• Journal of Distribution Science
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• v.11 no.8
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• pp.5-14
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• 2013

Purpose - We live in a world of constant change and competition. Many airports have specific competitiveness goals and strategies for achieving and maintaining them. The global economic recession, financial crises, and rising oil prices have resulted in an increasingly important role for facility investment and renewal and the implementation of appropriate policies in ensuring the competitive advantage for airports. It is thus important to analyze the factors that enhance efficiency and productivity for an airport. This study aims to determine the efficiency levels of 20 major airports in East Asia, Europe, and North America. Further, this study also suggests suitable policies and strategies for their development. Research design, data, and methodology - This paper employs the DEA-CCR, DEA-BCC, and DEA-Malmquist production index analysis models to determine airport efficiency. The study uses data on the efficiency and productivity of the world's leading airports between 2006 and 2010. The input variables include the airport size, the number of runways, the size of passenger terminals, and the size of cargo terminals. The output variables include the annual number of passengers and the annual cargo volume. The study uses basic data from the 2010 World Airport Traffic Report (ACI). The world's top 20 airports (as rated by the ACI report) are investigated. The study uses the expanded DEA Model and the Super Efficiency Model to identify the most effective airports among the top 20. The Malmquist productivity index analysis is used to measure airport effectiveness. Results - This study analyzes longitudinal and cross-sectional data on the world's top 20 airports covering 2006 to 2010. A CCR analysis shows that the most efficient airports in 2010 were Gatwick Airport (LGW), Zurich Airport (ZRH), Vienna Airport (VIE), Leonardo da Vinci Fiumicino Airport (FCO), Los Angeles International Airport (LAX), Seattle-Tacoma Airport (SEA), San Francisco Airport (SFO), HongKong Airport (HKG), Beijing Capital International Airport (PEK), and Shanghai Pudong Airport (PVG). We find that changes in airport productivity are affected more by technical factors than by airport efficiency. Conclusions - Based on the study results, we offer four airport development proposals. First, a benchmark airport needs to be identified. Second, inefficiency must be reduced and high-cost factors need to be managed. Third, airport operations should be enhanced through technical innovation. Finally, scientific demand forecasting and facility preparation must become the focus of attention. This paper has some limitations. Because the Malmquist productivity index is based on the hypothesis of the, the identified production change could be over- or under-estimated. Further, as DEA estimates the relative efficiency. It also cannot generalize to include all airport conditions because the variables are limited. To measure airport productivity more accurately, other input variables and environmental variables such as financial and policy factors should be included.

• Journal of Korea Water Resources Association
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• v.33 no.2
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• pp.145-157
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• 2000

The Water Quality Analysis Simulation Program 5 (WASP5) and HEC-2 models have been coupled and applied to find the possibility of simulation of long-term river water quality variation. The EUTR05 as a simulator of water quality simulation in WASPS model was used to simulate the water quality variables in the downstream of Geum-River from Daechung multi-purpose dam during the dry period. The water quality and flow rate conditions have been measured at the stage measurement stations located in the downstream of Geum-River from Daechung dam in December, 1998 and January and March, 1999. The water quality simulation model was calibrated with January data of 1999, and verified with December data of 1998 and March data of 1999. The trend of longitudinal variation of water quality variables simulated by model is consistent with that of measured water quality constituents except chlorophyll-a, $BOD_5,\;NH_3-N\;and\;PO_4-P$ simulated with March data of 1999. Furthennore, the chlorophyll a concentration in the mainstream of Geum-River was simulated by changing the concentrations of $PO_4-P$ and/or $NH_4-N$ flowing into the mainstream of Geum-River from Gabcheon and Mihocheon. The variation of chlorophyll a concentration in the mainstream was almost ignorable except only when $NH_3-N\;and\;PO_4-P$ concentrations decreased by 70% flow into the mainstream from Gabcheon and Mihocheon.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.64-70
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• 2018

In this study, eleven major coastal areas were selected and the climate environment and the greenhouse direction were analyzed. This research investigates the greenhouse heat loss according to the wind environment at target areas. The target areas were selected based on heated greenhouse cultivation area and wind environment standard. Temperature, wind speed, and wind direction among weather data for 30 years were collected and analyzed. The data were divided into the minimum, average, and maximum temperatures and the Meteorological Agency criteria applied to the weather and wind direction criteria. Data were collected in the range of $0{\sim}180^{\circ}$ considering the symmetry of the shape of the greenhouse. In addition, the wind direction is different for each region and the applied wind direction can be different when referring to the longitudinal direction of the greenhouse and the data are collected in the range of $0{\sim}90^{\circ}$. The results of this study are expected to be used to calculate the heating load of greenhouse installed in places wind speed high.

