• Title/Summary/Keyword: Seemingly Unrelated Regression

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소프트웨어의 품질 요인과 사업요구사항, 목표 간의 관계 분석

  • Jang, Yun-Hui;Jeong, Ho-Won
    • 한국경영정보학회:학술대회논문집
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    • 2007.06a
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    • pp.333-338
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    • 2007
  • 소프트웨어 개발 프로젝트의 15%는 시작하기도 전에 종결되며, 66%의 프로젝트는 실패로 간주되고 있다. 또한 평균적으로, 완료된 프로젝트의 43%가 비용을 초과하는 것으로 나타났다. 실제로 2002년도 미국에서 소프트웨어 프로젝트의 투자 실패로 인한 손실은 비용의 초과로 생긴 170억 달러를 포함해 총 손실 금액이 380억 달러인 것으로 추정하고 있다. 이러한 문제점을 해결하고자 하는 여러 시도 중에 하나가 ISBSG(International Software Benchmarking Standard Group, 2004)으로, 소프트웨어 프로젝트 관련 데이터를 국제적으로 수집하여 위와 같은 문제의 원인을 밝히고자 노력하고 있다. 본 연구는 ISBSG에서 수집한 데이터를 이용해 소프트웨어 시스템과 관련된 요인 중에서 기능성 품질, 문서화품질, 훈련정도, 소프트웨어크기, 전체결함수, 사업요구사항충족, 사용편리성, 목표달성이라는 6개 변수 간의 연관성을 분석하였다. 분석대상 프로젝트는 49개이고, 분석 방법으로는 SURE(Seemingly Unrelated REgression)를 사용하였다. 분석 결과 소프트웨어 기능성품질은 사업요구사항충족, 사용편리성과 정의 관계를 가지며, 사용편리성은 사업요구사항충족과 정의 관계를 가지는 것으로 밝혀졌다. 또한 사업요구사항충족은 목표달성과 정의 관계를 가지고 있다.

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The Burden of Private Educational Expenditure and Consumption Expenditure (사교육비 부담과 가계의 소비지출)

  • Lee Seong-Lim
    • Journal of Families and Better Life
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    • v.23 no.3 s.75
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    • pp.63-76
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    • 2005
  • Using the data from the Family Income & Expenditure Survey, this study investigated (1)the factors determining the level of burden of the private educational expenditure in households; (2) the influences of the level of the burden of private educational expenditure on the other household expenditures. For the analysis of data Chi-square, GLM, Multinomial legit, and Seemingly Unrelated Regression were applied. The major findings were: (1) The factors associated with the burden of private educational expenditure were the number of students by each of the school levels, housing tenure, location of residence, educational attainment of householder; (2) Households with the lower level of burden of the private educational expenditure adjusted the allocation of the expenditure shares of food, utility, and transportation and did not reduce the levels of consumption. Households with the higher level of burden of the private educational expenditure adjusted the extensive ranges of the household expenditure shares and reduced the levels of consumption.

Sentiment Shock and Housing Prices: Evidence from Korea

  • DONG-JIN, PYO
    • KDI Journal of Economic Policy
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    • v.44 no.4
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    • pp.79-108
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    • 2022
  • This study examines the impact of sentiment shock, which is defined as a stochastic innovation to the Housing Market Confidence Index (HMCI) that is orthogonal to past housing price changes, on aggregate housing price changes and housing price volatility. This paper documents empirical evidence that sentiment shock has a statistically significant relationship with Korea's aggregate housing price changes. Specifically, the key findings show that an increase in sentiment shock predicts a rise in the aggregate housing price and a drop in its volatility at the national level. For the Seoul Metropolitan Region (SMR), this study also suggests that sentiment shock is positively associated with one-month-ahead aggregate housing price changes, whereas an increase in sentiment volatility tends to increase housing price volatility as well. In addition, the out-of-sample forecasting exercises conducted here reveal that the prediction model endowed with sentiment shock and sentiment volatility outperforms other competing prediction models.

Substitution analysis among production factors of distant longline fisheries in IATTC waters using a translog cost function (초월대수 비용함수 추정을 통한 IATTC 해역 원양연승어업의 생산요소 간 대체성 분석)

  • Jo, Heon-Ju;Kim, Do-Hoon;Kim, Doo-Nam;Lee, Sung-Il;Lee, Mi-Kyung
    • Ocean policy research
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    • v.34 no.2
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    • pp.1-28
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    • 2019
  • The purpose of this study is to analyze the substitution among production factors of Korean distant water longline fisheries in IATTC waters. In the analysis, the translog function which have one output variable of total cost and input variables of labor, fuel, fishing gear, and capital was established and it was transformed into simultaneous equations by each cost. Then, variables of equations were estimated by SUR (seemingly unrelated regression) model. Since distant water longline fisheries is a fishing type with high fuel usage, substitution of fuel with other factors was mainly analyzed. Results showed a substitute relation between fuel and labor as well as fuel and fishing gear, while a complementary relation between fuel and capital. In addition, it was analyzed that magnitude of fuel elasticity with other factors would be inelastic.

