• Title/Summary/Keyword: interest development

Search Result 4,441, Processing Time 0.034 seconds

Influence of the Fluorine-doping Concentration on Nanocrystalline ZnO Thin Films Deposited by Sol-gel Process

  • Yoon, Hyunsik;Kim, Ikhyun;Kang, Daeho;Kim, Soaram;Kim, Jin Soo;Son, Jeong-Sik;Leem, Jae-Young
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.204.2-204.2
    • /
    • 2013
  • Wide band gap II-VI semiconductors have attracted the interest of many research groups during the past few years due to the possibility of their applications in light-emitting diodes and laser diodes. Among the II-VI semiconductors, ZnO is an important optoelectronic device material for use in the violet and blue regions because of its wide direct band gap (Eg ~3.37 eV) and large exciton binding energy (60 meV). F-doped ZnO (FZO) and undoped ZnO thin films were grown onto quartz substrate by the sol-gel spin-coating method. The doping level in the solution, designated by F/Zn atomic ratio of was varied from 0 to 5 in 1 steps. To investigate the effects of the structure and optical properties of FZO thin films were investigated using X-ray diffraction (XRD), UV-visible spectroscopy, and photoluminescence (PL). In the XRD, the residual stress, FWHM, bond length, and average grain size were changed with increasing the doping concentration. For the PL spectra, the high INBE/IDLE ratio of the FZO thin films doping concentration at 1 at.% than the other samples.

  • PDF

Study on Concentration Variation of 222Rn for Various Scintillators Using Low-Level Liquid Scintillation Counter (저 준위 액체섬광계수기를 이용한 섬광체 종류에 따른 222Rn 농도 변화 연구)

  • Jeon, JaeWan;Lee, Deuk-Hee;Kim, Jin-Seop
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.6
    • /
    • pp.847-856
    • /
    • 2019
  • The various environmental issues arose with the development of today's economy. naturally, people were increased interest in environment and the importance of research on drinking water and contamination are emerging especially. A number of country areas, uranium and 222Rn in ground water have been detected to people using as drinking water. So this study evaluated the way for more accurate measurements than when measuring 222Rn concentrations in the ground water containing. the experiment was performed using the low-level liquid scintillation counter with an alpha, beta analysis easy PSA function of pulse. the scintillator as the preparation of the ground water samples are mixed, the measure value detection is lowered over prepare period and expiration date. Energy spectrum was also moved to a lower side channel. As a long time to buy the scintillator and over time after opening, it was confirmed that detection is lowered. if the purpose is to use a different scintillator can see the energy through the channel change.

PHOTOCHEMISTRY AND PHOTOBIOLOGY OF PSORALENS

  • Shim, Sang-Chul;Jeon, Young Hee;Kim, DongWon;Han, GyuSeok;Yoo, Dong Jin
    • Journal of Photoscience
    • /
    • v.2 no.1
    • /
    • pp.37-45
    • /
    • 1995
  • INTRODUCTION : Psoralens are planar tricyclic furocoumarins present in numerous plants and fungi found throughout the world.' Naturally occurring and synthesized psoralen derivatives(see Figure 1) are photosensitizers of UVA especially from 320 nm to 400 nm, a range at which cellular nucleic acids and proteins are weakly absorbing if any at all. Because of their skinphotosensitizing properties, these compounds have been used in the photochemotherapy of psoriasis and vitiligo. However, undesirable side effects such as carcinoma development in hairless mice as well as possible liver damage from the use of 8-methoxypsoralen(8-MOP) have been reported. The other photobiological effects include inactivation of DNA viruses, killing and mutagenesis of bacteria, inhibition of tumor transmitting capacity of various cells, and hyperpigmentation on human and guinea pig skin. PUVA(psoralen+UVA) photochemotherapy is in fact thousands of years old, having been used in Egypt and India since B.C. 1200-2000. Photochemotherapy for a common disfiguring disease, vitiligo, was practiced in the ancient world by physicians and herbalists who used boiled extracts of the fruits of certain umbelliferous plants, e.g. Ammi majus Linnaeus in Egypt or the leguminous plants, Psoralea corylifolia L. in India. It was first described by Kuske in 19388 that photosensitization of skin by plants was related to the presence of psoralen. He identified natural psoralens in plants as photosensitizers and isolated bergapten(5methoxypsoralen) from the oil of bergamot. The scientific interest in photosensitizing psoralens, however, has grown considerably after the introduction into clinics of the psoralen photochemotherapy for the treatment of psoriasis and of other skin (abbreviation)

