• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.501-512
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• 2023

This study aimed to assess and determine the optimal model for predicting the full bloom date of 'Fuji' apples across South Korea. We evaluated the performance of four distinct models: the Development Rate Model (DVR)1, DVR2, the Chill Days (CD) model, and a sequentially integrated approach that combined the Dynamic model (DM) and the Growing Degree Hours (GDH) model. The full bloom dates and air temperatures were collected over a three-year period from six orchards located in the major apple production regions of South Korea: Pocheon, Hwaseong, Geochang, Cheongsong, Gunwi, and Chungju. Among these models, the one that combined DM for calculating chilling accumulation and the GDH model for estimating heat accumulation in sequence demonstrated the most accurate predictive performance, in contrast to the CD model that exhibited the lowest predictive precision. Furthermore, the DVR1 model exhibited an underestimation error at orchard located in Hwaseong. It projected a faster progression of the full bloom dates than the actual observations. This area is characterized by minimal diurnal temperature ranges, where the daily minimum temperature is high and the daily maximum temperature is relatively low. Therefore, to achieve a comprehensive prediction of the blooming date of 'Fuji' apples across South Korea, it is recommended to integrate a DM model for calculating the necessary chilling accumulation to break dormancy with a GDH model for estimating the requisite heat accumulation for flowering after dormancy release. This results in a combined DM+GDH model recognized as the most effective approach. However, further data collection and evaluation from different regions are needed to further refine its accuracy and applicability.

• Proceedings of the KOR-KST Conference
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• 1995.12a
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• pp.45-73
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• 1995

The current paper presents a system dynamics model which can generate the land use anq transportation system performance simultaneously is proposed. The model system consists of 7 submodels (population, migration of population, household, job growth-employment-land availability, housing development, travel demand, and traffic congestion level), and each of them is designed based on the causality functions and feedback loop structure between a large number of physical, socio-economic, and policy variables. The important advantages of the system dynamics model are as follows. First, the model can address the complex interactions between land use and transportation system performance dynamically. Therefore, it can be an effective tool for evaluating the time-by-time effect of a policy over time horizons. Secondly, the system dynamics model is not relied on the assumption of equilibrium state of urban systems as in conventional models since it determines the state of model components directly through dynamic system simulation. Thirdly, the system dynamics model is very flexible in reflecting new features, such as a policy, a new phenomenon which has not existed in the past, a special event, or a useful concept from other methodology, since it consists of a lots of separated equations. In Chapter I, II, and III, overall approach and structure of the model system are discussed with causal-loop diagrams and major equations. In Chapter V _, the performance of the developed model is applied to the analysis of the impact of highway capacity expansion on land use for the area of Montgomery County, MD. The year-by-year impacts of highway capacity expansion on congestion level and land use are analyzed with some possible scenarios for the highway capacity expansion. This is a first comprehensive attempt to use dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions. The model structure is not very elaborate mainly due to the problem of the availability of behavioral data, but the model performance results indicate that the proposed approach can be a promising one in dealing comprehensively with complicated urban land use/transportation system.

• Culinary science and hospitality research
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• v.22 no.3
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• pp.121-138
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• 2016

This study is intended to present effective career guidance and direction by identifying the various factors involved in the career preparation behavior for the improvement of the employment rate of culinary and foodservice management major field students. This study was established on the hypothesis of a structural relationship that career decision-making self-efficacy develops career maturity and career preparation behavior on the basis of social cognitive career theory, which was verified through empirical analysis. Out of 450 survey responses from by Culinary and Foodservice Management Major Students, a total of 302 questionnaires were used for the final analysis due to missing values and biased responses(response rate: 83.6%). Collected data were identified using SPSS 16.0 and AMOS 5.0. A higher-order factor model was employed (High-order model) before a confirmatory factor analysis, and this study examined its reliability and validity analysis for hypothesis testing. Career decision-making self-efficacy had positive effects on career maturity(t=6.86, p<0.001) and career preparation behavior(t=3.83, p<0.001), and career maturity had positive effects on career preparation behavior (t=2.79, p<0.01). As a result, all hypotheses were accepted. These results confirmed that strengthening students' faith in themselves with competencies is core competencies with career-related issue can be the driving force that can enable students to develop into mature professionals. Therefore, this study suggests an awareness of the importance of career decision-making self efficacy and proposes a need for a systematic and integrated career counseling program that can improve it.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.475-489
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• 2010

