Do I have to buy it now? A vehicle replacement model considering strategic consumer behavior

Choi, Hyunhong,Koo, Yoonmo Pergamon 2019 Transportation Research Part D. Transport & Enviro Vol.73 No.-

<P><B>Abstract</B></P> <P>This study proposes a vehicle replacement model that considers consumers’ strategic decision-making for the optimal purchase timing of a new vehicle. The model incorporates the effect of the currently owned vehicle (status quo) and future vehicles with different performance and market situations on consumers’ current purchase decisions. By identifying purchase timing, the model endogenously identifies new vehicle buyers for each period and derives the expected sales and stock share of the market. Choice experiments were conducted among 333 South Korean vehicle owners in 2018, and the results were applied to a simulation framework to forecast the future vehicle market (2018–2030). The proposed model showed significantly different results compared to models that ignored the effects of status quo and future vehicles on current purchase decisions. The key findings are as follows. First, consumers tend to prefer the same vehicle type as their status quo vehicle. Second, consumers tend to postpone their purchase of electric vehicles more than they do in the case of conventional vehicles, and they may delay or advance their purchase to the start or end of policies. Finally, market sales expand or shrink based on the existence of and the start or end timing of the policy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The proposed model considers the status quo effect and forward-looking behavior. </LI> <LI> Timing of consumer vehicle replacement is endogenously determined by the model. </LI> <LI> Consumer choice significantly depends on the heterogeneous status quo. </LI> <LI> Consumers may delay or advance their purchase by the start or end of policies. </LI> <LI> Sales vary based on the policy itself and also the timing of its start or end. </LI> </UL> </P>

Lowering customer’s switching cost using B2B services for telecommunication companies

Lee, Hyunsong,Choi, Hyunhong,Koo, Yoonmo Elsevier 2018 Telematics and Informatics Vol.35 No.7

<P><B>Abstract</B></P> <P>A B2B transaction is a transaction between organizations. However, the ripple effects of a B2B transaction can reach the members of the organization and generate additional economic impact. Enterprise LTE (Long term evolution) is a newly introduced B2B service in the South Korean telecommunications market. While it provides secure and fast telecommunications services to businesses, it can also affect the employees’ utility in the business, since the service provider can provide a variety of additional services to employees who use the same telecommunications provider for their mobile devices. In this study, we empirically analyze how B2B and Enterprise LTE services affect consumer churn-in in the telecommunications market. We estimate consumer benefit based on the additional services provided after the introduction of the B2B service using conjoint analysis. We also estimate consumer switching cost for changing one’s mobile telecommunications service provider using contingent valuation method. By comparing these values, we analyze the switching probability of employees when B2B services are introduced at their workplace. The results show that in order to maximize revenue, considering the revenue gained from new subscribers and from fees for providing additional services, lowering service fees for additional services and maximizing market share are advisable.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Consumer churn-in from the introduction of B2B service is possible. </LI> <LI> Free data service provides greater benefits than smartphone interphone and Enterprise messenger services. </LI> <LI> Not charging fees for additional services is advisable to maximize revenue. </LI> <LI> Maximizing market share to maximize revenue is recommended. </LI> </UL> </P>

Estimating the C2C market equilibrium: The case of the carpool market in South Korea

