• Title/Summary/Keyword: Systematic error

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Characteristics, Mapping Understanding, Mapping Errors, and Perceptions of Student-Generated Analogies by Elementary School Students' Approaches to Learning (초등학생의 학습접근양식에 따른 비유 만들기 특성, 대응 관계 이해도, 대응 오류, 비유 만들기에 대한 인식)

  • Kang, Hun-Sik;Cheon, Ji-Hyun
    • Journal of The Korean Association For Science Education
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    • v.30 no.5
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    • pp.668-680
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    • 2010
  • In this study, we investigated the characteristics, the mapping understanding, the mapping errors, and the perceptions of student-generated analogies on the separation of mixtures using the sizes of particles by elementary school students' approaches to learning. Fourth graders (N=92) were selected and administered with the tests on the approaches to learning, self-generating analogies, and perception of self-generating analogies. The results revealed that the meaningful learners made more analogies, especially structural/functional, enriched, and higher systematic ones than the rote learners. However, there were little difference in students' approaches to learning in the subcategories of representation (verbal, pictorial, and verbal/pictorial), artificiality (artificial and everyday), and abstraction (abstract and concrete). The meaningful learners had deeper understanding of the analogy and fewer mapping errors than the rote learners. In addition, the numbers of the shared attributes included in student-generated analogies and the scores of the mapping understanding of the meaningful learners were significantly higher than those of the rote learners. Many students, regardless of students' approaches to learning, had positive perceptions of the self-generating analogies in various cognitive and motivational aspects. However, they also point out the various difficulties in the self-generating analogies as their disadvantages. Educational implications of these findings are discussed.

An Estimation Model for the Replacement Parts based on the Operational Availability of Hi-Pass System (하이패스 운용가용도를 이용한 부품의 교체 추정 모델)

  • Hwang, Eui-duk;Heo, Seo Jeong;Kim, Chang Suk;Cheul, Son Dong
    • Journal of the Korea Convergence Society
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    • v.6 no.6
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    • pp.285-291
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    • 2015
  • FTMS, TCS, ITS equipment such as high-pass highway are just a situation that does not lack traceability and passive surveillance is related to fault DB has so far consisted of an integrated operations management to maximize utilization of the facility. In addition, there is no replacement parts are replaced when a failure occurs, increasing the number of parts and repair time I have trouble growing, and becoming a service interruption whenever you replace each time. In this study, proactively manage the failure history of a highway facility ITS tries to preventive maintenance. Therefore, the error history is based on the reliability of the high-pass facilities theory to calculate the reliability of the system through a systematic statistical analysis Operational Availability. The fault number and the time the replacement period through the estimate decreases and can reduce the budget expenses by securing the spare parts quantity, establish a management plan in part by improving the quality of the system through constant preventive maintenance, quality of service at all times It may direct the non-stop operation state of the available state.

Phylogenetic position of Neofinetia and Sedirea (Orchidaceae) and their species identification using the chloroplast matK and the nuclear ITS sequences (엽록체 matK 와 핵 ITS 염기서열을 이용한 나도풍란속 및 풍란속의 계통과 종동정)

  • Kim, Young-Kee;Jo, Sang Jin;Kim, Ki-Joong
    • Korean Journal of Plant Taxonomy
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    • v.44 no.1
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    • pp.39-50
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    • 2014
  • Phylogenetic positions of Sedirea and Neofinetia were addressed using the chloroplast matK and the nuclear ITS sequences. We also evaluate the usefulness of the makers for the identification of species and localities. Sedirea and Neofinetia form an independent monophyletic genus, respectively, in both matK and nuclear ITS trees. The sister genus of the Neofinetia was Vanda in both trees. In addition, our trees support the separate recognition of the Neofinetia from Vanda rather than the inclusion of Neofinetia into Vanda. The sister group of the Sedirea was (Dimorphorchis(Pteroceras(Saccolabiun+Phalaeonopsis))) clade. The Dimorphorchis was one of the most probable sister genus to the Sedirea. The sister group relationship between Sedirea and Aerides was suggested by their similar morphology, but not supported in molecular trees. The identification of species and localities of Neofinetia was possible using our two molecular markers. However, several pseudo-gene sequences are discovered from the public data base. In addition, the horizontal gene transfer of chloroplast genomes is frequent events in orchid hybrids. Therefore, we need a careful evaluation for the data prior to systematic use. Generation of sequence data from multiple accessions of a species may helpful to reduce these types of error.

