• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.3 no.6
• /
• pp.628-646
• /
• 2009

Users want to browse and search various web contents with mobile devices which can be used anywhere and anytime without limitations, in the same manner as desktop. But mobile devices have limited resources compared to desktop in terms of computing performance, network bandwidth, screen size for full browsing, and etc, so there are many difficulties in providing support for mobile devices to fully use desktop-based web contents. Recently, mobile network bandwidth has been greatly improved, however, since mobile devices cannot provide the same environment as desktop, users still feel inconvenienced. To provide web contents optimized for each user device, there have been studies about analyzing code to extract blocks for adaptation to a mobile environment. But since web contents are divided into several items such as menu, login, news, shopping, etc, if the block dividing basis is limited only to code or segment size, it will be difficult for users to recognize and find the items they need. Also it is necessary to resolve interface issues, which are the biggest inconvenience for users browsing in a mobile environment. In this paper, we suggest a personalized adaptation system that extracts item blocks from desktop-based web contents based on user interests, layers them, and adapts them for users so they can see preferred contents first.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1399-1402
• /
• 2007

We have demonstrated efficient white WOLEDs by using three emissive materials for primary colors (red, green, and blue). The characteristics of WOLEDs showed the maximum luminance of $37600\;cd/m^2$ at 13V, the maximum luminous efficiency of 20.6 cd/A, and the $CIE_{xy}$ coordinates of (x = 0.33, y = 0.33) at 10V.

• Journal of the Microelectronics and Packaging Society
• /
• v.21 no.2
• /
• pp.71-78
• /
• 2014

Silicon has been most widely used semiconductor material for power electronic systems. However, Si-based power devices have attained their working limits and there are a lot of efforts for alternative Si-based power devices for better performance. Advances in power electronics have improved the efficiency, size, weight and materials cost. New wide band gap materials such as SiC have now been introduced for high power applications. SiC power devices have been evolved from lab scale to a viable alternative to Si electronics in high-efficiency and high-power density applications. In this article, the potential impact of SiC devices for power applications will be discussed along with their Si counterpart in terms of higher switching performance, higher voltages and higher power density. The recent progress in the development of high voltage power semiconductor devices is reviewed. Future trends in device development and industrialization are also addressed.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.12
• /
• pp.1844-1852
• /
• 2001

Recent developments in microfluidic devices based on microelectromechanical systems (MEMS) technique find many practical applications, which include electronic chip cooling devices, power MEMS devices, micro sensors, and bio-medical devices among others. For the design of such micro devices, flows characteristics inside a microchannel have to be clarified which exhibit somewhat different characteristics compared to conventional flows in a macrochannel. In the present study microchannels of various hydraulic diameters are fabricated on a silicon wafer to study the pressure drop characteristics. The effect of abrupt contraction and expansion is also studied. It is found from the results that the friction factor in a straight microchannel is about 15% higher than that in a conventional macrochannel, and the loss coefficients in abrupt expansion and contraction are about 10% higher than that obtained through conventional flow analysis.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.6
• /
• pp.804-808
• /
• 2018

Interest in wireless power transfer (WPT) has been growing recently due to the rapid increase in the use of electronic devices. Wireless charging systems are currently being applied to mobile phones and many studies are being conducted to apply wireless charging systems to various devices. The current wireless charging systems are capable of 1:1 charging. For wireless charging, when the devices with the same resonance frequency are present in the vicinity, the charging efficiency may be significantly lowered due to frequency interference or the wireless charging systems may stop operating. In this paper, variable capacitors were applied to a superconducting WPT system to solve the frequency interference among multiple devices with the same frequency. When a wireless charging system was performing 1:1 operation, the frequency of the other devices was varied using variable capacitors. As a result, it was confirmed that the highly efficient WPT is possible without frequency interference even when multiple receivers are present.

• Research in Community and Public Health Nursing
• /
• v.33 no.3
• /
• pp.332-339
• /
• 2022

Purpose: Bus drivers are at high risk of chronic diseases due to risk factors associated with poor diet, physical inactivity, high levels of sedentary behaviors, and unfavorable working environments. This study developed a mHealth program for bus drivers, and examined the effectiveness of a mHealth program for promoting physical activity among bus drivers using wearable devices and health coaching. Methods: Forty-seven workers from two bus companies were allocated to the experimental group and the control group. Participants were asked to wear a wearable device (Fitbit Charge HR) during waking hours for a day. Participants in the experimental group were provided with a Fitbit, weekly face-to-face health coaching, a mHealth workbook, and text and photo messaging for 12 weeks. The control group only received a Fitbit. Results: By week 12, there were significant differences between the experimental and control groups in exercise self-efficacy (p<.015) and daily walking steps (p<.001). Conclusion: The findings have demonstrated that the mHealth program using wearable devices and health coaching is effective for bus drivers for promoting physical activity. Based on our findings, it is recommended to encourage the mHealth program using wearable devices and health coaching for bus drivers' wellness.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.3 no.1
• /
• pp.8-11
• /
• 2008

There are multiple reasons that caused the present serious status of network security, including Internet itself having a weak basis. However security is usually discarded when it contends with performance. As the world becomes more tightly interconnected, security technology continues to mature, organizations are feeling a greater need to rediscover network security. Network security technology generally concentrates on protection of the network infrastructure and, by implication, the protection of the user. This is a paper, describe current problems of network security and propose solutions.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.602-604
• /
• 2004

NPB surface morphologies deposited on different temperature substrates were investigated using atomic force microscopy(AFM). It has been found that the NPB morphology turned from island morphology at high temperature(100$^{\circ}C$) to grain morphology at room temperature. To characterize the effect of NPB surface morphology, the devices with the structure of Glass/ITO/NPB/$Alq_3$/Al were fabricated using NPB films deposited at different substrate temperature and their performances were compared.

• Electrical & Electronic Materials
• /
• v.15 no.9
• /
• pp.10-14
• /
• 2002

Plasma processing plays a significant role in semiconductor devices technology. Development of new plasma systems, such as high-density plasma reactors, required development of plasma theory to understand a whole process mechanism and to be able to explain and to predict processing results. A most important task in this way is to establish interconnections between input process parameters (working gas, pressure flow rate input power density) and a various plasma subsystems (electron gas, volume and heterogeneous gas chemistry, transport), which are closely connected one with other. It will allow select optimal ways for processes optimizations.

• Journal of the Korean Vacuum Society
• /
• v.3 no.2
• /
• pp.147-157
• /
• 1994

Valence or core electron excitations induced by Synchrotron radiation (SR) irradiation and ensuing chemical reactions can be applied for semiconductor processes i, e, deposition etching and modifications of thin film materials. Unique selectivity can be achieved by this photochemical reactions in deposition and etching. Some materials can be ecvaporated by SR irradiation which can be utilized for low temperature surface cleaning of thin films. Also SR irradiation significantly lowers the reaction temperature and photon activated surface reactions can be utilized for direct writing or projection lithography of electronic materials. This technique is especially effective in making nanoscale feature size with abrupt and well defined interfaces for next generation electronic devices.