• 한국수학교육학회지시리즈E:수학교육논문집
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• 제2권
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• pp.181-191
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• 1997

The purpose of this study is to provide the primary sources to improve the problem solving performance by analyzing the errors and the strategies selection of the high school students when solving given algebraic problems. To attain the purpose of this study, the questions for investigation in this study are : 1. What are the differences / similarities in the patterns of errors committed by successful and unsuccessful problem-solvers when solving particular algebraic problems ? 2. What are the error types chosen by unsuccessful problem-solvers when solving particular algebraic problems? 3. Do students utilize checking, either locally or globally, when solving particular algebraic problems? Twenty students were drawn out of 10th grade students in J girls' high school in Yengi -gun, Chung-Nam, for this study. The problem-solving test was used as a test instrument. From the data, the verbal protocols and the written protocols were analyzed by the patterns. The conclusions drawn from the results obtained in the present study are as follows: First, in solving particular algebraic problems, when the problems were solved with one strategy, most students didn't give any consideration to other strategies. So mathematics teachers should teach them to use the various strategies, and should develop the problems to be used the various strategies. Second, in solving particular algebraic problems, errors on notions or transformations of equations were found. Thus, the basic knowledges related to equation should be taught. In addition, most unsuccessful students seleted the strategies inadequately to solve the problems because of misunderstanding the problems. So, to improve the problem solving performance the processes of 'understanding problem' should be emphasized to students. Third, although the unsuccesful students used the 'checking' processes when solving the problems, most of them did not find the errors because of misconceptions related to the problems, carelessness, and unskillfulness of checking. Thus, students must be taught more carefully and encouraged to use the checking.

• 한국수자원학회논문집
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• 제34권4호
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• pp.357-364
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• 2001

실험 또는 계측에 의해 관측된 관측치들은 종종 어떤 기준치 이하의 작은 값들이 기록되는데, 이들 기준치 이하의 값들이 크기는 미소할지라도 평균이나 분산 추정시 왜곡된 결과를 줄 수 있다. 그러나 우리 나라에서는 관측오차로 간주하여 N.D.(Not Detected)로 처리하는 것을 관례로 하고 있어 미소치들이 기록되지 않고 있다. EK라서 본 연구에서는 부여 취수장의 암모니아성 질소(NH$_3$-N)자료가 크기에 따라 분표형이 다름을 조사하고 그 분포를 구별할 수 있는 기준치와 기준치 이하의 자료들에 대한 평균과 분산 추정시 가장 적절한 기법을 찾고자 하였다. 즉, 기준치 이하의 값들과 이상의 값들을 구분하여 평균과 분산을 위한 적절한 기법을 선정하여 추정하였다. 분석 결과 부여취사장의 자료는 편기 수정된 최우도(Bias Corrected ML)법이 가장 적합한 것으로 결정되었으며, 시행착오법에 의하여 기준치를 설정하였다.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.1-5
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• 2001

This paper presents an investigation into the operational comparison of SPOT triangulation to build GCP library by analytical plotter and DPW (digital photogrammetric workstation). GCP database derived from current SPOT images can be used to other image sensors of satellite, if any reasons, such as lack of topographic maps or GCPs. But, general formulation of a photogrammetric process for GCP measurement has to take care of the scene interpretation problem. There are two classical methods depending on whether an analytical plotter or DPW is being used. Regardless of the method used, the measurement of GCPs is the weakest point in the automation of photogrammetric orientation procedures. To make an operational comparison, five models of SPOT panchromatic images (level 1A) and negative films (level 1AP) were used. Ten images and film products were used for the five GRS areas. Photogrammetric measurements were carried out in a manual mode on P2 analytical plotter and LH Systems DPW770. We presented an approach for exterior orientation of SPOT images, which was based on the use of approximately eighty national geodetic control points as GCPs which located on the summit of the mountain. Using sixteen well-spaced geodetic control points per model, all segments consistently showed RMS error just below the pixel at the check points in analytical instrument. In the case of DPW, half of the ground controls could not found or distinguished exactly when we displayed the image on the computer monitor. Experiment results showed that the RMS errors with DPW test was fluctuated case by case. And the magnitudes of the errors were reached more than three pixels due to the lack of image interpretation capability. It showed that the geodetic control points is not suitable as the ground control points in DPW for modeling the SPOT image.

