• Journal of Korea Water Resources Association
• /
• v.53 no.4
• /
• pp.285-291
• /
• 2020

The Noah 3.3 Land Surface Model (LSM) was used to estimate the global soil moisture in this study and these soil moisture datasets were assessed against satellite-based and reanalysis soil moisture products. The Noah 3.3 LSM simulated soil moistures in four soil layers and root-zone soil moistures defined as a depth-weighted average in the first three soil layers (i.e., up to 1.0 m deep). The Noah LSM soil moisture products were then compared with a satellite-based soil moisture dataset (European Space Agency Climate Change Initiatives (ESA CCI) SM v04.4) and reanalysis soil moisture datasets (ERA-interim). In addition, the five major basins (Yangtze, Mekong, Mississippi, Murray-Darling, Amazon) were selected for the assesment with the Gravity Recovery and Climate Experiment (GRACE)-based Total Water Storage Anomaly (TWSA) and TWS Change (TWSC). The results revealed that high anomaly correlations were found in most of the Asia-Pacific regions including East Asia, South Asia, Australia, and Noth and South America. While the anomaly correlations in the Murray-Darling basin were somewhat low, relatively higher anomaly correlations in the other basins were found. It is concluded that this study can be useful for the development of soil moisture based drought indices and subsequently can be helpful to reduce damages from drought by timely providing an efficacious strategy.

• Management & Information Systems Review
• /
• v.37 no.2
• /
• pp.87-108
• /
• 2018

This article explores the international trade flow of Bangladesh's ready-made garments (RMG). We first suggest the brief history and an international structure of trade among countries by using the trade volume. Then we implemented a gravity model regression with the sample of 38 major partner countries in order to investigate the potential export market for the RMG industry. The fixed effect and random effect model for the panel data during the period of 1990 to 2011 are estimated. Our result shows that Bangladesh's RMG exports are affected positively by the size of economy, inflation, exchange rate, foreign direct investment(FDI) and trade openness. On the other hand, the distance between trading partners are related negatively with the trade volume. We used the estimated coefficients from the panel regression in order to predict RMG export potential of Bangladesh. This might show which country is the promising export market for Bangladesh RMG industry. We found that Bangladesh has the highest potential of RMG export with Japan and USA, which seem to have considerable room for export growth if trade barriers and constraints are removed. We added some policy implications for encouraging the RMG export of Bangladesh by using the results from the analysis.

• Asia-Pacific Journal of Business
• /
• v.15 no.1
• /
• pp.319-334
• /
• 2024

Purpose - The purpose of this study is to examine the gravity model commonly used for demand forecasting upon the implementation of new tourist facilities and analyze the main causation of forecasting errors to provide a suggestion on how to improve. Design/methodology/approach - This study first measured the errors in predicted values derived from past feasibility study reports by examining the cases of five national science museums. Next, to improve the predictive accuracy of the gravity model, the study identified the five most likely issues contributing to errors, applied modified values, and recalculated. The potential for improvement was then evaluated through a comparison of forecasting errors. Findings - First, among the five science museums with very similar characteristics, there was no clear indication of a decrease in the number of visitors to existing facilities due to the introduction of new facilities. Second, representing the attractiveness of tourist facilities using the facility size ratio can lead to significant prediction errors. Third, the impact of distance on demand can vary depending on the characteristics of the facility and the conditions of the area where the facility is located. Fourth, if the distance value is below 1, it is necessary to limit the range of that value to avoid having an excessively small value. Fifth, depending on the type of population data used, prediction results may vary, so it is necessary to use population data suitable for each latent market instead of simply using overall population data. Finally, if a clear trend is anticipated in a certain type of tourist behavior, incorporating this trend into the predicted values could help reduce prediction errors. Research implications or Originality - This study identified the key factors causing prediction errors by using national science museums as cases and proposed directions for improvement. Additionally, suggestions were made to apply the model more flexibly to enhance predictive accuracy. Since reducing prediction errors contributes to increased reliability of analytical results, the findings of this study are expected to contribute to policy decisions handled with more accurate information when running feasibility analyses.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.3 s.30
• /
• pp.43-50
• /
• 2004

This study has an object of searching for appropriateness in applying the trip distribution model by studying the changes of the character of parameter which the model contains and by analyzing and evaluating trip distribution technique out of few steps of pre-estimate technique for the traffic demand through computer simulation centering around Kwangju. Method of this study is investigating the basic theory for trip distribution model and with this grounding, I rearranged it as research data for trip distribution model compatible for Kwangju, using data such as research data on actual state, the statistics annual report and basic plan for traffic full equipment of Kwangju. So, The most stable measure of the type of trip distribution of Kwangju city was produced in Fratar and Detroit model, however, gravity model has a little bit low reliance in sharing of estimation and actual survey although it is astringent in short period.