  • PDF

Development of Moving Bandpass Filter for Improving Control Performance of Active Intake Noise Control under Rapid Acceleration (급가속 흡기계의 능동소음제어 성능향상을 위한 Moving Bandpass filter 개발)

  • Jeon, Ki-Won;Oh, Jae-Eung;Lee, Choong-Hui;Lee, Jung-Yoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.11a
    • /
    • pp.1016-1019
    • /
    • 2004
  • The study of the noise reduction of an automobile has been concentrated on the reduction of the automotive engine noise because the engine noise is the major cause of automotive noise. However, many studies of automotive engine noise led to the interest of the noise reduction of the exhaust and intake system. The method of the reduction of the induction noise can be classified by the method of passive control and the method of active control. However, the passive control method has a demerit to reduce the effect of noise reduction at low frequency (below 500Hz) range and to be limited by a space of the engine room. Whereas, the active control method can overcome the demerit of passive control method. The algorithm of active control is mostly used the LMS (Least-Mean-Square) algorithm because the LMS algorithm can easily obtain the complex transfer function in real-time. Especially, Filtered-X LMS (FXLMS) algorithm is applied to an ANC system. However, the convergence performance of LMS algorithm goes bad when the FXLMS algorithm is applied to an active control of the induction noise under rapidly accelerated driving conditions. So, in order to this problem, the modified FXLMS algorithm using Moving Bandpass Filter was proposed. In this study, MBPF was implemented and use ANC for automotive intake under revived rapidly accelerated driving conditions and it was verified its performance.

  • PDF

The Effective Methods of Teaching-learning by the Production of Instructional Media and Its Use - Centered on the Social Science and Natural Science - (교수매체 제작과 그 활용을 통한 학습의 효율화 방안 -과학, 사회과목을 중심으로-)

  • Kim Yong-Chul
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.22
    • /
    • pp.143-177
    • /
    • 1992
  • The main purpose of the school library is to present the various kinds of instructional media for an effective instruction including not only books, but also audiovisual materials and equipments. But unfortunately our school libraries have only books for the students and faculties at this time. But hereafter school library should house the various kinds of audiovisual media as well as printed media for the promotion of scholarstic achivemint. With a view to promoting the teaching method, and at the same time improving the scholarstic achivement of the students, instructional media were used in the class. To verify the efficiency of the instructional media, transparencies were used in the social science class of the 1st grade in the middle school and the natural science class of the 1st grade in the high school. In consequence, the academic achievement of the experimental class in which instructional media were used is superior to that of controlled class in which the textbook was only used. In < Social Science I >, the mean difference between the experimental class and the controlled class is 4.199 marks. And the difference, 0.032 is verified as a significant value in concordance to the t-test. In < Natural Science I >, the mean difference of the experimental class over the controlled class is 6.333. And the difference, 0.034 is verified as a significant value in concordance to the t-test. As shown in the above experimental research, using various kinds of the instructional media is more efficient than using textbook only. As a result of the questionaire on using the instructional media, most of the students desire to use of them continually because the use of the instructional media induce the interest, promote the comprehension, and entice the development of better memories.

  • PDF

Study on Underwater Welding ( Report 1 ) - Its Weldability -

  • 남기우
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.19 no.1
    • /
    • pp.63-70
    • /
    • 1983
  • Recently, many studies for developing the underwater welding techniques have been carried out in the advanced countries as a manufacturing process and a repairing method according as a great deal of interest in development for various marine industrial fields has been gradually increased. But no study on such underwater welding is available at present in our country. In this study, underwater welding was carried out for welding of domestic structural steel plates (SM41A) of 10 mm thickness, using six types of domestic coated arc welding electrodes on a self-made gravity type underwater welding device, resulting in investigation for the underwater weldability of the domestic structural steel plates as well as for the underwater welding properties and practicability of the domestic welding electrodes.

