• Title/Summary/Keyword: 정확도 분석

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The Study On Quality Control of Magnetic Resonance Imaging System (자기공명영상장치의 정도관리에 관한 연구)

  • Jeong, Cheon-Soo;Lim, Cheong-Hwan
    • The Journal of the Korea Contents Association
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    • v.9 no.6
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    • pp.178-186
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    • 2009
  • The quality control is needed to ensure the accuracy of medical information and achieved by evaluating the performance of and maintaining the system and practicing various measurements and evaluations. The Korean Institute for Accreditation of Medical Image, therefore, have held educational program for quality control of special medical equipments. The major of programs participants, however, are radiology specialists with only small number of radiological technologists from some hospitals, furthermore, the follow-up education and the share of information between participants and non-participants are insufficient in general, thus, the knowledge level of radiological technologists, regardless of their participation, is relatively low. This study carried out the questionnaire research for the 500 radiological technologists registered in Korean Society of MRI Technology, on the basis of 2008, and performed analysis for five months from May to Oct., 2008. The questionnaires were delivered by post to each radiological technologists and the response rate was 36%(n=180). The results of this revealed that the 86.7% of respondents felt the necessity of inspection on quality management, while only the 27.8% completed the educational program for manager of special medical equipment. and only the half(53.9%) had the knowledge about inspection on quality management. The completion of educational program had no correlations with sex, age, size of occupying hospital, the number of radiological technologists in occupying site and MRI laboratory, career year of general radiologist and in MRI laboratory, and the presence of biomedical engineering department in occupying hospital. The 78.0% of participants at the educational program for quality management held by the Korean Institute for Accreditation of Medical Image had the knowledge about inspection on quality management(p<.05) whereas the 43.9% of the hospitals held such program and the 54.4% of radiological technologists from those hospitals had related knowledge, which indicated that such programs held by hospitals had not effects on the knowledge level of radiological technologists. This indicates also that the contents, methods, and other conditional factors of educational programs are important for the outcome of them.

Focus Group Interview for the Development of an In-service Educational Program on the Practical Problem Focused Home Economics Curriculum (포커스 그룹 인터뷰를 통한 실천적 문제 중심 가정과 교육과정 연수 프로그램에 대한 요구 분석)

  • Lee, Soo-Hee;Yoo, Tae-Myung
    • Journal of Korean Home Economics Education Association
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    • v.20 no.3
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    • pp.107-129
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    • 2008
  • The purpose of this study was to get insights and data from home economics teachers for the development of an in-service educational program on practical problem focused home economics program, which was planned to be held from January 21st and to 29th, 2008. For this, focus group interview, one of qualitative research methods, was used. One session of pilot and three sessions of main focus group interview in which total of 18 from October 31st, 2007 to November 14, 2007. Home economics teachers that participated were carried out. Participants requested the followings contents of an in-service educational program regarding the practical problem focused home economics curriculum. First, most of participants strongly desired to participate in an in-service educational program when a program provided. The participants wanted to be a professional, who is able to explain logically with philosophical background and knowledge about the practical problem focused home economics curriculum. Second, participants requested the followings regarding practical problem focused home economics curriculum for the contents of an in-service educational program: philosophy of home economics, setting a perspective on each content areas, development of practical problem, watching a sample class unit, developing teaching materials and motivation stimulating questions, designing of instruction and lesson plans, class presentation and peer evaluation, constructing paper and pencil test items, and feedback from expects on the practical problem focused home economics curriculum. Third, participants wanted an in-service educational program to be a combination of theory and practice, and at least 50% of it allotted to practice. Participants thought that both peer participants and experts from university would evaluate them whether they achieved the objectives of the in-service educational program if an in-service program has to evaluate participants. Participants would evaluate an in-service educational program excellent when they become empowered to teach other home economics teachers the theoretical aspects of the practical problem focused home economics curriculum and the practical aspects as well. Based on the results of this study a framework of the 30 hours practical problem focused home economics curriculum was proposed.

