• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.4
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• pp.292-297
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• 2003

We fabricated a single crystal silicon thin film transistor for active matrix organic light emitting displays(AMOLEDs) using silicon on insulator wafer (SOI wafer). Poly crystal silicon thin film transistor(poly-Si TFT) Is actively researched and developed nowsdays for a pixel switching devices of AMOLEDs. However, poly-Si TFT has some disadvantages such as high off-state leakage currents and low field-effect mobility due to a trap of grain boundary in active channel. While single crystal silicon TFT has many advantages such as high field effect mobility, low off-state leakage currents, low power consumption because of the low threshold voltage and simultaneous integration of driving ICs on a substrate. In our experiment, we compared the property of poly-Si TFT with that of SOI TFT. Poly-Si TFT exhibited a field effect mobility of 34 $\textrm{cm}^2$/Vs, an off-state leakage current of about l${\times}$10$\^$-9/ A at the gate voltage of 10 V, a subthreshold slope of 0.5 V/dec and on/off ratio of 10$\^$-4/, a threshold voltage of 7.8 V. Otherwise, single crystal silicon TFT on SOI wafer exhibited a field effect mobility of 750 $\textrm{cm}^2$/Vs, an off-state leakage current of about 1${\times}$10$\^$-10/ A at the gate voltage of 10 V, a subthreshold slope of 0.59 V/dec and on/off ratio of 10$\^$7/, a threshold voltage of 6.75 V. So, we observed that the properties of single crystal silicon TFT using SOI wafer are better than those of Poly Si TFT. For the pixel driver in AMOLEDs, the best suitable pixel driver is single crystal silicon TFT using SOI wafer.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.579-588
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• 2010

Generalization of the web, development of one-person media such as the blog and mini homepage, and integration of video digital devices have generalized multimedia video services on the web. However, flash videos, the previously used bit map-based multimedia videos, exhibit problems like the waterfall phenomenon, lag phenomenon, or non-synchronization of audios or videos. Thereupon, This study is conducted to suggest a converting technique to provide efficient web video service on the web by solving problems of bitmap-based flash video through file format-converting software and movie editing programs. And this paper also conducts experiments on five videos for 13 CODECs and analyzes converted results comparatively. The recommendable method considering the characteristics of each videos is to utilize MainConcept H.264 Video CODEC using SWF2Video pro. The result of this research can be used to produce web videos on the web more effectively.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.133-141
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• 2014

Social needs of smart work have been increasing throughout the worldwide and several developed countries have been developing enabled framework for smart work's coming proceed for a long time. The government is leading the smart work in Korea to devise a more efficient and competitiveness. Design of public collaboration solution has been proposed to provide the integration among a variety of smart environments and the interoperability between end-to-end. This paper takes a objective to develop a universal solution applicable to between traditional PC and mobile devices, such as a home station, and to built smart workplace linking workplace, outside space and the home. In particular, this paper offer entry-level advantages of public collaboration solution in conjunction with collaboration platform and phone platform owned by mobile communication platform company are mutually interfaced and aimed at small and medium-sized businesses and public.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.134-143
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• 1998

Twin Blocks are simple bite-blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. These devices use upper and lower bite-blocks that engage on occlusal inclined planes. Twin Blocks use the forces of occlusion as the functional mechanism to correct the malocclusion. To get an excellent result in the treatment by using the Twin Block appliances, proper case selection must be needed. Twin Block treatment is performed in two stages. Twin Blocks are used in the active phase to correct the anteroposterior relationship and establish the correct vertical dimension. Once this phase is accomplished, the Twin Blocks are replaced with an upper Hawley type of appliance with an anterior inclined plane, which is then used to support the corrected position as the posterior teeth settle fully into occlusion. The Twin Block is the most comfortable, the most esthetic ane the most efficient of all the functional appliances. Twin Blocks have many advantages compared to other functional appliances. Patients can wear Twin Blocks 24 hours per day and can eat comfortably with the appliances in place. From the moment Twin Blocks are fitted, the appearance is noticeably improved. There is less interference with normal function. Integration with conventional fixed appliances is simpler than with any other functional appliance. Twin Blocks allow independent control of upper and lower arch width. Appliance design is easily modified for transverse and sigittal arch development. The authors treated Class II malocclusion with Twin Blocks. and the results as follows; 1. Rapid profile improvement was achieved in 2-3 months. 2. There was excellent patient cooperation. 3. Severe overjet and overbite were reduced. 4. Class II molar relationship was changed to Class I.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.216-220
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• 2007

A widely tunable add/drop filter composed of double ring resonators is implemented with high-index-contrast polymer waveguide. To enhance the productivity, directional couplers are designed to have good fabrication tolerance. The refractive indices of the core and cladding in the 1550 nm wavelength are 1.51 and 1.378, respectively. Drop response in comparison with neighborhood peak gets enhanced by more than 2.9 dB at the wavelength where both rings resonate. This filter can be used to build widely tunable laser diode through hybrid-integration with reflective SOA.

