• Title/Summary/Keyword: sampling points

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A Contour Generation Algorithm for Visualizing Non-Lattice Type Data (비격자형 자료의 시각화를 위한 등치선도 생성 알고리즘)

  • Lee, Jun;Kim, Ji-In
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.2
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    • pp.94-104
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    • 2002
  • As a part of scientific data visualization automatic generation algorithms for a contour map have been investigated mainly on data which are defined at every lattice point. But in actual situation like weather data measurement. it is impossible to get data defined at every lattice point This is because the exact value on every lattice point can not be obtained due to characteristics in sampling devices or sampling methods. In order to define data on every lattice point where data were not sampled an interpolation method. was applied to the sample data to assign approximate values for some lattice type data but by using the non-lattice type of sample data sets. A triangle data link was defined by using non lattice points directly based on actually sample data set, not by using the pre-processed rectangle lattice points. The suggested algorithm generates a contour map a contour map only by using sample data set which are much smaller than old one without data interpolation and there is no skew on data any more since it does not need any interpolation to get the values of the defined lattice points.

Traditional Food Consumption and Cultural Food Knowledge in Korean and Japanese Elementary School Students (한국과 일본에 거주하는 일부 초등학생들의 전통음식 섭취실태와 인식)

  • Choi, Jiyu;Kwon, Sooyoun;Chung, Sang-Jin
    • The Korean Journal of Food And Nutrition
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    • v.29 no.2
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    • pp.218-227
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    • 2016
  • This study was undertaken to examine the knowledge about food culture and intakes of traditional food in Korean and Japanese elementary school students. In 2012 and 2013, a total of 265 students were surveyed, consisting of 73 Korean fifth graders and 192 Japanese sixth graders. The questionnaire comprised of queries on general items, the recognition and sampling of traditional and celebration foods, the knowledge about the partner country's food culture, and the frequency of consuming the partner country's foods. As a result of this study, the frequency of consuming their own country's traditional foods for Korean children (3.1 out of 5.0 points) and Japanese children (3.2 out of 5.0 points) was similar to each other. Japanese children reported to eat Korean foods (2.9 points) more frequently than those of Korean children to eat Japanese foods (2.4 out of 5.0 points) (p<0.001). However, the Korean children reported to have more experience on given typical Japanese foods than Japanese children reported about Korean foods. Further studies are needed for the perception on traditional foods in Korean and Japanese children. The results of this study can be used as a basic data to succeed and develop traditional food cultures.

An efficient reliability analysis strategy for low failure probability problems

  • Cao, Runan;Sun, Zhili;Wang, Jian;Guo, Fanyi
    • Structural Engineering and Mechanics
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    • v.78 no.2
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    • pp.209-218
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    • 2021
  • For engineering, there are two major challenges in reliability analysis. First, to ensure the accuracy of simulation results, mechanical products are usually defined implicitly by complex numerical models that require time-consuming. Second, the mechanical products are fortunately designed with a large safety margin, which leads to a low failure probability. This paper proposes an efficient and high-precision adaptive active learning algorithm based on the Kriging surrogate model to deal with the problems with low failure probability and time-consuming numerical models. In order to solve the problem with multiple failure regions, the adaptive kernel-density estimation is introduced and improved. Meanwhile, a new criterion for selecting points based on the current Kriging model is proposed to improve the computational efficiency. The criterion for choosing the best sampling points considers not only the probability of misjudging the sign of the response value at a point by the Kriging model but also the distribution information at that point. In order to prevent the distance between the selected training points from too close, the correlation between training points is limited to avoid information redundancy and improve the computation efficiency of the algorithm. Finally, the efficiency and accuracy of the proposed method are verified compared with other algorithms through two academic examples and one engineering application.

