• 한국물환경학회지
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• 제36권2호
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• pp.89-97
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• 2020

North Han River is a very unique type of water system, where Hwacheon, Chuncheon, Soyanggang, Euiam and Cheongpyeong Dams are located consecutively. These dams are operated differently in the amount of discharge and release schedule according to their structure and purpose of use. They have different water quality characteristics depending on external pollutant inflow and internal mixing condition. Therefore, this study investigated the relationship between the upper dam and down stream river with respect to water quality indicators, such as water temperature, electrical conductivity, BOD, COD, TN and TP of the North Han River. The similarities and correlations representing the relationship were analyzed by Pearson's correlation r and t-test. The data was taken from the Ministry of Environment's water quality monitoring from 1999 to 2018. The results show that water temperature and electrical conductivity of the dam and river are similar and correlated. However, it turned out that there was no similarities and correlations in BOD, COD, TN and TP that are significantly affected by subaqueous reaction mechanism. The results of this study present the impact of the dam on the water quality of North Han River, which can be used as useful data for management of water quality.

• Advances in nano research
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• 제9권4호
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• pp.263-276
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• 2020

In this article, the acoustic responses of free vibrated natural fibre-reinforced polymer nanocomposite structure have been investigated first time with the help of commercial package (ANSYS) using the multiphysical modelling approach. The sound relevant data of the polymeric structure is obtained by varying weight fractions of the natural nanofibre within the composite. Firstly, the structural frequencies are obtained through a simulation model prepared in ANSYS and solved through the static structural analysis module. Further, the corresponding sound data within a certain range of frequencies are evaluated by modelling the medium through the boundary element steps with adequate coupling between structure and fluid via LMS Virtual Lab. The simulation model validity has been established by comparing the frequency and sound responses with published results. In addition, sets of experimentation are carried out for the eigenvalue and the sound pressure level for different weight fractions of natural fibre and compared with own simulation data. The experimental frequencies are obtained using own impact type vibration analyzer and recorded through LABVIEW support software. Similarly, the noise data due to the harmonically excited vibrating plate are recorded through the available Array microphone (40 PH and serial no: 190569). The numerical results and subsequent experimental comparison are indicating the comprehensiveness of the presently derived simulation model. Finally, the effects of structural design parameters (thickness ratio, aspect ratio and boundary conditions) on the acoustic behaviour of the natural-fibre reinforced nanocomposite are computed using the present multiphysical model and highlighted the inferences.

• The Plant Pathology Journal
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• 제24권3호
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• pp.289-295
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• 2008

RNA-RNA interactions and the dynamic RNA conformations are important regulators in virus replication in several RNA virus systems and may also involved in the regulation of many important virus life cycle phases, including translation, replication, assembly, and switches in these important stages. The 5' non-translated region of Potato virus X(PVX) contains multiple cis-acting elements that facilitate various viral processes. It has previously been proposed that RNA-RNA interactions between various RNA elements present in PVX RNA genome are required for PVX RNA accumulation(Hu et al., 2007; Kim and Hemenway, 1999). This model was based on the potential base-pairing between conserved sequence elements at the upstream of subgenomic RNAs(sgRNAs) and at the 5' and 3' end of RNA genome. We now provide more evidence that RNA-RNA base-pairing between elements present at the 5' end and upstream of each sgRNA is required for efficient replication of genomic and subgenomic plus-strand RNA accumulation. Site-directed mutations introduced at the 5' end of plus-strand RNA replication defective mutant(${\Delta}12$) increasing base-pairing possibility with conserved sequence elements located upstream of each sgRNAs restored genomic and subgenomic plus-strand RNA accumulation and caused symptom development in inoculated Nicotiana benthamiana plants. Serial passage of a deletion mutant(${\Delta}8$) caused more severe symptoms and restored wild type sequences and thus retained possible RNA-RNA base-pairing. Altogether, these results indicate that the RNA element located at the 5' end of PVX genome involved in RNA-RNA interactions and play a key role in high-level accumulation of plus-strand RNA in vivo.

