• 제목/요약/키워드: Dummy variables

검색결과 161건 처리시간 0.028초

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

  • Jeong, Gicheol
    • STI Policy Review
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    • 제2권2호
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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.

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

  • 박재순;국민구;김대희;탁태오
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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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
    • 유통과학연구
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    • 제10권12호
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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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농가 유형에 따른 농가부채 분석 (Analysis of Farm Household Debt by Farm Type)

  • 강마야
    • 농촌지도와개발
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    • 제24권1호
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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.

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

  • 전덕빈;박대근
    • 대한산업공학회지
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    • 제24권4호
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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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소셜네트워크게임에서 광고비와 고객 유형 변수간 동적 상호관계 (Dynamic Interactive Relationships among Advertising Cost and Customer Types of Social Network Game)

  • 이희태
    • 유통과학연구
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    • 제14권4호
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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.

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

  • 이승표;반현성;이주현
    • 감성과학
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    • 제21권1호
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    • pp.35-44
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    • 2018
  • 본 연구에서는 센서의 표면적 변화에 따른 입체적 호흡수 센서의 센싱 방식을 제안하고, 직물 기반의 입체적 호흡수 센서의 성능 평가 및 의복에 적용할 수 있는 디자인 방향성을 탐색하고자 한다. 이를 위해 입체적 구조의 차이에 따라 2가지 유형의 입체적 호흡수 센서를 제작하고 더미와 인체 대상으로 연구를 실시하였다. 연구I은 더미 대상 실험으로 센서의 유형 및 호흡 속도의 연구변인에 의해 입체적 호흡수 센서의 측정 가능성을 탐색하였다. 연구II는 7명의 20대 남성을 대상 실험으로 연구I의 연구변인 이외에 3개의 측정 위치별 적합한 유형의 센서를 제안하였다. 입체적 호흡수 센서의 정확도, 재현성, 신뢰도를 평가하기 위해, 의료기기 분야의 대표적 웨어러블 호흡수 센서인 BIOPAC을 사용하여 입체적 호흡수 센서와 동시에 호흡수를 측정하였다. 이상의 연구 결과를 통해 더미 대상으로 입체적 호흡수 센서의 측정 가능성을 탐색하였으며, 인체 대상으로 호흡수를 측정하여 측정 위치별 적합한 유형의 센서를 제안하였다.

법인의 전기 유보금이 당기 투자 및 배당에 미치는 효과 분석 : 업종별 더미변수를 통한 유의성 검증 (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)

  • 유준수
    • 벤처혁신연구
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    • 제2권1호
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    • pp.131-151
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    • 2019
  • 본 논문은 과연 법인의 전기 유보금이 당기 투자 및 배당에 유의한 영향을 미치는지를 업종별 더미변수를 통하여 살펴보고자 한다. 본 논문의 연구결과 양 년도에 걸쳐 물적 투자에서는 제조업, 기술서비스업, 도소매업, 정보서비스업, 건설업, 운수업종에서 전기 유보금이 당기 물적 투자에 유의한 영향을 미쳤으며, 이 중 개발비 및 경상개발비에 대한 투자보다는 유형자산에 대한 투자가 더 효과적인 것으로 나타났다. 인적 투자에서는 제조업, 기술서비스업, 정보서비스업, 운수업종에서 전기 유보금이 당기 인적 투자에 유의한 영향을 미쳤으며, 이 중 급여에 대한 투자보다는 교육훈련비 및 복리후생비에 대한 투자가 더 효과적인 것으로 나타났다. 배당에서는 제조업, 도소매업, 정보서비스업, 운수업, 기타 업종에서 전기 유보금이 당기 배당금에 유의한 영향을 미쳤으며, 이 중 배당률에 대한 지출보다는 배당금에 대한 지출이 더 효과적인 것으로 나타났다. 본 논문의 공헌점은 전기 유보금이 당기 투자 및 배당에 유의한 영향을 미치는지를 업종별로 구분하여 그 효과를 실증분석 하였다는 점이다. 이에 반해 본 논문의 한계점으로는 정확한 세무자료의 수집이 현실적으로 어려워 회귀분석 결과 나온 계량 적인 결과물들이 과연 정부의 정책 효과를 어느 정도 정확히 반영하고 있는지 그 기준을 찾는 연구가 필요하리라 생각된다. 이와 더불어 국내외 경제 및 경영 환경의 모호성과 불확실성에 대해 정부가 어떤 정책을 추진해야 기업이 안심하고 투자할 수 있는지 그 연구도 필요하리라 여겨진다.

기술 중소기업의 경영 특성에 대한 고성장 기업 결정 영향 요인분석: 4차 산업혁명기업과 일반 중소기업을 중심으로 (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)

  • 윤선중;서종현
    • 벤처창업연구
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    • 제16권6호
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    • pp.157-175
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    • 2021
  • 본 연구는 기술보증기금이 2017년부터 2019년까지 기술평가를 통하여 보증 지원한 기술 중소기업 중 3,214개 기업을 대상으로 4차 산업혁명 기업과 일반 중소기업으로 구분한 후 경영 특성이 고성장 기업 결정에 미치는 영향을 실증 분석하였다. 고성장 기업 판단은 OECD(2007)의 정의를 적용하여 최근 2년간 매출액 증가율이 연간 평균 20% 이상인 기업이다. 표본 대상의 두집단이 비정규분포를 따르고 있어 Mann-Whitney U test 비모수 검증으로 평균치 차이 분석을 하였다. 또한 정규성 가정이 덜 엄격한 이변량 로지스틱 회귀분석을 실시하였다. 독립변수는 대표자 역량, 인적자본 역량, 기술혁신 역량, 기본 특성, 지역더미, 기술수준 더미이다. 이에 대응하는 하위변수는 대표자 학력, 대표자 동업종 경험 수준, 상시 종업원, 연구 인력, 지식 재산권 수, 연구개발 투자금액, 기업 업력, 총자산, 지역_수도권, 지역_중부권, 기술수준_첨단기술, 기술수준_중기술이다. 분석결과, 4차 산업혁명 기업은 대표자 동업종 경험수준, 상시종업원, 기업업력, 총자산, 기술수준_첨단기술의 연구가설이 지지되었다. 일반 중소기업은 대표자 동업종 경험수준, 연구인력, 총자산, 지역_수도권의 연구가설이 지지되었다.

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

  • 차경욱
    • 가정과삶의질연구
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    • 제23권2호
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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.