• Journal of the Korean Data and Information Science Society
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• v.18 no.1
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• pp.211-218
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• 2007

Nonlinear ARMA model $X_n\;=\;h(X_{n-1},{\cdots},X_{n-p},e_{n-1},{\cdots},e_{n-p})+e_n$ is considered and easy-to-check sufficient condition for strict stationarity of {$X_n$} without some irreducibility or continuity assumption is given. Threshold ARMA(p, q) and momentum threshold ARMA(p, q) models are examined as special cases.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1233-1240
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• 2011

An augmented asymmetric power GARCH(p, q) process is considered and conditions for stationarity, geometric ergodicity and ${\beta}$-mixing property with exponential decay rate are obtained.

• The Korean Journal of Zoology
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• v.30 no.1
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• pp.44-52
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• 1987

The spontaneous bilateral asymmetry was analyzed in the hermaphroditic fish Rivulus marmoratus to obtain base line data on the developmental stability of this fish. The results obtained were as follows; 1. Eight kinds of countable anatomical characters except numbers of otolith and radii branchiostegi showed bilateral asymmetry at the frequency ranging from 9.8% to 64.7%. 2. Asymmetry index was not significantly different from that of gonochoristic fish species previously reported. Genetical implication of the results was discussed in relation to developmental stability and homozygosity of this species.

• Korean Journal of Construction Engineering and Management
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• v.23 no.4
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• pp.65-77
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• 2022

Schedule management is one of pivotal project success factors during construction projects. However, there are many difficulties in rapid scheduling and controlling since the existing planning techniques require considerable amount of manual work and manager's judgment in a construction project. This research aims to propose a new scheduling method and algorithm for automating and visualizing the planning process, which is called Countable-grid scheduling method. In this method, if the scope of work is defined via a visualized tool, the schedule plan is created automatically according to the productivity and workable conditions of each activity. The location of the work for each date can be visualized in grid-based approach. Moreover, the work schedule can be updated automatically according to the progress. The industrial applicability of the proposed method was verified in construction projects via case study with sample data. This research can contribute to the construction industry by automating the construction schedule management process.

• Journal of Distribution Science
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• v.14 no.10
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• pp.109-116
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• 2016

Purpose - This study investigates the purchase pattern relating to soybean products in Korea. Specifically, the effect of branding based on a regional name was analyzed in terms of consumer purchase frequencies. The primary purpose of this study is to understand why family characteristics affect product selection for a regional brand in the soybean food category. Research design, data, and methodology - We used data collected by the Rural Development Administration (RDA) of Korea. The RDA has monitored agricultural food consumers for years in order to obtain purchase records. Panel participants live in regions near the capital city of Seoul, Korea. Examining data from January 2010 to May 2016, 667 families were selected for analysis. The final data set was 1,335,402. Each purchase item by each individual family was aggregated to a countable weekly observation. To analyze the data set quantitatively, zero-inflation regression was adopted, which was appropriate to avoid biases from overly dispersed observations. Results - We hypothesized the effects of regional branding from the viewpoint of the family characteristics. The first hypothesis was that the number of children would be positively associated with the purchase of a regional brand of soybean products. The result strongly supported this hypothesis. The second hypothesis was that the number of family members would be negatively associated with the purchase of the soybean products of a regional brand. Based on empirical analysis, we concluded that this hypothesis was partially supported. The third hypothesis was the presence of an interaction effect between the number of children and the family size, which was supported by the results. As a supplementary analysis, we also tested mean-variance differences in terms of categories and regional branding with corporate branding. Conclusion - The results of this study provide insights for regional branding strategies in agricultural food management. This study appears to be one of the seminal studies trying to analyze purchase patterns from longitudinal observations. In addition, this study adopted variables characterizing family lifestyle. This study confirmed that children and family size should be considered when soybean product brands are introduced.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.119-129
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• 2014

