• Title/Summary/Keyword: data sampling

Search Result 5,029, Processing Time 0.03 seconds

A Study of Display Sampling and Visual Momentum (디스플레이 표집과 시각타성에 관한 연구)

  • Yang, Lee-Gha
    • Archives of design research
    • /
    • v.20 no.3 s.71
    • /
    • pp.39-48
    • /
    • 2007
  • This study explored the Eye Movement, the horizontal and vertical flow of vision, and genetic, cultural and empirical schema, and the differentiation of the visual system of the cerebrum through the engineering psychological or the cognitive neuroscientific experiments measuring Eye Movement to maximize the efficiency of the Public Sign System in the urban environment. Accordingly, the study derived an algorithm that can bring out the most efficient visual design measurement by using EMR test and bitmap counting method. The scientific test data in this study will show the existence of the momentum of differentiation and visual sampling by the Schema and Sensory Qualia of the human.

  • PDF

A Binomial Sampling Plans for Aphis gossypii (Hemiptera: Aphididae) in Greenhouse Cultivation of Cucumbers

  • Kang, Taek Jun;Park, Jung-Joon;Cho, Kijong;Lee, Joon-Ho
    • Horticultural Science & Technology
    • /
    • v.30 no.5
    • /
    • pp.596-602
    • /
    • 2012
  • Infestations of Aphis gossypii per leaf in greenhouse cultivation of cucumbers were investigated to develop binomial sampling plans. An empirical $P_T-m$ model, $ln(m)={\alpha}+{\beta}ln[-ln(1-P_T)]$, was used to evaluate relationship between the proportion of infested leaves with ${\leq}$ T aphids per leaf ($P_T$) and mean aphid density (m). Tally thresholds (T) were set to 1, 3, 5, 7, and 9 aphids per leaf to find appropriate T in greenhouse cultivation of cucumbers. Increasing sample size had little effect on the precision of the binomial sampling plan. However, the precision increased with tally threshold. The binomial model with T = 5 provided appropriate predictions of the mean densities of A. gossypii in the greenhouse cultivation of cucumbers. Using a binomial model with T = 5 (sample size = 200), a wide range of densities (1.2 - 222.8 aphids per leaf) could be estimated with precision levels of 0.346 - 0.380 for $P_T$ values between 0.15 and 0.96. Binomial models were validated at T = 5 and 7 using 12 independent data sets. Both binomial models were robust and adequately described aphid densities; most of the independent sampling data fell within 95% confidence intervals around the prediction model.

A study on the implementation simulation and system for 2-D doppler system using second-order sampling (2차 샘플링을 이용한 2-D 도플러 시스템의 시뮬레이션과 시스템구현에 관한 연구)

  • 임춘성;임용곤
    • Journal of Biomedical Engineering Research
    • /
    • v.11 no.1
    • /
    • pp.147-156
    • /
    • 1990
  • A two-dimensional pulsed doppler system for ultrasonic blood velocity doppler signals is studied and implemented. The second-order sampling method and serial data processing procedures are utillized in the sys- tem, which eliminates the untuning problems at phase channels in the quadrature detection method as well as in the channels of parallel data processing. rho digital signal processor used in this system allows a hardware savings and flexible design options. The efficiency of the various mean frequency estimators in the second-order sampling system is examined by computer simulation as a function of the intersequence sample delay time. The temporal delay for the quadrature component is changed from $1/(4f_o){\;}to{\;}3/(4f_o){\;}and{\;}5/(4f_o)$ where to is the center frequency of the transducer, It is found that autocorrelator is the optimum frequency estimator for the second-order sampling: with !he intersequence sample delay of $1/(4f_o){\;}to{\;}3/(4f_o){\;}and{\;}5/(4f_o)$. The qualitative variation and information proportional to blood velocity in the vessel system are obtained in the VIVO experiments.

  • PDF

Multivariate Shewhart control charts with variable sampling intervals (가변추출간격을 갖는 다변량 슈하르트 관리도)

  • Cho, Gyo-Young
    • Journal of the Korean Data and Information Science Society
    • /
    • v.21 no.6
    • /
    • pp.999-1008
    • /
    • 2010
  • The objective of this paper is to develop variable sampling interval multivariate control charts that can offer significant performance improvements compared to standard fixed sampling rate multivariate control charts. Most research on multivariate control charts has concentrated on the problem of monitoring the process mean, but here we consider the problem of simultaneously monitoring both the mean and variability of the process.

A Study on the Daily Life Experience of Medical Students using the Experience Sampling Method

  • Yoo, Hyo Hyun;Jun, Soo-Koung;Kim, Seong Yong;Park, Kwi Hwa
    • International Journal of Contents
    • /
    • v.13 no.4
    • /
    • pp.16-22
    • /
    • 2017
  • The purpose of this study was to investigate the daily life experiences of medical students and to explore gender differences in these experiences using the Experience Sampling Method (ESM) as the method. The instrument, the Experience Sampling Form (ESF), consisted of questions on the external and internal experiences of the respondents. Data were collected from 2,035 ESFs by 91 students (male=52, female=39) at three medical schools for one week. The data was analyzed using the statistical tests of the t-test and ${\chi}^2$ test. Activity places were significantly different by gender (${\chi}^2=16.576$, p=.001). Males spent more time in learning places such as schools, libraries, etc., whereas females spent their time in personal places, including their homes, dormitories, etc. Males undertook more learning activities than did females, and females undertook more social/leisure activities and basic life activities than did male students (${\chi}^2=18.753$, p=.001). They were in a learning place and performing learning activities. There were significant perceptual differences between males and females about their flow levels, competency levels, and difficulty levels, based on the activity type. These results can help us to understand the daily lives of medical students and can be useful in developing counseling programs and educational activities for students.

