• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.69-76
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• 1998

Due to the drastic improvement of computer hardware and operating system, it is easy to break through the main defects of limited computer memory and processing time, etc. To keep up with this situation, this paper is focused on developing the preprocessor program with the input method based on vector graphic editor and the preprocessing technique including automatic node generation algorithm for the $\rho$-version finite element program. To develop this preprocessor program, the special data structure and the OOP(Object Oriented Programming) have been used by the Visual Basic 4.0. The Special data structure is proposed to describe the geometric data of node numberings and coordinates suitable for the $\rho$-version finite element program, which are quite different from the comvential h-version finite element program.

• Environmental Engineering Research
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• 제11권3호
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• pp.143-148
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• 2006

The ultrasonics is a new technology in waste activated sludge(WAS) treatment. Ultrasonic treatment is well known method for the break up of microbial cells to extract out a variety of intercellular materials inside microorganism cell. This study was done to investigate the effects of the ultrasonic frequency and power on disruption of biosolids in WAS and to examine the effect on methane production of WAS treated by ultrasonics. Biosolids disruption with ultrasound is more effective at ultrasonic frequency of 40 kHz and power of 0.3 watt/mL. In the digestion with WAS pretreated by sonication time for 10 minute at 40 kHz and 0.3 watt/mL, the total quantity of generated methane increased by 75%, as compared with experimental control(non-treatment).

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.187-193
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• 2019

In this study, we attempted to identify the personality traits that influence one's likelihood to stalk an ex-partner on Facebook. Specifically, we focused on self-concept-related traits, given that the motivations for using social network sites (SNS) are highly associated with the concept of self. These include self-esteem, narcissism, and self-efficacy. To assess these factors, we controlled for extraneous variables while assessing the predictive power of personality traits, such as Facebook usage, length of the relationship, and time since the break-up. The results of a self-administered, web-based survey (N=207) showed that self-esteem, narcissism, and self-efficacy are all traits that can predict the stalking of an ex-partner on Facebook. More specifically, we showed a negative association between self-esteem and one's likelihood to stalk an ex-partner on Facebook, while it showed positive relationships between Facebook stalking and both narcissism and self-efficacy.

• 한국해양공학회지
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• 제14권2호
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• pp.44-52
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• 2000

The dispersion of surface oil is generally described as a break-up of oil slick into small oil droplets. These small droplets are subjected to turbulence and vertical circulation so that it can be entrained into subsurface. Sometimes they tend to be submerged into sea bottom permanently. The diameter of oil droplets is a critical parameter to determine their behavioral characteristics under water surface. At the same time the variations of droplet stability depends on the weathering of it. That is why the weathered oil has different mechanism from the unweathered one. The variability of physical properties of oil including viscosity and density contribute to interfere with effective separation of oil and emulsion droplets in water. Also in the presence of interactions among the droplets there are coalescing or coagulating effects on the dispersion process of droplets.

• 대한기계학회논문집B
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• 제20권6호
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• pp.1948-1958
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• 1996

Experimental and theoretical studies on the air-assist coaxial atomizer have been continuously carried out for a long time. But now the importance of the theoretical study is tending to increase as with the development of computer. This study is concerned to the spray modelization, especially, the instability of the liquid jet surrounded by the air stream which flows with high velocity. To study the phenomena of the break up, we used the linear theory based on the classical Kelvin-Helmholtz theory for capillary wave at a simple interface and we investigated the variation of liquid core radius. As a result, we obtained that the drop diameter and the variation of the liquid core radius predicted by using our model are reasonable.

• 천문학회지
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• 제52권4호
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• pp.121-131
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• 2019

I investigate the origin of arc degeneracies in satellite microlens parallax ${\pi}_E$ measurements with only late time data, e.g., t > $t_0+t_E$ as seen from the satellite. I show that these are due to partial overlap of a series of osculating, exactly circular, degeneracies in the ${\pi}_E$ plane, each from a single measurement. In events with somewhat earlier data, these long arcs break up into two arclets, or (with even earlier data) two points, because these earlier measurements give rise to intersecting rather than osculating circles. The two arclets (or points) then constitute one pair of degeneracies in the well-known four-fold degeneracy of space-based microlens parallax. Using this framework of intersecting circles, I show that next-generation microlens satellite experiments could yield good ${\pi}_E$ determinations with only about five measurements per event, i.e., about 30 observations per day to monitor 1500 events per year. This could plausibly be done with a small (hence cheap, in the spirit of Gould & Yee 2012) satellite telescope, e.g., 20 cm.

• 대한시과학회지
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• 제20권4호
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• pp.497-504
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• 2018

