• Geomechanics and Engineering
• /
• v.38 no.3
• /
• pp.249-260
• /
• 2024

In order to study the mechanical propertied and change rules of undrained shear behavior of saline soil under the freeze-thaw cycles, an improved constitutive model reflecting the effects of freeze-thaw cycles was proposed based on the traditional Duncan-Chang model. The saline soil in Qian'an County, western Jilin Province, was selected as the experimental object. Then, a set of freeze-thaw cycles (0, 1, 10, 30, 60, 90, 120) tests were conducted on the saline soil specimens, and conventional consolidated undrained triaxial shear tests were conducted on the saline soil specimens that underwent freeze-thaw cycles. The stress-strain relationship was obtained by the triaxial shear test. The model parameters have a corresponding regression relationship with the number of freeze-thaw cycles. Finally, based on the function expression of the model parameters, the modified Duncan-Chang model with the number of freeze-thaw cycles as the influence factor was established, whilst the calculation program of the modified model is compiled. Based on the test results, the stress-strain relationship of the saline soil specimen shows strain hardening. The shear strength gradually decreases with the increase of freeze-thaw cycle. The 10 freeze-thaw cycles are the turning point in the trend of changes of the mechanical properties of saline soils. The calculated and experimental stress-strain relationship are compared, and the comparison between the calculated value of the model and the experimental value showed that the two had a good consistency, which verified the validity of the modified Duncan-Chang model in reflecting the effects of the freeze-thaw cycle.

• Korean Journal of Agricultural Science
• /
• v.43 no.1
• /
• pp.136-143
• /
• 2016

Garlic and onion are staple agricultural products to Koreans and also are important with regard to agricultural producers' income. These products' acreage responses are highly correlated with each other. Therefore, it is necessary to test whether there is a cointegration relationship between garlic acreage and onion acreage when one tries to estimate the acreage response's function. Based upon the test result of cointegration, it is confirmed that there is no statistically significant cointegration relationship between garlic acreage and onion acreage. In this case, vector autoregressive model is preferred to vector error correction model. This study investigated the dynamic relationship between garlic and onion acreage responses using vector autoregressive (VAR) model. The estimated results of VAR acreage response models show that there is a statistically significant relationship between current and lagged acreage of more than one lag. Therefore, it is recommended that government should consider the long-run period's relationship of each product's acreage when it plans a policy for stabilizing the supply and demand of garlic and onion. For the price variables, garlic price only affects garlic acreage response while onion price affects not only onion acreage response but also garlic acreage response. This implies that the stabilizing policy for onion price could have bigger effects than that for garlic price stabilization.

• Korean Journal of Biological Psychiatry
• /
• v.26 no.2
• /
• pp.59-64
• /
• 2019

Objectives Internet gaming disorder (IGD) is associated with attention deficit/hyperactivity disorder (ADHD) or depression etc. We tried to examine the mediating effects of depression in the relationship between ADHD and IGD. Methods This study was conducted on 2000 people who participated in on-line survey among 14-39 year-old men and women in 2017. And we clarified the relationship among IGD, ADHD, and depression and tested the mediation model. The mean and standard deviation of the main variables were calculated and correlation analysis was performed to confirm the relationship among the main variables. In order to test the mediating effect of depression on the relationship between ADHD and IGD, the structural equation model was implemented using AMOS 21 (IBM). Results There were significant correlations among the variables; IGD, ADHD and depression. Depression had a mediating effect 0.23 (95% confidence interval : 0.17-0.28) in the relationship between IGD and ADHD. Conclusions This study showed that depression can mediate ADHD and IGD. Therefore, the evaluation and management of depression and ADHD should be included in the diagnosis and treatment of IGD.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.12
• /
• pp.271-282
• /
• 2021

In recent years, a significant number of empirical studies have examined the relationship between export and economic growth in India. However, this study analyses the relationship between exports and economic growth through the time series model. The main aim of this study is to investigate the causal relationship between exports and economic growth in India. The VAR model was used for the period 1961 to 2015 after verifying the stationarity of the variables through using Augmented Dickey-Fuller and Phillip-Perron tests. The Indian export sector has been found to have a significant and positive impact on economic growth and other long-term economic activities. The study also employed the Granger causality test to check the direction of causality and found that RXGS, RGDP, RPFC, and RGFC had a unidirectional relationship and RXGS and RMGS had a bidirectional relationship in long run. Also, the findings of this study suggest that a steady-state between exports and economic growth can be achieved in India over a long period. The overall outcome of this study provides a testimony of the fact that the export sector plays a vital role in economic growth in India and also leads to the long-term growth of other economic activities.

