• 제목/요약/키워드: Measure-specific Model

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Recent Change in the Fertility Pattern in Korea

  • Rhee, Hong-Joon
    • Journal of the Korean Statistical Society
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    • v.5 no.2
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    • pp.119-127
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    • 1976
  • By examining Table 1, it is confirmed that the two model fertility scheduels for 1960 and 1975 are close agreement with the census data in Korea. The declines of age-specific fertility are more remarkable among older women than among younger, as exhibited in Table 3 and Fig. 2. A merit of this fitted model schedule as compared to fitted conventional frequency distributions such as the Pearson Type III curve, is that the model schedule incorporates combinations of intuitively understandable demographic factors. The value of m, a measure of fertility control, increased remarkably from 0.531 in 1960 to 2.429 in 1975. Considering the fact that the average value of m for forty-three schedules shown in the 1965 Demographic Yearbook was 1.0, and the value of m in England and Wales for 1965 was 1.91, the recent level of fertility control in Korea may be considered higher than generally believed.

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Hydrogen Supplying System using Metal Hydride (금속 수소화물을 이용한 수소공급시스템)

  • Bae, Sang-Chul;Katsuta, Masafumi
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.13-19
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    • 2007
  • To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1 MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristics, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results are compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

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Performance of a direct methanol fuel cell (DMFCs)Using Nation 115 (Nafion 115를 사용한 DMFC MEA 의 성능실험)

  • Choi, Hoon;Hwang, Yong-Sheen;Cha, Suk-Won
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.43-46
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    • 2007
  • To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristic, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results rate compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

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Analysis and Comparison of Usability Models and Techniques Measuring User Performance Interacting with Websites

  • Abdulhak, Sami Abduljalil;Kang, Dae-Ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.210-212
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    • 2011
  • Human Computer Interaction is rapidly growing in different aspects and areas. One of the areas that grab many scholars and researchers interest is usability. Usability is a main factor and critical pillar of products success and acceptance. In this paper, we deeply analyze the current usability models that measure the user performance during the interaction with products. Then, we fairly compare between each model to discover and present the strength and weakness of each model for supporting developer and business organization with guidelines during the development process of the products before launching the actual and final one. Decomposing comparison between each model is performed based on specific criteria. Comparison is tabulated, graphically depicted, and analytically decomposed.

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Mutual Information and Redundancy for Categorical Data

  • Hong, Chong-Sun;Kim, Beom-Jun
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.297-307
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    • 2006
  • Most methods for describing the relationship among random variables require specific probability distributions and some assumptions of random variables. The mutual information based on the entropy to measure the dependency among random variables does not need any specific assumptions. And the redundancy which is a analogous version of the mutual information was also proposed. In this paper, the redundancy and mutual information are explored to multi-dimensional categorical data. It is found that the redundancy for categorical data could be expressed as the function of the generalized likelihood ratio statistic under several kinds of independent log-linear models, so that the redundancy could also be used to analyze contingency tables. Whereas the generalized likelihood ratio statistic to test the goodness-of-fit of the log-linear models is sensitive to the sample size, the redundancy for categorical data does not depend on sample size but its cell probabilities itself.

ADVANTAGES OF USING ARTIFICIAL NEURAL NETWORKS CALIBRATION TECHNIQUES TO NEAR-INFRARED AGRICULTURAL DATA

  • Buchmann, Nils-Bo;Ian A.Cowe
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1032-1032
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    • 2001
  • Artificial Neural Network (ANN) calibration techniques have been used commercially for agricultural applications since the mid-nineties. Global models, based on transmission data from 850 to 1050 nm, are used routinely to measure protein and moisture in wheat and barley and also moisture in triticale, rye, and oats. These models are currently used commercially in approx. 15 countries throughout the world. Results concerning earlier European ANN models are being published elsewhere. Some of the findings from that study will be discussed here. ANN models have also been developed for coarsely ground samples of compound feed and feed ingredients, again measured in transmission mode from 850 to 1050 nm. The performance of models for pig- and poultry feed will be discussed briefly. These models were developed from a very large data set (more than 20,000 records), and cover a very broad range of finished products. The prediction curves are linear over the entire range for protein, fat moisture, fibre, and starch (measured only on poultry feed), and accuracy is in line with the performance of smaller models based on Partial Least Squares (PLS). A simple bias adjustment is sufficient for calibration transfer across instruments. Recently, we have investigated the possible use of ANN for a different type of NIR spectrometer, based on reflectance data from 1100 to 2500 nm. In one study, based on data for protein, fat, and moisture measured on unground compound feed samples, dedicated ANN models for specific product classes (cattle feed, pig feed, broiler feed, and layers feed) gave moderately better Standard Errors of Prediction (SEP) compared to modified PLS (MPLS). However, if the four product classes were combined into one general calibration model, the performance of the ANN model deteriorated only slightly compared to the class-specific models, while the SEP values for the MPLS predictions doubled. Brix value in molasses is a measure of sugar content. Even with a huge dataset, PLS models were not sufficiently accurate for commercial use. In contrast an ANN model based on the same data improved the accuracy considerably and straightened out non-linearity in the prediction plot. The work of Mr. David Funk (GIPSA, U. S. Department of Agriculture) who has studied the influence of various types of spectral distortions on ANN- and PLS models, thereby providing comparative information on the robustness of these models towards instrument differences, will be discussed. This study was based on data from different classes of North American wheat measured in transmission from 850 to 1050 nm. The distortions studied included the effect of absorbance offset pathlength variation, presence of stray light bandwidth, and wavelength stretch and offset (either individually or combined). It was shown that a global ANN model was much less sensitive to most perturbations than class-specific GIPSA PLS calibrations. It is concluded that ANN models based on large data sets offer substantial advantages over PLS models with respect to accuracy, range of materials that can be handled by a single calibration, stability, transferability, and sensitivity to perturbations.

