• Journal of Industrial Convergence
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• v.20 no.2
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• pp.11-19
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• 2022

This study examines the role of economic uncertainty in stock price determination in the domestic stock market. To this end, we analyzed the relationship between economic uncertainty indices at home and abroad (USA, China) and stock returns for non-financial companies in Korea from January 2000 to 2017. For the analysis model, the 3-factor model of Fama and French (1992) and the 5-factor model including momentum and liquidity were used. As a result of the analysis, a portfolio with a high beta of economic uncertainty showed higher stock returns than a portfolio with a low beta. This was the same as the US analysis result. Also, the analysis results using the US uncertainty index were more significant than the regression analysis results using the Korean economic uncertainty index.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.153-163
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• 2024

Since the onset of the COVID-19 pandemic, there has been a significant shift in the lifestyle patterns of the populace across various domains. Concerns surrounding COVID-19 have emerged as pivotal catalysts of change in recreational habits with people giving a particular preference for environments with low population density and increased openness. This trend has resulted in an uptick in excursions to natural reserves, coastlines, and parks. However, during the peak of infectious outbreaks, widespread adherence to social distancing measures has precipitated a steep decline in tourist footfall across natural recreation forests, exacerbating financial deficits to a considerable extent. Thus, this research sought to compare and analyze the operational efficacy and productivity of national, public, and private natural recreation forests pre- and post-COVID-19 pandemic by utilizing non-parametric methodologies, such as data envelopment analysis and the Malmquist productivity index analysis. The objective was to identify the factors contributing to the decreases in efficiency and productivity and ultimately offer nuanced recommendations tailored to respective administrative bodies. This study's distinctive focus on the analysis of management efficiency and productivity in natural recreation forests nationwide offers significant academic and practical relevance.

• Asia pacific journal of information systems
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• v.7 no.1
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• pp.67-83
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• 1997

The utility of learning techniques in investment analysis has been demonstrated in many areas, ranging from forecasting individual stocks to entire market indexes. To date, however, the application of artificial intelligence to financial forecasting has focused largely on short predictive horizons. Usually the forecast window is a single period ahead; if the input data involve daily observations, the forecast is for one day ahead; if monthly observations, then a month ahead; and so on. Thus far little work has been conducted on the efficacy of long-term prediction involving multiperiod forecasting. This paper examines the impact of alternative procedures for extended prediction using knowledge discovery techniques. One dimension in the study involves temporal granularity: a single jump from the present period to the end of the forecast window versus a web of short-term forecasts involving a sequence of single-period predictions. Another parameter relates to the numerosity of input variables: a technical approach involving only lagged observations of the target variable versus a fundamental approach involving multiple variables. The dual possibilities along each of the granularity and numerosity dimensions entail a total of 4 models. These models are first evaluated using neural networks, then compared against a multi-input jump model using case based reasoning. The computational models are examined in the context of forecasting the S&P 500 index.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.53-62
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• 2006

The aim of this paper is to analyze the changes in the travel pattern of public transit users, service satisfaction before and after public transportation system reform in Daegu. For this purpose, we conducted a survey of people on public transit users and the results of study are as follows : First, it was found that transfer trip had increased, especially concerning the changes of travel pattern from bus trip to the transfer trip between the bus and subway. Because it makes a financial sense to transfer based on free charge transfer system. Secondly, the transfer satisfaction was improved for public transit users, but they are still reluctant to use transfer system.

• The Korean Journal of Health Service Management
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• v.8 no.2
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• pp.175-185
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• 2014

This study analyzed individual happiness exponent according to local residents' perception degree of Health-Cities. The data, which is accumulated by the survey on relationship between happiness and perception degree of Health-Cities targeting 662 of local residents living in Y-gu in Busan, were analyzed using PASW 18.0. The results are as follows. To begin with, the results of Correlation Analysis on the relation between happiness index and cognition degree of Health-Cites indicate that the higher perception of Health-Cities'facilities, administrations, services, education, health environment and transportation the local residents have, the lower individual happiness index they acquired. The cognition degree of transportation has effects on local society and daily life; the cognition degree of facilities and businesses has impact on financial stability. The cognition degree of administrations has influence on psychological relaxation, services have meaningful effects on psychological stability, work and residence, education have statistically meaningful effects on psychological stability, families and marriage, individual human relationships in respect.

