• 한국정보시스템학회지:정보시스템연구
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• 제27권1호
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• pp.89-110
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• 2018

Purpose There is much information in customer reviews, but finding key information in many texts is not easy. Business decision makers need a model to solve this problem. In this study we propose a multi-topic sentiment analysis approach using Latent Dirichlet Allocation (LDA) for user-generated contents (UGC). Design/methodology/approach In this paper, we collected a total of 104,039 hotel reviews in seven of the world's top tourist destinations from TripAdvisor (www.tripadvisor.com) and extracted 30 topics related to the hotel from all customer reviews using the LDA model. Six major dimensions (value, cleanliness, rooms, service, location, and sleep quality) were selected from the 30 extracted topics. To analyze data, we employed R language. Findings This study contributes to propose a lexicon-based sentiment analysis approach for the keywords-embedded sentences related to the six dimensions within a review. The performance of the proposed model was evaluated by comparing the sentiment analysis results of each topic with the real attribute ratings provided by the platform. The results show its outperformance, with a high ratio of accuracy and recall. Through our proposed model, it is expected to analyze the customers' sentiments over different topics for those reviews with an absence of the detailed attribute ratings.

• 보건행정학회지
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• 제28권3호
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• pp.263-271
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• 2018

Health technology assessment (HTA) is defined as multidisciplinary policy analysis to look into the medical, economic, social, and ethical implications of the development, distribution, and use of health technology. Following the recent changes in the social environment, there are increasing needs to improve Korea's healthcare environment by, inter alia, assessing health technologies in an organized, timely manner in accordance with the government's strategies to ensure that citizens' medical expenses are kept at a stable level. Dedicated to HTA and research, the National Evidence-based Healthcare Collaborating Agency (NECA) analyzes and provides grounds on the clinical safety, efficacy, and economic feasibility of health technologies. HTA offers the most suitable grounds for decision making not only by healthcare professionals but also by policy makers and citizens as seen in a case in 2009 where research revealed that glucosamine lacked preventive and treatment effects for osteoarthritis and glucosamine was subsequently excluded from the National Health Insurance's benefit list to stop the insurance scheme from suffering financial losses and citizens from paying unnecessary medical expenses. For the development of HTA in Korea, the NECA will continue exerting itself to accomplish its mission of providing policy support by health technology reassessment, promoting the establishment and use of big data and HTA platforms for public interest, and developing a new value-based HTA system.

• 정보보호학회논문지
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• 제26권3호
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• pp.809-820
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• 2016

스마트그리드는 사물인터넷의 핵심 응용서비스이고, 그 중 가장 핵심적인 구성요소인 AMI((Advanced Metering Infrastructure)는 전기사업자와 소비자의 접점에 위치하고 있으며, 스마트 미터는 소비자의 전기사용을 기록하고 사업자에게 전달하는 역할을 한다. 본 논문에서는 스마트그리드에서 소비자와 직접 맞닿아 있는 스마트 미터를 중심으로 AMI에 대한 NESCOR에서 제시하고 있는 사이버공격 및 피해 시나리오를 기반으로 피해비용을 산정한다. 본 연구의 결과는 정책입안자나 전기사업자가 스마트그리드 관련 투자의사결정을 하는데 참고가 될 수 있을 것이다.

• Journal of Public Diplomacy
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• 제1권1호
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• pp.80-110
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• 2021

Public diplomacy (PD) scholars tend to consider two main principals: the country or agent that conducts PD (Actor A), and target groups in the host country in which PD is conducted (Actor B). The field currently lacks theories of how communications between Actors A and B can be disrupted by a third party, such as a group of motivated trolls, an organised advocacy group, or a hostile country and its agents. The purpose of this article is to outline some theoretical considerations for how the PD research field might move away from a two-actor model of PD to one in which disruption is part of the discussion. The case study explores the activities of an interest group called Media Watchdogs of Sweden (MEWAS). MEWAS was a group of around 200 members who met in a hidden Facebook group to coordinate off-platform activities aimed at influencing perceptions of how the Swedish government handled the COVID-19 pandemic in the eyes of foreign governments, researchers, decision-makers, and media. Much critical news coverage in the international press has been linked to this group. Unpacking some of MEWAS' activities, which can be considered a quite typical mixture of legitimate and illegitimate communication techniques used by activist groups, can help to shed light on some difficult questions regarding disruption in PD.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.14-14
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• 2011

