• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.2B
• /
• pp.121-128
• /
• 2011

The paper presents trend analyses of the past 60-year-data of intensity (central pressure) and duration of the typhoons that influenced the Korean Peninsula. The singular spectrum analysis was employed to extract the trends. The result of linear regression of the trend component shows that the intensity of typhoons is slightly increased. A long-term change with period of about 30 years was detected, and thus the original series were separated into two sub-periods of 30 years. For these sub-periods, normal and Gumbel distributions of central pressure and duration of typhoons were estimated. The results show that during the second sub-period the overall intensity of typhoon was increased but the occurrence of extreme typhoons remains unchanged. The duration also showed an obvious increase during the second sub-period.

• The Korean Journal of Applied Statistics
• /
• v.29 no.6
• /
• pp.1129-1145
• /
• 2016

Functional neuro-connectivity is one of the main issues in brain science in the sense that it is closely related to neurodynamics in the brain. In the paper, we choose fMRI as a main form of response data to brain activity due to its high resolution. We review methods for analyzing functional neuro-connectivity assuming that measurements are made on physiological responses to neuron activation. This means that we deal with a state-space and measurement model, where the state-space model is assumed to represent neurodynamics. Analysis methods and their interpretation should vary subject to what was measured. We included analysis results of real fMRI data by applying a high-dimensional autoregressive model, which indicated that different neurodynamics were required for solving different types of geometric problems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.322-323
• /
• 2022

The most necessary thing for the optimal operation of a water purification plant is to accurately predict the pattern and amount of tap water used by consumers. The required amount of tap water should be delivered to the drain using a pump and stored, and the required flow rate should be supplied in a timely manner using the minimum amount of electrical energy. The short-term demand forecasting required from the point of view of energy optimization operation among water purification plant volume predictions has been made in consideration of seasons, major periods, and regional characteristics using time series analysis, regression analysis, and neural network algorithms. In this paper, we analyzed energy management methods through AI-based complex sensor applicability analysis such as LSTM (Long Short-Term Memory) and GRU (Gated Recurrent Units), which are types of cyclic neural networks.

• Journal of the Korea Society of Computer and Information
• /
• v.29 no.7
• /
• pp.99-107
• /
• 2024

In an environment where computer-related technologies are rapidly changing, cyber threats continue to emerge as they are advanced and diversified along with new technologies. Therefore, in this study, we would like to collect security-related news articles, conduct LDA topic modeling, and examine trends. To that end, news articles from January 2020 to August 2023 were collected and major topics were derived through LDA analysis. After that, the flow by topic was grasped and the main origin was analyzed. The analysis results show that ransomware attacks in 2021 and hacking of virtual asset exchanges in 2023 are major issues in the recent security sector. This allows you to check trends in security issues and see what research should be focused on in the future. It is also expected to be able to recognize the latest threats and support appropriate response strategies, contributing to the development of effective security measures.

• Korean Journal of Social Welfare
• /
• v.68 no.3
• /
• pp.51-71
• /
• 2016

The purpose of this study is to clarify macro causes influencing on the diversity of single-mother households poverty among OECD Countries including Korea. This study carried out pooled time series cross-section analysis applying unbalanced panel design on the period from 1981 to 2012. There is marked diversity on single-mother households poverty. GDP per capita does not contributes to reduce poverty, and female employment rate and % population 0-14 exacerbate poverty. Several factors contribute on poverty reduction including social spending, child cash spending, union density, employment protection on regular workers, proportional representation system, cumulative left cabinet, cumulative women seat. In Korea, it needs to overcome the limit of anti-poverty strategy mainly based on economic growth and labor market flexibility. And it needs to enlarge universal welfare institutions, child benefits, work-family reconciliation policy, and to design adjusted labor market institutions including union density and employment protection, to introduce consensus political model including proportional representation system to enhance left power and women's representation.

• Land and Housing Review
• /
• v.15 no.1
• /
• pp.39-55
• /
• 2024

The aim of this study is to analyse housing satisfaction among residents of different types of public rental housing-permanent, national, and happy housing-following the integration of housing types upon the full-scale supply of integrated public rental housing. By identifying key factors that influence residential satisfaction, our goal is to inform the planning of public rental housing complexes and derive policy implications. The study focuses on analysing discrepancies in residential satisfaction among residents of different types of public rental housing and comparing the factors influencing this satisfaction. Microdata from the Ministry of Land, Infrastructure, and Transport's 'Housing Situation Survey' in 2021 is utilized for analysis, employing one-way ANOVA and binomial logistic regression methods. Empirical analysis reveals variations in residential satisfaction levels between residents of permanent and national rental housing, with national rental housing residents exhibiting higher satisfaction. The influencing factors of overall condition satisfaction are consistent for permanent and national rental residents but differ for happy housing residents. Additionally, the influencing factors of overall residential environmental satisfaction vary across all three housing types. Nonetheless, common factors across all types include housing noise and facility accessibility, highlighting their significance in complex planning. Subsequent studies may involve time series analysis to assess changes in influencing factors over time.

