• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.05a
• /
• pp.396-399
• /
• 2009

Stereo vision system is useful method for inferring 3D depth information from two or more images. So it has been the focus of attention in this field for a long time. Stereo matching is the process of finding correspondence points in two or more images. A central problem in a stereo matching is that it is difficult to satisfy both the computation time problem and accuracy at the same time. To resolve this problem, we proposed a new stereo matching technique using weighted cost aggregation. To begin with, we extract the weight in given stereo images based on features. We compute the costs of the pixels in a given window using correlation of weighted color, brightness and distance information. Then, we match pixels in a given window between the reference and target images of a stereo pair. To demonstrate the effectiveness of the algorithm, we provide experimental data from several synthetic and real scenes. The experimental results show the improved accuracy of the proposed method.

• The Journal of Society for e-Business Studies
• /
• v.26 no.2
• /
• pp.45-59
• /
• 2021

As software(SW) has been considered as a key driver of the fourth industrial revolution, significant R&D investment has been made by Korean government. Despite the attention and support by the government, systematic analysis on the SW R&D efficiency has not been fully addressed. In this study, the efficiency of SW national research and development projects was analyzed using Data Envelopment Analysis(DEA) techniques. Efficiency was measured from both static and dynamic perspectives based on 1,463 projects conducted by the National IT Industry Promotion Agency(NIPA) from 2008 to 2018. The static efficiency analysis identified the causes of inefficiency as scale and technology problems. As a result of dynamic efficiency analysis, we present a sector-specific response model using an efficiency-stability matrix. This study is meaningful in that efficiency analysis was conducted on the entire SW national R&D project, and static/dynamic efficiency analysis results are expected to be used as a guideline for planning SW national R&D project.

• Applied Chemistry for Engineering
• /
• v.30 no.2
• /
• pp.205-211
• /
• 2019

Over the past several decades, the polymer dispersed liquid crystal (PDLC) has received particular attention as a material for developing smart window due to their electro-optical switchable properties. In this study, PDLC cells were fabricated using acrylate monomers, namely 2-hydroxyethyl acrylate (2-HEA) and ethylene glycol phenyl ether acrylate (EGPA), and the effect of the monomer composition on their electro-optical properties was investigated. The monomer mixture with a low viscosity (~10 cps) was easily filled between indium tin oxide (ITO) glasses by capillary action at room temperature. PDLC cells prepared using the mixture ratio of 1 : 9 (2-HEA : EGPA) did not show a complete opaque state at a 0 V condition but exhibited unstable electro-optical properties under an electric field. As the LC composition increased in the reaction mixture for PDLC cell preparation, the $V_{th}$ (threshold voltage) and $V_{sat}$ (saturation voltage) values as well as contrast ratio (CR) increased. $V_{th}$ and $V_{sat}$ values also increased with the cell gap thickness. PDLC cells with a $20{\mu}m$ cell gap thickness exhibited higher CR than those with 10 and $40{\mu}m$ cell gap thicknesses. Particularly, PDLC cells prepared using the mixture ratio of 7 : 3 (2-HEA : EGPA) showed excellent electro-optical properties such as a low driving voltage and high contrast ratio.

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.4
• /
• pp.335-351
• /
• 2015

Objective: The aim of this study was to perform a usability test for CPAD (Cognitive Perceptual Assessment for Driving) and improve it based on the test results. Background: The cognitive perceptual assessment for driving is a computer-based assessment tool to assess the driving capacity of people with brain-damages. It may be a good tool for evaluating the brain-damaged drivers' safe driving capabilities and screening cognitive and perceptual deficits related to driving. We performed a usability test to improve the CPAD based on the result. Method: Both the software consisting of 8 sub-tests (depth perception, sustained attention, divided attention, stroop test, field dependency, digit span, trail making A, trail making B) and the hardware including the input and output devices ( joystick, mouse, keyboard, touch screen) were evaluated through user interviews. Also we identified the problems and issues in using them by observing the participants performing the CPAD tasks. Results: Based on the results, the task instructions were visually and auditorily improved and more practice examples were added to help the users understand the instructions better and increase the input accuracy, a response time window was added and the joystick and touch screen were simplified, which made it easier for the user to perform the CAPD tasks. Conclusion: User discomforts were minimized by improving the task environment, unless it had affected the evaluation criteria. Application: We plan to distribute the improved version of the CPAD to the regional rehabilitation hospitals, and the driving support centers for people with disabilities throughout the country, so it could be used as an evaluation tool for disabled drivers' cognitive and perceptual functions.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.69-69
• /
• 2017

For several decades, industrial processes consume a huge amount of raw water for various objects that consequently results in the generation of large amounts of wastewater. There effluents are mainly treated by conventional technologies such are aerobic, anaerobic treatment and chemical coagulation. But, there processes are not suitable for eliminating all hazardous chemical compounds form wastewater and generate a large amount of toxic sludge. Therefore, other processes have been studied and applied together with these techniques to enhance purification results. These techniques include photocatalysis, absorption, advanced oxidation processes, and ozonation, but also have their own drawbacks. In recent years, electrochemical techniques have received attention as wastewater treatment process that show higher purification results and low toxic sludge. There are many kinds of electrode materials for electrochemical process, among them, boron doped diamond (BDD) attracts attention due to good chemical and electrochemical stability, long lifetime and wide potential window that necessary properties for anode electrode. So, there are many researches about high quality BDD, among them, researches are focused BDD on Si substrate. But, Si substrate is hard to apply electrode application due to the brittleness and low life time. And other substrates are also not suitable for wastewater treatment electrode due to high cost. To solve these problems, Ti has been candidate as substrate in consideration of cost and properties. But there are critical issues about adhesion that must be overcome to apply Ti as substrate. In this study, to overcome this problem, TiN interlayer is introduced between BDD and Ti substrate. TiN has higher electrical and thermal conductivity, melting point, and similar crystalline structure with diamond. The TiN interlayer was deposited by reactive DC magnetron sputtering (DCMS) with thickness of 50 nm, $1{\mu}m$. The microstructure of BDD films with TiN interlayer were estimated by FE-SEM and XRD. There are no significant differences in surface grain size despite of various interlayer. In wastewater treatment results, the BDD electrode with TiN (50nm) showed the highest electrolysis speed at livestock wastewater treatment experiments. It is thought to be that TiN with thickness of 50 nm successfully suppressed formation of TiC that harmful to adhesion. And TiN with thickness of $1{\mu}m$ cannot suppress TiC formation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.11
• /
• pp.1168-1172
• /
• 2011