The Trend of Korean Nursing Research with the LISREL (공변량 구조분석을 이용한 국내 간호연구의 동향)

  • 임난영;강현숙;이성은;서연옥;권영은
    • Journal of Korean Academy of Nursing
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    • v.31 no.2
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    • pp.221-231
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    • 2001
  • This study was conducted by analyzing all 33 articles based on the LISREL, published from January 1991 to March 1999 in Korea. The analyses consisted of the publication date of articles, principal dependent variables, subjects of the research, adequacy of sampling, adequacy of research purposes and results, accordance between theoretical model and hypothetical model, fit measures, theoretical base of model modification, and adequacy of conclusion. The results were as follows : . The thesis of 33 articles in total were outnumbered as 25 (75.8%) to 8 (24.2%) research articles. As for a sex classification of the subjects, 45.5% of the research were conducted around a female group of subjects, while 54.5% were done for both sex, The range of the sample size was 105 to 803, and the average was 259 subjects. . A single theoretical variable was measured for each measurement variable, any difference between variables was hardly found in 8 articles (24.2%), and 19 articles (57.6%) did not consider any measurement error. To analyze if the representative has been articles (21.2%) were seen with a sign of a representative. Questionnaires were used in a majority (31 articles) of the data collecting process. Only 2 articles (6.1%) were measured with a physiologic index simultaneously. . 14 articles (42.2%) were centered on theory development, 10 articles on theory synthesis, and 9 articles on theory test. The research purposes and results were consistent in 25 articles (75.5%) and 8 articles (24.2%) were inconsistent. The quality of life and health promotion behavior were the concepts most frequently studied as a dependent variable, and 7 articles centered on them. In applied theories a health promotion model was used on 4 articles (12.1%), while role theory and stress-coping models were in 3 articles respectively. . The articles were analyzed to see if the hypothetical model was elaborated and tested by the theoretical model. Twenty-five articles proved to be rationale for the inconsistencies. Also, 56.5% proposed hypotheses were supported among the subject articles, and 30 articles (90.0%) suggested a revised model. Path coefficient (17 articles) and theoretical adequacy (17 articles) were the standards mostly used. In conclusion, the principal factors were obtained from the research are to be considered as the principes of LISREL application. First, a model has to be established on a theoretical base rather than empirical results dependent on the data. The results are also required to be globally interpreted. Secondly, at least 200 samples are necessary to satisfy the need. Third, more than 3 measurement variables are to be adjusted to a single theoretical variable; the measurement errors must be suggested as well. Finally, normal distribution characteristics of the data and the estimation method need to be reported. Based on the research result, the follows are suggested; . Systematic criteria on the LISREL application and procedure need to be developed . Agreement form is required to report the results of research using the LISREL

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Estimation of Measurement Uncertainty in Vitamin C Analysis from Vegetable and Fruit Juice (야채음료 중 비타민 C 분석에 있어서의 측정불확도 추정)

  • Kim, Young-Jun;Kim, Hyeon-Wee
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1053-1059
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    • 2003
  • This study aimed to determine the amount of vitamin C from vegetable & fruit juice by high performance liquid chromatograhy (HPLC). Components for estimation of measurement uncertainty associated with the analysis of vitamin C, such as standard weight, purity, molecular weight, dilution of standard solution, calibration curve, recovery, and precision, were importantly applied. The estimation of uncertainty obtained with systematic and random error based on the GUM (Guide to the expression of uncertainty in measurement) and EURACHEM document with mathematical calculation and statistical analysis. The components, evaluated ty either Type A or Type B methods, were combined to produce an overall value of uncertainty known as the combined standard uncertainty. An expanded uncertainty was obtained by multiplying the combined standard uncertainty with a coverage factor (k) calculated from the effective degree of freedom. The content of vitamin C from vegetable and fruit juice was 27.53 mg/100g and the expanded uncertainty by multiplying by the coverage factor (k, 2.06) was 0.63 mg/100g at a 95% confidence level. It was concluded that the main sources were, in order of recovery and precision, weight and purity of the reference material, dilution of the standard solution, and calibration curve. Careful experiments on other higher uncertainties is further needed in addition to better personal proficiency in sample analysis in terms of accuracy and precision.

