• Journal of the Korean Statistical Society
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• v.33 no.4
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• pp.353-365
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• 2004

In this paper, we define the weighted U-empirical process for simple linear model and show the weak convergence to a Gaussian process under some conditions. Then we illustrate the usage of our result with examples. In the appendix, we derive the variance of the weighted U-empirical distribution function.

• Journal of the Korean Statistical Society
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• v.31 no.1
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• pp.109-120
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• 2002

In this paper, we show the weak convergence of U-empirical processes for two sample problem. We use the result to show the asymptotic normality for the generalized dodges-Lehmann estimates with the Bahadur representation for quantifies of U-empirical distributions. Also we consider the asymptotic normality for the test statistics in a simple way.

• Journal of the Korean Statistical Society
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• v.27 no.1
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• pp.113-132
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• 1998

In this paper, we consider a minimum distance (M.D.) estimation based on kernels for U-statistics. We use Cramer-von Mises type distance function which measures the discrepancy between U-empirical distribution function(d.f.) and modeled d.f. of kernel. In the distance function, we allow various integrating measures, which can be finite, $\sigma$-finite or discrete. Then we derive the asymptotic normality and study the qualitative robustness of M. D. estimates.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.269-282
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• 2014

The objective of this study is to find out whether the developed semi-empirical biofilm model can be applicable to real BAF pilot-scale wastewater treatment. In addition, the optimum operating conditions of BAF as a function of process variables such as organic loading change can be drawn based on the simulation results of model. The results will provide the economic and efficient BAF process design and operating control. As a result, developed semi-empirical biofilm model which is relatively simple compared to mathematical model can simulate three BAF processes consisted of 25 layers within 1 seconds. When this model was used for simulating real pilot scale BAF process and the simulated water quality values were compared to experimental ones, simulated TCOD, SCOD, TN, $NH_4{^+}$-N, $NO_x{^-}$-N, alkalinity values were different to experimental ones within 21%, 20%, 8.1%, 48%, 10%, and 23%, respectively. Therefore, if the BAF system was equipped with automatic control, the BAF process can be better efficiently adapted under the condition of significant change of influent loading.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.51
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• pp.417-439
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• 2011

In order to improve e-Trade service, this paper has deduced impeding factors after review of precedent research on e-Trade and analysis of e-Trade current status. Then an empirical analysis of whether variables deduced are detrimental factors to utilization of e-Trade service has been made on the basis of a research model and relevant hypotheses. The scope of e-Trade service indicated in this paper is limited to use of uTradeHub system. Analytical results for the improvement of e-Trade service clearly indicate that the higher the impeding factor to utilization of the system integration, logistics and customs clearance, marketing and users field, the more necessary the service improvement for invigoration of e-Trade service. However, foreign exchange field does not seem to require attention because SMEs have not active will to do electronic payment through the process of electronic documents.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.252-260
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• 2018

Energy, a critical input, is to be efficiently managed via waste heat recovery and energy reuse for the economic viability of a process industry. In particular, cement manufacture demands a huge quantum of energy, for the necessary reactions. Huge amounts of hot effluent gases are generated. Energy recovery from these waste gases is an area that is of contemporary research interest. Now, about 75% of total heat recovery takes place in the riser of the suspension pre-heater system. This article deals with the hydrodynamic and heat transfer aspects of riser typically used in the cement industry. An experimental apparatus was designed and fabricated with provision for the measurement of gas pressure and solid temperatures at different heights of the riser. The system studied was air - chalcopyrite taken in different particle sizes. Acceleration length ($L_A$) determined at different parametric levels was fitted to an empirical correlation: $L_A/d_t=4.91902(d_p/d_t)^{0.10058}(w_s/w_g)^{-0.11691}(u_g{\mu}_g/d_t^2g{\rho}_g)^{0.28574}({\rho}_p/{\rho}_g)^{0.42484}$. An empirical model was developed for Nusselt number as a function of Reynolds and Prandtl numbers using regression analysis: $Nu=0.40969(Re_p)^{0.99953}(Pr)^{0.03569}$.

