• Survey Research
• /
• v.6 no.2
• /
• pp.75-101
• /
• 2005

This study introduces and analyzes the data from Directory of Korean NGOs, which was published in 1997 and again in 200, to conduct a quantitative research on the growth of civic organization in South Korea. This paper focus on the information on membership size and founding year which are essential indicators for the growth of organizations. Missing rates on those two indicators are checked to evaluate the quality of data. We examine the changes in membership size between the two time periods, 1996 and 1999. It shows that there is a considerable decrease in the membership size for civic and advocary organizations that are oriented to national issues. It suggests the competition among the organizations over limited resources, which is consistent with an assumption of ecological theory of organization on non-linear growth pattern. Using founding year data from 1945 to 1996, we estimate pseudo growth curves of civic organizations based on logistic growth curve model to discuss different growth patterns of organizations across areas of activities.

• Journal of Wetlands Research
• /
• v.17 no.4
• /
• pp.436-446
• /
• 2015

It is suggested investigating method about the existing state of demand in this study. The total demand of 357 water amenity zones in 2014 is estimated based on the growth curve models. The effects of population density and distances between water amenity zones and metropolises populated over 1 million are investigated on each river system. The suitability like RMSE and MAPE of logistic and gompertz models are considered to select more suitable model for each water amenity zone. Demand for water amenity zones in 2014 is seemed to be rather high at Han Gang river system and Chungcheongbukdo after analyzing. The influence of population density is rarely effective except Geum Gang river system. The influence of metropolis on the demand for water amenity zones is higher at Geum Gang river system than others.

• The Korean Journal of Applied Statistics
• /
• v.6 no.2
• /
• pp.191-200
• /
• 1993

This study introduced speical characteristics of an epidemiologic study on blood pressure and compared several statistical methods for evaluating the tracking phenomenon of blood pressure for Korean children. While correlation coefficients adjusted for measurement error are commonly used for the evaluation of tracking, it is hard to interpretate the results when correlation functions for lag-difference are not monotonous. McMahan defined a tracking as maintenance of relative rank over time and calculated tracking index usng growth curve model. The tracking index in McMahan's model is complicate to calculate, and it is hard to determine the degree of growth curve parameter. Blomqvist showed the relationship between the rate of change and the initial value. This concept could be extended for the evaluation of tracking. However, it is not so easy to interpretate the estimates in his model when those are non-positive.

• Journal of the Korean Data and Information Science Society
• /
• v.18 no.1
• /
• pp.141-148
• /
• 2007

Recently, Korean national center for education statistics & information exhibits the results of forecast educational statistics from 2007 to 2021 year. The purpose of this paper is to suggest the errors and problems on the results of forecast educational statistics and the distribution of the number of students.

• Electronics and Telecommunications Trends
• /
• v.5 no.3
• /
• pp.43-51
• /
• 1990

주요 17개국의 전기통신 보급율과 이용량을 이용하여 각 발전단계별 특징을 도출하였다. 아울러 전기통신수요의 특성과 전기통신산업의 다양화에 대한 분석을 하였으며, 전기통신 네트워크 발전과정의 국제비교를 통하여 특징들을 추출하였다.

• Journal of Korean Society for Quality Management
• /
• v.25 no.1
• /
• pp.44-55
• /
• 1997

In order to determine procedures for a, pp.opriate model selection of technological growth curves, numerous time series that were representative of growth behavior were collected according to data characteristics. Three different growth curve models were fitted onto data sets in an attempt to determine which growth curve models achieved the best forecasts for types of growth data. The analysis of the results gives rise to an a, pp.oach for selecting a, pp.opriate growth curve models for a given set of data, prior to fitting the models, based on the characteristics of the goodness of fit test.