Groundwater in the Waikatoregion is a valuable resource for agriculture, water supply, forestry and industries. The 434,000 ha study area comprises the upper Waikato River catchment from the outflow of Lake Taupo (New Zealand's largest lake) through to Lake Karapiro (a man-made hydro lake with high recreational value) (Figure 1). Water quality in the area is naturally high. However, there are indications that this quality is deteriorating as a result of land use intensification and deforestation. Compounding this concern for decision makers is the lag time between land use changes and the realisation of effects on groundwater and surface water quality. It is expected that the effects of land use changes have not yet fully manifested, and additional intensification may take decadesto fully develop, further compounding the deterioration. Consequently, Environment Waikato (EW) have proposed a programme of work to develop a groundwater model to assist managing water quality and appropriate policy development within the catchment. One of the most important and critical decisions of any modelling exercise is the choice of the modelling platform to be used. It must not inhibit future decision making and scenario exploration and needs to allow as accurate representation of reality as feasible. With this in mind, EW requested that two modelling platforms, MODFLOW/MT3DMS and FEFLOW, be assessed for their ability to deliver the long-term modelling objectives for this project. The two platforms were compared alongside various selection criteria including complexity of model set-up and development, computational burden, ease and accuracy of representing surface water-groundwater interactions, precision in predictive scenarios and ease with which the model input and output files could be interrogated. This latter criteria is essential for the thorough assessment of predictive uncertainty with third-party software, such as PEST. This paper will focus on the attributes of each modelling platform and the comparison of the two approaches against the key criteria in the selection process. Primarily due to the ease of handling and developing input files and interrogating output files, MODFLOW/MT3DMS was selected as the preferred platform. Other advantages and disadvantages of the two modelling platforms were somewhat balanced. A preliminary regional groundwater numerical model of the study area was subsequently constructed. The model simulates steady state groundwater and surface water flows using MODFLOW and transient contaminant transport with MT3DMS, focussing on nitrate nitrogen (as a conservative solute). Geological information for this project was provided by GNS Science. Professional peer review was completed by Dr. Vince Bidwell (of Lincoln Environmental).

• 무역학회지
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• 제41권5호
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• pp.285-304
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• 2016

본 연구는 국제무역에 있어서 전자상거래가 중소기업의 성공에 어떠한 영향을 미치는지를, 중국 전자상거래 기업들의 설문조사를 통하여 실증적으로 분석한다. 또한 구조방정식 모형을 통하여 중국 기업의 전자상거래 핵심 성공요인을 추출, 분석하여 중국 중소기업의 전자상거래 발전 핵심요인으로 최고경영자의 혁신성, 최고경영자의 IT지원 및 기업 전략의 세 가지 요인을 통계적으로 유의미하게 도출하였고, 중국 중소기업 맞춤형 해외진출 플랫폼이 필요하다는 정책적 시사점을 함께 제언한다.

