• 한국초등과학교육학회지:초등과학교육
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• 제30권4호
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• pp.601-614
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• 2011

The purpose of this study was to investigate significant differences between the application group and nonapplication group of integrated science education in the science class about elementary teachers' perceptions and PCK. The results are as follows. First, no significant differences were found about science teachers' fundamental background variables between the two groups. This results showed that the application of integrated science education didn't have relation with the fundamental background variables. It was found that the application group of integrated science education has a lower frequency than the application group, however, it has been analysed that the application group has been applied at the introduction stage for students' motivation, focused on biology as twice every month. Second, to apply a successful integrated education in the elementary science class, it has analysed that not only teachers should need to understand about application method and concept of integrated science education but also science textbook and teaching-learning material should be developed and diffused in the well-integrated science. Third, it was found that professionality of elementary teachers to teach the scientific content knowledge is not comparatively high and non-application group of integrated science education has a lower PCK than the application group. Therefore, it should be provided that not only training programmes to learn interdisciplinary knowledge related to science, can lead to more understanding about instructional design, teaching strategies and concept for integrated science education should be developed but also chances to participate in various training programmes should be provided to enhance elementary teachers' professionality for integrated science education.

• 한국멀티미디어학회논문지
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• 제19권12호
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• pp.1936-1942
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• 2016

This paper presents a mobile color-compensating application using a RGB color compensation algorithm. The proposed application enables color vision deficiencies to differentiate images which cannot be distinguished by them. The suggested mobile application has two functions: converting images taken by camera and converting contents in the device screen. The proposed application is computationally inexpensive, since it does not require color space transformation. Simulation results show that the proposed application enables color vision deficiencies to receive information expressed by colors such as subway line maps.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.1113-1114
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• 2004

• 서비스연구
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• 제4권2호
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• pp.49-56
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• 2014

최근 스마트폰의 발전함에 따라 집 주변의 음식점조차도 스마트폰을 사용하여 찾아가는 일상이 당연시되었다. 이러한 장점들을 사용하여 여행에 관련된 어플리케이션 또한 많아졌는데, 여행에는 거리, 시간, 금액, 등 여러 가지 조건들이 필요하다. 하지만 정작 여행 어플리케이션의 카테고리를 이용하여 사용자가 원하는 기능을 사용하기에는 화면전환이 너무 많아 번거로운 경우가 많다. 게다가 금액과 거리 등을 따로 찾으려면 시간이 더 소모되는데 이러한 점들을 고려하여 사용자가 더욱 간편하게 여행 스케줄을 관리할 수 있도록 여행에 필요한 정보들이 하나로 합쳐진 어플리케이션을 개발하게 되었다.

• Current Optics and Photonics
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• 제4권3호
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• pp.238-246
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• 2020

The heat distribution in crystals in a 2-㎛ acousto-optic Q-switched Tm:LuAG laser pumped by pulsed-laser-diode (pulsed-LD) intermittent-pumping technology was analyzed using COMSOL software. The thermal lensing effect of the Tm:LuAG crystal can be mitigated by pulsed-LD intermittent-pumping techniques. An experimental setup using this kind of approach achieved maximum output energy of 8.31 mJ, minimum pulse width of 101.9 ns, and highest peak power of 81.55 kW, reached at a Q-switched repetition rate of 200 Hz. It offers significant improvement of performance of the output laser beam, compared to pulsed-LD double-ended pumping technology at the same repetition rate.

• Current Optics and Photonics
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• 제2권6호
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• pp.582-588
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• 2018

A $Nd:YVO_4$ laser dual-end-pumped by a wavelength-locked 878.6 nm laser diode is presented. At the repetition rate of 500 KHz, the absorbed pump power of 58 W, an output power of 26.1 W at 1064 nm is obtained, corresponding to an optical-optical efficiency of 45%. The pulse width is 44.2 ns. Meanwhile, the effects of traditional 808 nm pumping and 878.6 nm dual-end-pumping on the output laser beam quality and pulse width are compared and analyzed in an experiment.

• Current Optics and Photonics
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• 제5권1호
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• pp.59-65
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• 2021

This paper reports a tunable diode-pumped folded intracavity Q-switched singly resonant optical parametric oscillator based on multi-period MgO:PPLN. A wide tuning mid-infrared parametric light from 2.78 ㎛ to 4.17 ㎛ was obtained in real time by changing the poled periods and temperatures. The maximum output power of 1.89 W at 3.2 ㎛, 1.53 W at 3.5 ㎛, 0.87 W at 3.8 ㎛ and 0.486 W at 4.1 ㎛ were achieved. The highest optical-optical conversion efficiency was 7.89%. During experiments, a range tunable output of 2.78-4.17 ㎛ in the mid-infrared range was achieved.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2002년도 한국우주과학회보 제11권2호
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• pp.48.2-48
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• 2002

• Current Optics and Photonics
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• 제7권6호
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• pp.714-720
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• 2023

Laser cleaning has the advantages of environmental protection, precision, and high efficiency, and has good prospects for application in removing oxide films on the surface of aluminum alloy. This paper discusses the cleaning threshold and cleaning mechanism of aluminum alloy surface oxide film. A nanosecond pulsed laser was used to remove a 5-㎛-thick oxide film from the surface of 7A04 aluminum alloy, and the target surface temperature and cleaning depth were simulated. The effects of different laser energy densities on the surface morphology of the aluminum alloy were analyzed, and the plasma motion process was recorded using a high-speed camera. The temperature measurement results of the experiment are close to the simulation results. The results show that the laser cleaning of aluminum alloy oxide film is mainly based on the vaporization mechanism and the shock wave generated by the explosion.

• 한국작물학회지
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• 제45권4호
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• pp.237-240
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• 2000

This experiment was conducted to evaluate the effect of split application of nitrogen(N) on development of vascular bundle(VB) and yield components of rice. Two cultivars were used in this study; IR58, an indica type and Shinunbongbyeim a japonica type. The number and total cross sectional area of the VB in the peduncle and leaf blade were more and bigger in N split application than 100 percent basal fertilizer. Nitrogen split application at necknode differentiation stage increased the number and size of the VB. Nitrogen split application resulted in increased panicle number with application of N before transplanting and at tillering stage; increased spikelets number with N application at necknode differentiation stage; and increased spikelet fertility and 1000 grain weight with N application at necknode differentiation and heading stages. Grain yield increased 7-10% in N split as compared to all basal application. The total cross sectional area of VB in peduncle closely correlated with the number of spikelets per panicle. Nitrogen management can have an impact on spikelet differentiation through more and bigger VB and increase grain yield potential.