• Proceedings of the Korea Water Resources Association Conference
• /
• 2001.05a
• /
• pp.67-75
• /
• 2001

Anticipated water scarcity in the first half of this century is one of the most concerned international issues. However, even though the issue has an international impact and world wide monitoring is critical, there are limited number of global estimates at present. In this study, annual water availability was derived from annual runoff estimated by land surface models using Total Runoff Integrating Pathways (TRIP) with 0.5 degree by 0.5 degree longitude/latitude resolution globally. Global distribution of water withdrawal for each sector in the same horizontal spatial resolution was estimated based on country-base statistics of municipal water use, industrial water use, and agricultural intake, using global geographical information system with global distributions of population and irrigated crop land area. The total population under water stress estimated for 1995 corresponded very well with former estimates, however, the number is highly depend on how to assume the ratio how much water from outside of the region can be used for water resources within the region. It suggests the importance of regional studies evaluating the possibility of water intake as well as the validity of the investment for water resources withdrawal facilities.

• Korean Journal of Remote Sensing
• /
• v.25 no.6
• /
• pp.465-474
• /
• 2009

Convective/stratiform radar echo classification schemes by Steiner et al. (1995) and Biggerstaff and Listemaa (2000) are examined on a monsoonal front during the summer monsoon-Changma period, which is organized as a cloud cluster with mesoscale convective complex. Target radar is S-band with wavelength of 10cm, spatial resolution of 1km, elevation angle interval of 0.5-1.0 degree, and minimum elevation angle of 0.19 degree at Jindo over the Korean Peninsula. For verification of rainfall amount retrieved from the echo classification, ground-based rain gauge observations (Automatic Weather Stations) are examined, converting the radar echo grid data to the station values using the inverse distance weighted method. Improvement from the echo classification is evaluated based on the correlation coefficient and the scattered diagram. Additionally, an optimal use method was designed to produce combined rainfalls from the radar echo and Tropical Rainfall Measuring Mission Precipitation Radar (TRMM/PR) data. Optimal values for the radar rain and TRMM/PR rain are inversely weighted according to the error variance statistics for each single station. It is noted how the rainfall distribution during the summer monsoon frontal system is improved from the classification of convective/stratiform echo and the use of the optimal use technique.

• Earthquakes and Structures
• /
• v.3 no.3_4
• /
• pp.413-434
• /
• 2012

This paper presents a displacement-based seismic design method with damage control, in which the targets for the considered performance level are set as displacements and a damage distribution is proposed by the designer. The method is based on concepts of basic structural dynamics and of a reference single degree of freedom system associated to the fundamental mode with a bilinear behaviour. Based on the characteristics of this behaviour curve and on the requirements of modal spectral analysis, the stiffness and strength of the structural elements of the structure satisfying the target design displacement are calculated. The formulation of this method is presented together with the formulations of two other existing methods currently considered of practical interest. To illustrate the application of the proposed method, 5 reinforced concrete plane frames: 8, 17 and 25 storey regular, and 8 and 12 storey irregular in elevation. All frames are designed for a seismic demand defined by single earthquake record in order to compare the performances and damage distributions used as design targets with the corresponding results of the nonlinear step by step analyses of the designed structures subjected to the same seismic demand. The performances and damage distributions calculated with these analyses show a good agreement with those postulated as targets.

• Journal of the Korean Society for Railway
• /
• v.20 no.3
• /
• pp.413-422
• /
• 2017

In this study we investigate the importance of the subway station using network centrality measures. For centrality measures, we have used betweenness centrality, closeness centrality, and degree centrality. A new measure called weighted betweenness centrality is proposed, that combines both traditional betweenness centrality and passenger flow between stations. Through correlation analysis and power-law analysis of passenger flow on the Seoul metropolitan subway network, we have shown that weighted betweenness centrality is a meaningful and practical measure. We have also shown that passenger flow between any two stations follows a highly skewed power-law distribution.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.11
• /
• pp.21-29
• /
• 2021

The objective of this study is to see how a country's level of democracy impacts the relationship between financial development and income disparity. We argue that political regimes, supported by their degree of democracy, are important for various decentralization theories to predict the impact of financial development on income inequality. Our study tests this argument using Vietnam time series data for the period 2000-2020 through the ARDL model. The financial development variable is represented by five proxies, the income inequality variable is represented by the GINI coefficient and the role of democracy is represented by the Freedom House Index. Data serving for the study is taken from data sources with high reliability. The results of the study have strong evidence that (1) financial development has a positive impact on income inequality, (2) democratic government will reduce national income inequality. (3) And a higher degree of democracy tends to mitigate the positive impact of financial development on income inequality. Thus, our study contributes to the literature by providing a new look at the mixed results regarding the relationship between financial development and theoretical income inequality. Finally, the article provides policy implications for the Government of Vietnam.