• Journal of the Korean Geosynthetics Society
• /
• v.15 no.2
• /
• pp.65-75
• /
• 2016

In this study, we constructed a database by collecting field pullout test data of the soil nailing using pressurized grouting, and suggested a method to estimate the ultimate pullout resistance using nonlinear regression analysis to overcome the problems of ultimate pullout resistance estimation using graphical methods. The load-displacement curve estimated by nonlinear regression showed a very high correlation with the field pullout test data. Estimated ultimate pullout load by nonlinear regression method was average 29% higher than estimated ultimate pullout load using previous graphical method. A sigmoidal growth model was found to be the best-fitting nonlinear regression model against rapid pullout failure. Further, an asymptotic regression model was found to be the best fit against progressive nail pullout. The unit ultimate skin friction suggested in this research reflected in the domestic geotechnical characteristics and the specifications of the pressurized grouting method. This research is expected to contribute towards establishing an independent design standard for the soil nailing by providing solutions to the problems that occur when using design charts based on foreign research.

• The Korean Journal of Applied Statistics
• /
• v.12 no.2
• /
• pp.621-631
• /
• 1999

재료의 피로 파괴과정은 균열의 발생과 전파 및 성장의 과정을 거쳐 마침내 결정적 균열의 크기가 일정한도를 넘어서면 재료의 파괴가 일어난다. 이 때까지의 시간, 즉 피로 수명이 역정규분포를 따를 때 재료의 수명과 스트레스 수준과 관계를 나타 내는 S-N곡선에 대한 대수선형모형(log-linear model)을 제시하고, 이 모형하에서 피로수명시험에 대한 통계적 최적시험설계방법을 찾는다. 통계적 최적여부에 대한 판단기준으로 설계 스트레스 수준하의 특정 시점에서의 신뢰도에 대한 최우추정량의 점근분산을 최소화하는 방법을 사용하였다.

• Journal of the Korean Regional Science Association
• /
• v.39 no.4
• /
• pp.73-90
• /
• 2023

This research examines the impact of robotics integration on job dynamics in the U.S. manufacturing sector, adding to the critical dialogue on technological evolution and the future of jobs. Anchored in the task-model framework, the study hypothesizes that robotic integration exerts differential influences on diverse occupational clusters, each identified by their unique task-specific attributes. An in-depth examination was undertaken to elucidate the interplay between robotic integration and the occupation clusters. Employing a multilevel growth curve model, our empirical investigation tracked employment dynamics from 2012 to 2022 across 52 U.S. regions, covering 307 manufacturing occupations. The findings suggest a pronounced job decline within occupations necessitating manual dexterity. Nonetheless, the evidence does not conclusively support that the extent of robotics integration exacerbates this trend. These findings imply that the employment shifts in the U.S. manufacturing sector are predominantly driven by long-standing trends of deindustrialization and functional specialization, rather than by the recent diffusion of robotic technologies.

• Journal of Animal Science and Technology
• /
• v.44 no.2
• /
• pp.165-170
• /
• 2002

Mature weight (A) and rate of maturing (k) estimated by nonlinear regression were studied to determine the optimum age range over which the estimate of growth curve parameters can be estimated. The weight-age data from 1,133 Hanwoo bulls at Hanwoo Improvement Center of N.A.C.F. were used to fit the growth curve using Gompertz model. All available weight data from birth to the specific age of months were used for the estimation of parameters: the six specific ages used were 12, 14, 16, 18, 20 22 and 24 months of age. The mean estimates of mature weight (A) were 966.5, 1,255.9, 1,126.2, 916.5, 842.2, 780.9 and 767.0kg for ages 12 through 24 months, respectively. The mean estimates of mature weight (A) to 22 and 24 months of age were not different from each other. However, they were different from the estimates based on the data to other ages. Mean estimates of rate of maturing (k) were 3.362, 3.595, 3.536, 3.421, 3.403, 3.409 and 3.411 for ages 12 through 24 months, respectively. The mean estimates of maturing rate (k) for ages 18 through 24 months of age were not significantly different from each other. However, they were different from the estimates based on the data to other ages. Correlations among estimates of A at various ages showed the highest value of 0.93 between 22 and 24 months. Correlations among estimates of k at various ages were highest ranging from 0.91 to 0.99 among 18 to 24 months. The correlations between A and k were positive and tended to decrease with the increase of the age from 0.84 for the age of 12 months to 0.10 for the age of 24 months. Thus, the estimates of growth curve parameters, A and k, suitable for genetic studies can be derived from accumulated Hanwoo bulls after 22 months of age.