAS. These measurements were performed before and after treatment. Results: The PPT value was significantly increased in both groups after treatment (p<0.05) and VAS scores were significantly decreased after treatment in both groups (p<0.05). However, there were no significant differences between groups. Conclusions: ESWT is an effective treatment for the application of the UT TrP. Although there were significant effects of extracorporeal shock wave therapy on PPT and VAS scores, there were no signficant differences between high and low energy extracorporeal shock wave therapy.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.129-142
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• 2015

PURPOSES : The purpose of this study is to suggest a basis for setting appropriate safety goals specifically related to the threshold zone luminance in a vehicular traffic tunnel. METHODS : In the test, drivers were divided into two groups. One group consisted of all drivers (average drivers) group with an age ratio of drivers holding domestic driver's license and driver group by age to produce threshold zone luminance in the tunnel. The threshold zone luminance produced as a result was used to analyze how it affects the safety level of each driver group and provide a basis for setting an appropriate safety criterion that can be used to determine threshold zone luminance. We used test equipment, test conditions, and ananalysis of threshold zone luminance identical to that reported by ChoandJung(2014) but the values of adaptation luminance in our analys is were expanded to range from100 to $10,000cd/m^2$. RESULTS : Adaptation luminance and threshold zone luminance are found to be related by a quadratic function. The threshold zone luminance needed by older drivers to ensure a certain safety level is significantly higher than that for drivers of other age brackets when adaptation luminance increases. 56% of older drivers are at an increased risk of an accident at the same luminance for which the safety level of average drivers is 75%. The safety level that can be achieved for older drivers increases to above 60% when threshold zone luminance level is set with the goal of attaining a safety level of more than 85% for average drivers. The safety level that can be attained for average drivers is above 90% when the threshold zone luminance is high enough to ensure over 75% in the safety level of older drivers. Results of this study are applicable to highways and others whose designed speed is 100 km/h. CONCLUSIONS : Threshold zone luminance determined on the basis of drivers having average visual ability is of limited value as a performance standard for ensuring the safety of older drivers. Hence, safety level for older drivers should be considered separately from safety levels for drivers with an average ability to avoid risk. Upward adjustment of older drivers' safety level in the process of determining appropriate threshold zone luminance in a vehicular traffic tunnel may bring both tangible and intangible benefit as a result of reducing accidents. However, there is an associated dollar cost arising from installing and operating lights. As a result, the economic impact of these trade-offs should also be considered.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.55-57
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• 1992

Image display is the last step of imaging chain in which the diagnostic information is transformed into perceivable intensities and transformed to observer's eye-brain system. In this process, a certain part of information may be efficiently transfered and another part may be inefficiently transfered leading to information loss. In this study, the visual perceptual properties of image display on CRT monitor has been investigated. Psychophysical experiment of target image detection has been performed using CRT monitor for various background grey levels, and the threshold difference grey levels required for visual discrimination have been predicted by computer simulation with visual model.