Comparison of Sampling and Estimation Methods for Economic Optimization of Cumene Production Process (쿠멘 생산 공정의 경제성 최적화를 위한 샘플링 및 추정법의 비교)

  • Baek, Jong-Bae;Lee, Gibaek
    • Korean Chemical Engineering Research
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    • v.52 no.5
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    • pp.564-573
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    • 2014
  • Economic optimization of cumene manufacturing process to produce cumene from benzene and propylene was studied. The chosen objective function was the operational profit per year that subtracted capital cost, utility cost, and reactants cost from product revenue and other benefit. The number of design variables of the optimization are 6. Matlab connected to and controlled Unisim Design to calculate operational profit with the given design variables. As the first step of the optimization, design variable points was sampled and operational profit was calculated by using Unisim Design. By using the sampled data, the estimation model to calculate the operational profit was constructed, and the optimization was performed on the estimation model. This study compared second order polynomial and support vector regression as the estimation method. As the sampling method, central composite design was compared with Hammersley sequence sampling. The optimization results showed that support vector regression and Hammersley sequence sampling were superior than second order polynomial and central composite design, respectively. The optimized operational profit was 17.96 MM$ per year, which was 12% higher than 16.04 MM$ of base case.

A Study on the Improvement of Sampling Rate of Performance Test in Public Survey (공공측량 성과심사에서 심사비율 개선을 위한 연구)

  • Kim, Kyu-Seong;Lee, Young-Min;Jung, Byung-Chul;Choi, Yoon-Soo
    • Communications for Statistical Applications and Methods
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    • v.17 no.6
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    • pp.853-863
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    • 2010
  • The performance test in a public survey is conducted by a sample survey and the sampling rate of the performance test is a very important factor in the test process. Since the current sampling rate was decided empirically at an earlier time, it has been criticized for two points: the first is that it has a lack of a theoretical background on the decision for the sampling rate and the second is that the sampling rate should be improved in accordance with current test situations. In this paper, we review the present state of performance tests in public surveys in Korea and study the relationship between the rate of the performance test and fitness probability, number of tests, and the success rate in order to create a theoretical background to improve the test rate. In addition, we discuss relationship between the test rate and cost in the performance test.

A sampling and estimation method for monitoring poultry red mite (Dermanyssus gallinae) infestation on caged-layer poultry farms

  • Oh, Sang-Ik;Park, Ki-Tae;Jung, Younghun;Do, Yoon Jung;Choe, Changyong;Cho, Ara;Kim, Suhee;Yoo, Jae Gyu
    • Journal of Veterinary Science
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    • v.21 no.3
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    • pp.41.1-41.12
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    • 2020
  • Background: The poultry red mite, Dermanyssus gallinae, is a serious problem in the laying hen industry worldwide. Currently, the foremost control method for D. gallinae is the implementation of integrated pest management, the effective application of which necessitates a precise monitoring method. Objectives: The aim of the study was to propose an accurate monitoring method with a reliable protocol for caged-layer poultry farms, and to suggest an objective classification for assessing D. gallinae infestation on caged-layer poultry farms according to the number of mites collected using the developed monitoring method. Methods: We compared the numbers of mites collected from corrugated cardboard traps, regarding with length of sampling periods, sampling sites on cage, and sampling positions in farm buildings. The study also compared the mean numbers of mites collected by the developed method with the infestation levels using by the conventional monitoring methods in 37 caged-layer farm buildings. Results: The statistical validation provided the suitable monitoring method that the traps were installed for 2 days on feed boxes at 27 sampling points which included three vertical levels across nine equally divided zones of farms. Using this monitoring method, the D. gallinae infestation level can be assessed objectively on caged-layer poultry farms. Moreover, the method is more sensitive than the conventional method in detecting very small populations of mites. Conclusions: This method can be used to identify the initial stages of D. gallinae infestation in the caged-layer poultry farms, and therefore, will contribute to establishment of effective control strategies for this mite.

Estimation of PTT (Pulse Transit Time) by Multirate Filtering Analysis (다중레이트 필터링 기법을 이용한 맥파전달시간 추정)

  • Kim, Hyun-Tae;Kim, Jeong-Hwan;Kim, Kyeong-Seop;Lee, Jae-Ho;Lee, Jeong-Whan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.1020-1026
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    • 2013
  • Multirate filtering process on the biological signals like Electrocardiogram (ECG) and Photoplethysmogram (PPG) can be defined as the digital signal processing algorithm in which the sampling rate varies to omit or interpolate the intermediate values between the sampled data. With this aim, we suggest a new multirate filtering algorithm by deleting the extraneous data to eliminate the unwanted degradations such as granular noise due to the usage of high sampling frequency and simultaneously to detect the fiducial features of ECG and PPG with reducing the complexity of resolving fiducial points such as R-peak, Pulse peak and Pulse Transit Time (PTT). After the experimental simulations performed, we can conclude the fact that we can detect the fiducial features of ECG and PPG signal in terms of R-peak, Pulse peak and PTT without the loss of accuracy even if we do not maintain the original sampling frequency.