Improvement of COMS land surface temperature retrieval algorithm by considering diurnal variation of air temperature (기온의 일 변동을 고려한 COMS 지표면온도 산출 알고리즘 개선)

  • Choi, Youn-Young;Suh, Myoung-Seok
    • Korean Journal of Remote Sensing
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    • v.32 no.5
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    • pp.435-452
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    • 2016
  • Land Surface Temperature (LST) has been operationally retrieved from the Communication, Ocean, and Meteorological Satellite (COMS) data by the spilt-window method (CSW_v2.0) developed by Cho et al. (2015). Although the CSW_v2.0 retrieved the LST with a reasonable quality compared to the Moderate Resolution Imaging Spectroradiometer (MODIS) LST data, it showed a relatively poor performance for the strong inversion and lapse rate conditions. To solve this problem, the LST retrieval algorithm (CSW_v2.0) was updated using the simulation results of radiative transfer model (MODTRAN 4.0) by considering the diurnal variations of air temperature. In general, the upgraded version, CSW_v3.0 showed a similar correlation coefficient between the prescribed LSTs and retrieved LSTs (0.99), the relatively smaller bias (from -0.03 K to-0.012 K) and the Root Mean Square Error (RMSE) (from 1.39 K to 1.138 K). Particularly, CSW_v3.0 improved the systematic problems of CSW_v2.0 that were encountered when temperature differences between LST and air temperature are very large and/or small (inversion layers and superadiabatic lapse rates), and when the brightness temperature differences and surface emissivity differences were large. The bias and RMSE of CSW_v2.0 were reduced by 10-30% in CSW_v3.0. The indirect validation results using the MODIS LST data showed that CSW_3.0 improved the retrieval accuracy of LST in terms of bias (from -0.629 K to -0.049 K) and RMSE (from 2.537 K to 2.502 K) compared to the CSW_v2.0.

A Study on the Patternwork Departments of Apparel Manufacturing Companies in Korea (국내(國內) 의류업계(衣類業界)의 패턴실(室) 운용(運用) 실태(實態) 연구(硏究))

  • Koh, Ji-Young;Sohn, Hee-Soon
    • Journal of Fashion Business
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    • v.3 no.4
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    • pp.139-146
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    • 1999
  • The purpose of this study is to analyze the efficiency and working conditions of the patternwork departments by surveying the apparel manufacturing companies sampled in Seoul for their organization, working enviornment and technology of their patternwork departments, and thereby, find the ways to promote the functions of the patternwork department. The results of this study can be summarized as follows; 1. As a result of analyzing the working environment of patternwork departments, it was found that the problems counted by most of the pattern workers were lack of workforce, unhygienic or unpleasant workplaces. 2. As a consequence of analyzing the sample production in terms of tacking methods and times, They rarely tacked the white cotton. Such an omission of tacking procedure may serve to save time, but if a sewing error occurs, the working time would rather be longer due to the defects of pattern to be remedied. 3. As a result of reviewing the general patternwork conditions, it was found that the patterns were still worked out in two dimensions. On the other hand, more than 60% of the pattern workers were applying to their patternworks the styles which they had learned from their seniors. Few patterns are being developed in conformity to apparel trends or body shape changes. 4. As a consequence of examining the problems involving the production of patternsl, the problems involved primarily the patterns incised off no-dart pattern and body structure, and in light of items, involved mainly the trousers and in light of material, involved much the stretch or velvet. Moreover, it is deemed necessary to establish a special institute devoted to a systematic development of pattern technology. 5. Most of the CAD patternworks are used not for pattern designing but for grading and marking works, which suggests that pattern workers need to be educated on this new technology for more diverse and precise patternworks. 6. Lastly, as a result of examining the conditions of patternwork departments and their relevant works, most of the pattern workers were found to be subject to irregular and excessive workload, having little time to produce good patterns. This finding suggests that it is necessary to mandate the pattern workers to more involve the commodity planning.