PURPOSES : The purpose of this study is to develop the U-turn accident model at 4-legged signalized intersections in urban areas. METHODS : In order to analyze the characteristics of the accidents which are associated with U-turn operation at 4-legged signalized intersections in urban areas and develop an U-turn accident model by regression analysis, the tests of overdispersion and zero-inflation are conducted about the dependent variables of number of accidents and EPDO (Equivalent Property Damage Only). RESULTS : As their results, the Poisson model fits best for number of accident and the ZIP (Zero Inflated Poisson) fits best for EPOD, the variables of conflict traffic, width of opposing road, traffic passing speed are adopted as independent variable for both models. The variables of number of bus berths and rate of U-turn signal time at which the U-turn is permitted are adopted as independent variable only for EPDO. CONCLUSIONS : These study results suggest that U-turn would be permitted at the intersection where the width of opposing road is wider than 11.9 meters, the passing vehicle speed is not high and U-turn operation is not hindered by the buses stopping at bus stops.

• Journal of the Korean Data and Information Science Society
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• v.21 no.4
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• pp.699-708
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• 2010

Korean universities have selected candidates through admission officer system since 2009. However, the universities now have to settle several problems that they faced at the first stage of the system. Therefore, this research, taking the admission screening data of J University as examples, aims to discuss how differently the weight of the screening factors appears depending on the subjects related to college entrance, such as parents, teachers, and admission officers. The research indicates that the subjects have different perspectives about entrance screening requisites. Parents and teachers more value the student record that is a countable indicator than the letter of self-recommendation that is a uncountable indicator. However, it also indicates that admission officers take attitude against parents and teachers.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.1
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• pp.141-162
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• 2012

This study was conducted to propose a new "Statistical Indicators of Libraries for the Disabled (SILD)" to collect objective and reliable data from such libraries. The previous researches and related literature were reviewed to compare current national statistical indicators. The draft of a new SILD, which was based on the current SILD, was made by deriving from countable factors at the library. These were selected from various parts of the library sectors, such as the library-related laws, library standards, evaluation indices of library service for the disabled, and statistical indicators of libraries for the disabled from IFLA, ISO, and other major countries. The draft was compared to the current SILD. The draft was then reviewed by five librarians and on-site experts working at the library for the disabled to see if they have any comments on each item of the draft. The new SILD is composed of 26 items in seven categories, and it can be used in understanding the present situation of libraries for the disabled.

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.427-450
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• 2012

This study was to propose an improvement direction in statistical indicators of public libraries to collect objective data from such libraries. This improvement direction was made by deriving from countable factors at the library. These were selected from various parts of the library sectors, such as the library-related laws, public library standard of our country, and statistical indicators of IFLA and other major countries. Also The these statistical indicator was compared to the current statistical indicator of public library in Korea. The results will be able to develop new draft of statistical indicator, which can be used in understanding the present situation of public libraries.

• Biomedical Science Letters
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• v.25 no.4
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• pp.431-435
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• 2019

Chlorine dioxide is an effective chemical to inhibit the growth of bacteria and viruses or to disinfect infected areas. In this study, the effects of chlorine dioxide on several bacteria in hospitals were analyzed. Alloiococcus otitis, Kocuria rosea, Leuconostoc mesenteroides spp. and Staphylococcus lentus as gram-positive bacteria and Acinetobacter lwoffii, Aeromonas salmonicida, Brucella melitensis, Oligella ureolytica as gram-negative bacteria were done for the inhibitory analysis. The growth and morphology of the bacteria were analyzed by placing a plastic stick which was called "FarmeTok (medistick/Puristic)" provided by Purgofarm, co, Ltd. to release ClO₂ (13 ppmv/hr) next to the plate where the bacteria were incubated for 24 hours. Less than 10 bacterial colonies were evaluated as having 99% inhibitory effect. The initial bacterial culture concentration of 0.5 McFaland turbidity was good for analyzing the chlorine dioxide inhibitory effect. All bacteria could be easily counted post 24 hr co-incubation with ClO₂, but A. otitis and A. lwoffii without ClO₂ gas were not countable due to very dispersed colony types which were not affected for result analysis. As shown in this study, the FarmeTok plastic stick, which discharges chlorine dioxide at 13 ppmv / hour, was evaluated to be sufficient to suppress the above bacteria in the hospital. Bacteria existing in the clinic such as this hospital will be used as a data to inhibit the growth of bacteria by using ClO₂, and molecular biology analysis using the gene of bacteria will be possible in the future rather than inhibiting the growth of bacteria itself.