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Rational Spirit for Painting Theory of the Song Dynasty (宋代画论中的理性精神)

  • Chen, Gu Xiang
    • (The)Study of the Eastern Classic
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    • no.59
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    • pp.405-428
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    • 2015
  • Painting theorists in Song dynasty often spoke 'Li' when they talked about paintings. But 'Li' of the song dynasty is not limited to the 'ethics'. First, it includes visible 'natural's truth', such as the differences of 'geography' and 'physics' between the depicted objects. Second, it also includes 'common sense' which was based on both the observation and the thinking. The theorists thought if the 'common sense' was improper in the painting, the whole work was invalid. Thirdly, it also includes 'the reasonable sense in special situation', which requires great imagination ability and elaborative faculty. For example, when playing wind instruments and stringed instruments in the same time at the same concert, the painter should accurately draw the different gestures of musicians according to that the wind instrument is 'sound when the finger lift' and the stringed instrument is 'sound after the finger have left' in that moment. Fourthly, it includes 'art reason', theorists call it as 'ShenLi' or 'MiaoLi'. 'ShenLi' or 'MiaoLi' require the creator to join the spiritual concept besides his observation and thinking. For example, 'banana in snow' is neither observed available nor thought of available, but is the result of spiritual concept of creators for seeking everlasting. And at last, it certainly includes 'the principle of ethics'. Painters often highlighted the ethical relations of the feudal nation and the value of individual gentleman through the allegory story of figure painting and even the sudden composition in the landscape painting. 'Geography', 'physical', and 'common sense' are required the meticulous observation and the rational thinking for the painted object. And 'the reasonable sense in special situation', 'the art reason', 'the principle of ethics' are required enhancing painting style in the painting artistic conception and realm of life based on the nuanced observation, making 'technology' into the 'Tao'. This is the six reasonable increasing requirements for the painting work. Therefore, 'seeking the final reason' is the fundamental spirit of painting theory of Song Dynasty.

Automated patient set-up using intensity based image registration in proton therapy (양성자 치료 시 Intensity 기반의 영상 정합을 이용한 환자 자동화 Set up 적용 방법)

  • Jang, Hoon;Kim, Ho Sik;Choe, Seung Oh;Kim, Eun Suk;Jeong, Jong Hyi;Ahn, Sang Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.30 no.1_2
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    • pp.97-105
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    • 2018
  • Purpose : Proton Therapy using Bragg-peak, because it has distinct characteristics in providing maximum dosage for tumor and minimal dosage for normal tissue, a medical imaging system that can quantify changes in patient position or treatment area is of paramount importance to the treatment of protons. The purpose of this research is to evaluate the usefulness of the algorithm by comparing the image matching through the set-up and in-house code through the existing dips program by producing a Matlab-based in-house registration code to determine the error value between dips and DRR to evaluate the accuracy of the existing treatment. Materials and Methods : Thirteen patients with brain tumors and head and neck cancer who received proton therapy were included in this study and used the DIPS Program System (Version 2.4.3, IBA, Belgium) for image comparison and the Eclipse Proton Planning System (Version 13.7, Varian, USA) for patient treatment planning. For Validation of the Registration method, a test image was artificially rotated and moved to match the existing image, and the initial set up image of DIPS program of existing set up process was image-matched with plan DRR, and the error value was obtained, and the usefulness of the algorithm was evaluated. Results : When the test image was moved 0.5, 1, and 10 cm in the left and right directions, the average error was 0.018 cm. When the test image was rotated counterclockwise by 1 and $10^{\circ}$, the error was $0.0011^{\circ}$. When the initial images of four patients were imaged, the mean error was 0.056, 0.044, and 0.053 cm in the order of x, y, and z, and 0.190 and $0.206^{\circ}$ in the order of rotation and pitch. When the final images of 13 patients were imaged, the mean differences were 0.062, 0.085, and 0.074 cm in the order of x, y, and z, and 0.120 cm as the vector value. Rotation and pitch were 0.171 and $0.174^{\circ}$, respectively. Conclusion : The Matlab-based In-house Registration code produced through this study showed accurate Image matching based on Intensity as well as the simple image as well as anatomical structure. Also, the Set-up error through the DIPS program of the existing treatment method showed a very slight difference, confirming the accuracy of the proton therapy. Future development of additional programs and future Intensity-based Matlab In-house code research will be necessary for future clinical applications.