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Data processing system and spatial-temporal reproducibility assessment of GloSea5 model (GloSea5 모델의 자료처리 시스템 구축 및 시·공간적 재현성평가)

  • Moon, Soojin;Han, Soohee;Choi, Kwangsoon;Song, Junghyun
    • Journal of Korea Water Resources Association
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    • v.49 no.9
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    • pp.761-771
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    • 2016
  • The GloSea5 (Global Seasonal forecasting system version 5) is provided and operated by the KMA (Korea Meteorological Administration). GloSea5 provides Forecast (FCST) and Hindcast (HCST) data and its horizontal resolution is about 60km ($0.83^{\circ}{\times}0.56^{\circ}$) in the mid-latitudes. In order to use this data in watershed-scale water management, GloSea5 needs spatial-temporal downscaling. As such, statistical downscaling was used to correct for systematic biases of variables and to improve data reliability. HCST data is provided in ensemble format, and the highest statistical correlation ($R^2=0.60$, RMSE = 88.92, NSE = 0.57) of ensemble precipitation was reported for the Yongdam Dam watershed on the #6 grid. Additionally, the original GloSea5 (600.1 mm) showed the greatest difference (-26.5%) compared to observations (816.1 mm) during the summer flood season. However, downscaled GloSea5 was shown to have only a -3.1% error rate. Most of the underestimated results corresponded to precipitation levels during the flood season and the downscaled GloSea5 showed important results of restoration in precipitation levels. Per the analysis results of spatial autocorrelation using seasonal Moran's I, the spatial distribution was shown to be statistically significant. These results can improve the uncertainty of original GloSea5 and substantiate its spatial-temporal accuracy and validity. The spatial-temporal reproducibility assessment will play a very important role as basic data for watershed-scale water management.

The affect of Writing Programs on the Writing Strategies of College Students - Focused on the Occupational Therapy Students - (글쓰기 프로그램이 대학생의 글쓰기 전략에 미치는 영향 - 작업치료 전공 학생 중심으로 -)

  • Paik, Young-Rim
    • The Journal of Korean society of community based occupational therapy
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    • v.8 no.1
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    • pp.45-54
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    • 2018
  • Objective : It is one of the most important job tasks to write to occupational therapist, so I want to apply the writing program to the students who use mobile language as the main communication and to investigate the effect. Methods : This study was conducted with 7 freshman students for a total of 10 sessions, once a week, for 2 hours at a time. In addition, after reading the recommended books, I made a total of two manuscripts with the book report and then carried out the supplementary instruction. Changes in the writing program were made using self - questionnaires and changes in the writing of the manuscripts were confirmed by the number of times. Results : As a result of the self-questionnaire, the participants considered the logical aspect of the writing and the consistency of the writing after participating in the writing program, and after the writing, the grammatical aspect was reviewed and the sentence was revised. In addition, the number of secondary corrections was reduced by an average of 7 times more than the number of primary corrections. Conclusion : In order to create a document which is one of the important tasks for occupational therapist, systematic education will be needed to create a more logical and grammatical error-free article.

Study on the design optimization of injection-molded DVD-Tray parts using CAE Simulation (플라스틱 DVD-Tray의 박막 사출성형을 위한 최적화 설계 Simulation에 관한 연구)

  • Chung, Jae-Youp;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1726-1732
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    • 2008
  • Injection molding is one of plastic forming technology which can easily mass-produce plastic parts with various and even complex shape. The technology has lots of difficulties in making a good part due to phase change of material, high applied pressure, and fast melt flow speed in the cavity. To overcome the problems, they had to make trial and error method until the CAE(Computer Aided Engineering) could be a tool for concurrent engineering. In this paper, we investigate the optimal design for a plastic DVD tray part by systematic approach of the commercial CAE program. In design, we should consider two objectives which are both dimensional stability and cost-down. The dimension of the part is crucial because the tray should carry a DVD correctly, but the part is too thin to injection-mold easily. In order to improve the moldability, the mold is designed in the form of stack mold which is a kind of 4 hot runner system. In first, we changed the stack-mold system with one hot-runner to cost down, and decided the optimal position of the gate. After that, we investigate the effect of both the layout of cooling channels and the cooling temperature on the shrinkage of the DVD tray. A optimal simulation approach, the gate design is 2Gate#3 and the layout is Case2 cooling line as the optimal temperature of $70^{\circ}C$. The Moldflow and PC+ABS are used for the CAE program and material respectively.