In order to verify the enhancement of ozone and carbon monoxide (CO) during springtime in East Asia, we investigated weather conditions and data from remote sensors, air quality models, and air quality monitors. These include the geopotential height archived from the final (FNL) meteorological field, the potential vorticity and the wind velocity simulated by the Meteorological Mesoscale Model 5 (MM5), the back trajectory estimated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the total column amount of ozone and the aerosol index retrieved from the Total Ozone Mapping Spectrometer (TOMS), the total column density of CO retrieved from the Measurement of Pollution in the Troposphere (MOPITT), and the concentration of ozone and CO simulated by the Model for Ozone and Related Chemical Tracers (MOZART). In particular, the total column density of CO, which mightoriginate from the combustion of fossil fuels and the burning of biomass in China, increased in East Asia during spring 2000. In addition, the enhancement of total column amounts of ozone and CO appeared to be associated with both the upper cut-off low near 500 hPa and the frontogenesis of a surface cyclone during a weak Asian dust event. At the same time, high concentrations of ozone and CO on the Earth's surface were shown at the Seoul air quality monitoring site, located at the surface frontogenesis in Korea. It was clear that the ozone was invaded by the downward stretched vortex anomalies, which included the ozone-rich airflow, during movement and development of the cut-off low, and then there was the catalytic photochemical reaction of ozone precursors on the Earth's surface during the day. In addition, air pollutants such as CO and aerosol were tracked along both the cyclone vortex and the strong westerly as shown at the back trajectory in Seoul and Busan, respectively. Consequently, the maxima of ozone and CO between the two areas showed up differently because of the time lag between those gases, including their catalytic photochemical reactions together with the invasion from the upper troposphere, as well as the path of their transport from China during the weak Asian dust event.

• Management & Information Systems Review
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• v.28 no.4
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• pp.175-197
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• 2009

Numerous researches related to internet shopping malls have been researched by numerous researchers. Such as, establishing criteria to evaluate service quality of electronic commerce, identifying factors affecting successful internet shopping mall operation, and examining relationships among the factors in electronic commerce based shopping mall needed to be focused on. However, most researches that have been undertaken only consider the service quality model or basic functional dimension. In accordance with this indispensability, the integrated structural relationship among variables, which are potentially inherent in customer's perception and affect personnel royalty on internet shopping mall needs to be acknowledged. The purpose of this study is to examine which factors should be able to facilitate performance of internet shopping mall. Based on the relevant literature, it has been empirically analyzed how corporate image, system quality, service quality and delivery quality affect customer satisfaction as well as customer royalty. The research's problem is that it was tested with data collected from 212 respondents. This study developed and empirically analyzed a model representing the relationship by using the Structural Equation Model. The major findings of this study are, firstly, that the higher corporate image is positively affecting the system quality and delivery quality. Secondly, the higher delivery quality is positively affecting the service quality. Thirdly, the higher service quality is positively affecting the customer satisfaction. Finally, the higher customer satisfaction is affecting the customer royalty.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.17-30
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• 2002

Incident duration prediction is one of the most important steps of the overall incident management process. An accurate and reliable estimate of the incident duration can be the main difference between an effective incident management operation and an unacceptable one since, without the knowledge of such time durations, traffic impact can not be estimated or calculated. This research presents several multiple linear regression models for incident duration prediction using data consisting of 384 incident cases. The main source of various incident cases was the Traffic Incident Reports filled out by the Motorist Assistant Units of the Korea Highway Corporation. The models were proposed separately according to the time of day(daytime vs. nighttime) and the fatality/injury incurred (fatality/injury vs. property damage only). Two models using an integrated dataset, one with an intercept and the other without it, were also calibrated and proposed for the generality of model application. Some findings are as follows ; ?Variables such as vehicle turnover, load spills, the number of heavy vehicles involved and the number of blocked lanes were found to significantly affect incident duration times. ?Models, however, tend to overestimate the duration times when a dummy variable, load spill, is used. It was simply because several of load spill incidents had excessively long clearance times. The precision was improved when load spills were further categorized into "small spills" and "large spills" based on the size of vehicles involved. ?Variables such as the number of vehicles involved and the number of blocked lanes found not significant when a regression model was calibrated with an intercept. whereas excluding the intercept from the model structure signifies those variables in a statistical sense.

