• 센서학회지
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• 제26권3호
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• pp.186-191
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• 2017

In this study, we investigated the simultaneous detection properties of organic vapor, pressure difference, and magnetic field using a single rugate-structured free-standing porous silicon (RFPS) thin film. Both the wavelength and the intensity of the rugate peaks were changed in the reflectivity spectrum measured at the thin film surface while the organic vapor was exposed to the RFPS thin film. However, when the pressure difference and the magnetic field were exposed to the film, only the rugate peak intensity was changed. Therefore, it is possible to distinguish whether or not the organic vapor is detected by simultaneously changing the rugate peak wavelength and intensity. In addition, a method of distinguishing between the pressure difference and the magnetic field detection signal has been derived by rapidly modulating the direction of the magnetic field. This study shows that it is possible to simultaneously detect and distinguish various objects using a single RFPS thin film, and it is found that porous silicon can be utilized as a sensor sufficiently.

• Journal of Radiation Protection and Research
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• 제36권4호
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• pp.183-189
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• 2011

To quantitatively evaluate how setup errors in conjunction with dose gradients contribute to the error in IMRT dose quality assurance (DQA) measurements. The control group consisted of 5 DQA plans of which all individual field dose differences were less than ${\pm}5%$. On the contrary, the examination group was composed of 16 DQA plans where any individual field dose difference was larger than ${\pm}10%$ even though their total dose differences were less than ${\pm}5%$. The difference in 3D dose gradients between the two groups was estimated in a cube of $6{\times}6{\times}6\;mm^3$ centered at the verification point. Under the assumption that setup errors existed during the DQA measurements of the examination group, a three dimensional offset point inside the cube was sought out, where the individual field dose difference was minimized. The average dose gradients of the control group along the x, y, and z axes were 0.21, 0.20, and 0.15 $cGy{\cdot}mm^{-1}$, respectively, while those of the examination group were 0.64, 0.48, and 0.28 $cGy{\cdot}mm^{-1}$, respectively. All 16 plans of the examination group had their own 3D offset points in the cube. The individual field dose differences recalculated at the offset points were mostly diminished and thus the average values of total and individual field dose differences were reduced from 3.1% to 2.2% and 15.4% to 2.2%, respectively. The offset distribution turned out to be random in the 3D coordinate. This study provided the quantitative data that support the large individual field dose difference mainly stems from possible geometric errors (e.g., random setup errors) under the influence of steep dose gradients of IMRT field.

• 한국초지조사료학회지
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• 제30권3호
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• pp.237-246
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• 2010

본 연구는 논에서의 파종기에 따른 사일리지용 옥수수의 생육특성 및 수량을 비교 분석할 뿐 아니라 논과 밭의 생육특성 및 수량도 비교 분석하고자 수행하였다. 논에서의 파종기에 따른 사일리지용 옥수수의 출사일수는 4월 22일 파종기에 81일, 5월 20일 파종기에 70일, 6월10일 파종기에 62일로 파종기가 늦어짐에 따라출사일수는 짧아졌다. 논과 밭 간의 출사일수는 차이가 없었다. 논에서의 간장은 4월 22일 파종기와 5월 20일 파종기 간 차이는 없었으나 6월 10일 파종기에 간장이 급격히 줄어드는 결과를 나타내었다. 논과 밭 간의 간장은 차이가 없었다. 논에서의 파종기에 따른 도복은 차이가 없었으나, 논과 밭 간의 도복은 차이가 있었다. 논에서 파종기에 따른 후기녹체성의 차이는 없었으며 논과 밭 간의 차이도 없었다. 논에서 파종기에 따른 암이삭 비율이 파종기가 늦어짐에 따라 암이삭 비율이 낮아지는 경향이었다. 논과 밭 간의 암이삭 비율 차이는 없었다. 논에서의 파종기에 따른 사일리지용 옥수수의 생초수량은 파종기가 늦어짐에 따라 4월 22일 파종기에 비하여 각각 15%, 32% 감소하였다. 논과 밭 간의 생체수량은 차이가 없었다. 건물수량은 5월 20일 파종기가 4월 22일 파종기에 비하여 각각 9% 증가하였으나, 6월 10일 파종기는 4월 22일 파종기에 비하여 24% 감소 하였다. 논의 건물수량이 밭에 비해 9% 감소하였다. TDN 수량은 5월 20일 파종기가 4월 22일 파종기에 비하여 각각 5% 증가하였으나, 6월 10일 파종기는 4월 22일 파종기에 비하여 28% 감소하였다. 그리고 논의 TDN 수량은 밭에 비해 11% 감소하였다.