• Current Optics and Photonics
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• 제1권4호
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• pp.263-270
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• 2017

Solar radiation data measured by pyranometers is of fundamental use in various fields. In the field of atmospheric optics, the measurement of solar energy must be precise, and the equipment needs to be maintained frequently. However, there seem to be many errors with the existing type of pyranometer, which is an element of the solar-energy observation apparatus. In particular, the error caused by the thermal dome effect occurs because of the thermal offset generated from a temperature difference between outer dome and inner casing. To resolve the thermal dome effect, intensive observation was conducted using the method and instrument designed by Ji and Tsay. The characteristics of the observed global solar radiation were analyzed by classifying the observation period into clear, cloudy, and rainy cases. For the clear-weather case, the temperature difference between the pyranometer's case and dome was highest, and the thermal dome effect was $0.88MJ\;m^{-2}\;day^{-1}$. Meanwhile, the thermal dome effect in the cloudy case was $0.69MJ\;m^{-2}\;day^{-1}$, because the reduced global solar radiation thus reduced the temperature difference between case and dome. In addition, the rainy case had the smallest temperature difference of $0.21MJ\;m^{-2}\;day^{-1}$. The quantification of this thermal dome effect with respect to the daily accumulated global solar radiation gives calculated errors in the cloudy, rainy, and clear cases of 6.53%, 6.38%, and 5.41% respectively.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.51-58
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• 2011

The energy makes the basic element which improves the quality of life with motive power of industry and life. However, using the fossil fuel resources was restricted through it's abuse and exhaustion, and that cause a global warming resultingly. According to the reason, the world increased the interest that are stability and use of new and renewable energy which is clean energy with environment. Therefore, the property data of new and renewable is needed for developing and supplying the energy. In other words, the data of new and renewable energy becomes the standards for supply and evaluation of new and renewable energy with development of industry and technology. Also, the necessity came to the fore as the reference and standards of new and renewable energy data. Therefore, in this study, we evaluate and collect the solar radiation data as the new and renewable data and process the collected data through the standards for valuation. We evaluate uncertainty with standards which are NREL, WMO, and GUM. Whereby the data becomes reference standards data and gains the credibility. For the reliability data, we correct the measuring instrument with correction period. Using the DQMS and SERI QC, we efficiently manage and evaluate the solar radiation data. As a result, we evaluate uncertainty as 1,120 case about 16 area. we achieve credibility of data from evaluated solar radiation data and provide an accurate information to user. The annual average of horizontal radiation presents between 1,484 and 4,577, then the uncertainty evaluates from 163 to 453. The error of uncertainty presents smaller than the measurement values. So, we judge a credibility of data by expression of reliability quantitatively. In additional, the reference standards data which is possible to approach anywhere will be used for the supporting related industry and policy making.

• 간호행정학회지
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• 제21권5호
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• pp.542-551
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• 2015

Purpose: This study was done to evaluate validity and reliability of the Korean version of the expanded nursing stress scale (ENSS). Methods: Forward-backward translation of ENSS from English to Korean was conducted. The translated instrument was pilot-tested and administrated to 285 nurses who worked in five general hospitals in Korea. Internal consistency reliability was assessed using Cronbach's ${\alpha}$ and composite reliability. Validity was evaluated through construct validity with confirmatory factor analysis, convergent and discriminant validity. Results: The Korean version of ENSS showed a reliable internal consistency with Cronbach's ${\alpha}$ .95 and composite reliability .99. Model fit indexes for 46 items were validated by confirmatory factor analysis(goodness of fit index .82, Tucker-Lewis index .92, root mean square error of approximation .04), indicating suitable construct validity. Factor loading of the 48 items (.47~.88) and average variance extracted out of nine factors (.52~.71.) indicated satisfactory convergent validity. Some values of square of the correlation coefficient between factors (.12~.89) were higher than average variance extracted values of each factor (.52~.71) so that it partly satisfied discriminant validity. Conclusion: Findings show that the Korean version ENSS has good reliability and suitable validity; therefore, can be used to assess and identify Korean nurses' job stress.

• Molecules and Cells
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• 제43권3호
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• pp.298-303
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• 2020

Cryo-electron microscopy (cryo-EM) is now the first choice to determine the high-resolution structures of huge protein complexes. Grids with two-dimensional arrays of holes covered with a carbon film are typically used in cryo-EM. Although semi-automatic plungers are available, notable trial-and-error is still required to obtain a suitable grid specimen. Herein, we introduce a new method to obtain thin ice specimens using real-time measurement of the liquid amounts in cryo-EM grids. The grids for cryo-EM strongly diffracted laser light, and the diffraction intensity of each spot was measurable in real-time. The measured diffraction patterns represented the states of the liquid in the holes due to the curvature of the liquid around them. Using the diffraction patterns, the optimal time point for freezing the grids for cryo-EM was obtained in real-time. This development will help researchers rapidly determine high-resolution protein structures using the limited resource of cryo-EM instrument access.