• Journal of the Korean Regional Science Association
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• v.35 no.4
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• pp.47-60
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• 2019

The purpose of this study is to analyze gender gaps in wage and job satisfaction according to skill characteristics and gender composition in occupation type. Most of the previous studies dealing with gender gaps in wage and job satisfaction have limitations in using a model at a single level. To overcome these limitations, this study integrated the analysis of worker level and job level variables through the application of hierarchical linear model. For the empirical analysis, the 20th year of the Korea Labor Institute Panel Survey and Korea Network for Occupations and Workers data used, factor analysis was utilized to derive cognitive, technical and physical skills. According to the empirical results, female workers in the metropolitan area showed lower average wage and job satisfaction than male worker. these gender gaps were alleviated in occupations which requiring a high level of cognitive skill, while deepening in occupation with a high occupational segregation. The purpose of this study is to derive implications for the policy aimed at reducing the gender gap in the labor market by analyzing the relationship between gender gaps in wage and job satisfaction according to skill characteristics and gender composition rates of wage workers in the metropolitan area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.67-74
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• 2020

One of the missions of active-duty units in charge of managing reserve forces is providing combat supplies to reserve forces to exercise their combat capabilities quickly when declaring a mobilization order. Rear area active-duty units must support large local reserve forces. On the other hand, military units have difficulties due to a lack of forces and the storage of large quantities of firearms and ammunition. For this reason, local reserve forces should move to an integrated storing place and receive their firearms and ammunition. The existing distribution plan (existing plan) is a first-in-first-out plan that can produce inconsistent distribution orders. The inconsistent distribution orders can increase the complete distribution time, which will affect the combat power of local reserve forces. Therefore, firearms and ammunition should be distributed quickly. Accordingly, this paper proposes the priority selection of firearms and ammunition for local reserve forces with a minimum complete distribution time using Dynamic Programming. To verify the proposed model, the existing plan was compared with the proposed model using real data, and the result showed that the proposed model outperformed the existing plan.

• Journal of Technology Innovation
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• v.18 no.2
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• pp.91-120
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• 2010

This paper examines the effect of bargaining power over intermediate goods prices on innovation and economic growth using a Schumpeterian growth model. The notion of "intermediate goods prices" broadly indicates the reward to innovators including innovative SMEs as well as intermediate goods producers that are vertically integrated to big businesses. From this viewpoint, this paper sets up a Schumpeterian growth model that incorporates the market power between final goods producers and intermediate goods producers. The results show that the reduction of intermediate goods prices slows down long-run growth rates as it erodes the reward to innovations. Lower intermediate goods prices decrease marginal productivity of capital and real interest rates. However, the harmful effect of lower profits on innovations outweighs the beneficial effect of lower interest rates. Simulations using Korea's data for various cases show that in all cases the policies that raise the share of intermediate goods producers are as powerful as the R&D subsidy policies in raising growth rates. Therefore, fair trade policies that enable intermediate goods producers-especially SMEs to obtain more fruits of innovations will be helpful for long-run economic growth.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.40.1-40.1
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• 2017

The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared spectro-photometric instrument optimized to the Next Generation of small satellite series (NEXTSat). To achieve the major scientific objectives for the study of the cosmic star formation in local and distant universe, the spectro-photometric survey covering more than 100 square degree will be performed. The main observational targets will be nearby galaxies, galaxy clusters, star-forming regions and low background regions. The off-axis optics was developed to cover a wide field of view ($2deg.{\times}2deg.$) as well as the wide wavelength range from 0.95 to $2.5{\mu}m$, which were revised based upon the recent test and evaluation of the NISS instrument. The mechanical structure were tested under the launching condition as well as the space environment. The signal processing from infrared sensor and the communication with the satellite were evaluated after the integration into the satellite. The flight model of the NSS was assembled and integrated into the satellite. To verify operations of the satellite in space, the space environment tests such as the vibration, shock and thermal-vacuum test were performed. The accurate calibration data were obtained in our test facilities. Here, we report the test results of the flight model of the NISS.