Beam projector is popularly used for presentation. In order to pay attention to local area of the beam projector display, a laser pointer is used together with a pointing device(Mouse). Simple wireless presenter has limited functions of a pointing device such as "go to next slide" or "back to previous slide" in a specific application(Microsoft PowerPoint) through wireless channel; thus, there is inconvenience to do other tasks e.g., program execution, maximize/minimize window etc. provided by clicking mouse buttons. The main objective of this paper is to implement a multi-functional laser-pointer mouse that has the same functions of a computer mouse. In order to get position of laser spot in the projector display, an image processing to extract the laser spot in the camera image is required. In addition, we propose a transformation of the spot position into computer display coordinates to execute mouse functions on computer display.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.21 no.12
• /
• pp.1120-1131
• /
• 2011

Researches using time reversal acoustics(TRA) for impact localization have been paid attention to recently. Dispersion characteristics of Lamb waves, which restrict the utility of classical nondestructive evaluation based on time-of-flight information, can be compensated through the application of TRA to Lamb waves on a plate. This study investigates the spatial focusing performance of time reversal Lamb waves on a plate using finite element analysis. In particular, the virtual sensor effect caused by multiple wave reflections at the boundaries of a plate is shown to enable the spatial focusing of Lamb waves though a very small number of surface-bonded piezoelectric(PZT) sensors are available. The time window size of forward response signals, are normalized with respect to the number of virtual active sensors. Then their effects on the spatial focusing performance of Lamb waves are investigated.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.125.2-125.2
• /
• 2016

Semiconductor nanowires are essential building blocks for various nanotechnologies including energy conversion, optoelectronics, and thermoelectric devices. Bottom-up synthetic approach utilizing metal catalyst and vapor phase precursor molecules (i.e., vapor - liquid - solid (VLS) method) is widely employed to grow semiconductor nanowires. Al has received attention as growth catalyst since it is free from contamination issue of Si nanowire leading to the deterioration of electrical properties. Al-catalyzed Si nanowire growth, however, unlike Au-Si system, has relatively narrow window for stable growth, showing highly tapered sidewall structure at high temperature condition. Although surface chemistry is generally known for its role on the crystal growth, it is still unclear how surface adsorbates such as hydrogen atoms and the nanowire sidewall morphology interrelate in VLS growth. Here, we use real-time in situ infrared spectroscopy to confirm the presence of surface hydrogen atoms chemisorbed on Si nanowire sidewalls grown from Al catalyst and demonstrate they are necessary to prevent unwanted tapering of nanowire. We analyze the surface coverage of hydrogen atoms quantitatively via comparison of Si-H vibration modes measured during growth with those obtained from postgrowth measurement. Our findings suggest that the surface adsorbed hydrogen plays a critical role in preventing nanowire sidewall tapering and provide new insights for the role of surface chemistry in VLS growth.

• Journal of the Korean Society of Costume
• /
• v.50
• /
• pp.183-196
• /
• 2000

Andy Warhol is one of the great artists in the modern history of art who compares favorably with Picasso. His activities had his object on pervasion of a pop art and profit of the art industry. Many previous studies on his activities have attracted and held the attention of his works of art after 1960s. However in spite of his working as publisher of a fashion magazine fashion illustrator fashion model displayer and etc. in 1950s. there are few studies on his activities of 1950s. Hence this study investigates his works of art in 1950s. and intensively analyzes his effect on modern fashion. In 1950s, Andy Warhol had already been distinguished in works of art from other commercial designers through the illustration for advertising design window display of stores and usage of Hollywood stars as anessential element in his works for whom he had sighed when he was young His works were also characterized by a rejection of they originality of commercial arts. He had an great effect on youth's fashion in 1950s and has activities in 1950s had influence on the diffusion of the public punk fashion in 1970s and the street fashion in 1980s.

• KIEAE Journal
• /
• v.11 no.6
• /
• pp.139-149
• /
• 2011

This study focuses on design tendencies in office buildings of public institutions after tightening up Korea's building energy performance criteria. Important office design criteria and recommendations pay attention to the issues such as building orientation, greening buildings, building form, space and envelop by intensifying building energy performance related laws, government guidelines and evaluation systems. The design tendencies explored in this research are as follows. Office buildings mainly face south and have various types of indoor and roof green spaces not for ecological reasons but for the rest. Building depth becomes thinner and atria are inserted into office buildings to improve daylighting and natural ventilation. Building cores are located on north or west and east sides acting as buffer spaces to reduce heat loss and to block solar radiation. Office building envelop design includes various creative ideas to control or utilize solar energy as like three dimensional or double structured skin and window size variation to cope with the intensity of solar radiation. Further, solar energy generation systems are integrated with building component such as roofs, sun screens and windows. This study demonstrates that government's reinforcement of the building energy performance criteria drives the change in design methods and approach.