• 한국초등과학교육학회지:초등과학교육
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• 제40권1호
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• pp.36-54
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• 2021

The purpose of this study was to investigate pre-service elementary school teachers' understanding about alternative energy and to identify their alternative conceptions. The two-tier instrument had been developed by Cheong et al. (2015) were used for this study. Twelve items from the instrument consisted of four categories: 'source of alternative energy', 'greenhouse gas emission', 'cost in electricity and construction' and 'advantages and disadvantages'. One hundred and fifteen pre-service elementary school teachers were participated in online survey during the semester. The results analyzed using SPSS 26.0. were as follows: First, the correct response rate varied depending on the content of item. Items related to characteristics and advantages & disadvantages of alternative energy showed high percentage of correct answers. Whereas, items regarding the principles of alternative energy showed relatively low percentage of correct answers. Second, there are some items showing statistically meaningful differences according to students' high school track. Nevertheless, there are no significant differences in overall. Third, we identified twelve alternative conceptions about alternative energy from students' answer distribution. Educational implications were discussed based on the results.

• 한국진공학회지
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• 제9권3호
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• pp.290-295
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• 2000

KAIST-TOKAMAK에서 재현성이 좋은 저항가열 플라즈마를 발생시키는데 필요한 전이온화(pre-ionization)에 응용하기 위해 2.45 GHz 마그네트론을 사용하여 간편한 마이크로파 발생장치를 개발하였다. 장치에 사용한 마그네트론은 출력 500 W, 주파수 2.45 GHz이며, 일반적인 가정용 전자오븐(microwave oven)에 사용된다. 기존의 가정용 마그네트론은 음극(cathode)과 양극(anode)사이에 걸리는 고전압이 60 Hz의 주기를 갖기 때문에 약 16ms마다 약 8 ms 동안만 주기적으로 마이크로파를 발생한다. 이 마그네트론을 사용하여 토카막 전이온화에 충분할 정도로 연속적으로 발생되는 마이크로파를 얻기 위해서 음극과 양극사이에 개량된 회로로 리플전압이 작은 DC 고전압(5 kV 1 A)을 인가하였다. 본 논문에서는 주기적으로 생성.소멸하는 ECH 플라즈마와 연속적인 ECH 플라즈마를 발생시켜 랑뮈어탐침과 광증배관(PMT)을 이용한 이온 포화전류와 $H_\alpha$/ 방출(emission)을 측정하여 마이크로파 발생장치의 특성을 조사하였다.

• 한국음향학회지
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• 제42권4호
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• pp.370-376
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• 2023

수중영상은 수중 잡음과 낮은 해상도로 표적의 형상과 구분이 명확하지 않다. 그리고 딥러닝의 입력으로 수중영상은 전처리가 필요하며 Segmentation이 선행되어야 한다. 전처리를 하여도 표적은 명확하지 않으며 딥러닝에 의한 탐지, 식별의 성능도 높지 않을 수 있다. 따라서 표적을 구분하며 명확하게 하는 작업이 필요하다. 본 연구에서는 수중영상에서 표적 그림자의 중요성을 확인하고 그림자에 의한 물체 탐지 및 표적 영역 획득, 그리고 수중배경이 없는 표적과 그림자만의 형상이 담긴 데이터를 생성하며 더 나아가 픽셀값이 일정하지 않은 표적과 그림자 영상을 표적은 흰색, 그림자는 흑색, 그리고 배경은 회색의 3-모드의 영상으로 변환하는 과정을 제시한다. 이를 통해 딥러닝의 입력으로 명확히 전처리된 판별이 용이한 영상을 제공할 수 있다. 또한 처리는 Open Source Computer Vision(OpenCV)라이브러리의 영상처리 코드를 사용했으면 처리 속도도 역시 실시간 처리에 적합한 결과를 얻었다.

• 한국농공학회논문집
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• 제64권4호
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• pp.1-10
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• 2022

A vegetative filter strip (VFS) is one of the best management practices (BMPs) to reduce pollutant loads. This study aims to assess the effectiveness of VFS in dense upland field areas. The study areas are agricultural fields in the Maedae (MD), Gaa (GA), and Jaun (JU) watersheds, where severe sediment yields have occurred and the Korean government has designated them as non-point management regions. The agricultural fields were divided into three or four clusters for each watershed based on their slope, slope length, and area (e.g., MD1, MD2). To assess the sediment trapping (STE) and pesticide reduction efficiency (PRE) of VFS, the Vegetative Filter Strip Modeling System (VFSMOD) was applied with three different scenarios (SC) (SC1: VFS with rye vegetation; SC2: VFS with rye vegetation and a gentle slope in VFS range; and SC3: VFS with grass mixture). For SC1, there were relatively short slope lengths and small areas in the MD1 and GA3 clusters, and they showed higher pollutant reduction (STE>50%, PRE>25%). For SC2 and SC3, all clusters in GA and some clusters (MD1 and MD3) in MD show higher pollutant reduction (>25%), while the uplands in JU still show a lower pollutant (<25%). With correlation analysis between geographic characteristics and VFS effectiveness slope and slope length showed relative higher correlations with the pollutant efficiency than a area. The results of this study implied that slope and slope length should be considered to find suitable upland conditions for VFS installations.