• Asia Marketing Journal
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• 제16권1호
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• pp.35-69
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• 2014

The impact of competition on pricing has been studied in the context of counterfactual merger analyses where expected optimal prices in a hypothetical monopoly are compared with observed prices in an oligopolistic market. Such analyses would typically assume static decision making by consumers and firms and thus have been applied mostly to data obtained from consumer packed goods such as cereal and soft drinks. However such static modeling approach is not suitable when decision makers are forward looking. When it comes to the markets for durable products with indirect network effects, consumer purchase decisions and firm pricing decisions are inherently dynamic as they take into account future states when making purchase and pricing decisions. Researchers need to take into account the dynamic aspects of decision making both in the consumer side and in the supplier side for such markets. Firms in a two-sided market typically subsidize one side of the market to exploit the indirect network effect. Such pricing behaviors would be more prevalent in competitive markets where firms would try to win over the battle for standard. While such qualitative expectation on the relationship between pricing behaviors and competitive structures could be easily formed, little empirical studies have measured the extent to which the distinct pricing structure in two-sided markets depends on the competitive structure of the market. This paper develops an empirical model to measure the impact of competition on optimal pricing of durable products under indirect network effects. In order to measure the impact of exogenously determined competition among firms on pricing, we compare the equilibrium prices in the observed oligopoly market to those in a hypothetical monopoly market. In computing the equilibrium prices, we account for the forward looking behaviors of consumers and supplier. We first estimate a demand function that accounts for consumers' forward-looking behaviors and indirect network effects. And then, for the supply side, the pricing equation is obtained as an outcome of the Markov Perfect Nash Equilibrium in pricing. In doing so, we utilize numerical dynamic programming techniques. We apply our model to a data set obtained from the U.S. video game console market. The video game console market is considered a prototypical case of two-sided markets in which the platform typically subsidizes one side of market to expand the installed base anticipating larger revenues in the other side of market resulting from the expanded installed base. The data consist of monthly observations of price, hardware unit sales and the number of compatible software titles for Sony PlayStation and Nintendo 64 from September 1996 to August 2002. Sony PlayStation was released to the market a year before Nintendo 64 was launched. We compute the expected equilibrium price path for Nintendo 64 and Playstation for both oligopoly and for monopoly. Our analysis reveals that the price level differs significantly between two competition structures. The merged monopoly is expected to set prices higher by 14.8% for Sony PlayStation and 21.8% for Nintendo 64 on average than the independent firms in an oligopoly would do. And such removal of competition would result in a reduction in consumer value by 43.1%. Higher prices are expected for the hypothetical monopoly because the merged firm does not need to engage in the battle for industry standard. This result is attributed to the distinct property of a two-sided market that competing firms tend to set low prices particularly at the initial period to attract consumers at the introductory stage and to reinforce their own networks and eventually finally to dominate the market.

• 통상정보연구
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• 제15권2호
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• pp.109-128
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• 2013

콘텐츠산업의 성장과 함께 국내 문화콘텐츠의 해외 진출이 활발하게 이루어지고 있다. 하지만, 좋은 성과를 내고 있는 게임, 음악, 영화 등의 분야와는 달리 교육콘텐츠의 경우 해외 시장에서 유의미한 성과를 내지 못하고 있다. 이에, 본 연구에서는 성공적인 교육콘텐츠의 해외 진출 사례로 C연구소의 G러닝 미국 공교육 진출 사례를 살펴보고자 한다. 본 사례에서 C연구소는 많은 어려움을 극복하고 LA라발로나 초등학교에서 5학년 정규 과정 G러닝 수학수업을 진행하고 학생들의 성적을 향상시켰다. 본 사례의 분석을 통해 이러한 성공이 가능했던 이유에 대한 전략적 시사점을 다음과 같이 제시할 수 있었다. 첫째, 제품의 차별성이고, 둘째, 현지 인력을 중심으로 지원조직을 구성하여 현지 인적 네트워크를 효율적으로 활용할 수 있었으며, 셋째, 지속적인 커뮤니케이션을 통한 정보 공유를 통해 연쇄적인 설득과정을 유도할 수 있었다.