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Long-term forecasting reference evapotranspiration using statistically predicted temperature information (통계적 기온예측정보를 활용한 기준증발산량 장기예측)

  • Kim, Chul-Gyum;Lee, Jeongwoo;Lee, Jeong Eun;Kim, Hyeonjun
    • Journal of Korea Water Resources Association
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    • v.54 no.12
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    • pp.1243-1254
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    • 2021
  • For water resources operation or agricultural water management, it is important to accurately predict evapotranspiration for a long-term future over a seasonal or monthly basis. In this study, reference evapotranspiration forecast (up to 12 months in advance) was performed using statistically predicted monthly temperatures and temperature-based Hamon method for the Han River basin. First, the daily maximum and minimum temperature data for 15 meterological stations in the basin were derived by spatial-temporal downscaling the monthly temperature forecasts. The results of goodness-of-fit test for the downscaled temperature data at each site showed that the percent bias (PBIAS) ranged from 1.3 to 6.9%, the ratio of the root mean square error to the standard deviation of the observations (RSR) ranged from 0.22 to 0.27, the Nash-Sutcliffe efficiency (NSE) ranged from 0.93 to 0.95, and the Pearson correlation coefficient (r) ranged from 0.97 to 0.98 for the monthly average daily maximum temperature. And for the monthly average daily minimum temperature, PBIAS was 7.8 to 44.7%, RSR was 0.21 to 0.25, NSE was 0.94 to 0.96, and r was 0.98 to 0.99. The difference by site was not large, and the downscaled results were similar to the observations. In the results of comparing the forecasted reference evapotranspiration calculated using the downscaled data with the observed values for the entire region, PBIAS was 2.2 to 5.4%, RSR was 0.21 to 0.28, NSE was 0.92 to 0.96, and r was 0.96 to 0.98, indicating a very high fit. Due to the characteristics of the statistical models and uncertainty in the downscaling process, the predicted reference evapotranspiration may slightly deviate from the observed value in some periods when temperatures completely different from the past are observed. However, considering that it is a forecast result for the future period, it will be sufficiently useful as information for the evaluation or operation of water resources in the future.

Detection of Arctic Summer Melt Ponds Using ICESat-2 Altimetry Data (ICESat-2 고도계 자료를 활용한 여름철 북극 융빙호 탐지)

  • Han, Daehyeon;Kim, Young Jun;Jung, Sihun;Sim, Seongmun;Kim, Woohyeok;Jang, Eunna;Im, Jungho;Kim, Hyun-Cheol
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.1177-1186
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    • 2021
  • As the Arctic melt ponds play an important role in determining the interannual variation of the sea ice extent and changes in the Arctic environment, it is crucial to monitor the Arctic melt ponds with high accuracy. Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2), which is the NASA's latest altimeter satellite based on the green laser (532 nm), observes the global surface elevation. When compared to the CryoSat-2 altimetry satellite whose along-track resolution is 250 m, ICESat-2 is highly expected to provide much more detailed information about Arctic melt ponds thanks to its high along-track resolution of 70 cm. The basic products of ICESat-2 are the surface height and the number of reflected photons. To aggregate the neighboring information of a specific ICESat-2 photon, the segments of photons with 10 m length were used. The standard deviation of the height and the total number of photons were calculated for each segment. As the melt ponds have the smoother surface than the sea ice, the lower variation of the height over melt ponds can make the melt ponds distinguished from the sea ice. When the melt ponds were extracted, the number of photons per segment was used to classify the melt ponds covered with open-water and specular ice. As photons are much more absorbed in the water-covered melt pondsthan the melt ponds with the specular ice, the number of photons persegment can distinguish the water- and ice-covered ponds. As a result, the suggested melt pond detection method was able to classify the sea ice, water-covered melt ponds, and ice-covered melt ponds. A qualitative analysis was conducted using the Sentinel-2 optical imagery. The suggested method successfully classified the water- and ice-covered ponds which were difficult to distinguish with Sentinel-2 optical images. Lastly, the pros and cons of the melt pond detection using satellite altimetry and optical images were discussed.