• Journal of the Korean Solar Energy Society
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• v.40 no.5
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• pp.23-34
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• 2020

Concentrator photovoltaic (CPV) system consists of high-quality complex optical elements, mechanical devices, and electronics components and can have the advantages of high integration and high-efficiency energy sources. III-V compound semiconductor cells have proven performance based on high reliability in the aerospace field, but have characteristics that require absolute support of the balance of systems (BOS) such as solar position trackers, receivers with heat sinks, and housing instruments. To determine the optimum parameters of secondary optical elements (SOEs) design for CPV systems, we designed three types of CPV modules, classified as non-SOEs type, reflective mirror type, and CPC lens type. We measured the I-V and P-V characteristics of the prototype CPV modules with the angle of inclination varying from 0° to 12° and with a 500-magnification Fresnel lens. The experimental results assumed misalignment of the solar position tracker or module design of pinpoint accuracy. As a result, at the 0° tilt angle, the CPC lens produced lower power due to the quartz transmittance ratio compared to that by other SOEs. However, for tilt angles greater than 3°, the CPC lens type module achieved high efficiency and stability. This study is expected to help design high-performance CPV systems.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.307-313
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• 1997

he photoconductive gain mechanism in amorphus silicon devices was investigated in connection with applications to radiation detection. Various device types such as p-i-n, n-i-n and i-i-p-i-n structures were fabricated and tested. Photoconductive gain was measured in two time scales : one for short pulses of visible light(<$1{\mu}sec$) which simulate the transit of energetic charged particles or ${\gamma}$-rays, and the other for rather long pulses of light(1msec) which simulate x-ray exposure in medical imaging, We used two definitions of phtoconductive gain : current gain and charge gain which is an integration of the current gain. We obtained typical charge gains of 3~9 for short pulses and a few hundreds for long pulses at a dark current density level of 10mA/$cm^2$. Various gain results are discussed in terms of the device structure, applied bias and dark current density.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.650-662
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• 2011

The competition among companies in converged market of broadcasting and telecommunications has become severe. Companies in this market have vertically integrated critical resources by acquiring or strategically allying with relevant companies. However, the expansion of business territory accompanies financial, organizational, and technological risks. As such, it is important to identify critical success factors that highly affect the company's competency. This study is aimed at delivering strategic implications for firms playing in the converged market of broadcasting and telecommunications by drawing the priorities of competitive resources to acquire. To do this, we selected four teen specific core resources on CPNT (content- platform - network - terminal) value chain. Then, we conducted an Analytic Hierarchical Process (AHP) using data from experts in this industry. As a result, the priority for acquisition of competitive resources is presented as follows: broadcasting programs, implementation of TV application store, multi-platform, investment on wireless network, and diffusion of mobile devices. In addition, the result shows that the platform-centric vertical integration is the most promising strategy for competition.

• Journal of the Society of Disaster Information
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• v.13 no.4
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• pp.476-482
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• 2017

For the bridges managed by the municipalities, there is a need for a maintenance management system for the municipal governments for the scientific and systematic maintenance standard and the scientificization of the budget acquisition and execution through the quantified data base. The purpose of this study is to develop a system for efficient management of small bridgies maintained by the municipality and use ICT convergence technology such as BIM / GIS technology. The details of the system development include the development of the small bridgies maintenance program for mobile devices, the development of the small bridgies maintenance database, the development of the small bridgies integration maintenance management, and the reliability of the program system developed by checking the construction and operation contents of the small bridgies test-bed. The developed program system is linked to the development of smart name plate and reader module of non - power system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.430-433
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• 2010

In-vehicle networks have been developed to increase capacity and reduce wiring in the car. These would make communication possible with each heterogeneous networks by the advent of networks attached to the vehicle. However, these come with a variety of unique features in each network-specific communication which creates difficulty using and supporting the service. To solve this problem, local networks need a standard integration framework. In this paper, a framework, consists of a standard protocol using XML to improve compatibility and portability, is proposed and implemented. Each network is compatible with the framework by applying unique information and messages of the network in the XML standard ducument. The results obtained by implementation show that the framework supports the communication of information between heterogeneous in-vehicle networks.