• 대한원격탐사학회지
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• 제36권1호
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• pp.15-27
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• 2020

Accurate knowledge of land use/land cover (LULC) features and their relative changes over upon the time are essential for sustainable urban management. Urban sprawl growth has been always also a worldwide concern that needs to carefully monitor particularly in a developing country where unplanned building constriction has been expanding at a high rate. Recently, remotely sensed imageries with a very high spatial/spectral resolution and state of the art machine learning approaches sent the urban classification and growth monitoring to a higher level. In this research, we classified the Quickbird satellite imagery by object-based image analysis of Dempster-Shafer (OBIA-DS) for the years of 2002 and 2015 at Karbala-Iraq. The real LULC changes including, residential sprawl expansion, amongst these years, were identified via change detection procedure. In accordance with extracted features of LULC and detected trend of urban pattern, the future LULC dynamic was simulated by using land transformation model (LTM) in geospatial information system (GIS) platform. Both classification and prediction stages were successfully validated using ground control points (GCPs) through accuracy assessment metric of Kappa coefficient that indicated 0.87 and 0.91 for 2002 and 2015 classification as well as 0.79 for prediction part. Detail results revealed a substantial growth in building over fifteen years that mostly replaced by agriculture and orchard field. The prediction scenario of LULC sprawl development for 2030 revealed a substantial decline in green and agriculture land as well as an extensive increment in build-up area especially at the countryside of the city without following the residential pattern standard. The proposed method helps urban decision-makers to identify the detail temporal-spatial growth pattern of highly populated cities like Karbala. Additionally, the results of this study can be considered as a probable future map in order to design enough future social services and amenities for the local inhabitants.

• 지능정보연구
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• 제29권1호
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• pp.79-105
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• 2023

지구온난화와 기후변화 등의 유례없는 기상이변으로 전 세계 곳곳이 극심한 몸살을 앓고 있으며, 경제적 손실 또한 눈덩이처럼 불어나고 있다. 이러한 문제를 해결하기 위해 2016년 '파리기후변화협정(The Paris Agreement)'이 체결되어 지구의 평균온도 상승을 1.5℃ 아래로 유지하기 위한 정부간 협의체가 결성되었으며, 우리나라도 2050년 탄소중립을 선언함으로써 기후재앙을 막기 위한 노력을 진행하고 있다. 특히, 온실가스 배출로 인한 기온상승은 수출 의존도가 높은 우리나라 경제는 물론 환경과 사회 전반에 부정적인 영향을 미칠 것으로 예상된다. 또한, 교통수단의 다변화가 가속화되면서 수단선택의 변화도 크게 증가하고 있는 가운데 저성장 시대의 개발 패러다임이 도시재생으로 변화함에 따라, 노선의 수요 감소, 선형 개량, 도심 철도의 외곽 이설 등에 영향을 받아 증가하고 있는 철도 유휴부지 활용에 대한 관심이 높아지고 있다. 한편, 철도 유휴부지를 활용한 태양광발전은 '재생에너지 3020'의 태양광발전 목표를 일부 달성하면서도, 입지를 둘러싼 환경훼손과 주민 수용성 문제에서 자유로워질 수 있는 장점에도 불구하고, 설비실태나 설비계획에 있어 미진한 상황이다. 이에, 본 연구에서는 국가철도공단과 재생에너지클라우드플랫폼에서 제공하는 데이터를 활용하여 태양광발전 설비 설치가 가능한 적합 유휴지를 발굴 및 분석하는 알고리즘을 개발하고, 사용자가 원하는 조건을 고려한 잠재적인 적합 지역을 탐색 및 도출함으로써, 개발 초기 설비나 확충 등에 소요되는 막대한 비용을 절약할 수 있는 방안을 마련하고자 하였다. 본 연구는 다양한 군집분석을 활용하여 철도 유휴부지에 태양광발전 설치입지를 도출할 수 있는 최적의 알고리즘을 개발하고, 면적, 설치용량, 발전량, 예상수익 등이 모두 높은 '태양광발전 설치 적극권장 지역' 202곳을 도출하였다. 이를 바탕으로 경제와 환경을 동시에 고려한 관점에서 의사결정자의 합리적인 판단을 도울 수 있을 것으로 기대한다.