  • PDF

A Study on the Recognition of Elementary Teacher on Fire Safety : Focusing on Yeongju city (초등학교 교사의 소방안전의식에 관한 연구 -영주시를 중심으로-)

  • 방창훈
    • Fire Science and Engineering
    • /
    • v.18 no.1
    • /
    • pp.37-41
    • /
    • 2004
  • The purpose of this study is to help the education of fire safety in elementary schools be given effectively by teachers through the investigation of their recognition on fire safety. To achieve the purpose, 203 elementary school teachers in Yeongju city were interviewed for 5 days from Sep. 5 to 9, 2003. The results of this study are as follows; Teachers recognized the education of fire safety to be very necessary, but they gave less consequence to it relatively and classes for fire safety were done quite a little in actual education. Teachers put the traffic safety on the top in the list of safety education and play safety, facility safety and fire safety follows it in order. Teachers stated lack of interest (36.0%), lack of material and class hours(31.5%) for the difficulty of the fire safety education and they recognized that a fire safety expert's lecture(62.1 %) and development and propagation of teaching material were required for the efficient fire safety education.

Theoretical Consideration on Concepts and Features of the Entrepreneurial Gifted (기업영재의 개념 및 특성에 대한 이론적 고찰)

  • Choi, MinGyeong
    • Journal of Gifted/Talented Education
    • /
    • v.23 no.6
    • /
    • pp.1117-1145
    • /
    • 2013
  • Research on entrepreneurial giftedness is in its initial stage and the importance is increasing these days. The purpose of this article is to establish a foundation of entrepreneurial giftedness research by conceptualizing the concept and characteristics of entrepreneurial giftedness. The author reviewed prior research on entrepreneur and entrepreneurship, potential entrepreneur, gifted youth in invention, and entrepreneurial gifted youth, and proposed a new perspective on entrepreneurial gifted youth based on the findings from the review. Entrepreneurial giftedness proposed in this study is someone who is risk-taking to achieve opportunities and innovation and who has potential to be competent in managing resources. The author also proposed that entrepreneurial giftedness study needs to focus on developmental characteristics, management ability, and practical intelligence. Finally, based on the findings from previous research on entrepreneurial giftedness, environmental and personality characteristics, temperament and character, cognitive traits, and vocational interest of entrepreneurial giftedness are discussed. Implications and further research directions were discussed.

Integrated editing system for 3D stereoscopic contents production (3차원 입체 콘텐츠 제작을 위한 통합 저작 시스템)

  • Yun, Chang-Ok;Yun, Tae-Soo;Lee, Dong-Hoon
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.13 no.1
    • /
    • pp.11-21
    • /
    • 2008
  • Recently, it has shown an increased interest in 3D stereoscopic contents due to the development of the digital image media. Therefore, many techniques in 3D stereoscopic image generation have being researched and developed. However, it is difficult to generate high immersion and natural 3D stereoscopic contents, because the lack of 3D geometric information imposes restrictions in 2D image. In addition, control of the camera interval and rendering of the both eyes must be repetitively accomplished for the stereo effect being high. Therefore, we propose integrated editing system for 3D stereoscopic contents production using a variety of images. Then we generate 3D model from projective geometric information in single 2D image using image-based modeling method. And we offer real-time interactive 3D stereoscopic preview function for determining high immersion 3D stereo view. And then we generate intuitively 3D stereoscopic contents of high-quality through a stereoscopic LCD monitor and a polarizing filter glasses.

  • PDF

Analysis of Research on Compassion Satisfaction among Nurses (간호사의 공감만족에 대한 국내 연구 분석)

  • Lee, Soon-Neum;Kim, Jung-A
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.9
    • /
    • pp.599-609
    • /
    • 2016
  • This study aimed to review and summarize the trends in research pertaining to the compassion satisfaction of nurses in Korea and to make suggestions for future research. For this study, RISS, KISS, NDSL, and National assembly library databases were searched using the key words 'nurse' and 'compassion satisfaction' or 'professional quality of life' and 'nurse'. Eighteen papers on compassion satisfaction of nurses were reviewed. This was a non-experimental study (100%), and included hospital nurses (100%). The general characteristics of interest pertaining to compassion satisfaction were age, position, career, educational status, and etc. The variables with respect to compassion satisfaction were burn out, compassion fatigue, job satisfaction, resilience, and etc. The findings of this study provide preliminary data on research trends in the compassion satisfaction of nurses. Nursing managers need to maximize strategies to enhance compassion satisfaction of nurses. A qualitative study and a development of a program focused on compassion satisfaction are recommended for future research.