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Oil Price and Total Factor Productivity of Korean Manufacturing Industries
Wonho Song,Sinuk Park 한국계량경제학회 2011 JOURNAL OF ECONOMIC THEORY AND ECONOMETRICS Vol.22 No.4
This paper estimates the effects of oil price change on the productivity changes of Korean manufacturing industry. We applied a stochastic frontier production model to estimate the changes of total factor productivity. The model is estimated by the recently developed KSS panel data estimator (Kneip et al, 2012) which allows for arbitrary patterns of time-varying individual effects. We decompose the sources of total factor productivity (TFP) growth into technical progress, technical efficiency change, scale effects change and allocation efficiency change following Kumbhakar (2000). Empirical results based on data from 2001–2010 show that productivity growth was driven mainly by declining technical progress together with improving technical efficiency. Scale effects and allocation efficiency exert marginal impacts on TFP growth. For the derived TFP components, the impacts of oil price have been analyzed. The effects of oil price change were different across the sample period. When the oil price is low and moves smoothly during 2001-2006, only scale effects are marginally affected. When the oil price is high and fluctuated greatly during 2007-2010, however, all the components were significantly affected, thus technical progress and scale effects increased, and technical efficiency and allocation efficiency decreased.
Information Quality of Online Reviews in the Presence of Potentially Fake Reviews
( Wonho Song ),( Sangkon Park ),( Doojin Ryu ) 한국경제학회 2017 The Korean Economic Review Vol.33 No.1
Online reviews are important in the evaluation of product quality. This paper seeks to assess information quality of online reviews using the TripAdvisor data for Korean hotels. We first estimate the review model developed by Dai, Jin, Lee, and Luca (2012) and show that high-quality reviews contain most of the information for the quality of hotels. Second, we assess the degree of distortions caused by fake reviews through numerical experiments and show that the distortions of fake reviews are serious. Third, we compare the simple average and weighted average aggregation methods. Weighted average method is better than simple average in finding the quality of hotels but it is more vulnerable to fake reviews. Fourth, we suggest excluding low-quality reviews to deal with fake reviews and show that the benefit of avoiding serious distortions from potentially fake reviews is greater than the cost of losing information from low-quality reviews.
Impacts of Olympics on Exports and Tourism
SONG, WONHO 경제연구소 2010 Journal of Economic Development Vol.35 No.4
There have been debates on the effects of Olympics on economy. Previous studies estimated the direct benefits and costs of Olympic Games, and concluded that the net effects were positive or negative depending on specific assumptions used for evaluations. Recent studies turn attentions to indirect benefits. For example, signaling model by Rose and Spiegel (2010) argues that mega events are the signals of liberalization the country sends, and that the hosting of mega events spurs exports. This paper more thoroughly estimates the effects of Summer Olympics on exports and tourism using the Rose and Spiegel’s data set extended up to 2008. Our empirical results show that the Summer Olympics have positively and significantly affected exports and tourists. The patterns are, however, different for exports and tourists. The effects on exports are slow and persist for long periods of time, whereas those on tourists are quick and short-lived. This finding is robust to different specifications. This result implies that, without carefully considering the time horizons of the effects of mega events, impact studies may be prone to over- or under-estimating the benefits of the mega events.
The Determinants of Convention Site Selection: An Experimental Analysis
Wonho Song,Sukyoung Han THE KOREAN ECONOMIC SOCIETY 2013 JOURNAL OF ECONOMIC THEORY AND ECONOMETRICS Vol.24 No.4
This paper examines the determinants of convention site selection with experimental data. The meetings and conventions industry is becoming more competitive and gaining importance in a national economy. However, there are only a few studies available on this issue. Moreover, analytical tools used are limited to statistical variance analysis or simple linear regressions and they lacked theoretical backgrounds. This paper tries to fill this gap and examines the determinants of site selection and their relative importance in Korean meetings and conventions industry. We employ the random utility theory to investigate individual choice decisions and estimate the mixed logit model for the choices with different selection attributes. After careful examination of previous literature, fifteen candidate factors are finally chosen and the logit and the mixed logit models are estimated. Both methods show that meeting facilities, exhibition, access to site, reputation, local support and shopping are the most important factors.
송원호(Wonho Song),손홍규(Hong-Gyoo Sohn) 대한공간정보학회 2017 한국지형공간정보학회 학술대회 Vol.2017 No.5
본 연구에서는 구글맵을 기반으로 건물을 자동으로 추출하는 방법을 실험하였다. 구글맵의 영상에 따라 Canny 계수를 달리 적용하여 건물에 최적화되도록 좌표로 추출하였다. 추출된 벡터 지도(이하 ‘스케치맵’)는 도로와 건물의 경계가 혼재되어 있어 구분이 어려울 뿐 아니라 아주 작은 벡터들의 집합으로 다각형화 하기에 어려움이 있다. 여러 가지 실험결과 벡터를 단순화 시키는 알고리즘은 DouglasPeuckers 알고리즘이 가장 우수한 것으로 나타났다.
송원호(Wonho Song),이준석(Junseok Lee),박상성(Sangsung Park) 한국지능시스템학회 2016 한국지능시스템학회논문지 Vol.26 No.3
급변하는 글로벌 시장 환경에서 기술은 계속해서 급속히 발전하고 있다. 이러한 급변하고 있는 환경을 반영한 연구개발은 기업에 있어서 필수가 되었다. 즉, 기업의 경쟁력 향상을 위해서는 자사가 보유한 기술에 대한 체계적인 분석이 필요하다. 최근에는 객관적이며 정량화된 기술분류를 위하여 특허문서의 IPC 코드를 이용하여 기술분류를 수행하고 있다. 국제특허분류인 IPC 코드는 국제적으로 규격화된 기술분류 코드이기 때문에, 이를 활용하면 객관적이고 정량화된 기술분석 수행이 가능하다. 본 논문에서는 C社의 특허에 대하여 전수조사를 실시하고, IPC 코드기반 분석 Matrix를 구축한 후 해당특허들을 신뢰도 기반의 연관규칙 마이닝을 실시하며 구조화된 연관맵을 생성한다. 연관맵을 이용하면 해당회사의 특허 현황 파악에 유용하게 활용된다. 또한, 구조화된 연관맵을 이용하면 상호 연관있는 기술에 대하여 군집화를 가능하게 하기 때문에, 본 논문에서 제시한 C社의 기술을 파악할 수 있으며 이를 기반으로 기술 흐름과 향후 기술 전략 수립을 가능하게 한다. A technology is continuously developed in a rapidly changing global market. A company requires an appropriate R&D strategy for adapting to this environment. That is, the technologies owned by the company needs to be thoroughly analyzed to improve its competitiveness. Alternatively, technology classification using IPC codes is carried out recently in an objective and quantitative way. International Patent Classification, IPC is an internationally specified classification system, so it is helpful to conduct an objective and quantitative patent analysis of technology. In this study, all of the patents owned by company C are investigated and a matrix representing IPC codes of each patent is created. Then, a structured association map of the patents is made through association rules mining based on Confidence. The association map can be used to inspect the current situation of a company about patents. It also allows highly associated technologies to be clustered. Using the association map, this study analyzes the technologies of company C and how it changes with time. The strategy for future technologies is established based on the result.