• Journal of Intelligence and Information Systems
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• v.9 no.3
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• pp.23-47
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• 2003

Traditional studies for customer relationship management (CRM) generally focus on static CRM in a specific time frame. The static CRM and customer behavior knowledge derived could help marketers to redirect marketing resources fur profit gain at that given point in time. However, as time goes, the static knowledge becomes obsolete. Therefore, application of CRM to an online retailer should be done dynamically in time. Customer-based analysis should observe the past purchase behavior of customers to understand their current and likely future purchase patterns in consumer markets, and to divide a market into distinct subsets of customers, any of which may conceivably be selected as a market target to be reached with a distinct marketing mix. Though the concept of buying-behavior-based CRM was advanced several decades ago, virtually little application of the dynamic CRM has been reported to date. In this paper, we propose a dynamic CRM model utilizing data mining and a Monitoring Agent System (MAS) to extract longitudinal knowledge from the customer data and to analyze customer behavior patterns over time for the Internet retailer. The proposed model includes an extensive analysis about a customer career path that observes behaviors of segment shifts of each customer: prediction of customer careers, identification of dominant career paths that most customers show and their managerial implications, and about the evolution of customer segments over time. furthermore, we show that dynamic CRM could be useful for solving several managerial problems which any retailers may face.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.16-28
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• 2007

Objective: Evaluation of individual growth is important in orthodontics. The aim of this study was to develop a convenient software that can evaluate current growth status and predict further growth. Methods: Stature data of 2 to 20 year-old Koreans (4893 boys and 4987 girls) were extracted from a nationwide data. Age-sex-specific continuous functions describing percentile growth curves were constructed using natural cubic spline function (NCSF). Then, final stature prediction algorithm was developed and its validity was tested using longitudinal series of stature measurements on randomly selected 200 samples. Various accuracy measurements and analyses of errors between observed and predicted stature using NCSF growth curves were performed. Results: NCSF growth curves were shown to be excellent models in describing reference percentile stature growth curie over age. The prediction accuracy compared favorably with previous prediction models, even more accurate. The current prediction models gave more accurate results in girls than boys. Although the prediction accuracy was high, the error pattern of the validation data showed that in most cases, there were a lot of residuals with the same sign, suggestive of autocorrelation among them. Conclusion: More sophisticated growth prediction algorithm is warranted to enhance a more appropriate goodness of model fit for individual growth.

• Korean Journal of Adult Nursing
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• v.12 no.1
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• pp.40-51
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• 2000

Purpose : This study was carried out to identify the factor of decisional balance for exercise. This was composed of a set of variables at the level of decision making when the elderly decide to do exercise. It was used to classify and identify the characteristics of the stages of change for exercise to which the elderly belong, and was used to identify the variables of decisional balance which influence the stage of change for exercise in the elderly. Methods : Convenient samples of 198 subjects over age 60 in Seoul( mean age=70) were selected from community living, mentally competant older adults and the data was collected from April 1, 1999 to May 31, 1999. The research instrument was the Decisional Balance Measure for Exercise(Marcus & Owen., 1992), Stage of Change Measure(Marcus et al,1992). The data was analyzed by SAS Program. Results: 1. According to stage of change measure, without missing data,191 subjects were distributed in each stage of change for exercise : 50 subjects(26.1%), 7 subjects (3.6%), 52 subjects(27.2%), 4 subjects(2%), and 78(40.8%) belonged to the precontemplation stage, contemplation stage, preparation stage, action stage and maintenace stage. 2. Factor analysis identified 3 factors of decisional balance as appropriate factors for exercise of the elderly and named by researchers; 1)'Perceived Physical-psychological benefit', 2)'Perceived Physical-psychological burden', and 3)'Perceived time burden'. 3. The analysis of variance showed that the two components Perceived Physical - psychological benefit(F=45.95, P=.0001), and Perceived Physical-psychological burden (F=26.52, P=.0001) were significantly associated with stage of change. 4. Through the discriminant analysis, it was found that both 'Self Perceived Physical - Psychological benefit' and 'Perceived Physical-Psychological burden' were the influential variables in discriminating the three stages of change(pre-contemplation, preparation, and maintenance). Conclusion : Results are consistent with the application of the Transtheoretical model, which has been used to understand how people change health behaviors. Even though this study is a cross-sectional, not a longitudinal study, the findings of this study give useful information for exercise intervention about especially the factors relating to decision making for exercise of the elderly in the different stages of change of exercise.

