• 한국토양비료학회지
• /
• 제50권5호
• /
• pp.391-400
• /
• 2017

Italian ryegrass (IRG) is one of the fastest growing grasses available to farmers. It offers rapid establishment and starts growing early in the following spring and has fast regrowth after defoliation. So, IRG can be utilized as the dominant/single species of grass used in a farming system, or to play a role as a large producing pasture and sacrificial paddock. The objective of this study was to develop the use of unmanned aerial vehicle (UAV) for the evaluation of feed value of IRG. For this study, UAV imagery was taken on the Nonsan regions two times during the IRG growing season. We analyzed the relationships between $NDVI_{UAV}$ and feed value parameters such as fresh matter yield, dry matter yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN) and crude protein at the season of harvest. Correlation analysis between $NDVI_{UAV}$ and feed value parameters of IRG revealed that $NDVI_{UAV}$ correlated well with crude protein (r = 0.745), and fresh matter yield (r = 0.655). According to the relationship, the variation of $NDVI_{UAV}$ was significant to interpret feed value parameters of IRG. Eight different regression models such as Linear, Logarithmic, Inverse, Quadratic, Cubic, Power, S, and Exponential model were used to estimate IRG feed value parameters. The S and exponential model provided more accurate results to predict fresh matter yield and crude protein than other models based on coefficient of determination, p- and F-value. The spatial distribution map of feed values in IRG plot was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to regression equation. These lead to the result that the characteristics of variations in feed value of IRG according to $NDVI_{UAV}$ were well reflected in the model.

• Environmental Engineering Research
• /
• 제15권1호
• /
• pp.9-14
• /
• 2010

The objective of this study was to assess the variation in the concentration of assimilable organic carbon (AOC) in a drinking water resource, and investigate the characteristics of AOC derived from algae. The seasonal change in AOC at the Kamafusa dam corresponded to changes in the algal cell number. In order to understand the relationship between AOC and algae in a water resource and water purification plant, two kinds of laboratory experiment were performed. The algal culture experiment showed that extracellular organic matter (EOM) that was released during the growth of Phormidium tenue with M-11 medium led to significant increases in the AOC concentration, but no significant variation in the AOC concentration was observed with CT medium containing a high dissolved organic carbon concentration. The chlorination experiment showed that the AOC included in EOM was not easily removed by chlorination, although the AOC included in intercellular organic matter released from the algal cells by chlorination was removed under conditions where residual chlorine was detected.

• 문화기술의 융합
• /
• 제4권1호
• /
• pp.325-329
• /
• 2018

실내 거주공간에는 건축 자재, 환기, 조리 등으로 인하여 많은 오염물질이 발생한다. 이중 미세먼지는 1급 발암물질로 인체에 매우 유해한 물질이며, 주로 조리시에 가장 많이 발생한다. 따라서 실내공기질을 잘 관리하기 위해서는 조리시 발생하는 미세먼지의 농도와 환기방법과의 관계를 평가할 필요가 있다. 이에 본 연구에서는 음식물의 종류 및 환기방법에 따른 미세먼지(PM2.5)의 농도변화를 측정하고 분석하여, 주방 조리시 발생하는 미세먼지의 관리방안을 제시하고자 하였다.

• 한국항해학회지
• /
• 제18권2호
• /
• pp.111-127
• /
• 1994

A Contract of marine insurance is a contract whereby the insurer undertakes to indemnity the assurd, in manner and to the extent thereby agreed, against marine losses that is to say, the losses incident to marine adventure. But the matter is that whether the problem of increased risk in insurance law should be understood by matching to nay state under general principle of contract law and whether that we should give any effect is more proper to the original object of the system. For this, it is understood that it is a case to be applied a "clausula rebus sic stantibus" in general today, but it is regarded as the matter that whether "clausula rebus sic stantibs" is charging any position in change of risk and whether we should understood the concept of the risk on the substance of the risk. Accordingly the recognition for the problem like this, study should examine closely into whether any system for the effect of increase in change of risk is more proper and rational system provide the supplementing points through our principle of insurance law and the study by comparing method.by comparing method.

• 한국물환경학회지
• /
• 제26권2호
• /
• pp.326-331
• /
• 2010

Montmorillonite is one of representative inorganic clay particles. As the characteristics of clay particulate matter in aqueous environment determine the efficiencies of wastewater treatment and some industrial operations, it is essential to understand its aquatic behavior in relation with turbidity. The change of electrokinetic potential of montmorillonite suspension shows that it tends to negatively increase as the pH of suspension increases. In addition, it is observed that its potential is around 0mV when the solution pH is ca. 5. The turbidity of suspension is shown to be very low when pH is lower than its isoelectric point. However, the turbidity gradually enhances according to beyond isoelectric point. These results reveal that the correlation between electrokinetic potential and turbidity for clay mineral suspension is peculiar which should be fundamentally considered for systematic treatment of wastewater.

• 상하수도학회지
• /
• 제12권4호
• /
• pp.59-69
• /
• 1998

Biological treatment systems generally can be divided into two main classes of a suspended sludge process and attached one like a fluidized bed reactor. These process are considered to bring remarkable change in species composition of microorganisms, due to difference of a state of biofilm, a concentration and diffusion velocity of dissolved oxygen, a concentration and diffusion velocity of substance or poisonous matter. The change of species composition bring different treatment result for influence factors like F/M ratio, DO concentration, pH or poisonous matter. This study is to investigate the reaction characteristics of both microorganisms, namely, a suspended sludge and attached sludge, through the changes of pH, temperature and substance concentration.

