• Title/Summary/Keyword: dummy variables

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Development of a Recursive Multinomial Probit Model and its Possible Application for Innovation Studies

  • Jeong, Gicheol
    • STI Policy Review
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    • v.2 no.2
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    • pp.45-54
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    • 2011
  • This paper develops a recursive multinomial probit model and describes its estimation method. The recursive multinomial probit model is an extension of a recursive bivariate probit model. The main difference between the two models is that a single decision among two or more alternatives can be considered in each choice equation in the proposed model. The recursive multinomial probit model is developed based on a standard framework of the multinomial probit model and a Bayesian approach with a Gibbs sampling is adopted for the estimation. The simulation exercise with artificial data sets is showed that the model performed well. Since the recursive multinomial probit model can be applied to analyze the causal relationship between discrete dependent variables with more than two outcomes, the model can play an important role in extending the methodology of the causal relationship analysis in innovation research.

Evaluation of Motorized retractor locking mechanism based on predetermined collision scenarios (충돌 예상 시나리오에 따른 모터 구동형 리트랙터의 잠김 작용 평가)

  • Park, Jae-Soon;Kuk, Min-Gu;Kim, Dae-Hee;Tak, Tae-Oh
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.903-908
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    • 2007
  • A retractor is the major component of a seatbelt system that restraints passengers by locking the movement of webbing. Recently, in order to increase the effectiveness of seatbelt systems, motorized retractors that remove slack and correct passenger posture just before airbag expansion when collision is predicted are widely used. Key component of motorized retractors is the one-way clutch that engages and disengages the winding action of webbing according to the direction of motor revolution. Analytical investigation of action of the one-way clutch mechanism has been carried out to figure out conditions for one-way locking, and to study the effect of various kinematic and dynamic design variables of one-way clutch. Using combination of ADAMS and LifeMOD soft-wares, dynamic simulation of operation of motorized retractors including Hybrid-III dummy model has been carried out to evaluate the performance of the motorized retractors in various crash scenarios.

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How APEC Affects the Intra-trade of Members: An Empirical Study

  • Lee, Donghae
    • Journal of Distribution Science
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    • v.10 no.12
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    • pp.13-17
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    • 2012
  • Purpose - The Asia-Pacific Economic Cooperation (APEC) forum has evolved and is actively facilitating free and open trade. It is debated whether APEC has effectively reduced trade barriers in a preferential manner to encourage liberalized trade and whether increased trade between member countries has reduced trade with nonmember countries. Research designs, data, methodology -This paper empirically tests whether APEC creates or diverts trade, using an extended gravity model with tariff rates, exchange rates, and dummy variables to analyze how APEC affects intra-trade between members.The model utilizes the annual panel data between 1990 and 2007 of 16 selected APEC members and nonmembers. Results - Results reveal the changing role of APEC only between 2002 and 2007 has it created trade, fostering increased trade among trading partners and between members and nonmembers. Conclusion - APEC can be expected to demonstrate a stronger trade creating effect once its advanced and developing members complete tariff reductions by 2010 and 2020, respectively.

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Analysis of Farm Household Debt by Farm Type (농가 유형에 따른 농가부채 분석)

  • Kang, Maya
    • Journal of Agricultural Extension & Community Development
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    • v.24 no.1
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    • pp.63-81
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    • 2017
  • The purpose of this study is to analyze the changes of time series, the use by farm type and the causes of farm household debt. First, the mid and long term changes in farm household debt over the past 50 years have increased. Since 2010, the share of non-agricultural debt has exceeded the share of agricultural debt. Second, as a result of the analysis of the farm household debt use by farm type - full time&part time, farming type, land size, age, family members - there was a difference between the agricultural and the non-agricultural debt according to the type of farm household in a significant level of 1%. Finally, as a result of the cause analysis of the farm household debt, the related non-agricultural expenditure variables and the dummy variable of the manager's age, family member and land size has a common influence on the farm household debt increase.

A Bayesian Analysis of Structural Changes in Aggregate Demand and Supply of Korean Economy (한국경제의 총수요와 총공급에서의 베이지안 구조변화 분석)

  • Jun, Duk-Bin;Park, Dae-Keun
    • Journal of Korean Institute of Industrial Engineers
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    • v.24 no.4
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    • pp.475-483
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    • 1998
  • Structural changes in an economy system bring about serious problems in establishing economic policies. The boom of middle-east export, the oil shock, and the recent dollar crisis in Korean economy are such examples. Hence, it is necessary to identify and estimate those structural changes. This study focuses on an output and price and analyzes structural changes in aggregate demand and supply. The aggregate demand and supply structures are described by conventional dynamic simultaneous equations model, where each structural change is represented by dummy variables and estimated by the proposed Bayesian method. By applying this model to Korean output and price, structural changes in the aggregate demand and supply are analyzed.