RPC Correction of KOMPSAT-3A Satellite Image through Automatic Matching Point Extraction Using Unmanned AerialVehicle Imagery (무인항공기 영상 활용 자동 정합점 추출을 통한 KOMPSAT-3A 위성영상의 RPC 보정)

  • Park, Jueon;Kim, Taeheon;Lee, Changhui;Han, Youkyung
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.1135-1147
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    • 2021
  • In order to geometrically correct high-resolution satellite imagery, the sensor modeling process that restores the geometric relationship between the satellite sensor and the ground surface at the image acquisition time is required. In general, high-resolution satellites provide RPC (Rational Polynomial Coefficient) information, but the vendor-provided RPC includes geometric distortion caused by the position and orientation of the satellite sensor. GCP (Ground Control Point) is generally used to correct the RPC errors. The representative method of acquiring GCP is field survey to obtain accurate ground coordinates. However, it is difficult to find the GCP in the satellite image due to the quality of the image, land cover change, relief displacement, etc. By using image maps acquired from various sensors as reference data, it is possible to automate the collection of GCP through the image matching algorithm. In this study, the RPC of KOMPSAT-3A satellite image was corrected through the extracted matching point using the UAV (Unmanned Aerial Vehichle) imagery. We propose a pre-porocessing method for the extraction of matching points between the UAV imagery and KOMPSAT-3A satellite image. To this end, the characteristics of matching points extracted by independently applying the SURF (Speeded-Up Robust Features) and the phase correlation, which are representative feature-based matching method and area-based matching method, respectively, were compared. The RPC adjustment parameters were calculated using the matching points extracted through each algorithm. In order to verify the performance and usability of the proposed method, it was compared with the GCP-based RPC correction result. The GCP-based method showed an improvement of correction accuracy by 2.14 pixels for the sample and 5.43 pixelsfor the line compared to the vendor-provided RPC. In the proposed method using SURF and phase correlation methods, the accuracy of sample was improved by 0.83 pixels and 1.49 pixels, and that of line wasimproved by 4.81 pixels and 5.19 pixels, respectively, compared to the vendor-provided RPC. Through the experimental results, the proposed method using the UAV imagery presented the possibility as an alternative to the GCP-based method for the RPC correction.

Development of 3D Printed Snack-dish for the Elderly with Dementia (3D 프린팅 기술을 활용한 치매노인 전용 영양(수분)보충 식품섭취용기 개발)

  • Lee, Ji-Yeon;Kim, Cheol-Ho;Kim, Kug-Weon;Lee, Kyong-Ae;Koh, Kwangoh;Kim, Hee-Seon
    • Korean Journal of Community Nutrition
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    • v.26 no.5
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    • pp.327-336
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    • 2021
  • Objectives: This study was conducted to create a 3D printable snack dish model for the elderly with low food or fluid intake along with barriers towards eating. Methods: The decision was made by the hybrid-brainstorming method for creating the 3D model. Experts were assigned based on their professional areas such as clinical nutrition, food hygiene and chemical safety for the creation process. After serial feedback processes, the grape shape was suggested as the final model. After various concept sketching and making clay models, 3D-printing technology was applied to produce a prototype. Results: 3D design modeling process was conducted by SolidWorks program. After considering Dietary reference intakes for Koreans (KDRIs) and other survey data, appropriate supplementary water serving volume was decided as 285 mL which meets 30% of Adequate intake. To consider printing output conditions, this model has six grapes in one bunch with a safety lid. The FDM printer and PLA filaments were used for food hygiene and safety. To stimulate cognitive functions and interests of eating, numbers one to six was engraved on the lid of the final 3D model. Conclusions: The newly-developed 3D model was designed to increase intakes of nutrients and water in the elderly with dementia during snack time. Since dementia patients often forget to eat, engraving numbers on the grapes was conducted to stimulate cognitive function related to the swallowing and chewing process. We suggest that investigations on the types of foods or fluids are needed in the developed 3D model snack dish for future studies.

