• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.235-238
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• 2017

This study was to develop a portable digital radiography (PDR) system with a function measuring the X-ray source-with-detector angle (SDA) and to evaluate the imaging performance for the diagnosis of chest imaging. The SDA device consisted of an Arduino, an accelerometer and gyro sensor, and a Bluetooth module. According to different angle degrees, five anatomical landmarks on chest images were assessed using a 5-point scale. Mean signal-to-noise ratio and contrast-to-noise ratio were 182.47 and 141.43. Spatial resolution (10% MTF) and entrance surface dose were 3.17 lp/mm ($157{\mu}m$) and 0.266mGy. The angle values of SDA device were not significant difference as compared to those of the digital angle meter. In chest imaging, SNR and CNR values were not significantly different according to different angle degrees (repeated-measures ANOVA, p>0.05). The visibility scores of the border of heart, 5th rib and scapula showed significant differences according to different angles (rmANOVA, p<0.05), whereas the scores of the clavicle and 1st rib were not significant. It is noticeable that the increase in SDA degree was consistent with the increase of visibility score. Our PDR with SDA device would be useful to be applicable to clinical radiography setting according to the standard radiography guideline at various fields.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.137-142
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• 2013

The displacement Deep-V catamaran concept was developed in Newcastle University(UNEW) through development of the systematic Deep-V catamaran series. One of the most important Deep-V catamaran launched to date is Newcastle University's own multi-purpose research vessel, The Princess Royal. The vessel was launched in 2011 and enhanced the Deep-V catamaran concept further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. It was however identified that the vessel has substantial amount of dynamic trim that limited the visibility of the captain. The dynamic trim also increased the wave-making resistance thereby preventing the vessel from attaining its maximum speed in certain sea states. This paper therefore presents the application of devices such as Trim Tabs, Interceptors, Transom Wedges and Integrated Transom Wedges-Tabs to control the dynamic trim and improvement of fuel efficiency of the vessel. All of these energy saving devices were fitted into a model for tests in Newcastle University's Towing Tank. Model test verification confirmed that the optimum appendage was the interceptors, they produced a 5% power saving and 1.2 degree trim reduction at 15 knots, and investigations of full scale trials will be scheduled with and without application of device to compare the improvement of performance.

• Korean Journal of Human Ecology
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• v.14 no.5
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• pp.833-846
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• 2005

The purpose of this study is to find out the various impressions that tone-on-tone coloration of shirts and ties gives. This experiment was based on the $2\times4\times4\times2$ factorial designs; colors (purple and green), shirt tones (vivid, light, dull, and dark), tie tones (vivid, light, dull, and dark) and perceivers' genders (male and female). The materials in the experiment developed for this study were composed of various stimuli and the response scales for each stimulus. The stimuli were 32 upper body photographs, which were color printed by CAD system (4D-box program). We unified those colors of shirts and ties, and then made shirt and tie tone different. 27 bi-polar adjectives, each of which was graded into seven in its degree, were used to evaluate the impression. The subjects of this research were 192 male and 192 female college students in Gyeongnam province including Jinju City. The data was analyzed by using SPSS program. Analyzing methods were one-way ANOVA and LSD test. The items of the adjectives were classified into 5 impression dimensions; potency, activeness, attractiveness, visibility and tenderness. In conclusion the impression through matching shirts and ties could be varied by the colors and the tones of shirts and ties. This study can be used as the basic color data in the males' clothes market which gradually pursuits high-quality, personality, and variety.

• Journal of the Korea Fashion and Costume Design Association
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• v.8 no.2
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• pp.1-16
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• 2006

The purpose of this study was to find out the various impressions that tone-on-tone coloration of shirts and ties gives. This experiment was based on the $2{\times}4{\times}4{\times}2$ factorial design: colors(red and blue), shirt tones(vivid, light, dull, and dark); tie tones(vivid, light, dull, and dark) and perceivers' gender(male and female). The materials in the experiment developed for this study were composed of 32 upper body photographs which were color printed and 27 bi-polar adjectives, each of which was graded into seven in its degree, were used to evaluate the impression. We unified those colors of shirts and neckties, and then made shirt and necktie tone different. The subjects of this research were 192 male and 192 female college students in Gyeongnam province including Jinju City The data was analyzed by using SPSS program. Analyzing methods were one-way ANOVA and LSD test. The items of the adjectives were classified into 5 impression dimensions - potency, activity, attractiveness, visibility and tenderness. All the image by the match of shirt and tie could be possible to make various images by the color, the shirt tone and the tie tone. Blue was given more effective potent image, vivid or light tone shirt in blue was the active image. As shirt and tie had different tone, regarded as the attractive image. Vivid tone tie was evaluated the visible image, light tone shirt is the tend image.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4A
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• pp.219-226
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• 2012

We investigated the performance of a visible light communication (VLC) transceiver applicable to both of illumination and wireless communication. we considered the visibility of VLC, the easy connection for wireless communication and high-speed transmission and implemented VLC transceiver based on edge-emitting laser diode and silicon photodiode. The proposed VLC transceiver is designated to operate in a full duplex mode at high speed of 120 Mbit/s. The shielding method that is employed as a means to reduce the light cross coupling effect inside the VLC transceiver is proposed and its performance is experimentally measured. We also applied optical antenna to have the larger angle of field of view (FOV) to novel structure of VLC transceiver and examined and analyzed their bit error rate performance, photometric result with respect to the transmission distance, the coverage range and the tilt degree as transmission link characteristic between two transceivers without optical antenna and with optical antenna.