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Dynamic Interactive Relationships among Advertising Cost and Customer Types of Social Network Game (소셜네트워크게임에서 광고비와 고객 유형 변수간 동적 상호관계)

  • Lee, Hee-Tae
    • Journal of Distribution Science
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    • v.14 no.4
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    • pp.47-53
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    • 2016
  • Purpose - The objective of this study is to investigate the dynamic relationships among Advertising Cost (AD), Newly Registered Users(NRU), and Buying Users(BU) of Social Network Game(SNG). SNG is getting pervasive mainly due to the rapid growth of mobile game and Social Network Service(SNS). It would be helpful for marketing researchers interested in SNG and related practitioners to understand the changes in AD, NRU, and BU with time as well as the effects on one another in mutual and dynamic way. Research Design, Data, and Methodology - Necessary data were collected from Social Network Game(SNG) company. AD, NRU, and BU are endogenous variables, but new event such as launching (event) and holidays(holiday) are exogenous dummy variables. Vector Auto regression (VAR) model is generally used to examine and capture the dynamic relationships among endogenous variables. VAR model can easily capture dynamic and endogenous relationships among time-series variables. Vector Auto regression with Exogenous variables(VARX) is a model in which exogenous variables are added to VAR. To investigate this study, VARX is applied. Result - By estimating the VARX model, the author finds that the past periods' NRU affect negatively and significantly the present AD, and past periods' BU have a positive and significant impact on the increase of AD. In addition, the author shows that the past periods' AD and BU have a positive and significant effect on the increase of NRU, and the past periods' AD affect positively and significantly BU. While the impact of AD on NRU happens after 3 or 4 days (carryover effect), that of AD on BU comes about within just 1 or 2 days (immediate effect). The effect of BU on NRU can be considered as word of mouth (WOM effect). Therefore, SNG companies can obtain not only the growth of revenue but also the increase of NRU by increasing BU. Through those results, the author can also find that there are significant interactions between endogenous variables. Conclusion - This study intends to investigate endogenous and dynamic relationships between AD, NRU, and BU. They also give managerial implications to practitioners for SNS and SNG firms. Through this study, it is found that there exist significant interactions and dynamic relationships between those three endogenous variables. The results of this study can have meaningful implications for practitioners and researchers of SNG. This research is unique in that it deals with "actual" field data and intend to find "actual" relationships among variables unlike other related existing studies which intend to investigate psychological factors affecting the intention of game usage and the intention of purchasing game items. This study is also meaningful by showing that the increase of BU can be a good strategy for "killing birds with one stone" (i.e., revenue growth and NRU increase). Although there are some limitations related with future research topics, this research contributes to the current research on SNG marketing in the above mentioned ways.

A Study on the Possibility of Three-dimensional Wearable Respiration Rate Sensor based on Surface Area Changes (표면적 변화에 기반한 입체적 웨어러블 호흡수 센서의 가능성 탐색)

  • Lee, Seungpyo;Ban, Hyunsung;Lee, Joohyeon
    • Science of Emotion and Sensibility
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    • v.21 no.1
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    • pp.35-44
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    • 2018
  • This study suggests the sensing method of the Three-dimensional respiration rate sensor based on surface area changes, and exploring the design direction of the three-dimensional breathing sensor and the design orientation of the garment. To achieve this, two types of three-dimensional respiration rate sensor were produced, and the study of the dummy and the subjects studied. The study I investigated the possibility of measurement of the three-dimensional respiration sensor by the study variables of the sensor type and speed of respiration. The study II proposes a suitable type of sensor for each of the three measuring positions in addition to the study variables in the study I. To evaluate accuracy, reproducibility, and reliability of the three-dimensional respiration rate sensor, the BIOPAC was used to measure the respiration rate simultaneously with the three-dimensional respiration rate sensor. Through all these results of the experiment, it explored the possibility of measurement of the three-dimensional respiration sensor for the dummy. It also proposed a suitable type of sensor by measuring the respiration rate for the human body.