• Journal of Distribution Science
• /
• v.13 no.8
• /
• pp.41-48
• /
• 2015

Purpose - This study's objective is to confirm the effects of the perceived relationship value, alternative attractiveness, and investment size on Korean food service franchisees' commitment, using an investment model. Among the three factors, the study examines which factors enhance or weaken the commitment in the franchising investment model. Research design, data, methodology - The data were collected from 495 franchisees and analyzed by a SEM (Structure Equation Model) using path analysis by SPSS 18.0 and AMOS 18.0. Results - 1) The perceived relationship value has a positive effect on franchisee commitment. 2) The alternative attractiveness has a negative effect on franchisee commitment. 3) The investment size has a positive effect on franchisee commitment. Conclusions - The findings show that the investment model can be adapted to franchising and confirms previous investment model study results. We can assume that the higher the perceived relationship value and the bigger the investment, the stronger the commitment, and the greater the alternative attractiveness, the weaker the commitment. These results offer managerial implications for a franchisor wanting to strengthen franchisee commitment.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.4 s.20
• /
• pp.79-86
• /
• 2004

One of the most difficult tasks in pavement management information systems is establishing the links between performance measures of a structure and the design and construction inputs. In-situ pavement performance can be considered a response variable to many project input variables, such as design, construction, and traffic loading effects. If we are to fully understand the component of pavement performance and specify the inputs through design and construction specifications to achieve that performance we must develop quantitative relationship between input and response variables through a scientific, fully integrated Pavement Performance Analysis System (PPAS). Hence, the objective of this study is to design a database model required for developing an effective database template that will allow analysis of pavement performance measures based on design and construction information linked by location. In order to select the most appropriate database model, a conceptual database model (Entity Relationship Model) and dimensional model, which is believed to be the most effective modeling technique for data warehouse project, are designed and compared. It is believed that other state highway agencies could adopt the proposed design strategy for implementing a PPAS at the discretion of the state highway agencies.

• Korean Business Review
• /
• v.20 no.2
• /
• pp.1-13
• /
• 2007

The purpose of this study is to investigate a simple present value model Involving earnings (i.e., the earnings discount model) that presumes a relationship between stock prices and earnings. The model suggests a simple linear equilibrium relationship between stock prices and earnings. The tests for cointegration render strong support for the cointegration hypothesis between stock prices (Pt) and earnings (Xt) even at the one-percent significance level. The tests are based on residuals from a cointegrating regression of Pt on Pt+l + Xt. This suggests that there is a stable long-nu equilibrium relationship between stock prices and earnings. The results of the tests lead to the acceptance of the present value model of stock prices involving earnings.

• Journal of Computing Science and Engineering
• /
• v.9 no.2
• /
• pp.73-82
• /
• 2015

Understanding how the topic evolves is an important and challenging task. A topic usually consists of multiple related events, and the accurate identification of event evolution relationship plays an important role in topic evolution analysis. Existing research has used the traditional vector space model to represent the event, which cannot be used to accurately compute the semantic similarity between events. This has led to poor performance in identifying event evolution relationship. This paper suggests constructing a semantic aspect-based vector space model to represent the event: First, use hierarchical Dirichlet process to mine the semantic aspects. Then, construct a semantic aspect-based vector space model according to these aspects. Finally, represent each event as a point and measure the semantic relatedness between events in the space. According to our evaluation experiments, the performance of our proposed technique is promising and significantly outperforms the baseline methods.

• Knowledge Management Research
• /
• v.13 no.4
• /
• pp.55-69
• /
• 2012

This paper developed measurement indices for intellectual capital of public R&D organizations and investigated causal relationships among the components. We developed 10 measurement factors and 37 indicators and confirmed the reliability of these measurements. We offered an alternative to the existing model for searching causal relationships. From our survey research, using the structural equation model, we found a new relationship. In contrast to the existing model, we found a cycling relationship among three variables: human capital causes structural capital, structural capital causes relational capital, and relational capital causes human capital.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.5
• /
• pp.11-17
• /
• 2011

In this paper, we propose ER_Modeler, which is a logical database design tool based on entity-relationship model. ER_Modeler provides the entity-relationship diagrams to be built graphically on windows and generates the graphs into the appropriate data definition language for creating relational database tables. Furthermore, ER_Modeler provides the import/export functions using XML to guarantee the interoperability with ERwin which is one of the most popular commercial products.