• Journal of Korean Society of Forest Science
• /
• v.103 no.3
• /
• pp.383-391
• /
• 2014

Long-term changes in the hydrological characteristics of a small forest watershed were examined using a master baseflow recession curve and the measured rainfall-runoff data from the experimental forest watershed in the measured years 2003-2011. The results of the study showed that the recession coefficient of direct runoff was lower than that of baseflow. In small forested watershed, the direct flow was lower than that of large scale watershed, flow due to its shorter period of occurrence. And baseflow was similar to large scale watershed's. A regression equation $y=0.7528e^{-0.022x}$($R^2=0.8938$, range 0.3~0.8 mm) was obtained using the master baseflow recession curve for the study period and the recession coefficient was calculated as K = 0.978. Changes between master baseflow recession curve and runoff showed great association and relevance such as increasing runoff was associated with the gentle slope of master baseflow recession curve and decreasing runoff was associated with the slope of master baseflow recession curve contrary. In the later years of the study period, the slope of the master baseflow recession curve appreciably became more gentle due to increases in baseflow. This suggests that the forested experimental watershed exhibit improved structural functioning of normal flood control and reduced occurrence of water shortage problems.

• Journal of the Economic Geographical Society of Korea
• /
• v.22 no.4
• /
• pp.458-471
• /
• 2019

DMSP-OLS nighttime satellite imagery could be used to derive the sum of lights (SOL) and built-up area, and the two indices have been widely employed to make the estimation of socio-economic variables and the dynamics of urban developments. Considering it, this research investigated the spatiotemporal patterns of economic growth and urbanized area in Jilin Province, China, using DMSP-OLS data for a time span between 1992 and 2012. This study found the SOLs of both the province and most cities to tend to grow during the period. While SOL-weighted centroids' means moved towards northwestern direction, urban-area centroids' means followed the trend of south-eastern migration. These directional patterns could be associated with the Northeast Revitalization Plan of Chinese governments. Nonetheless, a future study will need to consider SNPP VIIRS DNB imagery in order to overcome temporal limitation of DMSP-OLS data. In addition, it is also necessary to estimate socio-economic indices, e.g., growth regional domestic product, using a regression model developed with correlation relationship between economic statistics ad SOL.

• International Area Studies Review
• /
• v.17 no.4
• /
• pp.89-106
• /
• 2013

In this paper, we analysed the absolute and conditional convergency hypothesis and the determinants of productivity in manufacturing industries from 2000 to 2009 with 16 provinces and metro-cities by using panel analysis. In terms of convergency hypothesis test, the results show that both of the convergency hypothesis, the absolute vs. conditional hypothesis, reject the null hypothesis(H0) implying the labor productivity of the 16 province and metro-cities converged to the steady state equilibrium. Also, the speed of the absolute and conditional convergency for the 16 province and metro-cities are average 4.4% and 0.73% respectively. In addition, the results of the determinants of the labor productivity in manufacturing industry show that human capital and manufacturing location coefficient affect to the value- added per capita significantly, but government expenditure per capita doesn't affect to the value- added per capita. As for the total factor productivity, government expenditure per capita and fixed capital per capita are important factors, but research and development doesn't. Hence the government has to revise the balanced regional development policy to develop regional manufacturing industries for the vulnerable regions. Also, it requires more study regarding income disparities and productivity.

• KDI Journal of Economic Policy
• /
• v.10 no.1
• /
• pp.107-131
• /
• 1988

본고(本稿)는 세수증대(稅收增大)가 충분치 않은 경우 재정적자(財政赤字)를 충당하기 위한 국채발행(國債發行)은 본원통화(本源通貨)의 증대가 뒤따르지 않을 경우에도 물가를 즉시 상승시킬 수 있음을 정부(政府)의 동태적(動態的) 예산제약(豫算制約)이 나타내는 단순한 산수(算數)를 이용해서 보여주고 있다. 본고(本稿)가 가정하는 상황(합리적(合理的) 기대(期待), 정확(正確)한 정보(情報) 등)에서는 정부의 예산제약(豫算制約)을 동태적(動態的)으로 계속 연결해서 얻을 수 있는 실제의 동태적(動態的) 예산제약식(豫算制約式)을 검증할 수 있는 형태의 식으로 대체할 수 있다. 이 새로운 예산제약식(豫算制約式)에 의하면 미래잉여금(未來剩餘金)의 기대액(期待額)이 변하지 않는 상태에서의 국채발행(國債發行)은 즉각적으로 현재의 물가상승(物價上昇)을 유발(誘發)하고, 미래잉여금(未來剩餘金)의 기대액(期待額)의 감소(減少)(미래재정적자를 포함) 또한 같은 결과를 초래한다. 전후(戰後) 미국(美國)과 주요공업국가(主要工業國家)의 시계열자료(時系列資料)를 벡터자기회귀분석방법(自己回歸分析方法)에 의해서 분석한 결과 이들 잘 발달된 자본시장(資本市場)을 가진 나라에서는 본고(本稿)의 이론(理論)과 부합(符合)되게 물가(物價)와 국채(國債) 그리고 잉여금(剩餘金)이 변동해 왔음을 알 수 있다. 한국(韓國)의 자본시장여건(資本市場興件)이 현재는 이들 국가와 다르지만 곧 근접해 갈 것이 기대되므로, 앞으로 재정적자(財政赤字)를 국채발행(國債發行)에 의해서 조달해야 할 경우 물가(物價)에 대한 파급효과(波及效果)를 감안해서 세수(稅收)의 확대(擴大)가 뒤따르는 경우에 한하도록 하여야 할 것이다.