• 가족자원경영과 정책
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• 제9권2호
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• pp.127-144
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• 2005

The purpose of this study was to find out the characteristics of the exchange resources when women choose their spouse, and their marital satisfaction in accordance with those resources. For this, women under marriage of less than five years were subjected, categorized into three groups according to the age difference of the couple, and were examined the influence of the personal and parental resources when choosing their spouse on the early marital satisfaction. The results of the study were as follows: First, the personal and parental resources for each age difference of the married couple didn't have a meaningful difference in general. Second, it is shown from the characteristics of the marital satisfaction of each age difference group that there is no particular meaningful difference. Finally, when it comes to the difference in marital satisfaction in accordance with the exchange resources, the personal resources had a meaningful difference in the value field in case of having the same religion. In case both the husband and wife were the second child or younger, there was a meaningful difference in the mutual action field than there was when they were both first-born. In the emotional and the mutual action field of marital satisfaction, a meaningful difference was seen when the couple had the same kind of jobs than when wives had upper level jobs. Concerning the parental resources, a meaningful difference was shown in the mutual action field of the marital satisfaction when the parents of the both sides had the same level of scholastic attainment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.17-20
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• 2002

The methods that track and detect motion field based on image difference of successive images from camera can separate motion field and background effectively, but because of noise and background images getting proper difference images is hard to achieve. In this paper we propose a method that can improve difference image quality significantly. Three step process is used. At the first step, existence of motion field is determined, the second step is finding proper threshold value using 'Contrast Streching' technique which enables us to find proper motion field even in complex images. At last step, remaining noise is removed and motion field is determined.

• Journal of Magnetics
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• 제19권2호
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• pp.174-180
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• 2014

In this paper, a new and simple method is proposed to quickly estimate the induced electric field in the human child exposed to a 100 kHz-10 MHz magnetic field, for the sake of electromagnetic field (EMF) safety assessment. The quasi-static finite-difference time-domain (FDTD) method is used to calculate the induced electric fields in high resolution 3D human child models with various body size parameters, in order to derive the correction factor for the estimation equation. The calculations are repeated for various frequencies and incident angles of the magnetic field. Based on these calculation results, a new and simple estimation equation for the 99th percentile value of the body electric field is derived that depends on the body size parameters, and the incident magnetic field. The estimation errors were equal to or less than 5.1%, for all cases considered.

• 한국초등과학교육학회지:초등과학교육
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• 제22권2호
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• pp.149-155
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• 2003

The objective of this research was to study the impact of metacognitive lesson models on the formation of magnetic field concepts. The subjects of this research was eighty students from two sixth grade classes. One class of forty of these students was the experimental group, which the metacognitive strategic lesson model was applied, and the other class of forty students was the control group which the traditional lessons were conducted. As the result of the experiment, the experimental group and the control group, which previously did not show difference in terms of achievement of conceptualizing magnetic field, displayed a significant difference. According to the comparison between the pre-experiment test on the students' previous concepts and the achievement of the students after the experiment, the middle group showed difference between the experimental group and the control group in a small degree. The lower group showed a notable difference between the two groups and the higher group showed no difference. In terms of achievements shown in different questions asked, there was little difference in the questions that were stated in the textbook while there was a significant difference in the questions that applied the contents of the textbook. The higher academic group, according to the test on the previous concepts, did not show much difference between the experimental group and the control group when they were asked about the concepts of the textbook. In terms of the comparison in the metacognitive levels, both the higher and lower metacognitive experimental groups' average grade was higher than the control groups' and showed an important statistical difference.