Jiyeon Jung(정지연),Yoonmo Koo(구윤모) 한국혁신학회 2022 한국혁신학회지 Vol.17 No.4

토픽모형을 활용한 산업분류 연구

최현홍(Hyunhong Choi),구윤모(Yoonmo Koo) 한국혁신학회 2020 한국혁신학회지 Vol.15 No.5

국가의 경제 발전을 위한 산업 정책을 수립하기 위해서는 국가 경제의 근간이 되는 산업의 구조를 적절히 파악할 필요가 있다. 산업 구조를 파악함에 있어 가장 중요한 논점 중 하나는 이질적 성격을 가진 산업들을 어떻게 동질적 집단으로 분류할 것인가이다. 현재 여러 나라에서 활용되는 국제표준산업분류는 Fisher-Clark의 분류(1차, 2차, 및 3차 산업)를 기본으로 한다. 그런데, 20세기 중반 Fisher-Clark의 산업 분류가 제시된 지 오랜 시간이 흘렀고, 이에 따라 개별 산업의 성격 및 전반적인 산업 구조가 크게 변화함에 따라 Fisher-Clark의 분류로는 현 국가 산업구조를 적절하게 파악하기에 부족한 측면이 있다. 특히, 경제 수준이 높아짐에 따라 3차 산업 혹은 서비스업의 비중이 주요 선진국의 경우 70~80% 수준까지 비대해져 분류가 가지는 의미가 퇴색하는 문제(분류 내 동질성이 약해지는 문제)가 발생하고 있다. 본 연구에서는 국내 산업 간 투입산출표 자료에 대하여 토픽모형을 적용, 산업 간 투입산출 구조 내에 잠재되어 있는 산업 토픽을 식별하고, 이를 이용하여 각 산업을 설명하는 확률적 접근법을 통해 산업을 분류하였다. 분석 결과, 확률적 접근법을 통하여 산업 분류가 적절하게 이루어질 수 있음을 관찰할 수 있었다. 특히, Fisher-Clark의 산업 분류에 따르면 3차 산업(서비스업)으로 분류되었을 산업들이 그 유형에 따라 다양하게 분류되는 것을 관찰할 수 있었다. 또한, 본 연구는 산업을 설명함에 있어 확률적 접근법을 취함에 따라 기존 선행연구에서 지적한, 단일 산업이 그 안에서 다양한 성격을 복합적으로 가지는 경향을 정량적으로 관찰할 수 있었다. Understanding the industrial structure of a nation is an essential step before designing effective industrial policy for economic growth. One of the most critical issue in understanding a nation’s industrial structure is how to classify heterogeneous industries into homogeneous groups. Most countries utilize the industrial classification system proposed by Fisher and Clark, which classifies the industry into primary, secondary, and tertiary industries. However, as long time has passed since Fisher-Clark’s industry classification system was first proposed in mid 20th century, and characteristics of individual industry and overall industrial structure has changed meanwhile, Fisher-Clark system alone may not be enough to appropriately interpret the industrial structure of a nation. To be specific, proportion of tertiary (service) industry from the whole industry is expanding, especially for developed countries (up to 70~80%). This makes the heterogeneity within classification group rise, and makes the implications from the classification system less significant. This study applied the Korean input-output table data to the topic model to identify latent industrial topic that lies in input-output structure between industries. Then, the study classify individual industry using these industrial topic by taking probabilistic approach. The results show that industrial classification can be appropriately done with probabilistic approach. Industries that may have been classified merely as tertiary (service) industry could be subdivided according to their input and output characteristics. Moreover, this study could empirically analyze the existence of heterogeneous characteristics within individual industry, which was suggested in previous literature.

중공 ZIF를 이용한 RuO₂/h-Co₃O₄ 촉매의 합성 및 산소 발생 반응으로의 활용

구윤모,이영빈,임경민,김진수,Yoonmo Koo,Youngbin Lee,Kyungmin Im,Jinsoo Kim 한국공업화학회 2023 공업화학 Vol.34 No.2

To improve the efficiency of water electrolysis, it is essential to develop an oxygen evolution reaction (OER) electrocatalyst with high performance and long-term stability, accelerating the reaction rate of OER. In this study, a hollow metal-organic framework (MOF)-derived ruthenium-cobalt oxide catalyst was developed to synthesize an efficient OER electrocatalyst. As the synthesized catalyst increases the surface exposure of ruthenium, a low overpotential (386 mV) was observed at a current density of 10 mA/cm² with a low Tafel slope. It is expected to be able to replace noble metal catalysts by showing higher mass activity and stability than commercial RuO₂ catalysts.

디지털 플랫폼에서의 데이터 이동성에 대한 선호 실증분석

정지연 ( Jiyeon Jung ),구윤모 ( Yoonmo Koo ),박유리 ( Yuri Park ) 정보통신정책학회 2021 정보통신정책연구 Vol.28 No.3