Development of Standarized Staffing Indices in School Foodservice System (학교급식시스템 유형별 표준 조리인력 산정모델 개발)

  • 이보숙
    • Journal of Nutrition and Health
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    • v.31 no.3
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    • pp.354-362
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    • 1998
  • The purposes of this study were to develop standardized indices of staffing needs in each school, foodservice system through work sampling methodology . Conventional school foodservices were classified into 5 groups depending on size of meals served. Commissary school foodservices were also classified into 5 groups by cluster analysis using number of meals served, number of satellite schools, and time for transportation of food. Work measurement through work sampling methodology was conducted in 15 conventional and 21 commissary foodservices during 3 consecutive days from September to October in 1995. Statistical data analysis was completed using the SAS programs for descriptive analysis, cluster analysis, and simple linear regression. The results were as follows : Average points of leveling factors of conventional and commissary foodservices were 1.066 and 1.061 , respectively. Mean labor hours per work force was 328 minutes and 366 minutes in conventional and commissary foodservice , respectively. Standardized work time was calculated using leveling factor, ILO allowance rate (175) , and observational work time. The model for standardized indices of staffing needs was developed based on simple linear regression in each school foodservice system. In conventional school foodservice systems(for 100-1,900 meals per day) standardized staffing needs=3.2497 +0.005267$\times$number of meals served (F=273.1, R-square 0.9750, p<0.001). In commissary school foodservice systems (for 200-1,600 meals per day ) Standardized staffing needs=3.393384 +0.0063$\times$number of meals served (F=30.78, R-square 0.6580, p<0.001).

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Estimation for Seaweed Biomass Using Regression: A Methodological Approach (회귀분석을 이용한 해조류 생물량 측정을 위한 방법론)

  • Ko, Young-Wook;Sung, Gun-Hee;Kim, Jeong-Ha
    • ALGAE
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    • v.23 no.4
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    • pp.289-294
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    • 2008
  • To estimate seaweed biomass or standing crop, a nondestructive sampling can be beneficial because of not much destroying living plants and saving time in field works. We suggest a methodological procedure to estimate seaweed biomass per unit area in marine benthic habitats by using species-specific regression equations. Percent cover data are required from the field samplings for most species to convert them to weight data. However, for tall macroalgae such as kelps we need density data and their size (e.g., size class for subtidal kelps) of individuals. We propose that the field sampling should be done with 5 replicates of 50 cm x 50 cm quadrat at three zones of intertidals (upper, middle, lower) and three depth points (1, 5, 10 m) in subtidals. To obtain a reliable regression equation for a species, a substantial number of replicate is necessary from destructive samplings. The regression equation of a species can be further specified by different locality and different season, especially for the species with variable morphology temporally and spatially. Example estimation carried out in Onpyung, Jeju Island, Korea is provided to compare estimated values with real weight data.

Hydrofoil optimization of underwater glider using Free-Form Deformation and surrogate-based optimization

  • Wang, Xinjing;Song, Baowei;Wang, Peng;Sun, Chunya
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.6
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    • pp.730-740
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    • 2018
  • Hydrofoil is the direct component to generate thrust for underwater glider. It is significant to improve propulsion efficiency of hydrofoil. This study optimizes the shape of a hydrofoil using Free-Form Deformation (FFD) parametric approach and Surrogate-based Optimization (SBO) algorithm. FFD approach performs a volume outside the hydrofoil and the position changes of control points in the volume parameterize hydrofoil's geometric shape. SBO with adaptive parallel sampling method is regarded as a promising approach for CFD-based optimization. Combination of existing sampling methods is being widely used recently. This paper chooses several well-known methods for combination. Investigations are implemented to figure out how many and which methods should be included and the best combination strategy is provided. As the hydrofoil can be stretched from airfoil, the optimizations are carried out on a 2D airfoil and a 3D hydrofoil, respectively. The lift-drag ratios are compared among optimized and original hydrofoils. Results show that both lift-drag-ratios of optimized hydrofoils improve more than 90%. Besides, this paper preliminarily explores the optimization of hydrofoil with root-tip-ratio. Results show that optimizing 3D hydrofoil directly achieves slightly better results than 2D airfoil.