• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기설비전문위원
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• pp.44-46
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• 2005

An Electrical facilities of fountain is one of the vulnerable facilities because it is exposed to water. Especially, some children enter the fountain and play in the water in the hot season. For example, death from electrical shock in fountain was reported in domestic and foreign papers. In this paper, we analyzed the riskiness of electrical shock on the basis of a fact-finding survey and comparing the domestic and international standard of electrical facilities in fountains.

• 대한수학회지
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• 제57권2호
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• pp.489-506
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• 2020

In this paper, we study the existence of infinitely many large energy solutions for the supercubic fractional Schrödinger-Poisson systems. We consider different superlinear growth assumptions on the non-linearity, starting from the well-know Ambrosetti-Rabinowitz type condition. We obtain three different existence results in this setting by using the Fountain Theorem, all these results extend some results for semelinear Schrödinger-Poisson systems to the nonlocal fractional setting.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 하계학술발표회
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• pp.74-75
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• 2000

The past few decades have witnessed the development of very robust technique, known as magneto-optical trap(MOT), for cooling and trapping of neutral atoms using lasers and magnetic fields. This technique can easily produce cooled atoms to a temperature range of nano-kelvin $s^{(1)}$ . These laser cooled and trapped atoms have found applications in various fields, such as ultrahigh resolution spectroscopy, precision atomic clocks, very cold atomic collision physics, Bose-Einstein Condensation, the Atom laser, etc. Particularly, a few isolated atoms of very low temperature are needed in the cavity QED studies in the optical regime. One can obtain such atoms from a MOT using the atomic fountain technique. The widely used technique for atomic fountain is, first to cool and trap the neutral atoms in MOT. And then launch them in the vertical (1, 1, 1) direction with respect to cooling beams, using moving molasses technique. Recently, this technique combined with the cavity-QED has opened an active area of basic research. This way atoms can be strongly coupled to the optical radiation in the cavity and leads to various new effects. Trapping of single atom after separating it from MOT in the high Q-optical cavity is actively initiated presentl $y^{(2.3)}$. This will help to sharpen our understanding of atom-photon interaction at quantum level and may lead to the development of single-atom laser. Our efforts to develop an $^{85}$ Rb-atomic fountain is in progress. (omitted)

• 한국통신학회논문지
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• 제37권2B호
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• pp.110-119
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• 2012

본 논문은 이종 무선망 환경에서 효과적인 영상 스트리밍 시스템에 대해 다룬다. 제안하는 영상 스트리밍 시스템은 파운틴 코드를 영상 스트리밍 서비스에 적합하도록 변형하고, 파운틴 코드의 지연 및 블록 복구 실패율 제약 조건들을 만족시키면서 다중 경로를 통해 영상 스트림의 비트율을 최대화한다. 마지막으로, 제안하는 시스템이 이종 무선망 환경에서 각 경로의 상태 정보를 기반으로 제어 변수를 동적으로 설정함으로써 고화질의 안정적인 영상 스트리밍 서비스를 사용자에게 제공할 수 있음을 보인다.

• 천문학회보
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• 제38권2호
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• pp.77.2-77.2
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• 2013

We present the interim results of simultaneous time monitoring observations of $^{28}SiO$ v = 1, 2, J = 1-0, $^{29}SiO$ v = 0, J = 1-0 and $H_2O$ $6_{16}-5_{23}$ maser lines toward 10 known water fountain sources at a post-AGB stage. The observations have been carried out from 2009 June to 2013 September using the 21m single dish radio telescopes of the Korean VLBI Network. From six sources, we detected well separated red- and blue-shifted $H_2O$ maser features with large velocity ranges more than 100 km $s^{-1}$. From four sources, we detected red- and/or blue-shifted $H_2O$ maser features depended on observational epochs. However, we could not detected SiO maser emission from any sources and any epochs. For a representative water fountain source W43A, we obtained $H_2O$ maser spectra at 17 epochs which show a clear bipolar and discontinuous mass ejections. They also showed a periodic change between red-shifted and blue-shifted peaks. However, we need a more regular and short-time interval monitoring observations in order to fix the period and peak intensity variation interval.

• 대한기계학회논문집B
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• 제30권8호
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• pp.722-730
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• 2006

In this study, the flow characteristics of a FPN (Fountain Pen Nano-Lithography) using active membrane pumping are investigated. The FPN has integrated chamber, micro channel, and high capacity reservoir for continuous ink feed. The most important aspect in this probe provided control of fluid injection using active membrane pumping in chamber. The flow rates in channel by capillary force are theoretically analyzed, including the control of the mass flow rates by the deflection of the membrane. The above results are compared with the numerical simulations that calculated by commercial code, FLUENT. The velocity of the fluid in micro channel shows linear behaviors. And the mass flows are proportional to the second order function of the pumping pressure that is imposed to the membrane.

• Journal of Communications and Networks
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• 제15권4호
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• pp.411-421
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• 2013

Digital fountain codes are record-breaking codes for erasure channels. They have many potential applications in both wired and wireless communications. Most existing digital fountain codes operate over binary fields using an iterative belief-propagation (BP) decoding algorithm. In this paper, we propose a new iterative decoding algorithm for both binary and nonbinary fields. The basic form of our proposed algorithm considers both degree-1 and degree-2 check nodes (instead of only degree-1 check nodes as in the original BP decoding scheme), and has linear complexity. Extensive simulation demonstrates that it outperforms the original BP decoding scheme, especially for a small number of source packets. The enhanced form of the proposed algorithm combines the basic form of the algorithm and a guess-based algorithm to further improve the decoding performance. Simulation results demonstrate that it can provide better decoding performance than the guess-based algorithm with fewer guesses, and can achieve decoding performance close to that of the maximum likelihood decoder at a much lower decoding complexity. Last, we show that our nonbinary scheme has the potential to outperform the binary scheme when choosing suitable degree distributions, and furthermore it is insensitive to the size of the Galois field.

• 한국광학회:학술대회논문집
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• 한국광학회 1998년도 제15회 광학 및 양자전자 학술발표회 논문집
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• pp.106-107
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• 1998

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 하계학술발표회
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• pp.28-29
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• 2001

• 대한기계학회논문집
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• 제11권6호
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• pp.1026-1035
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• 1987

본 연구에서는 두께방향에 따른 유동을 해석하는데 "fountain effect" 및 열 전달 현상을 동시에 고려하면서 진전하는 자유표면의 형상을 정확히 구하기 위한 유한 요소법을 이용한 수치해석법을 제안하고 그 방법을 적용하여 금형벽의 온도를 변화시 켜가면서 구체적인 유동특성을 해석하였다.특성을 해석하였다.