• Journal of Preventive Medicine and Public Health
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• v.52 no.4
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• pp.214-223
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• 2019

Objectives: Equity in financial protection against healthcare expenditures is one the primary functions of health systems worldwide. This study aimed to quantify socioeconomic inequality in facing catastrophic healthcare expenditures (CHE) and to identify the main factors contributing to socioeconomic inequality in CHE in Iran. Methods: A total of 37 860 households were drawn from the Households Income and Expenditure Survey, conducted by the Statistical Center of Iran in 2017. The prevalence of CHE was measured using a cut-off of spending at least 40% of the capacity to pay on healthcare services. The concentration curve and concentration index (C) were used to illustrate and measure the extent of socioeconomic inequality in CHE among Iranian households. The C was decomposed to identify the main factors explaining the observed socioeconomic inequality in CHE in Iran. Results: The prevalence of CHE among Iranian households in 2017 was 5.26% (95% confidence interval [CI], 5.04 to 5.49). The value of C was -0.17 (95% CI, -0.19 to -0.13), suggesting that CHE was mainly concentrated among socioeconomically disadvantaged households in Iran. The decomposition analysis highlighted the household wealth index as explaining 71.7% of the concentration of CHE among the poor in Iran. Conclusions: This study revealed that CHE is disproportionately concentrated among poor households in Iran. Health policies to reduce socioeconomic inequality in facing CHE in Iran should focus on socioeconomically disadvantaged households.

• Land and Housing Review
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• v.11 no.2
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• pp.33-46
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• 2020

As the fastest growing office transaction volume in Korea, there's been a need for development of indicators to accurately diagnose the office capital market. The purpose of this paper is experimentally calculate to the office price index for effective benchmark indices in Seoul. The quantitative methodology used a Case-Shiller Repeat Sales Model (1991), based on actual multiple office transaction dataset with over minimum 1,653 ㎡ from Q3 1999 to 4Q 2019 in the case of 1,536 buildings within Seoul Metropolitan. In addition, the collected historical data and spatial statistical analysis tools were treated with the SAS 9.4 and ArcGIS 10.7 programs. The main empirical results of research are briefly summarized as follows; First, Seoul office price index was estimated to be 344.3 point (2001.1Q=100.0P) at the end of 2019, and has more than tripled over the past two decades. it means that the sales price of office per 3.3 ㎡ has consistently risen more than 12% every year since 2000, which is far above the indices for apartment housing index, announced by the MOLIT (2009). Second, between quarterly and annual office price index for the two-step estimation of the MIT Real Estate Research Center (MIT/CRE), T, L, AL variables have statistically significant coefficient (Beta) all of the mode l (p<0.01). Third, it was possible to produce a more stable office price index against the basic index by using the Moore-Penrose's pseoudo inverse technique at low transaction frequency. Fourth, as an lagging indicators, the office price index is closely related to key macroeconomic indicators, such as GDP(+), KOSPI(+), interest rates (5-year KTB, -). This facts indicate that long-term office investment tends to outperform other financial assets owing to high return and low risk pattern. In conclusion, these findings are practically meaningful to presenting an new office price index that increases accuracy and then attempting to preliminary applications for the case of Seoul. Moreover, it can provide sincerely useful benchmark about investing an office and predicting changes of the sales price among market participants (e.g. policy maker, investor, landlord, tenant, user) in the future.