Design of Low Area Decimation Filters Using CIC Filters (CIC 필터를 이용한 저면적 데시메이션 필터 설계)

  • Kim, Sunhee;Oh, Jaeil;Hong, Dae-ki
    • Journal of the Semiconductor & Display Technology
    • /
    • v.20 no.3
    • /
    • pp.71-76
    • /
    • 2021
  • Digital decimation filters are used in various digital signal processing systems using ADCs, including digital communication systems and sensor network systems. When the sampling rate of digital data is reduced, aliasing occurs. So, an anti-aliasing filter is necessary to suppress aliasing before down-sampling the data. Since the anti-aliasing filter has to have a sharp transition band between the passband and the stopband, the order of the filter is very high. However, as the order of the filter increases, the complexity and area of the filter increase, and more power is consumed. Therefore, in this paper, we propose two types of decimation filters, focusing on reducing the area of the hardware. In both cases, the complexity of the circuit is reduced by applying the required down-sampling rate in two times instead of at once. In addition, CIC decimation filters without a multiplier are used as the decimation filter of the first stage. The second stage is implemented using a CIC filter and a down sampler with an anti-aliasing filter, respectively. It is designed with Verilog-HDL and its function and implementation are validated using ModelSim and Quartus, respectively.

Outpput Regulation of Nonlinear Systems and Time-Sampling Effects (비선형 시스템 출력 조절과 샘플링 영향)

  • Chung, Sun-Tae
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.35S no.11
    • /
    • pp.96-105
    • /
    • 1998
  • The effects of time-sampling to be considered in digital implementation of a nonlinear output regulator is investigated. It is found that the output regulatability of nonlinear systems is generally not robust with respect to time-sampling although the output regulatedness of nonlinear systems is preserved under time-sampling. Also, a certain class of nonlinear systems is clarified for which the preservation of the output regulatability under time-sampling can be decided without difficulty. These results imply that one needs to seek a better approximate sampled-data nonlinear output regulator since a digital output regulator resulting from discretizing the continuous-time nonlinear output regulator designed based on the underlying continuous-time nonlinear system model is nothing but a 1st order approximate one with respect to sampling-time.

  • PDF

Estimation of P(X > Y) when X and Y are dependent random variables using different bivariate sampling schemes

  • Samawi, Hani M.;Helu, Amal;Rochani, Haresh D.;Yin, Jingjing;Linder, Daniel
    • Communications for Statistical Applications and Methods
    • /
    • v.23 no.5
    • /
    • pp.385-397
    • /
    • 2016
  • The stress-strength models have been intensively investigated in the literature in regards of estimating the reliability ${\theta}$ = P(X > Y) using parametric and nonparametric approaches under different sampling schemes when X and Y are independent random variables. In this paper, we consider the problem of estimating ${\theta}$ when (X, Y) are dependent random variables with a bivariate underlying distribution. The empirical and kernel estimates of ${\theta}$ = P(X > Y), based on bivariate ranked set sampling (BVRSS) are considered, when (X, Y) are paired dependent continuous random variables. The estimators obtained are compared to their counterpart, bivariate simple random sampling (BVSRS), via the bias and mean square error (MSE). We demonstrate that the suggested estimators based on BVRSS are more efficient than those based on BVSRS. A simulation study is conducted to gain insight into the performance of the proposed estimators. A real data example is provided to illustrate the process.

A Sample Design for National Nutrition Servey (국민영양조사(國民營養調査)를 위한 표본설계(標本設計) 소고(小考))

  • Jun, Tae-Yoon;Chung, Kee-Hey
    • Journal of Nutrition and Health
    • /
    • v.17 no.3
    • /
    • pp.236-241
    • /
    • 1984
  • In order to make clear the relationship between sample design and sample survey in community, it was conducted research on sample design for National Nutrition Survey in 1983. In this paper it was tried to analize the data based on The Report of a Settled Population, 1981 conducted by National Bureau of Statistics Economic Planning Board. The sample was basically using stratified two-stage sampling with systematic sampling of Ban or Li as administrative unit. The population represents the whole nation excluding Jeju-do because of budget. The selection of sampling unit and sampling procedure was as follows. 1) Stratify the nation-wide area in 20 sections according to administrative districts. 2) Determine the sample size in each section according to equal proportional rate (1 / 8040) and to about 1,000 households in the sample. 3) Select the 25 sampling units by section according to households proportion. 4) Select the 10 households at random from each Ban or Li according to equal probability proportion as the final sampling unit. Using the procedure, it was sampled 1,000 households for National Nutrition Survey in 1983.

  • PDF

A Complex Sampling Design for the Estimation of Korean Livestock Production Cost (축산물생산비조사를 위한 복합표본설계)

  • Kim, Soo-Taek;Kim, Young-Won
    • The Korean Journal of Applied Statistics
    • /
    • v.21 no.4
    • /
    • pp.675-694
    • /
    • 2008
  • We propose a new sampling design for the Korean Livestock Production Cost Survey. In this sampling design, the survey population is derived from the 2005’s agricultural census of Korea. And coefficient of variation(CV) is estimated from the current livestock production cost survey data, and the estimated CV’s are used to find the optimal sample size which satisfies the predetermined precision of estimation. In order to save the enumeration cost, the agriculture enumeration districts are used as a primary sampling unit(psu). Final sample is selected by double sampling. Also, we propose the estimator which is able to reflect the change of the population of livestock production households.