• 대한방사선기술학회지:방사선기술과학
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• 제43권4호
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• pp.235-242
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• 2020

Scanogram is that combine several practical images into one image to observation. So it is an important consideration in many clinical situation such as iliac measurement, leg alignment measurement and Scoliosis. Currently, scanogram examinations are mainly conducted for children and elderly patients. In this study, in order to apply the longbone detector to children or elderly patients who are difficult to cooperate with, we compared the longbone detector from D equipment with the G equipment discovery 656 Puls equipment in reproducibility of images, distribution of irradiation dose, scattering dose, irradiation time and image acquisition time. D equipment took more than twice as much time as G equipment. The scattered dose generated about 50% more G equipment than D equipment. In the whole spine scanogram and the measurement length of the lower leg, D equipment was also measured longer than G equipment. However, both methods did not show much difference from the CT scanogram, so there was no problem in measurement. The height of the thyroid radiation dose of G equipment was produced more radiation than D equipment. However, the longbone detector deviated from the x-ray center line relative to the tube rotation method, and was measured lower by the directionality of the measuring instrument, so that the error could not be corrected. In the conclusion of study, using the longbone detector is excellent for applying to children or elderly patients to reduce scattering dose. However, using CR may be useful to normal patients. Because, the image quality may deteriorate due to an imbalance of dose difference in thickness depending on the body part. So, it is useful to using a compensation filter or tube rotation method when we take a whole spine scanogram.

• 대한의용생체공학회:의공학회지
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• 제23권5호
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• pp.397-403
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• 2002

뇨당 측정 시스템은 소변 속의 글루코오스 농도를 측정함으로서 당뇨 수치를 모니터링하는 비침습적인 당뇨병 자가 진단 장치이다. 본 논문에서는 기존의 침습형 혈당측정방법의 불편성과 비색계를 이용한 뇨당 검사법의 단점을 보완한 뇨당 측정시스템을 설계하였다. 뇨당 측정시스템은 뇨당 측정용 화학센서, 신호검출부, 디지털 제어 및 신호분석부, 디스플레이부 및 전원부로 구성된다. 뇨당측정용 센서로는 재현성이 뛰어나고 다루기가 간편하며 저렴한 가격으로 대량 생산할 수, 있는 일회용 뇨당측정용 전류화학센서를 개발하였다. 설계한 뇨당 측정시스템의 성능을 평가하기 위하여 사람의 소변에 임의의 농도의 글루코오스 성분을 섞은 용액에 대하여 글루코오스 성분 분석시 사용되는 표준장비와의 비교분석을 통해서 글루코오스 농도 검출에 대한 신뢰성 평가를 수행하였다. 회귀분석에 기초한 신뢰성 평가를 수행한 결과 표준오차는 2.85282로 나타났다. 또한, 화학센서를 사용해서 측정하는 시스템을 평가 시 중요한 파라미터인 S.D(Standard Deviation)는 10%로서 임상적으로 유효한 15% 범주 내에 있음을 확인하였고, C.V(Coefficient of Validation)값은 ,5%이내이므로 혈당센서의 기준으로 평가해 볼때 만족하는 결과를 보였다.

• 한국의류학회지
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• 제29권11호
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• pp.1399-1409
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• 2005

The purpose of this study was to analyze the shape of gathered skirts using a three-dimensional measurement system. And in this experiment, I try to accumulate three-dimensional data of wearing model and to figure out analyzing method made by shape of clothes. The experimental design consists of two factorial designs. I set up three different kinds of fabrics, ratio of gathers. Therefore nine samples were made. The instrument and tools for three-dimensional measurement was whole body 3D scanner. Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. T-test to effect an inspection of evidence, there was difference about measurement times. One-way ANOVA to analysis effect of gather made by gathering conditions. The following results were obtained; 1. As a result of inspecting an error several times using a three-dimension measurement system, convinced data was obtained. 2. At front, distribution of gap amount was larger than back. And as ratio of gathers increased, distribution of gap amount showed regularly. 3. After analyzing horizontal sectional figure of skirts, as a height of skirt changed from waist to the bottom of skirts, the results showed as follows. While section width, section thickness, node width, node depth increased, node count decreased. 4. With the horizontal section levels of gather skirt, the silhouette on middle hip section was similar with the silhouette of body line. And as ratio of gathers around hip section increased, nodes showed regularly. At the bottom of skirts showed different nodes by different gathering condition.