• Korean Journal of Food Science and Technology
• /
• v.46 no.3
• /
• pp.295-302
• /
• 2014

This study investigated the effects of storage temperature and time on the physicochemical properties of eggs, and the corelationship of quality factors with egg freshness and the palatability during storage. As storage temperature and time increased, weight loss significantly increased (p<0.05), while the specific gravity, Haugh unit, yolk index, albumen index, and yolk viscosity decreased significantly (p<0.05). A multiple regression equation of $Y_1$ (freshness)=$106.50286-0.81196X_1$ (weight loss)-$77.51667X_5$ (specific gravity)-$2.27156X_8$ (yolk pH)+$0.00178X_{16}$ (yolk viscosity) with $r^2$=0.89 was obtained for the evaluation of egg freshness. Also, sensorial palatability through the multiple regression equation was determined as $Y_2$ (palatability)=$104.98174-0.81466X_1$ (weight loss)-$76.53434X_5$ (specific gravity)-$2.20338X_8$ (yolk pH)+$0.00178X_{16}$ (yolk viscosity) with $r^2$=0.89 indicating that weight loss, specific gravity, yolk pH and yolk viscosity are major factors that affect the freshness and palatability of eggs during storage.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.1
• /
• pp.91-105
• /
• 2020

This study is the basic study for improving the range of influence and potency of mixing bars in the chamber of Shield TBM. Currently, there are many studies on disk cutters, cutter bits and segments in the study of the domestic Shield TBM. However, studies that mix soil and rocks that come from the membrane during the Shield TBM excavation and scatter them with screw conveyors are not as good as those abroad. In this study, the existing Shield TBM Chamber was manufactured as a miniature and the experiment. Inside the chamber, different sizes (4 mm, 6 mm, 8 mm, 10 mm) and colors (black, white, red, and blue) were used to form layers. This experiment was carried out by different shapes and sizes of RPM and mixing bars. In addition, the difference between a miniature model and a reclining one was checked to determine the effect of the direction of gravity on the mixing efficiency. This was done in the same way for all other conditions other than differences in the direction of gravity. Through this experiment, we identified the orientation of the chamber model, the size and shape of the mixing bar inside, and the mixing effect and torque depending on RPM. A comparative review of the mixing effect and torque confirmed that the shape and size of the mixing bar affect the mixing of samples, and that the direction of gravity affects torque.

• Journal of the Korean Geographical Society
• /
• v.50 no.5
• /
• pp.527-541
• /
• 2015

The purpose of this study is to investigate the changes in the inter-city passenger flows since adapting the express rail system in Korea(KTX). For the purpose, we analyze the express bus and rail passenger annual flow data of the before and after adapting KTX. In first, we examine the changes in the time-distance parameters in the inter-city passenger flows of the express bus, general rail, and KTX by applying gravity model. The results reveal that express bus passenger flows are less sensible to the time-distance compare to the rail passenger flows, and the trends have been intensified over time. However, the time-distance parameters for the KTX passenger flows reveal the reverse relationships with the gravity model. The KTX passenger flows expand between the long distance cities. We also apply the MST(Maximum Spanning Tree) method to find out the spatial structural changes in the inter-city passenger flows. The number of hierarchies has been increased in the express bus and general rail passenger flows, while single hierarchical structure has been lasted in the KTX passenger flows.

• Journal of the Korea Concrete Institute
• /
• v.18 no.3 s.93
• /
• pp.405-414
• /
• 2006

In the present study, a numerical analysis was performed for interior connections of continuous flat plate to analyze the effect of design parameters such as column section shape, gravity load and slab span on the behavioral characteristics of the connections. For the purpose, a computer program for nonlinear FE analysis was developed, and the validity was verified. Through the parametric study, the variations of shear stress distribution around the connection were investigated. According to the result of numerical analysis, as the length of the cross section of column in the direction of lateral load increases and gravity load increases, the effective area and the maximum shear strength providing the torsional resistance decrease considerably. And as the slab span loaded with relatively large gravity load increases, the negative moment around the connection increases and therefore the strength of connection against unbalanced moment decreases. By considering the effect of design parameters on the strength of the connections, the effective shear strength to calculate the torsional moment capacity of connection was proposed and the effectiveness of the proposed shear strength was verified.

• The Journal of the Korea Contents Association
• /
• v.22 no.7
• /
• pp.216-226
• /
• 2022

With the signing of the China-Korea FTA agreement, it is of great practical significance to study the potential of electronic product trade between China and South Korea under the new situation to promote the development of electronic product trade between the two countries. Based on this, this paper selects the data related to the trade of electronic products between China and South Korea from 2005 to 2019. First, it analyzes the factors of the trade potential of electronic products between the two countries by building a trade gravity expansion model, and then calculates and compares the electronic products between China and South Korea. trade potential. The research results show that: (1) The economic scale, population scale and APEC member countries have a promoting effect on the trade volume between China and South Korea. The geographical distance has an inhibitory effect on the trade volume between China and South Korea. Trade freedom has a significant misuse of promotion for China's electronics trade, while it has no significant effect on South Korea's electronics trade. (2) After 2015, China's electronic product export trade potential to South Korea is huge. There is also a certain potential in South Korea's trade in electronic products with China, which needs to be explored with active policies.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.9
• /
• pp.91-103
• /
• 2004

A series of shaking table model tests were performed to verify the validity of similitude law, which is suggested by lai (1989) to simulate the dynamic behavior of soil-fluid-structure system for is shaking table tests. In the tests, the similitude law suggested by lai was applied to determine the length and the time scaling factors. Also, the steady state concept was used in determining the density of model backfill soil, which is a key factor in simulating the development of excess pore pressure during shaking. The similitude law was verified by checking whether three different sizes of quay walls show the identical behavior or not. The similar responses of acceleration, excess pore pressure and horizontal displacement of walls were obtained far the small and large models. However, the medium model showed larger responses than those of the small and large models because of the resonance between the frequency of input acceleration and the natural frequency of the wall system. In addition, the vertical displacement and rotational angle of the walls became larger with the increase of model size.