• Korean Journal of Culture and Social Issue
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• v.29 no.1
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• pp.75-99
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• 2023

The current study aimed to explore the suicidal behaviors and risk factors of completed suicides using psychological autopsy and use them as index variables to classify suicidal types. In addition, this study looked into the influential factors that affect each suicidal type. related to suicidal behaviors and suicidal risk factors by psychological autopsy. In addiction, the distinctions among the classes were analyzed. For this, psychological autopsies were conducted on the families and the close ones of 128 completed suicides. Then, the index variables were finally chosen for classifying suicidal types. The selected index variables for suicidal risk factors were mental disorders, suicide/self-harm, significant changes in physical appearance, marital conflict, adjustment and relationship issues at work/school, unemployment/layoff, jobless status and serious financial problems. The selected index variables for suicidal behaviors were expressing their suicidal attempts, writing suicidal notes, asking for help, the time/place/method of suicidal behavior, past suicidal/self-harm experience and the first person who witnessed the suicide. The Latent Class Analysis(LCA) and the 3-step method were used for classifying suicidal types. Then external variables(financial changes, cohabitation, existence of stressors, changes in stress level or relationships and family members with mental disorder/alchohol problems/ physical disorders, and work/school stisfaction) were applied for distinguishing classes. As a result, 5 classes(financial problems, adjustment problems, complex problems, psychiatric problems, and response to event[s]) were revealed on suicidal behaviors and 3 classes(residence- suicidal attempt- found by family, nonresidence- nonsuicidal attempt- found by acquaintances, residence- nonsuicidal attempt- found by family) were presented on suicidal risk factors. External variables such as gender, marital status, cohabitation, changes in relationships significantly differentiated among the 3 classes. Especially, class 3(residence- nonsuicidal attempt- found by family) tended to cohabit with others, were married, and had a significantly high level of interpersonal conflicts. When comparing the 5 classes of suicidal risk factors, auxiliary variables such as economic changes, cohabitation, stress, relationship changes, and family-related problems, and school/work satisfaction significantly differentiated the 5 classes. Especially class 3 (complex problems) experienced comparatively less family-related problems, but showed an aggravating level of personal stress. Suicial prevention strategies should be provided considering the characteristics of each class and the influential factors.

• Knowledge Management Research
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• v.22 no.4
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• pp.119-133
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• 2021

As a large amount of data is produced in each industry, a number of time series pattern prediction studies are being conducted to make quick business decisions. However, there is a limit to predicting specific patterns in nonlinear time series data due to the uncertainty inherent in the data, and there are difficulties in making strategic decisions in corporate management. In addition, in recent decades, various studies have been conducted on data such as demand/supply and financial markets that are suitable for industrial purposes to predict time series data of irregular random walk models, but predict specific rules and achieve sustainable corporate objectives There are difficulties. In this study, the prediction results were compared and analyzed using the Chaos analysis method for roulette data and financial market data, and meaningful results were derived. And, this study confirmed that chaos analysis is useful for finding a new method in analyzing time series data. By comparing and analyzing the characteristics of roulette games with the time series of Korean stock index future, it was derived that predictive power can be improved if the trend is confirmed, and it is meaningful in determining whether nonlinear time series data with high uncertainty have a specific pattern.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3B
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• pp.185-192
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• 2012

Drought vulnerability index was developed by selecting drought-related indicators with trend test. Study areas were determined by considering the weir locations from the four major rivers restoration project in Nakdong and Geum river watersheds. Ten indicators were selected and they were categorized into three groups, water resources, precipitation pattern, and social aspects. Annual average surface water level, annual minimum surface water level, annual average groundwater level, and annual minimum groundwater level data sets were collected for water resources aspects. The number of non-rainy days, rainfall concentration ratio, and rainfall deviation were considered for precipitation pattern category. The amount of water available per capita, financial soundness for water resources, and water usage equity were related to social aspects. Mann-Kendall, Hotelling-Pabst, and Sen trend tests were performed for the ten indicator data sets and the results were scored for the drought vulnerability index. The results shows Gumi, Sangjoo, and Hapcheon weirs are relatively vulnerable to drought. The indices were relatively low for the regions in Geum river watershed compared to those in Nakdong river watershed.