본 연구에서는 거대 플랫폼의 데이터 집중을 해결하기 위한 대안으로 최근 활발히 논의되고 있는 데이터 이동성에 대한 이용자의 선호를 이산선택모형을 이용하여 실증분석하였다. 디지털 플랫폼의 다양한 특성을 반영하기 위해 분석 대상으로 검색서비스, 소셜네트워크서비스, 그리고 데이터 기반 맞춤형 모바일 금융 서비스의 세 가지 서비스를 포함하였다. 분석 결과 데이터 이동성에 대해 소비자는 긍정적 선호를 보이는 것으로 나타났고, 특히 소셜네트워크 서비스에서 데이터의 이동에 대한 지불의사가 큰 것으로 나타났으며, 생성 데이터와 추론 데이터가 모두 이동되는 경우를 더 선호하는 것으로 나타났다. 개인특성에 따른 영향을 살펴본 결과, 서비스의 이용시간이나 이용기간은 데이터 이동성 속성에 유의한 영향을 미치지 않았으나 이용집중도는 검색서비스를 제외한 두 디지털 플랫폼 서비스에서 데이터 이동에 부정적 영향을 미치는 것으로 나타났다. 즉, 특정 서비스에 고착된 이용자 일 경우 데이터 이동에 대한 선호가 낮게 나타났다. This study evaluates empirically consumer preferences for data portability, arising as a solution to data concentration on a few large-scale digital platforms. A discrete choice model accounting for individuals' characteristics is used to study preferences for data portability across platforms such as search engines, social networking services and online banking platforms. The results show that users have positive attitudes toward data portability and prefer to be able to transport both observed and inferred data. Among digital platforms, users showed a higher willingness to pay for data portability at social networking services, which are subject to network effects. Users thus have higher preferences for data portability on digital platforms with higher network effects. The frequency and duration of platform use do not affect users' preference for portability significantly. However, users with a higher concentration of usage on fewer search service and online banking platforms (eg. all digital platforms except search engines) - that is, users locked in for a few specific services - have a lower preference for data portability.

Ex-ante Evaluation of Economic Costs from Power Grid Blackout in South Korea

Kim, Chang-Seob,Jo, Manseok,Koo, Yoonmo The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.3

South Korea is recently under serious situation in supplying electricity with enough power reserve. A single fault of power plant at a peak-load time may lead to a total blackout for whole area connected by a single electric grid and isolated from other grids. Despite of the seriousness of blackout, however, there are scarce studies with ex-ante analysis of the economic costs from blackout. In order to evocate the seriousness, we calculate the economic costs for both industrial and household sectors with using some survey data and statistical methodologies. As a result, total economic costs are 39.23 trillion KRW (35.83 trillion KRW for industrial sector, 3.40 trillion KRW for household sector).

Ex-ante Evaluation of Economic Costs from Power Grid Blackout in South Korea

Chang-Seob Kim,Manseok Jo,Yoonmo Koo 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.3

South Korea is recently under serious situation in supplying electricity with enough power reserve. A single fault of power plant at a peak-load time may lead to a total blackout for whole area connected by a single electric grid and isolated from other grids. Despite of the seriousness of blackout, however, there are scarce studies with ex-ante analysis of the economic costs from blackout. In order to evocate the seriousness, we calculate the economic costs for both industrial and household sectors with using some survey data and statistical methodologies. As a result, total economic costs are 39.23 trillion KRW (35.83 trillion KRW for industrial sector, 3.40 trillion KRW for household sector).

Media channels and consumer purchasing decisions

Woo, JongRoul,Ahn, Joongha,Lee, Jongsu,Koo, Yoonmo Emerald Group Publishing Limited 2015 Industrial Management & Data Systems Vol. No.

<P><B>Purpose</B></P> <P> – The purpose of this paper is to explore the factors determining which communication mediums influence a given consumer deciding to purchase a specific product. </P> <P><B>Design/methodology/approach</B></P> <P> – Using a consumer survey and a multivariate probit (MVP) model, the authors explore consumer information searches related to purchases in nine categories: milk, instant noodles, shampoo, mobile phones, televisions, cars, mobile communication services, credit card services, and life insurance. </P> <P><B>Findings</B></P> <P> – The media channels that motivate a given consumer to make a given purchase vary depending on both socio-demographic variables and product categories. </P> <P><B>Practical implications</B></P> <P> – As consumers can now obtain product information through different and multiple media channels according to their personal characteristics and the category of the product they seek to purchase, these findings will help companies develop media planning strategies that will effectively target specific market segments. </P> <P><B>Originality/value</B></P> <P> – Unlike previous studies, the authors consider which media channels actually affect a consumer’s product purchase decisions, and the authors do so across product categories and media types to provide practical implications for media planning. Furthermore, this is the first application of the MVP model in this context.</P>

Symbiosis of Effective Microorganisms

Leesl MOON,KiSeok YOON,SungUng HEO,YoungJun KIM,YoonMo KOO 한국생물공학회 2009 한국생물공학회 학술대회 Vol.2009 No.10