• Management & Information Systems Review
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• v.22
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• pp.1-23
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• 2007

This paper investigates the relationships between exports, firm size, and firm dynamics. It is based on a longitudinal data covering listed firms in the Korean manufacturing industry. We found the stylized fact that the probability that a firm is exporter increases with firm size. A regression model for the determinant of export/sales ratio including dynamic adjustment process is tested on a cross-section sample for the year 2001. Empirical findings suggest that there is a positive and inversely U-shaped relationship between firm size and export/sales ratio, just for basic material and capital good industry. Except for firm size, the hypotheses concerning human capital intensity, physical capital intensity, R&D intensity, and patent are rejected. Using Granger causality test, we found that the rate of growth of total sales influences the change of the export/sales ratio with time lag for medium-sized firms. Finally, some policy implications are presented.

• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.563-573
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• 2000

In this thesis, we propose the test statistic for ordered alternatives on c-sample ranked set samples(RSS). The proposed test statistic JRSS is Jonckheere type statistic using the median of the i-th samples in each cycle. We obtained the asymptotic property of the proposed test statistic and the asymptotic relative efficiencies of the proposed test statistic with respect to J SRS which Jonckheere type statistic on simple random samples(SRS). From the simulation works, J RSS is superior to J SRS. We compared the empirical powers of J RSS with respect to U RSS on ranked set sample and U SRS on simple random sample using all samples, which are proposed by Kim, Kim and Lee(1999). The powers of J RSS are nearly the same values when entire sample size is large. J RSS is superior to U RSS. J RSS is simpler than U RSSon calculating process.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.4
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• pp.1-14
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• 1994

This study attempted to characterize conflict frames of environmental disputes by examining twelve actual wetland permitting cases in Ohio. The participants consisted of such interested parties as applicants, technical, legal or environmental consultants to applicants, U.S.Army Corps of Engineers, U.S.Environmental Protection Agency, U.S.Fish and Wildlife Service, Ohio Environmental Protection Agency, Ohio Department of Natural Resoures, local agencies, the environmental community, and citizens who have been involved of the permitting process. The purpose of this study is to provide empirical evidence of how different perceptual frames existed in the wetland conversion disputes, and to understand different environmental conflict frames that influenced disputants' perception relating to dispute resolution. The vehicles used to collect the necessary data were three survey instruments : Open-ended questionnaires, Likert-type questionnaires, and ranking questionnaires. Forty-three subjects were contacted for open fact-to-fact interviews, 53 subject for Kikert-type mail survey and 54 subjects for ranking instrument mail survey. Analyses of survey results revealed that six different types of frames were clearly identified from all the parties involved in Ohio wetland conversion disputes. It revealed that disputants had statistically significantly different levels of perception to the frames based on the participants' role (i.e. regulator, applicant, commentor), the number of involved parties in the process, processing time and the issuance of a permit. The findings also revealed that information sharing among disputants played a significant role in the process of froming and reframing. The alternative idea, building cooperation through negotiation, was proposed to provide new insight into the resolution of the dispute.

• Journal of Technology Innovation
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• v.21 no.1
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• pp.109-139
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• 2013

The objective of this study attempt to examine the prospect whether conventional catch-up theory is also applicable to knowledge intensive industry like Open Source Software(OSS), and the implication from this study can be working as a stepping stone for followers. To do this, we conducted Korean SW firm's interview, and examined U.S. firm's archivings and second source of informations by means of empirical study. We use the inflection point of paradigm shift and difference of technology regime as a framework for empirical study of catch-up process between U.S. and Korean OSS firms. We find that conventional catch-up theory is no more applicable to explain OSS firm's catch-up processes. We also identified the elements that will accelerate the catch-up processes more effectively from the comparison of technology regime between U.S. and Korean OSS firms. As a result, we diagnose the limitation of conventional catch-up theory and discuss the new technology regime which will, ironically, promote the catch-up processes from the condition of low appropriation.