Quality Evaluation through Inter-Comparison of Satellite Cloud Detection Products in East Asia (동아시아 지역의 위성 구름탐지 산출물 상호 비교를 통한 품질 평가)

  • Byeon, Yugyeong;Choi, Sungwon;Jin, Donghyun;Seong, Noh-hun;Jung, Daeseong;Sim, Suyoung;Woo, Jongho;Jeon, Uujin;Han, Kyung-soo
    • Korean Journal of Remote Sensing
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    • v.37 no.6_2
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    • pp.1829-1836
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    • 2021
  • Cloud detection means determining the presence or absence of clouds in a pixel in a satellite image, and acts as an important factor affecting the utility and accuracy of the satellite image. In this study, among the satellites of various advanced organizations that provide cloud detection data, we intend to perform quantitative and qualitative comparative analysis on the difference between the cloud detection data of GK-2A/AMI, Terra/MODIS, and Suomi-NPP/VIIRS. As a result of quantitative comparison, the Proportion Correct (PC) index values in January were 74.16% for GK-2A & MODIS, 75.39% for GK-2A & VIIRS, and 87.35% for GK-2A & MODIS in April, and GK-2A & VIIRS showed that 87.71% of clouds were detected in April compared to January without much difference by satellite. As for the qualitative comparison results, when compared with RGB images, it was confirmed that the results corresponding to April rather than January detected clouds better than the previous quantitative results. However, if thin clouds or snow cover exist, each satellite were some differences in the cloud detection results.

A Comparative Evaluation of Multiple Meteorological Datasets for the Rice Yield Prediction at the County Level in South Korea (우리나라 시군단위 벼 수확량 예측을 위한 다종 기상자료의 비교평가)

  • Cho, Subin;Youn, Youjeong;Kim, Seoyeon;Jeong, Yemin;Kim, Gunah;Kang, Jonggu;Kim, Kwangjin;Cho, Jaeil;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.37 no.2
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    • pp.337-357
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    • 2021
  • Because the growth of paddy rice is affected by meteorological factors, the selection of appropriate meteorological variables is essential to build a rice yield prediction model. This paper examines the suitability of multiple meteorological datasets for the rice yield modeling in South Korea, 1996-2019, and a hindcast experiment for rice yield using a machine learning method by considering the nonlinear relationships between meteorological variables and the rice yield. In addition to the ASOS in-situ observations, we used CRU-JRA ver. 2.1 and ERA5 reanalysis. From the multiple meteorological datasets, we extracted the four common variables (air temperature, relative humidity, solar radiation, and precipitation) and analyzed the characteristics of each data and the associations with rice yields. CRU-JRA ver. 2.1 showed an overall agreement with the other datasets. While relative humidity had a rare relationship with rice yields, solar radiation showed a somewhat high correlation with rice yields. Using the air temperature, solar radiation, and precipitation of July, August, and September, we built a random forest model for the hindcast experiments of rice yields. The model with CRU-JRA ver. 2.1 showed the best performance with a correlation coefficient of 0.772. The solar radiation in the prediction model had the most significant importance among the variables, which is in accordance with the generic agricultural knowledge. This paper has an implication for selecting from multiple meteorological datasets for rice yield modeling.