• 한국작물학회지
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• 제45권2호
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• pp.103-107
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• 2000

The viviparity of 28 rice varieties was tested at 25 days after heading(DAH), 35DAH, and 45DAH in the laboratory and field condition for 12 days. The incubation temperature was 20/l$0^{\circ}C$ (day/night), 25/15$^{\circ}$C$ and 30/20$^{\circ}$C$ in the laboratory test, and under field water conditions in the field test. The biggest varietal difference of viviparity was found in the laboratory test when examined at 45DAH with the 6-day incubation under 25/15$^{\circ}$C$ . At this conditions the mean viviparous ratio was 32.1 % with the range of 53.9 and the variance of 259.5. In the field test, the significant varietal difference in the viviparity was also found in the lodging treatment at 45 DAH for 6 days. Correlation coefficient analysis between the field and laboratory tests was highly significant from 4 days after incubation at 45 DAH and after 6-day incubation at 35 DAH, and correlation coefficient was higher as incubation days in the laboratory and submerged days under field water became longer. Considering the correlation between the field and laboratory tests, varietal difference of viviparity and convenience of testing, the laboratory test at 45 DAH for 6-day incubation under 25/15$^{\circ}$C$ was the most efficient evaluation method for the viviparity of rice cultivar.

• 천문학회보
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• 제44권1호
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• pp.43.3-43.3
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• 2019

Magnetic fields play an important role in supporting molecular clouds against gravitational collapse. The measured magnetic field strengths in molecular clods enable us to see the effect of magnetic fields in star-forming regions. People have used the Chandrasekhar and Fermi (CF) method to estimate magnetic field strength from observational quantities of molecular cloud density, turbulent velocity and polarization angle dispersion. However, previous studies obtained just one magnetic field strength over the quite large region of a molecular cloud by using the CF method. We here suggest a way to estimate magnetic field strength distribution in Orion A region. We used 450 and 850-micron polarization data of James Clerk Maxwell Telescope (JCMT). Magnetic field strengths were estimated in two wavelengths with 4 pixel resolutions of 16, 20, 24 and 28". Through statistical analysis, we proved the difference of magnetic field strengths between two wavelengths were caused by the difference of their beam sizes. Additionally, we calculated the radii of curvature of polarization segments to select a best pixel resolution for estimating the magnetic field distribution. The pixel resolution should be larger than a radius of curvature. We selected that 20 or 24" pixel resolutions are good choices towards Orion A region.

• Computers and Concrete
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• 제26권4호
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• pp.343-350
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• 2020

Concrete-filled steel tubular (CFST) members have been widely used in engineering, and their tube diameters have become larger and larger. But there is no research on the thermal field of large-diameter CFST structure. These studies focused on the thermal field of the large-diameter CFST structure under solar radiation. The environmental factors and the actual placement position were considered, and the finite element model (FEM) of the thermal field of CFST members under solar radiation (SR) was established. Then the FEM was verified by practical experiments. The most unfavorable temperature gradient model in the cross-section was proposed. The testing results showed that the temperature field of the large-diameter CFST member section was non-linearly distributed due to the influence of SR. The temperature field results of CFST members with different pipe diameters indicated that the larger the core concrete diameter was, the slower the central temperature changed, and there was a significant temperature difference between the center and the boundary. Based on the numerical model, the most unfavorable temperature gradient model in the section was proposed. The model showed that the temperature difference around the center of the circle is small, and the boundary temperature difference is significant. The maximum temperature difference is 15.22℃, which appeared in the southern boundary area of the specimen. Therefore, it is necessary to consider the influence of SR on the thermal field of the member for large-diameter CFST members in actual engineering, which causes a large temperature gradient in the member.