• Fire Science and Engineering
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• v.22 no.5
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• pp.55-60
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• 2008

In this study, we conducted an FDS numerical simulation for the purpose of carrying out a basic assessment of the usefulness of the water spray for fire extinguishing. We analyzed the effect of securing the stability in temperature and smoke density in case of fire according to fire intensities (20MW, 50MW) and changes in wind speed. When there was no wind speed in tunnels, it was effective in securing the safety of people because the cooling effect of the water spray system had an excellent effect on reducing temperatures and smoke densities there. The higher a fire intensity is, the less effect it has on reducing smoke flows. When an air current exists in tunnels, its cooling effect disturbs the smoke stratification and lowers the visibility degree during evacuation. Therefore, the water spray for fire extinguishing should be put into action only after people take shelter during fire.

• Journal of the Korean Geographical Society
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• v.45 no.6
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• pp.788-805
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• 2010

The present USN (Ubiquitous Sensor Networks) node deployment practices have many limitations in terms of positional connectivity. The aim of this research was to minimize a redundancy of USN route nodes, by integrating spatially weighted parameters such as visibility, proximity to cell center, road density, building density and cell overlapping ratio into a comprehensive GIS database. This spatially weighted approach made it possible to reduce the number of route nodes (11) required in the study site as compared to that of the grid network method (24). The field test for RSSI (Received Signal Strength Indicator) indicates that the spatially weighted deployment could comply with the quality assurance standard for node connectivity, and that reduced route nodes do not show a significant degree of signal fluctuation for different site conditions. This study demonstrated that the spatially weighted deployment can be used to minimize a redundancy of USN route nodes in a routine manner, and the quantitative evidence removing a redundancy of USN route nodes could be utilized as major tools to ensure the strong signal in the USN, that is frequently encountered in real applications.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.73-83
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• 2012

Effective use of traffic marking can lead to driver's safer driving by speed management and visibility enhancement. One of the critical factors in designing traffic marking is how to incorporate human factor issues into the design process. This study presented a methodology for evaluating the effectiveness of Hi-pass marking on Korean freeways based on kansei engineering. Hi-pass marking scenarios made by a virtual reality tool were used to evaluate the user's perceptions. Various combination of chevron angles and peripheral transverse(PT) bars were used for the evaluation. The results show that the most effective scenario is a combination of 60 degree chevron angle and an askew parallelogramshaped PT bar shaped. It is expected that the proposed method and outcome will be useful for making safer driving maneuvers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.985-990
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• 2007

The method of enhancing visibility in optical fiber sensor was investigated by improving coherence length of light source. The optical feedback technique is used to enhance coherence length in fiber laser which generates laser in near infrared wavelength region and utilizes low loss characteristics of optical communication grade fiber. In this paper, the effect to coherence length by short and long optical feedback paths are investigated by using Mach-Zehnder interferometer technique. The effect to coherence length by changing optical feedback power and optical modulation are investigated. The spectral drift was calculated by measuring the degree of phase perturbation in unbalanced Mach-Zehnder interferometer having loom path difference. The short optical feedback path was effective to reduce spectral drift to 450kHz/sec and the long optical feedback path in combination with short optical feedback path was found to further reduce spectral drift to 50kHz/sec.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.37-49
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• 2015

In Space Syntax, the greater the degree of integration between separate links, the greater the links' accessibility from the target network. As such, planning pedestrian walks so that links with high degrees of integration are connected, or else inducing high integration value land use are both valid options. The travel distribution model reflects how walking demand, or more specifically, the pedestrian, partakes in route choosing behavior that minimizes select criteria, notably level of discomfort, as measured using travel distance and time. The model thus demonstrates travel patterns associated with demand pertaining to minimization of discomfort experienced by the pedestrian. This research introduces a method that integrates Space Syntax and the pedestrian travel distribution model. The integrated model will determine whether regions with high degrees of integration are actually being used as pivots for pedestrian demand movement, as well as to explain whether the degree of integration is sustained at an appropriate level while considering actual movement demand. As a means to develop the integrated model, a method that combines display of the visibility of the space syntax network and road-divided links is proposed. The pedestrian travel distribution model also includes an alternative path finding mechanism between origin and destination, which allows for uniform allocation of demand.