• Ceramist
• /
• v.22 no.3
• /
• pp.218-229
• /
• 2019

The development of highly efficient thermally activated delayed fluorescence (TADF) materials is an active area of recent research in organic light emitting diodes (OLEDs) since the first report by Chihaya Adachi in 2011. Traditional fluorescent materials can harvest only singlet excitons, leading to the theoretically highest external quantum efficiency (EQE) of 5% with considering about 20% light out-coupling efficiency in the device. On the other hand, TADF materials can harvest both singlet and triplet excitons through reverse intersystem crossing (RISC) from triplet to singlet excited states. It could provide 100% internal quantum efficiencies (IQE), resulting in comparable high EQE to traditional rare-metal complexes (phosphorescent materials). Thanks to a lot of efforts in this field, many highly efficient TADF materials have been developed. This review focused on recent molecular design concept and optoelectronic properties of TADF materials for high efficiency and long lifetime OLED application.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.08a
• /
• pp.201-207
• /
• 1999

The automatic pinhole detection system is described. The goal of this project is to study the feasibility test of the new concept for hole detection. The developed method is able to detect almost 50$\mu\textrm{m}$ pinhole by evaluating the shining of the light as if there is pinhole in the strip. Moreover, it is possible to inspect up to the 200$\mu\textrm{m}$ inclined pinhole. The system cosists of three main functional parts: the source part of the light which is using the linear halogen lamp, the image gathering part which is using a line CCD and the image processing part. The light spot can be controlled and optimized corresponding to the situation of the strip. To eliminate back ground noise, the binary image processing method is adopted.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07a
• /
• pp.300-303
• /
• 2003

The design rule for 8.5kV LTT was discussed here. An inherent integrated breakover diode (BOD) for self -protection function and multi-amplified gate (AG) for improved di/dt capability of LTT was introduced in principle. The trade-off between light triggering input source and high dV/dt limitation has been treated via narrow grooved P-base for gate design. Key process technology for LTT was given, too.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.1409-1416
• /
• 2006

In measuring, uncertainty in measurement is essential to improve measuring reliability. Currently, however, in measuring impact sound insulation of floors, there are no guidelines to estimate uncertainty in measurement. In addition, the concept of uncertainty in rating is required to recognize the relation between measuring and rating. Therefore, through this paper, the efforts have been made to establish uncertainty in measurement and rating of light impact insulation of floors. The result of estimating of uncertainty in measurement and rating in our laboratory is considered reliable, considering ${\pm}0.46{\sim}1.44dB$ of uncertainty in measurement and 1 dB of uncertainty in rating.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.12 no.2
• /
• pp.33-38
• /
• 2012

The purpose of luminance measurement in lighting design of urban scale is to prevent light trespass and light pollution, caused by over-bright. Specially, the illumination of road, tunnel and sports complex as urban infrastructure is measured by international standard for illuminance and luminance. It has been used the spot luminance meter and the image photometer to define the characteristics of qualitative and quantitative in exterior lighting. This study introduced the concept of HDR Image, procedure of HDR Image creation and analysis. Applications of HDR Image, particularly within the apartment building exterior lighting design analysis, have been demonstrated. The procedure proposed in this study is a affordable method that is useful for the assessment of luminance distribution in the scene with electric light. It also provides a measurement capability with the high resolution luminance data within a large field of view efficiently and quickly, which is not possible to achieve with a luminance meter.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.21 no.3
• /
• pp.41-45
• /
• 2013

In this study, we surveyed the operating status of the Runway for the Light Sport Aircraft(LSA) in Korea, and analyzed the Airfield Facilities Manual for the Air Leisure and the Standard Specification for Recreational Airpark Design. Based on the information, we presented the displacement of the threshold concept, to ensure the Runway Length and the Runway Safety Area, and operation of LSA in Korea.