• 비파괴검사학회지
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• 제35권2호
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• pp.128-133
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• 2015

원격진료를 요하는 응급현장에서 사용을 위하여 1차원 배열 탐촉자를 손으로 조작하는 동안 변하는 방사빔의 위치를 추적하여 정적인 3차원 초음파영상을 구성하였다. 탐촉자에 고정된 모션센서의 병진운동 및 회전운동에 대한 정보를 기준직교좌표계로 변환하는 이론적 모델을 제시하였으며, 신호 증폭과 시리얼 통신을 위한 인터페이스 용도의 모듈을 상용의 센서를 사용하여 제작하였다. 실리콘 퍼티로 제작된 시험용 팬텀에 대한 B-모드의 동영상과 센서의 신호를 동기화하여 기록하였다. 동영상으로부터 주기적으로 추출한 B-모드 영상과 각 영상내의 픽셀 각각의 그레이 레벨을 이용하여 3차원 복셀의 그레이 레벨을 재구성하였다. 이 복셀의 데이터를 이용하여 3차원 영상과 임의단면의 B-모드 방식의 2차원 영상을 구성하였으며, 이 영상들은 시험용 팬텀의 형상과 잘 일치하였다.

• 전기학회논문지
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• 제64권7호
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• pp.1056-1063
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• 2015

In this paper, we develop an interface for aerial photograph platform which consists of a quadrotor and a gimbal using the human body and the head posture. As quadrotors have been widely adopted in many industries such as aerial photography, remote surveillance, and maintenance of infrastructures, the demand of aerial video and photograph has been increasing remarkably. Stick type remote controllers are widely used to control a quadrotor, but this method is not an intuitive way of controlling the aerial vehicle and the camera simultaneously. Therefore, a new interface which controls the serial photograph platform is presented. The presented interface uses the human head movement measured by head-mounted display as a reference for controlling the camera angle, and the human body posture measured from Kinect for controlling the attitude of the quadrotor. As the image captured by the camera is displayed on the head-mounted display simultaneously, the user can feel flying experience and intuitively control the quadrotor and the camera. Finally, the performance of the developed system shown to verify the effectiveness and superiority of the presented interface.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.104-105
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• 1998

To minimize the Y2K (year 2000) date aware problem of medical devices, we are developing a database that keeps the data such as equipment type, specification, serial number, model number, acquisition date, vendor, manufacturer of the device as well as the names of departments that installed and that is currently responsible for the management of the medical device. The database also keeps the information as to whether the device awares the date, whether it is affected by the Y2K problem or not, how to solve the problem, reference home page address, and so on. The data was collected via internet search of the FDA web site and related of manufacturers homepages. To manage the Y2K problem effectively, the database should be updated regularly to include recent information.

• Progress in Superconductivity
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• 제3권2호
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• pp.241-246
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• 2002

We have performed the current and voltage loading tests of resistive superconducting fault current limiters (SFCLS) based on $YBa_2$$Cu_3$$O_{7}$(YBCO) films with the diameter of 2 inch. The SFCL consists of meander-type YBCO stripes covered with 200 nm Au layer grown in situ for current shunt and heat dispersion at hot spots. The minimum quench current of an SFCL unit was about 25 Apeak. Seven SFCL units were connected in parallel fur the current load ing tests at power source of 100 $V_{rms}$ $/2,000A_{rms}$. This SFCL units had maximum limiting current of 170 Apeak during the fault instant and then successfully controlled the fault current below 100 Apeak within 1~2 msec after short circuit. Increased short current also reduced the quench completion time with little change of current limiting characterization. We connected six SFCL units in series fur the voltage loading tests at power source of $1,200 V_{rms}$/170 $A_{rms}$ at this time. The shunt resistors were inserted into each SFCL unit to eliminate power imbalance originated from serial connection of SFCL units. Each SFCL unit was quenched simultaneously during the fault condition. The current increased up to 40 $A_{peak}$ and decreased to 14 $A_{peak}$ after 3 cycles. Quench was completed within 1 msec after the fault. We confirmed operating characteristics of 140 kVA($120 A_{rms}$ $\times$ 1,200 $V_{rms}$) SFCL and presented the manufacturing possibility of 3.3 kV SFCL using 4 inch YBCO films.BCO films.lms.