목적 : 백내장 환자를 대상으로 수술 전과 후의 안구표면의 온도변화 양상을 열화상카메라의 서모그래피를 이용하여 연구 하고자 하였다. 방법 : 본 연구는 백내장 수술을 받은 환자 50-79세까지 75명 75안의 환자 군을 대상으로 하였다. 과거에 굴절교정수술, 각막관련 수술을 받은 자와 콘택트렌즈를 사용하는 자, 눈물관 이상자, 전신질환 치료 약물을 복용하는 자 등 눈물분비와 눈물막에 영향을 줄 수 있는 자는 연구 대상자에서 제외하였고 눈물막파괴시간 검사(Tear Break Up Time, BUT), 쉬르머 검사(Schirmer's Test), 맥모니테스트(Mcmonnies questionnaire)를 시행한 후 열화상카메라(Cox CX series, Answer., Korea)를 이용하여 안구표면의 온도변화를 실시간으로 측정하였다. 결과 : 전체 대상자의 술 전 안구표면 온도는 $35.20{\pm}0.54^{\circ}C$이었고 술 후에는 $35.30{\pm}0.53^{\circ}C$로 표면온도가 상승하였으나 유의한 차이를 보이지 않았다. 안구표면 온도변화는 술전에서 $-0.12{\pm}0.08{\Delta}$ ($^{\circ}C/sec$)에서 술 후 $-0.18{\pm}0.07{\Delta}$ ($^{\circ}C/sec$)로 통계학적으로 유의한 결과를 나타냈다. 연령 별 비교에서는, 50 대군은 백내장 술 전 대상자의 안구표면 온도변화가 $-0.14{\pm}0.09{\Delta}$ ($^{\circ}C/sec$)에서 $-0.19{\pm}0.05{\Delta}$ ($^{\circ}C/sec$)으로 나타났고 60 대군에서는 $-0.12{\pm}0.08{\Delta}$ ($^{\circ}C/sec$)에서 $-0.15{\pm}0.07{\Delta}$ ($^{\circ}C/sec$)으로 나타났으며 70 대군에서는 술 전 대상자의 안구표면 온도변화는 $-0.12{\pm}0.08{\Delta}$($^{\circ}C/sec$)에서 $-0.18{\pm}0.07{\Delta}$($^{\circ}C/sec$)으로 전 연령에서 모두 유의한 안구표면 온도변화를 보였다. 결론 : 백내장 술 후에는 안구건조증 평가지표가 모두 감소하였고 안구표면 온도변화가 유의함을 보였다. 안구표면의 서모그래피 기술은 비침습적으로 안구건조증을 평가하는데 용이하였고 객관적으로 수치화할 수 있는 장점이 있어 다양한 안구건조증 연구에 활용 될 것으로 기대된다.

• 천문학회지
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• 제43권3호
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• pp.95-104
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• 2010

We outline our GRB afterglow observation program using the 1-m telescope at Mt. Lemmon Optical Astronomy Observatory (LOAO), and report the first observations of the GRB afterglows. During the 2007B semester, we performed follow-up imaging obsrevations of 6 GRBs, and succeeded in detecting four GRB afterglows (GRB 071010B, GRB 071018, GRB 071020, and GRB 071025) while placing useful upper limits on the light curves of the other GRBs. Among the observed events, we find that three events are special and interesting. GRB 071010B has a light curve which has an unusually long jet break time of 11.8 days. For GRB 071025, its red R-I(~2) color suggests that it is likely to be at z~5. GRB 071020 has a light curve which shows a clear brightening at 0.3-1 days after the burst, where our LOAO data play a crucial role by providing an unambiguous evidence for the brightening. These are the first successful detections of GRB afterglows by a facility owned and operated by a Korean institution, demonstrating the usefulness of the 1-m telescope for transient phenomena such as GRBs up to very high redshift.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.125-127
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• 2014

일본의 메이저 애니메이션 제작 회사인 스튜디오 지브리는 그 동안 명작 애니메이션을 발표, 상업적, 예술적 성공을 거두면서 일본을 넘어서 세계의 유수한 애니메이션 제작 회사로 명성을 떨쳐왔다. 하지만 지브리를 이끌었던 미야자키 하야오의 후계자 양산에 실패하고 미야자키 하야오의 은퇴가 임박하자 스튜디오 해체설이 나돌았다. 결국 2014년 6월 지브리 주주총회에서 제작팀 해산을 발표하게 되었다. 이는 스튜디오 해체는 아니지만 제작방식을 변경하게 된 것이다. 이 논문에서는 왜 스튜디오 지브리가 고유의 제작방식을 변경하게 되었는지 그 이유와 여러 요인에 대해 알아보고자 한다.

• 한국수자원학회논문집
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• 제47권7호
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• pp.599-614
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• 2014

본 연구에서는 삼각형 및 사각형 혼합격자의 적용이 가능하도록 기 개발된 2차원 유한체적모형의 계산속도를 개선하기 위해 모형의 병렬화를 수행하였다. 모형의 병렬화를 위해 코어 수의 제약에 자유로운 MPI 기법을 이용하였고, 프로그램 내의 흐름률 및 계산시간간격의 계산영역에 대해 논블록킹 점대점통신을 이용하였다. 병렬화 된 개발모형의 기존모형에 대한 계산결과의 일치성을 검증하고, 계산시간에 대한 성능향상도와 효율성을 검토하기 위해, $90^{\circ}$의 만곡이 존재하는 L자형 실험하도에 대한 댐 붕괴해석과 자연하천인 Malpasset 댐의 붕괴사상에 대해 모형을 적용하였다. 또한 격자수에 따라 4개의 Case로 구분하여 각각 모의함으로써, 입력규모의 크기에 따른 계산시간의 성능향상도를 함께 검토하였다. 분석결과 병렬화 모형에 의한 모의 결과는 기존모형 및 실측치와 비교하여 만족할 만한 정확도를 확보하였고, 기존모형에 대비해 약 3배 정도의 계산시간에 대한 성능이득을 얻을 수 있었다. 또한 입력자료 규모에 대한 Case별 모의 결과를 통해 적절한 입력자료의 규모와 프로세스 개수를 사용하는 것이 통신부하를 최소화할 수 있는 방안임을 확인할 수 있었다.