• Journal of Korean Academy of Nursing
• /
• v.30 no.5
• /
• pp.1368-1378
• /
• 2000

This study was conducted to explore the nurse's perception of technological development and professional self-concept. The research subjects were 560 clinical nurses in Korea, who worked the general hospitals in Seoul, Kyeonggi, and the Kangwon province. Data sampling was done for the month, of December. 1997. The research tool consisted of 82 items questionnaires which were demographic data, TIQ, PSCNI. The research findings were as follows: 1. Nurses perceived the technological development as slightly positive (Mean =48.8). Also, nurses saw that the fastest developing technological nursing unit was the cardiac care unit, while the lowest technological developing nursing unit was the psychiatric unit. 2. The view of technological development was found to be significantly different according to religion (P=.0109), marital status (P=.0431), and the practical setting (P=.0048). Professional self concept was significantly different according to age (P=.0001), religion (P=.0001), education (P=.0007), marital status (P=.0000), career (P=.0001), and position (P=.0000). 3. The relationship between a nurse's perception of technological development and professional self-concept was highly correlated(r=.26, P=.0001). In the results of the multiple regression, the factors influencing professional self-concept were career, the nurse's perception of technological development, the level of technological development in nursing unit, and education. All these parameters showed the explaining power of 15.4% of the professional self-concept. In conclusion, nurses recognized the technological development was related to the professional self-concept. This study shed light on the meaning of technological development and vision of the nursing profession. Inservice education program should be developed to help the adaptability to technological development and conduct the qualitative research to explore the world of technological development which the nurses are experiencing in nursing.

• Korean Institute of Interior Design Journal
• /
• v.14 no.5 s.52
• /
• pp.44-51
• /
• 2005

This study focuses 'Korean characteristics' in architectural interior design. In this study, some Korean characteristics was extracted by analysing traditional Korean spaces and as well as by considering the architectural interior spaces which are designed with Korean character since 1970. This paper started with differenciating the elements and principles that consist of space, and then classified the elements into 8 categories such as Spatial system, Enclosure system, Circulation system, Material system, Furnishing system, Light, Color, Context which are analysing frames. As a conclusion, the concepts of Korean characteristics are extracted and suggested as design concept with Korean characteristics by analysing the contents of each category. These concepts were presented with simple diagrams and supporting cases were also presented in this paper. The design concepts of 'Korean characteristics' are classified in the 25 concepts: Holonic composition, Transitional space, Hierarchy by floor level, Gradation of privacy, Changeability, Various central yards, Space with opened edges, Gray space, Continuity of space, Translucent wall, Folding-lifting wall, Skeleton, Abstract facet, Path as a message, Mild light, Multii-layered vista, Fluidity, framed scenery, Serial view, Interpenetrating Space, Harmony with nature, Organic interrelationship, Complementary Dual Structure, Temporal change of space, Hierarchical order.

• Korean Institute of Interior Design Journal
• /
• no.26
• /
• pp.79-87
• /
• 2001

This study is focused on three major museum projects completed during 1990's by Richard Meier who is known as the romantic modernist as well as one of the architects who continue their devotion on completing the fourth dimensional spatial concept through the practice. Main focus of the study will be analyzing the space and design elements shown in the Museum of Contemporary Art (Barcelona, Spain, 1986-95), Museum of Television & Radio (Beverly Hills, CA., 1994-96) and the Getty Center(Los Angeles, CA., 1984-97), and find out the new meaning of museum design suggested by the architect. The analyzation was done based on the actual sight visits and through the acquired references. The museum designs done by Richard Meier show consistency between visual language, use of 'light, space and form' as the design elements to connect interior and exterior to create openness and harmony with surrounding condition. Additionally, greatness of the architectural elevation, efficient use of interconnecting space, adoption of natural light, affective use of the space, careful consideration to the exhibiting items, spread of information centers, balance between large and small exhibition spaces, and his concept on providing choices to the viewer within the museum are the main issues in designing the museum in order to give various spatial experience to the visitors.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.2
• /
• pp.110-115
• /
• 2012

This study describes the characteristics of combustion and exhaust emission in the special engine applying a fuel reactivity controlled compression ignition (RCCI) concept with two different energizing type (solenoid and piezoelectric) injectors for diesel injection. A diesel-gasoline mixed dual-fuel reactivity controlled compression ignition concept is demonstrated as a promising method to achieve high thermal efficiency and low emission in internal combustion engines for transportation vehicles. For investigating the combustion characteristics of RCCI, engine experiments were performed in a light-duty diesel engine over a range of injection timing and mixing rate of gasoline in mass. It was investigated that by increasing the nozzle hole diameter, increasing the combustion pressure and the net indicated mean effective pressure. $NO_x$ and soot can be reduced by advancing start of injection in 84 mixing rate of gasoline in mass. The resulting operation showed that light duty engine could achieve 48 percent net indicated efficiency and 191[g/kW-hr] net indicated specific fuel consumption with lower levels of nitrogen oxides and soot.