The Analysis of the Effects of the Previous Corporate Internal Reservation on the Current Investments and Dividends : The Verification of Significance through Dummy Variables under Industrial Classification (법인의 전기 유보금이 당기 투자 및 배당에 미치는 효과 분석 : 업종별 더미변수를 통한 유의성 검증)

  • Yoo, Joon-soo
    • Journal of Venture Innovation
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    • v.2 no.1
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    • pp.131-151
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    • 2019
  • This paper is conducted to find out if the previous corporate internal reservation has a significant effect on current investment and dividend payments by using the dummy variables of each classified industry. The results of the research show that previous corporate internal reservation had a significant effect on current material investments in following fields - manufacturing industries, technical services, wholesale and retail industries, information services, construction and transportation industries - over two years. Especially, investments in tangible assets were more effective than those in development expenses. In human resource investment, previous corporate internal reservation had a significant effect on current human investments in fields of manufacturing, technical services, information services and transportation industries. Among them, investments in education training expense and welfare benefit expense were more effective than those in wages. In the dividend section, previous corporate internal reservation had a significant effect on current dividends in the fields of manufacturing, wholesale and retail, information services, transportation industries, and in other businesses. Among them, Expenditure on dividend amounts was found to be more effective than that on dividend ratio. This paper contributed to the field in a way of empirically demonstrating the effects of previous corporate internal reservation on current investments and dividends by using the method of industrial classification. On the other hand, it also has a limitation since collecting precise taxation data was practically difficult. Therefore, a further developed study is required to find out the standard which shows exactly how much the measured results of the regression analysis reflect the effects of the government policies. Moreover, it is considered necessary for the government to devise policies on vagueness and uncertainties in the domestic and overseas economic and business environments so that companies can conduct investment with confidence.

Analysis of the Factors Influencing the Management Characteristics of Tech SMEs in Determination of High-growth Firms: Focusing on Fourth Industrial Revolution Related Businesses and General SMEs (기술 중소기업의 경영 특성에 대한 고성장 기업 결정 영향 요인분석: 4차 산업혁명기업과 일반 중소기업을 중심으로)

  • Yoon, Sun-jung;Seo, Jong-hyen
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.6
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    • pp.157-175
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    • 2021
  • This study categorized 3,214 companies out of the tech firms supported by the Korea Technology Finance Corporation's "technology guarantee scheme" through technology assessment from 2017 to 2019 into Fourth Industrial Revolution-related companies and general SMEs. The impact of the management characteristics of these 1,752 tech firms on the determination of high-growth firms was then empirically analyzed. This study used the OECD(2007) definition to define a "high-growth firm" as "an enterprise with average revenue growth greater than 20% per annum, over a two-year period." As the two sample groups showed non-normal distribution, this study conducted the Mann-Whitney U test, a nonparametric test, to analyze the mean differences and bivariate logistic regression in which the normality assumption is less stringent. The independent variables include fundamental characteristics; a regional dummy; a technological level dummy; and the capabilities of company representatives, human capital, and technological innovation. The corresponding sub-variables are representatives' level of education and experience in the same industry, full-time workers, research personnel, the extent of intellectual property rights, investment in research and development, firm age, total assets, region_metropolitan area, region_central region, technological level_high technology, and technological level_medium technology. As a result, the research hypothesis about representatives' level of experience in the same industry, full-time workers, total assets, and technological level_high technology was supported for the Fourth Industrial Revolution-related companies. For the general SMEs, the research hypothesis about representatives' level of experience in the same industry, research personnel, total assets, and region_metropolitan area was supported.

The Differences in Household Economic Structure between Low-Fertility and Birth-Planned Households (저출산 가계와 출산계획 있는 가계의 경제구조 비교 분석)

  • Cha Kyung-Wook
    • Journal of Families and Better Life
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    • v.23 no.2 s.74
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    • pp.137-148
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    • 2005
  • This study compared one-child households' economic structures between those who determined not to have more children and those who have a birth plan. This study examined the demographic characteristics and economic variables such as income, consumption expenditures, assets. debt, and a subjective evaluation of future economic status. Especially, it compared the effects of socioeconomic variables on expenditures on a child between low-fertility and birth-planned households. From a questionnaire completed by a husband or wife of one-child households, 154 low-fertility households and 201 birth-planned households were obtained. A t-test, chi-square test, multiple regression analysis and a dummy variable interaction technique were used. The findings of this study are as follows: First, low-fertility households were older, had higher income, and had more educated, employed wives. Their marital duration was longer, and their child was older than those of birth-planned households. Second, low-fertility households had higher consumption expenditures than did birth-planned households. Especially, expenditures of apparel and shoes, health care, education, and entertainment were significantly higher for low-fertility households. Also, low-fertility households spent more than did birth-planned households on a child. However, low-fertility households had significantly more debt than did their counterparts, and their expectation level of future economic status were lower than that of birth-planned households. Third, the effects of socioeconomic variables on expenditures on a child were different between low-fertility and birth-planned households. Age, education level, husband's occupation, wife's employment status, income, net asset, and subjective evaluation of future economic status showed significant differences. Income elasticity of expenditure on a child was significantly higher for low-fertility households than their counterparts.