• 조형예술학연구
• /
• 제1권
• /
• pp.165-188
• /
• 1999

When we think about visual art, we can't pass over the matter of images and spaces. An image is fixed in a painting space. If the image were posited in the river of time, it would be changed as time flowed on. Its image might be created, rigged, transfigured or it might vanish or remain as traces. The image is changed through the process of expressing them on the painting surfaces. In paintings the changing of the image is caused not only by working processes but also recognizing the objects. In modernist painting, the idea of space was important, but in postmodernist view, the idea of time becomes essential. In this thesis I will focus on the matter of time and image of painting in the late 20th century. Studying the relationship of image and time is not familiar because we had considered the space as being more related to painting distinction than time. Presently, the concept of space can't be divided from that of time. In Physics, they recently called it as a united concept- time-space. Painting space also becomes one asking and recieve the concept of time actively. Now in painting, time is no more a supporting matter but becomes a major matter. In the late 20th century, we can find many trials to catch the change of images as time flowes on and express them as a trace through using verioty media. One of the way to drawing the change of images as time passes could be seen through various joint images in one painting space and another in the traces of one image. The other could be done by using new media such as computer in the example of fractal art. It shows the images chainging of practically as time changes. New understanding about time of this era has to be affirmatively accepted because it reflects the contemporary cultural situation and in art, the concern about the possiblity of it and finding new medias which has to go on.

• 한국대기환경학회지
• /
• 제34권5호
• /
• pp.651-658
• /
• 2018

Particulate matter (PM) emitted from fossil fuel-combustion facilities can be classified as either filterable or condensable PM. The U.S. Environmental Protection Agency (EPA) defined condensable PM as material that is in the phase of vapor at the stack temperature of the sampling location which condenses, reacts upon cooling and dilution in the ambient air to form solid or liquid in a few second after the discharge from the stack. Condensable PM passed through the filter media and it is typically ignored. But condensable PM was defined as a component of primary PM. This study investigates the change of condensable PM according to the variation in the sulfur dioxide of combustion gas. Domestic oil boilers were used as the source of emission ($SO_2$) and the level of $SO_2$ concentration (0, 50, 80, and 120 ppm) was adjusted by diluting general light oil and marine gas oil (MGO) that contains sulfur less than 0.5%. Condensable PM was measured as 2.72, 6.10, 8.38, and $13.34mg/m^3$ when $SO_2$ concentration in combustion gas were 0, 50, 80, and 120 ppm respectively. The condensable PM tended to increase as the concentration of $SO_2$ increased. Some of the gaseous air pollutants emitted from the stack should be considered precursors of condensable PM. The gas phase pollutants which converted into condensable PM should reduced for condensable PM control.

• 방사선산업학회지
• /
• 제12권4호
• /
• pp.267-276
• /
• 2018

A Hoffman 3D Brain Phantom was used to evaluate two PET/CT scanners, BIO_40 and D_690, according to the radiation dose of CT (low, medium and high) at a fixed kilo-voltage-peak (kVp) with the tube current(mA) varied in 17~20 stages(Bio_40 PET/CT scanner: the tube voltage was fixed to 120 kVp, the effective tube current(mAs) was increased from 33 mAs to 190 mAs in 10 mAs increments, D_690 PET/CT scanner: the tube voltage was fixed to 140 kVp, tube current(mA) was increased from 10 mAs to 200 mAs in 10 mAs increments). After obtaining the PET image, an attenuation correction was conducted based on the attenuation map, which led to an analysis of the difference in the image. First, the ratio of white to gray matter for each scanner was examined by comparing the coefficient of variation (CV) depending on the average ratio. In addition, a blind test was carried out to evaluate the image. According to the study results, the BIO_40 and D_690 scanners showed a <1% change in CV value due to the tube current conversion. The change in the coefficients of white and gray matter showed that the Z value was negative for both scanners, indicating that the coefficient of gray matter was higher than that of white matter. Moreover, no difference was observed when the images were compared in a blind test.

• 한국과학교육학회지
• /
• 제29권1호
• /
• pp.10-21
• /
• 2009

이 연구에서는 중학교 3학년 '물질의 구성' 단원과 '물질 변화에서의 규칙성' 단원에서 다루는 가설과 법칙들을 과학 교사들이 어떻게 이해하고 있는지 알아보고, 귀추적 관점을 경험하였을 때 이들의 사고가 어떻게 변화하는지 알아보았다. 22명의 대학원 과정 화학 교사들을 대상으로 3주간 귀추법에 관련된 토론 수업을 진행하고, 수업에 참여한 교사들 중에 4명을 선발하여 사고의 변화를 면담과 보고서 등을 통해 조사하였다. 조사 결과, 교과서 내용 순서에 문제점을 인식하지 못하였던 교사 2명은 토론 수업 후에 법칙과 가설의 차이를 인식하는 사고로 변화하였다. 수업 전에 교과서의 내용 전개 순서에 문제가 있다고 생각하였던 교사 2명은 수업을 통해 귀추적 관점을 획득하였다. 또한 이들은 학생들의 지도 방식에 대한 새로운 견해와 귀추적 관점이 가지는 교육적 의미도 깨달았다.