• 한국정밀공학회지
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• 제28권10호
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• pp.1146-1152
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• 2011

Ink transfer process is very important to determine quality of printed pattern, therefore its mechanism should be understood to control printing quality. Although there have been many attempts to understand ink transfer mechanism by numerical simulation and experimental studies, their model was too much simple to model realistic printing process and our understanding is not enough yet. In this paper we designed ink transfer visualization system to present flow visualization of ink transfer process for gravure offset printing. We considered rotational effect of blanket roll which is related with printing speed and used non-Newtonian fluid as working fluid such as Ag paste. For printing unit, cantilever-type blanket roll is used for convenient visualization of ink transfer. Serial images were captured continuously by using high-speed CMOS camera and long range microscope. We investigated the effects of various design parameters such as printing speed and pattern angle on the ink transfer process. We found more stretched ink filament for non-Newtonian fluid than Newtonian fluid. As increasing printing speed, length of stretched ink filament and height of break-up point are also increased. We also compared ink transfer process between CD and MD pattern and its relationship with ink transfer mechanism.

• 센서학회지
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• 제11권1호
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• pp.1-8
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• 2002

온도 측정이 필요한 다양한 용도의 소자에 응용되고 있는 열전쌍열(thermopile) 제작에 SOI 구조를 응용하여, 특성을 개선하였다. 열전쌍열을 구성하는 저항체가 단결정 실리콘으로, 제벡 계수(seebeck coefficient)가 높은 재료일 뿐 아니라, 실리콘 저항체를 산화막을 이용하여 실리콘 기판과 절연 분리한 구조로 되어있어서, 기존의 이온주입 공정에 의해 불순물을 주입하는 방법으로 제작된 저항체에 비해서 두 접점(hot junction 및 cold junction) 사이의 열 전달을 극적으로 감소시킬 수 있어서 소자의 특성을 개선할 수 있었다. 열전쌍열은 p형 단결정 실리콘 저항체 17개 및 n형 17개를 직렬 연결로 구성했다. 저항체의 길이 $1600{\mu}m$, 폭 $40{\mu}m$, 두께 $1{\mu}m$으로 제작된 열전쌍열에 빛을 조사하여 소자 양단에 온도차를 발생시키고, 그 때 발생하는 기전력을 측정한 결과 130mV/K의 우수한 특성을 나타냈다.

• 한국환경교육학회지:환경교육
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• 제17권1호
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• pp.67-76
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• 2004

This study is considered how to use newspapers to apply education by the way of analyses of environment coverage in newspapers. Data for the study were gathered by content analyses of KINDS(Korean Integrated News Database System) established by Korean Press Institute. The environment coverage is mainly placed in social and regional magazines of newspapers, and the news story are mainly assigned to straight/feature magazines in type. The news of environment coverage is mostly gathered from data by government-informer, and the news is positive/agreement or negative/disagreement in tenor. The news gathering methods of planning/magazine newspaper serial are scientific and objective, and they are of the firsthand data by news reporter, contributions by experts and interviews. The spaces of the news are specially edited. The environment news is often negative/disagreeable in tenor because the news is mostly of straight ones written by non-experts. Applying newspapers in education is a useful learning method which students could develop thinking power and induce concerning and interest by themselves. From the results of the study, the useful suggestions to apply newspapers to learning are as follows. At first, spaces and types of news must be read in detail. Secondly, it is hopeful that indirect news by not writer himself might be possibly avoided in learning. Thirdly, the themes of news would be picked up in relation with learning contents. Lastly, it suggests that the tenor of news is neutral or, in cases, positive and negative together possibly.