• Korea journal of population studies
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• v.35 no.1
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• pp.211-238
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• 2012

Using data from Korean Longitudinal Study on Aging (KLoSA), this study examines how continuity and change of marital status is associated with health over time among older women, focusing on the moderating effects of age and parent-child relationships. KLoSA data set has two waves of interviews, and for this study, 2046 women aged 65 and over were selected. To analyze data, Structural Equation Modeling (SEM) was used. The major findings are as follows. First, there was no statistically significant difference in health between continuously married older women and continuously single older women. However, older women who had transition from being married to being single showed lower physical health than continuously married and continuously single older women. Second, there were statistically significant differences in the effect of marital status on mental health according to the age of older women. Older women who had transition from being married to being single showed lower mental health than continuously married elders when older women were younger. Third, contact with children moderated the effect of marital status on physical health. Older women who had transition from being married to being single showed lower physical health than continuously single and continuously married older women when older women had less contact with their children. The findings imply after the loss of marital role, older women's relationship with adult children plays a significant role in promoting health. In conclusion, the findings of this study show the different pathways through which marital status is associated with health for 3 different groups of older women, being continuously single, being continuously married, and making transition from being married to being single.

• Korean Parent-Child Health Journal
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• v.5 no.2
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• pp.129-144
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• 2002

This longitudinal quasi-experimental research was conducted to develop parent role education program and to evaluate the effect of this program for mother-infant interaction, childrearing environment and infant development. The subjects were the healthy infants weighing over 2,500gm at birth, whose gestational age was more than 37weeks, and their healthy mothers. The sample consisted of eighteen mother-infant dyads for intervention group and sixteen dyads for control group. Data were collected from March 15th in 1999 to Jun 20th in 2000. The intervention group received programmed education consisted of discharge education, telephone counselling, and home visiting care. But control group were collected data without programmed education. In this study, the Nursing Child Assessment Teaching Scale(NCATS) devised by Barnard was used to determine the mother-infant interaction, HOME was used to determine the childrearing environment, and Griffiths mental development scale was used to determine the infant development. The data were analyzed using SPSS Win using chi-square test, t-test, and repeated measure ANOVA. This study was focused on the results of twelve months time point. Summaries of the results were as follows: 1. There was no significant difference in mother-infant interaction(NCATS) between intervention group and control group. But both of two groups showed significantly higher in interaction score at twelve months than at six months in the subscales of social-emotional growth fostering, and responsiveness to caregiver. 2. There was no significant difference in childrearing environment(HOME) between two groups at twelve months. But when each subscale of HOME was examined, intervention group showed higher scores in the dimensions of maternal involvement with child(p=.001), and maternal emotional-verbal responsivity(p=.048). 3. There was no significant difference in GQ of the Griffiths mental development scale between two groups, although significant difference was found in performance subscale. 4. Infant development at twelve months showed significant correlation with mother-infant interaction and childrearing environment at six months, although mother-infant interaction and childrearing environment at twelve months did not show significant correlations with infant development at twelve months. 5. Developmental scores at six months showed significant correlations with variety in daily stimulation, and mother's emotional, verbal responsivity, whereas developmental scores at twelve months showed significant correlations with acceptance of child behavior at six months, and appropriate play material at twelve months. In conclusion, the maternal education program for primipara showed long term effect in some categories in organizing the childrearing environment, and fostering the infant development. We suggest further study and implications of parent role education program for high risk parents such as parents in low economic status or with premature babies.