• International Journal of Knowledge Content Development & Technology
• /
• v.8 no.4
• /
• pp.55-74
• /
• 2018

Faculty advisors play a vital role in a learning and adjustment process of doctoral students at their work, department, university and discipline by sharing and exchanging relevant information and knowledge in the profession. Despite the important role of information practice in doctoral advising, few studies have investigated the informational aspects of faculty advisors and their students. Thus, this study aims to consider the distribution of information exchanged between faculty advisors and their doctoral students and relate them to doctoral students' demographic characteristics (gender, age, race and/or ethnicity, degree, and stage of doctoral work). The findings of this study show that overall information exchange is most frequent at the work level followed by the discipline, school/department, and university levels. In particular, information exchange at the work and discipline levels explains the characteristics of doctoral education, socializing students into both student and professional roles. In addition, there are statistically significant differences in information exchange along certain dimensions according to the advisee's gender, age, race and/or ethnicity, degree, and stage of doctoral study, suggesting that information needs and seeking behavior may vary according to the demographic characteristics of advisees.

• Journal of odor and indoor environment
• /
• v.17 no.4
• /
• pp.381-388
• /
• 2018

In this study, various conditions and phenomena that occur in the process of removing odorous VOCs by using electrolyzed oxidant were examined. The formation of hypochlorous acid, which is an oxidant produced by electrolysis, was investigated and the properties of the oxidizing agent used to decompose toluene, xylene, and cyclohexane were investigated. As a result, it was found that the production rate and the final concentration of the oxidizing agent increased with the current density. It was found that the degree of removal varies depending on the property of each pollutant. Interestingly, in the batch experiments in which the pH of the produced oxidant was controlled, it was found that the degree of elimination varied depending on the pH of the substance. These results suggest that the difference in the concentration and distribution of hypochlorous acid (HOCl) and hypochlorite ($OCl^-$) due to the pH change leads to the difference in oxidizing power on the oxidation characteristics of each substance. Styrene and terpineol showed better degradation characteristics than toluene and xylene in odorous VOC removal experiments by spraying electrolytic oxidant using a lab-scale continuous reactor. In conclusion, the removal of odorous VOCs by the electrolytic oxidant can have various applications in that it can oxidize pollutants of various spectra.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.4
• /
• pp.563-570
• /
• 2021

This study aims at exploring the corporate social responsibility (CSR) practices in the listed companies of Bangladesh. One hundred eighty-two different companies from fifteen different sectors have been selected as a sample. A weighted disclosure index having fifty-two items has been applied to ensure the degree of CSR practices of the sample companies. Each of the content has been assigned a three-scale value starting from zero to two. After that, eight dimensions of CSR are identified from CSR literature and have been evaluated by the predetermined disclosure index. Finally, a composite CSR disclosure (CSRD) score has been computed to measure the extent of CSR practices of the sample companies. The findings of the study reveal a poor CSRD score by the sample companies. Besides, it has been found that the listed companies provide more CSR activities on employee-related issues and community service-related issues while the listed companies provide less information on energy-related CSRD and customer-related CSRD in the context of Bangladesh. The findings of the study imply that the government and the regulatory authority should give more attention to develop a harmonized standards or policies to measure the degree of CSR practices for comparative purposes.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.7
• /
• pp.2531-2546
• /
• 2021

For several years, virtual reality (VR) and augmented reality (AR) technologies have been improving. However, some hurdles remain that slow down the distribution of VR and AR devices, such as head-mounted display (HMD), and related consumer content. One issue is VR motion sickness, which has been experienced by users using 360 degree VR content via HMD. This paper discusses the related international standardization work that classifies the factors causing VR sickness, and proposes the process for VR sickness level evaluation. Among the factors causing VR sickness, many research institutes regard minimizing MTP (Motion-to-Photon) latency as the key enabler to mitigate VR sickness. Thus, this paper introduces research trends of MTP latency measurement and MTP latency mitigation. This paper categorizes the research on MTP latency measurement into 2 categories of hardware-based approach and software code-level approach. The 2 approaches have different pros and cons depending on use-case, purpose, and architecture of each multimedia system. The pros and cons are addressed in this paper. Additionally, the research on mitigating MTP latency with diverse strategies such as proactive computing, caching, and edge server technology is explained, and compared to conventional technologies, shows improved performance.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.5
• /
• pp.171-176
• /
• 2022

The article analyzes the impact of psychological factors on the level of loans used by investors in Vietnam's real estate market. Individual investors in the Vietnamese real estate industry were surveyed using a questionnaire. A total of 320 questionnaires were collected for the survey. The author finalized 314 questionnaires after deleting those that were invalid due to too many blank cells. SPSS 25 was used to conduct quantitative research. According to the findings, Excessive Optimism (EO) is the factor that has the highest impact on the level of loan used by investors in the Vietnamese real estate market, and this relationship is positive. With an influence level of 0.261 and 0.130, the elements of herd psychology and overconfidence also have a beneficial impact on the degree of loan used by investors in Vietnam's real estate market. Fear of loss is a factor that has a negative relationship with the level of loan utilization by investors in the Vietnamese real estate market, although, with a beta coefficient of 0.134, the degree of influence is not significant. Studies on psychological aspects and human behavior in general, and investors in particular, can help investors avoid falling into these psychological traps.