A Study on the Key Factors Affecting Travel Time Budget for Elderly Pedestrians (고령자 통행시간예산의 영향요인 규명에 관한 연구)

  • Choi, Sung-taek;Kim, Su-jae;Jang, Jin-young;Lee, Hyang-sook;Choo, Sang-ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.4
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    • pp.62-72
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    • 2015
  • Nowadays the issue of aging society has received considerable critical attention, especially in transportation planning and demand forecasting. This study identified the factors related to travel time budget for elderly by purpose using seemingly unrelated regression model (SUR model). The SUR model is suitable when error terms of each equation are assumed to be correlated across the equations in terms of travel time budget which is constant in 2 hours per day commonly. The results showed that elderly's travel time budget was affected by individual, household, urban facility and transportation service. The leisure travel comprised a large proportion of total travel time and had a positive relationship with elderly, sports, religious facilities. Moreover, the elderly who had low income or unemployed person had low frequency of social activity such as leisure, shopping and business. This study can provide a comprehensive implications of forecasting the future travel demand and analyzing the travel behavior.

The Relationships between Educational Investment as a Human Capital Formation and the National Economic Growth: Focusing on non-English-Speaking OECD Countries (인적자본형성으로서의 교육투자와 경제성장과의 관계 : OECD 비영어권 국가들을 중심으로)

  • Kim, Seon-Jae;Lee, Young-Hwa;Im, Kwang-Hyuk
    • The Journal of the Korea Contents Association
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    • v.10 no.3
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    • pp.315-325
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    • 2010
  • The issues on education as a human capital formation in recent years have been focused for all of the countries with emerging of the knowledge-based economy. The present study compared and analyzed the relationships between the educational investment and national economic growth of ten non-English-speaking OECD countries during 1970-2008, using Ordinary Least Square (OLS) and Seemingly Unrelated Regression Estimation (SURE) as the main analytical methods. Findings indicate that educational investment, R&D investment, and fertility rate were statistically significant in the estimation of the variables related to the human capital formation, and these elements had also positive influence on the national economic growth. The most salient factor was the fertility rate, and the R&D investment and educational investment appeared as the next factors in the national economic growth. In particular, the dimensions in the coefficient of the fertility rate showed 1.8 times of the R&D and 3.5 times of the educational investment, respectively. These results imply that educational investment, R&D investment, and the policies which promote fertility rate should be taken into account for the continuous economic growth of each country.

Information in the Implied Volatility Curve of Option Prices and Implications for Financial Distribution Industry (옵션 내재 변동성곡선의 정보효과와 금융 유통산업에의 시사점)

  • Kim, Sang-Su;Liu, Won-Suk;Son, Sam-Ho
    • Journal of Distribution Science
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    • v.13 no.5
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    • pp.53-60
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    • 2015
  • Purpose - The purpose of this paper is to shed light on the importance of the slope and curvature of the volatility curve implied in option prices in the KOSPI 200 options index. A number of studies examine the implied volatility curve, however, these usually focus on cross-sectional characteristics such as the volatility smile. Contrary to previous studies, we focus on time-series characteristics; we investigate correlation dynamics among slope, curvature, and level of the implied volatility curve to capture market information embodied therein. Our study may provide useful implications for investors to utilize current market expectations in managing portfolios dynamically and efficiently. Research design, data, and methodology - For our empirical purpose, we gathered daily KOSPI200 index option prices executed at 2:50 pm in the Korean Exchange distribution market during the period of January 2, 2004 and January 31, 2012. In order to measure slope and curvature of the volatility curve, we use approximated delta distance; the slope is defined as the difference of implied volatilities between 15 delta call options and 15 delta put options; the curvature is defined as the difference between out-of-the-money (OTM) options and at-the-money (ATM) options. We use generalized method of moments (GMM) and the seemingly unrelated regression (SUR) method to verify correlations among level, slope, and curvature of the implied volatility curve with statistical support. Results - We find that slope as well as curvature is positively correlated with volatility level, implying that put option prices increase in a downward market. Further, we find that curvature and slope are positively correlated; however, the relation is weakened at deep moneyness. The results lead us to examine whether slope decreases monotonically as the delta increases, and it is verified with statistical significance that the deeper the moneyness, the lower the slope. It enables us to infer that when volatility surges above a certain level due to any tail risk, investors would rather take long positions in OTM call options, expecting market recovery in the near future. Conclusions - Our results are the evidence of the investor's increasing hedging demand for put options when downside market risks are expected. Adding to this, the slope and curvature of the volatility curve may provide important information regarding the timing of market recovery from a nosedive. For financial product distributors, using the dynamic relation among the three key indicators of the implied volatility curve might be helpful in enhancing profit and gaining trust and loyalty. However, it should be noted that our implications are limited since we do not provide rigorous evidence for the predictability power of volatility curves. Meaning, we need to verify whether the slope and curvature of the volatility curve have statistical significance in predicting the market trough. As one of the verifications, for instance, the performance of trading strategy based on information of slope and curvature could be tested. We reserve this for the future research.