• Journal of Korean Academy of Nursing
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• v.15 no.3
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• pp.62-73
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• 1985

The problems of growth & development due to maladjustment are gradually increasing while need for the treatment of children's diseases is decreasing. The level of developmental deficiency or delay correlates with neonatal birth weight and also with gestational age, i.e. degrees of prematurity. There-fore, developmental defects and potential risk factors' are more Common in premature infants than in full term infants. The purpose of this study is to define the difference in the growth at developmental status between premature and full term infants, and to define the relation between the developmental status and the physical growth during the first 3 years' Data were collected from January 10, 1985 to April 6, 1985 at 3 hospitals including St. Mary's Hospital, and through home visiting. The subjects of this study consisted of 79 Premature infants (G.A. <37wks. & B.W. <2.5kg) and 94 full term infants (G.A.≥37 wks. & B.W.≥2.5kg). The study method used was a questionnaire, anthropometric assessment and DDST for normative data of growth & development. The collected data were analyzed using descriptive statistics, chi-square test and t-test. The results of the study were as follows: Hypothesis: 1 : That the prematures will differ from the full term infants in the physical growth status during the first 3 years was partially supported (p＜0.02) : The prematures reached up the full term infants in the physical growth status in the first 6 months. And, the first hypothesis was supported (P<0.01) : There are more cases which is below‘the Korean children's physical. growth standards’in prematures than in full term infants. Hypothesis 2 : That the prematures will differ from the full term infants in the developmental status during the first 3 years was supported (P< 0.001)；‘Normal’developmental status due to DDST was less in prematures than in full term infants. And, the second hypothesis was Partially supported (P<0.02) : The developmental status of the pre-matures was different from that of the full term infants within the first 3 months by analysis of passed items in DDST, Hypothesis 3 : That the prematures' developmental status will relate to their physical growth during the first 3 years was supported (P<0.001) : If the prematures' developmental status is in delayed status, then, their physical growth status is also in delayed status. This study shows that the prematures differed significantly from the full term infants in the growth at developmental status during their infancy. This means that the nurse can foster the growth & development of the prematures by supportive care during their infancy. Further longitudinal study is needed to verify these findings for the environmental factors.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.1
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• pp.108-127
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• 1996

The purpose of this research was to determine whether or not a education program of low back pain would have benificial effect on nurses. Nonequivalent control group pre-post test research was designed. Subjects for this study were 50 selected from nurses who work at a general hospital in Taegu. Of them, twenty seven were assigned to experimental group, twenty-three to control group. The data were collected during the period from June 27 to August 31, 1994. The instruments used in this study were Visual Analog Scale for low back pain, Sit-and-reach test for trunk flexibility, and 1 min sit up test for abdominal muscle endurance. Data related to general chracteristics and factors of low back pain were collected with questionnaire developed by this reseacher. The data were analyzed by $X^2-test$, t-test and paired t-test, using the SAS package program. The results of this study are summerized as follows : 1. The numbers of the experimental group with low back pain were not a statistically significant difference from pre to posttesting($X^2=0.77$, p=.379), and the numbers of the control group with low back pain were also not a statistically significant difference from pre to posttesting($X^2=0.09$, p=.767). 2. The severity of low back pain of the experimental group was not a statistically significant difference from pre to posttesting(t=-0.55, p=.5857), and the severity of low back pain of the control group was also not a statistically significant difference from pre to posttesting(t=-0.70, p=.3101). 3. The trunk flexibility of the experimental group was not a statistically significant difference from pre to posttesting(t= 1.08, p=.2835), and the control group's trunk flexibility was also not a statistically significant difference from pre to posttesting(t=0.85, p=.4026). 4. The abdominal muscle endurance of the experimental group was a statistically significant difference from pre to posttesting(t=-2.42, p=.0190), but the control group's abdominal muscle endurance was not a statistically significant difference from pre to posttesting(t=-0.06, p=.9556) This study suggest that replication of study with more sample and more rigid treatment should be needed. And furthermore, the longitudinal research is needed to determine the effectiveness of education program.