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A Study on the Priority Analysis of Information Systems by Stakeholders (이해당사자별 정보시스템 사용의 우선순위 분석에 대한 연구)

  • Kyung, Tae-Won;Kim, Sang-Kuk;Lee, Jie-Young
    • The Journal of Information Technology
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    • v.12 no.2
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    • pp.13-29
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    • 2009
  • ERP in the past, primarily centering on large enterprises and the introduction of competition in the global e-business, but along with the proliferation of small and medium-sized enterprises are now in earnest, or to take advantage of the introduction of the ERP plan. However, the introduction of the ERP cost and the effort required to develop, because many never previously introduced ERP expect that the introduction of cost and performance comparisons with the measurement is necessary. Until now, however, the introduction of a framework of analysis followed the introduction of ERP primarily to measure performance of a major improvement. This research, in addition to improving the performance of these tasks have been overlooked until now for the system's user satisfaction BSC (Balanced Scorecard) models and techniques using AHP-specific understanding of the Company (Group executives, middle managers groups, and user groups) Importance of priorities you want to analyze. In summary, the key findings of this study follows. First, ERP user satisfaction measurement for the balanced scorecard indicators in terms of the redevelopment. Second, the information system user satisfaction to the user layer (Layer 3), grouped by the measure. Thirdly, the user satisfaction of the important topics for attention as quantified by measuring the hierarchy. This model is for satisfaction levels as quantitative of future users of the new system, information systems and the introduction of a new model of development based on the evaluation data will be able to take advantage of.

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Test Case Generation for Simulink/Stateflow Model Based on a Modified Rapidly Exploring Random Tree Algorithm (변형된 RRT 알고리즘 기반 Simulink/Stateflow 모델 테스트 케이스 생성)

  • Park, Han Gon;Chung, Ki Hyun;Choi, Kyung Hee
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.12
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    • pp.653-662
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    • 2016
  • This paper describes a test case generation algorithm for Simulink/Stateflow models based on the Rapidly exploring Random Tree (RRT) algorithm that has been successfully applied to path finding. An important factor influencing the performance of the RRT algorithm is the metric used for calculating the distance between the nodes in the RRT space. Since a test case for a Simulink/Stateflow (SL/SF) model is an input sequence to check a specific condition (called a test target in this paper) at a specific status of the model, it is necessary to drive the model to the status before checking the condition. A status maps to a node of the RRT. It is usually necessary to check various conditions at a specific status. For example, when the specific status represents an SL/SF model state from which multiple transitions are made, we must check multiple conditions to measure the transition coverage. We propose a unique distance calculation metric, based on the observation that the test targets are gathered around some specific status such as an SL/SF state, named key nodes in this paper. The proposed metric increases the probability that an RRT is extended from key nodes by imposing penalties to non-key nodes. A test case generation algorithm utilizing the proposed metric is proposed. Three models of Electrical Control Units (ECUs) embedded in a commercial vehicle are used for the performance evaluation. The performances are evaluated in terms of penalties and compared with those of the algorithm using a typical RRT algorithm.

Financial Integration in East Asia: Evidence from Stock Prices (주가지수를 통해 살펴본 동아시아의 금융통합에 대한 연구)

  • Zhao, Xiaodan;Kim, Yoonbai
    • KDI Journal of Economic Policy
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    • v.33 no.4
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    • pp.27-48
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    • 2011
  • This paper investigates the extent of global and regional integration in East Asia using stock price index as a measure of economic performance. We employ a structural VAR model to separate the underlying shocks into "global", "regional" and "country-specific" shocks. The estimation results show that country-specific shocks still play a dominant role in East Asia although their role appears to have declined over time, especially after the 1997 financial crisis. Global and regional shocks are responsible for small but increasing shares of stock price fluctuations in all countries. The results indicate that the stock markets in East Asia remain dissimilar and are subject to asymmetric shocks in comparison to European countries.

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A Robust and Adaptive Trust Management System for Guaranteeing the Availability in the Internet of Things Environments

  • Wu, Xu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.5
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    • pp.2396-2413
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    • 2018
  • Trust management is one of the most challenging issues for the highly heterogeneous Internet of Things (IoT). In the context of the IoT, it is difficult to evaluate the node's trustworthiness in the same trust model when a node provides different services. Guaranteeing the availability of the trust management service is another significant challenge because of the dynamic nature of IoT environments. With these issues in mind, this paper propose a robust and adaptive trust management system for the IoT that is able to measure the trustworthiness of nodes based on feedbacks collected from participants in a specific context and ensure the availability of trust management services. The main contributions of our system are: 1) Proposing a partly decentralized trust management framework, which improves the resiliency of the trust mechanism; 2) Proposing an adaptive trust evaluation scheme and a three-dimensional context representation makes trust evaluation more accurate and specific; 3) Enhancing the adaptive trust evaluation scheme by incorporating a bad behavior factor in trust estimation, which efficiently distinguishes misleading feedbacks from On-Off attacks. Simulation results show the good performance of the proposed system and especially show effectiveness against On-Off attacks compared to other trust mechanisms.