• 한국산학기술학회논문지
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• 제18권9호
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• pp.425-435
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• 2017

구조해석은 대기업뿐 만 아니라 중소 중견기업에서도 제품 납품을 위한 인증절차의 강화 및 개념설계에서 상세설계로 진행되는 프로세스에서의 시간 단축을 위해 시험과 함께 필수 절차로 활용되고 있다. 적은 비용으로 활용이 가능한 오픈소스 솔버는 자동으로 전처리 데이터를 생성해주는 상용 솔버와 다르게 격자와 같은 입력데이터가 문제가 있을 경우 계산단계에서 오류나 실패하는 경우가 빈번하게 발생할 수 있기 때문에 비 전문가가 활용하기가 어렵다. 본 논문에서는 기존의 구조해석 오픈소스 솔버(Caculix, Code_Aster)를 이용하여 사용자가 손쉽게 기계적 구조 문제의 분석에 활용이 가능한 전 후 처리기를 개발하였다. 특히, 3D 모델, 격자, 시뮬레이션 조건, 결과 정보 분석 등의 각 단계에서 오픈소스 솔버에 따라서 상이한 형태의 데이터를 분석하고 그에 맞는 정확한 정보를 추출 및 생성하는 알고리즘을 개발하여 적용하였다. 또한, 오픈소스 솔버의 계산 정확도를 높이고 오류를 방지하기 위하여 솔버 특성에 맞는 격자를 생성해주고 격자 모델의 자동 힐링 기능을 개발하였다. 마지막으로 해당 시스템의 정확성을 검증하기 위하여 사용소프트웨어와 비교한 검증 결과와 활용 결과를 설명한다.

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1618-1622
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• 2006

Bacteriophage T7 gp4A' is a ring-shaped hexameric DNA helicase that catalyzes duplex DNA unwinding using dTTP hydrolysis as an energy source. To investigate the effect of single-stranded DNA (ssDNA) on the kinetic pathway of dTTP hydrolysis by the T7 DNA helicase complexed with ssDNA, we have first determined optimal concentration of long circular M13 single-stranded DNA and pre-incubation time in the absence of $Mg^{2+}$ which is necessary for the helicase-ssDNA complex formation. Steady state dTTP hydrolysis in the absence of $Mg^{2+}$ by the helicase-ssDNA complex provided $k_{cat}$ of $8.5\;{\times}\;10^{-3}\;sec^{-1}$. Pre-steady state kinetics of the dTTP hydrolysis by the pre-assembled hexameric helicase was monitored by using the rapid chemical quench-flow technique both in the presence and absence of M13 ssDNA. Pre-steady state dTTP hydrolysis showed distinct burst kinetics in both cases, indicating that product release step is slower than dTTP hydrolysis step. Pre-steady state burst rates were similar both in the presence and absence of ssDNA, while steady state dTTP hydrolysis rate in the presence of ssDNA was much faster than in the absence of ssDNA. These results suggest that single-stranded DNA stimulates dTTP hydrolysis reaction by T7 helicase by enhancing the rate of product release step.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1358-1365
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• 2018

Objective: The effect of pre-converted nitrites from natural sources (spinach, lettuce, celery, and red beet) on color development in raw and cooked pork sausage was investigated in this study. Methods: The pork sausage was manufactured with six treatments: NC (negative control, nitrite free), PC (positive control, 150 ppm sodium nitrite), FS (3.0% fermented spinach extracts), FL (3.0% fermented lettuce extracts), FC (3.0% fermented celery extracts), and FR (3.0% fermented red beet extracts). Results: The pH value of the pre-converted nitrites groups was lower than those treated with 150 ppm sodium nitrite (p<0.05). The color values of raw and cooked pork sausage added with pre-converted nitrite showed slightly lower and/or similar lightness, lower redness, and higher yellowness values than PC. Color development (redness values) of cooked samples added with FS was higher than those of the NC and other treatments (FL, FC, and FR). Additionally, treatments with FS and FL were most effective for reducing thiobarbituric acid reactive substances and volatile basic nitrogen than the NC. Conclusion: Effects of natural nitrites from fermented vegetables on shelf stability of raw and cooked pork sausages were investigated. Fermented spinach extract was much more useful for maintaining the color development, but also inhibiting lipid and protein oxidation of cooked pork sausage. Therefore, pre-converted nitrite from spinach as a natural nitrite could be used as another natural nitrite source for making processed meat products.