A study on Estimation of CO2 Abatement Cost in Korean Offshore Fishery (우리나라 근해어업의 CO2 배출 저감비용함수 추정)

  • Shin, Yongmin;Jeong, Gyeowoon
    • Environmental and Resource Economics Review
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    • v.27 no.3
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    • pp.399-420
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    • 2018
  • This study has attempted environmental economic analysis on the cost structure of offshore fisheries based on fishery management data published by the Fisheries Research Institute to examine the effect of the environmental policy on the fisheries for the effective implementation of the Paris Convention. Under the assumption that both fisheries and carbon dioxide are simultaneously produced, the cost structure of offshore fisheries were analyzed. Cost function in a translog form was estimated and SUR (Seemingly Unrelated Regression) model was used for the analysis. Here, $CO_2$ emission of offshore fishery was calculated by using National Federation of Fisheries Cooperatives' data on supply of tax exemption oil (2003~2016). The cost function estimation showed that there is a weak disposition between catches and $CO_2$ emissions during the sample period, and the marginal abatement cost (MAC) is estimated at 1,457 won per year. In addition, for the same period, when 1% of $CO_2$ per horsepower is to be reduced MAC increases by 2.2%, and when 1% of $CO_2$ per 1 ton of catch is to be reduced, MAC increases by 1.4%.

The Exploration of Intersectoral Convergence of Spatial Information Industry and Forecast of its Market Size (공간정보산업 융·복합부문 탐색 및 시장규모 전망 연구)

  • Kwon, Young-Hyun
    • Journal of Cadastre & Land InformatiX
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    • v.52 no.2
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    • pp.121-135
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    • 2022
  • The purpose of this study is to explore the convergence sector of the spatial information industry based on the business transaction data of spatial information companies and to predict the market size of the industry using the Seemingly Unrelated Regression(SUR) model. The convergence part of spatial information industry, which cannot be identified in the Spatial Data Industry Survey, was analyzed by exploring keywords related to spatial information using the business DB of Korea Enterprise Data (2010-2019). The convergence of spatial information businesses mainly appeared in the business relationship between the value chain between Seoul and Gyeonggi Province. The convergence business has the largest sales in the value chain 2 (utilization, service) & 3 (convergence), and also the convergence in the value chain 1 (production, construction) & 2, 2 & 3 stages has doubled in 2019 compared to 2010. In 2019, the total sales of the spatial information industry based on the Statistical Korea were announced at about 8 trillion won, but in this study, the total sales of the spatial information industry were estimated at 28 trillion won considering convergence activities. Finally, when scenario 1 (0.38% population growth, 2020-2024) and 0.07% (2026-2030) were applied using the SUR model to predict the expected market size of the industry, sales decreased by -0.37% to 0.069% in 2025 and 2030 by respectively. When scenario 2 (average wage growth 1.2%) was applied during the same period, sales in the industry increased by 2.326% to 12.185%. In other words, the sales in the spatial information industry depends on Labor, Total Factor Productivity, and Capital Productivity so it is necessary to additional research on policy development and alternatives of enhancing each productivity.

Analysis of Spatial Association of Regional Economic Growth and Land Use Considering Regional Economic Sphere (광역경제권 설정을 고려한 지역경제성장과 토지이용에 관한 공간연관성 분석)

  • Choi, Yeol;Kim, Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5D
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    • pp.713-721
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    • 2008
  • The aim of this study is to analyze the spatial association of regional economic growth and land use considering 5 plus 2 regional economic sphere (Capital region zone, Chungchung zone, Honam zone, Daekyung zone, Dongnam zone and kangwon zone, Jejudo zone) in Korea. The factors of regional economic growth are GRDP and the rate of self-finance and land use, especially industrial and manufactering zone. The data for this research are obtained by National Statistical Office web-site etc. For this, the Seemingly Unrelated Regression(SUR), as a kind of simultaneous equation model, is employed as empirical analysis. Overall results of this study show that the spatial association of the capital region zone and other zones is complementary. but Honam zone and Dongnam zone or Daekyung zone is competitive. We conclude from this study that the policy of regional development will be considered in accordance with the regional economic growth and land use. Also, this study found that Economic growth of regional economic sphere will be achieved from that of cities within zone and the results will be helpful to policy makers and regional planners when establishing regional planning in the future.