• 천문학회보
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• 제37권2호
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• pp.137.1-137.1
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• 2012

If all Coronal mass ejections (CMEs) have flux ropes, then the CMEs should keep their helicity signs from the Sun to the Earth according to the helicity conservation principle. We select 34 CME-ICME pairs whose source active regions (ARs) have continuous SOHO/MDI magnetogram data covering more than 24 hr without data gap during the passage of the ARs near the solar disk centre. The helicity signs in the ARs are determined by estimation of accumulating amounts of helicity injections through the photospheric surfaces in the entire source ARs. The helicity signs in the ICMEs are estimated by applying the cylinder model developed by Marubashi (2000) to 16 second resolution magnetic field data from the MAG instrument onboard the ACE spacecraft. It is found that 30 out of 34 events (88%) are helicity sign-consistent events, while 4 events (12%) are sign-inconsistent. Through a detailed investigation of the AR solar origins of the 4 exceptional events, we find that those exceptional events can be explained by the local AR helicity sign opposite to that of the entire AR helicity (2000 July 28 ICME), incorrectly reported solar source in CDAW (2005 May 20 ICME), or the helicity sign of the pre-existing coronal magnetic field (2000 October 13 and 2003 November 20 ICMEs). We conclude that the helicity signs of the ICMEs are quite consistent with those of the injected helicities in the AR regions where CMEs were erupted.

• 한국멀티미디어학회논문지
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• 제16권11호
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• pp.1272-1280
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• 2013

본 논문에서는 실시간으로 위험한 소리를 인식하고 그 방향을 파악하여 이를 통해 PTZ Camera가 위험한 소리 방향으로 회전하여 해당 지역 영상을 획득하여 전송할 수 있도록 지원하는 소리 감시 시스템을 제안한다. 제안 소리 감시 시스템은 적응 혼합 가우시안 모델(AGMM)을 사용하여 일상적인 배경 소리와는 비정상적인 소리를 전경 소리로 검출하고, AGMM 모델로 미리 학습된 전경 소리들 중의 하나로 분류한다. 분류된 소리가 위험한 소리에 속하는 경우, Dual delay-line 방법에 기반을 둔 음원 방향 추정 기법을 사용하여 그 방향을 파악한다. 최종적으로 방향 정보를 사용하여 PTZ 카메라를 조절하여 그 방향 지역의 해당 영상을 획득하고 전송될 수 있도록 지원한다. 제안하는 소리 감시 시스템은 전경 위험 소리들을 안정적으로 검출하고, 79%의 정확도로 위험소리들을 분류하고, 작은 오차범위 이내 음원 방향 추정 성능을 나타냄을 실험결과를 통해 확인하였다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2002년도 제1차워크샵
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• pp.5-23
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• 2002

Motivation: Protein-protein interaction plays a critical role in the biological processes. The identification of interacting proteins by bioinformatical methods can provide new lead In the functional studies of uncharacterized proteins without performing extensive experiments. Results: Protein-protein interactions are predicted by a computational algorithm based on the weighted scoring system for domain interactions between interacting protein pairs. Here we propose potential interaction domain (PID) pairs can be extracted from a data set of experimentally identified interacting protein pairs. where one protein contains a domain and its interacting protein contains the other. Every combinations of PID are summarized in a matrix table termed the PID matrix, and this matrix has proposed to be used for prediction of interactions. The database of interacting proteins (DIP) has used as a source of interacting protein pairs and InterPro, an integrated database of protein families, domains and functional sites, has used for defining domains in interacting pairs. A statistical scoring system. named "PID matrix score" has designed and applied as a measure of interaction probability between domains. Cross-validation has been performed with subsets of DIP data to evaluate the prediction accuracy of PID matrix. The prediction system gives about 50% of sensitivity and 98% of specificity, Based on the PID matrix, we develop a system providing several interaction information-finding services in the Internet. The system, named PreDIN (Prediction-oriented Database of Interaction Network) provides interacting domain finding services and interacting protein finding services. It is demonstrated that mapping of the genome-wide interaction network can be achieved by using the PreDIN system. This system can be also used as a new tool for functional prediction of unknown proteins.