• Korean Journal of Remote Sensing
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• v.36 no.6_2
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• pp.1493-1507
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• 2020

The LEOP Cal/Val (Launch and Early Operation Phase Calibration/Validation) was carried out during 6 months after KOMPSAT-3A (KOMPSAT-3A Korea Multi-Purpose Satellite-3A) was launched in March 2015. After LEOP Cal/Val was successfully completed, high resolution KOMPSAT-3A has been successfully distributing to users over the past 8 years. The sub-meter high-resolution satellite image data obtained from KOMPSAT-3A is used as basic data for qualitative and quantitative information extraction in various fields such as mapping, GIS (Geographic Information System), and national land management, etc. The KARI (Korea Aerospace Research Institute) periodically checks and manages the quality of KOMPSAT-3A's product and the characteristics of satellite hardware to ensure the accuracy and reliability of information extracted from satellite data of KOMPSAT-3A. To minimize the deterioration of image quality due to aging of satellite hardware, payload and attitude sensors of KOMPSAT-3A, continuous improvement of image quality has been carried out. In this paper, the Cal/Val work-flow defined in the KOMPSAT-3A development phase was illustrated for the period of before and after the launch. The MTF, SNR, and location accuracy are the key parameters to estimate image quality and the methods of the measurements of each parameter are also described in this work. On the basis of defined quality parameters, the performance was evaluated and measured during the period of after LEOP Cal/Val. The current status and characteristics of MTF, SNR, and location accuracy of KOMPSAT-3A from 2016 to May 2020 were described as well.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.647-652
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• 2006

본 논문에서는 스마트 홈을 위한 실내 위치 추적 방법을 제안한다. 스마트 홈 환경에서 개인의 상황에 맞는 서비스를 제공하기 위해서 위치는 중요한 정보 중의 하나이며 최근에는 위치 정보를 확장하여 거주자의 행동 정보를 활용하여 거주자의 행동에 따른 서비스를 제공하는 것이 이슈가 되고 있다. 이를 위해서 제안된 적외선 기반 실내 위치 추적 시스템인 ubiTrack은 스마트 홈 내의 거주자로부터 거주자의 행동을 추론하기 위한 여러 컨텍스트 정보를 추출할 수 있다. 제안된 방법은 발신기, 수신기, 그리고 클라이언트 부분으로 나뉜다. 발신기는 천장에 부착되어 있는 적외선 발신기로부터 각각의 아이디를 가진 적외선 신호를 발생한다. 두 개의 적외선 수신 센서로 구성된 수신기는 발신기에서 발신된 아이디를 수신하여 클라언트 부분으로 보낸다. 클라이언트는 이 개별 아이디를 실제 위치정보로 전환하고 이를 활용하여 거주자의 방위와 속력 정보를 추출한다. 추출된 속력 및 방위 정보를 활용하여 거주자의 간단한 행동 정보를 추론할 수 있다. ubiTrack에서 추출된 이러한 정보는 거주자의 최종 행동 정보, 즉 거주자가 TV를 보려는지, 전등을 사용하려는지 등의 정보를 추론하는데 사용될 수 있다. 제안된 방법은 스마트 홈 테스트 베드인 ubiHome에 적용이 되었으며 몇 가지 실험을 통하여 거주자의 행동을 통하여 스마트 홈 환경에서 거주자의 행동을 통한 서비스 제공이 가능함을 보였다.

• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.73-91
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• 2013

Advertising market has been facing new challenges due to dramatic change in advertising channels and the advent of innovative media such as mobile devices. Recent research related to mobile devices is mainly focused on the fact that mobile devices could identify users'physical location in real-time, and this sheds light on how location-based technology is utilized to achieve competitive advantage in advertising market. With the introduction of smartphone, the functionality of smartphone has become much more diverse and context awareness is one of the areas that require further study. This work analyses the influence of context awareness value resulted from the transformation of advertising channel in mobile communication market, and our research result reflects recent trend in advertising market environment which is not considered in previous studies. Many constructs has intensively been studied in the context of advertising channel in traditional marketing environment, and entertainment, irritation and information are considered to be the most widely accepted variables that has positive relationship with advertising value. Also, in smartphone advertisement, four main dimensions of context awareness value are recognized: identification, activity, timing and location. In this study, we assume that these four constructs has positive relationship with context awareness value. Finally, we propose that advertising value and context awareness value positively influence smartphone advertising attitude. Partial Least Squares (PLS) structural model is used in our theoretical research model to test proposed hypotheses. A well designed survey is conducted for college students in Korea, and reliability, convergent validity and discriminant validity of constructs and measurement indicators are carefully evaluated and the results show that reliability and validity are confirmed according to predefined statistical criteria. Goodness-of-fit of our research model is also supported. In summary, the results collectively suggest good measurement properties for the proposed research model. The research outcomes are as follows. First, information has positive impact on advertising value while entertainment and irritation have no significant impact. Information, entertainment and irritation together account for 38.8% of advertising value. Second, along with the change in advertising market due to the advent of smartphone, activity, timing and location have positive impact on context awareness value while identification has no significant impact. In addition, identification, activity, location and time together account for 46.3% of context awareness value. Third, advertising value and context awareness value both positively influence smartphone advertising attitude, and these two constructs explain 31.7% of the variability of smartphone advertising attitude. The theoretical implication of our research is as follows. First, the influence of entertainment and irritation is reduced which are known to be crucial factors according to previous studies related to advertising value, while the influence of information is increased. It indicates that smartphone users are not likely interested in entertaining effect of smartphone advertisement, and are insensitive to the inconvenience due to smartphone advertisement. Second, in today' ubiquitous computing environment, it is effective to provide differentiated advertising service by utilizing smartphone users'context awareness values such as identification, activity, timing and location in order to achieve competitive business advantage in advertising market. For practical implications, enterprises should provide valuable and useful information that might attract smartphone users by adopting differentiation strategy as smartphone users are sensitive to the information provided via smartphone. Also enterprises not only provide useful information but also recognize and utilize smarphone users' unique characteristics and behaviors by increasing context awareness values. In summary, our result implies that smartphone advertisement should be optimized by considering the needed information of smartphone users in order to maximize advertisement effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1412-1417
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• 2012

Building new town 'Pangyo', it is proposed to estalbish a memorial park. But memorial parks are considered as a 'disliked' facilities among people, so its location selection is very difficult to decide. In this study the location possibility is reviewed in two steps through interview with professionals. For selection a location, many components are also checked and evaluated such as natural conditions, technical points and social factors. This study can be helpful to study more location selection for other 'disliked' facilities.

• Asia pacific journal of information systems
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• v.16 no.4
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• pp.239-254
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• 2006

Location-based advertising or application has been one of the drivers of third-generation mobile operators' marketing efforts in the past few years. As a result, many studies on location-based marketing or advertising have been proposed for recent several years. However, these approaches have two common shortcomings. First. most of them just suggested the theoretical architectures, which were too abstract to apply it to the real-world cases. Second, many of these approaches only consider service provider (seller) rather than customers (buyers). Thus, the prior approaches fit to the automated sales or advertising rather than the implementation of CRM. To mitigate these limitations, this study presents a novel advertisement recommendation model for mobile users. We call our model MAR-CF (Mobile Advertisement Recommender using Collaborative Filtering). Our proposed model is based on traditional CF algorithm, but we adopt the multi-dimensional personalization model to conventional CF for enabling location-based advertising for mobile users. Thus, MAR-CF is designed to make recommendation results for mobile users by considering location, time, and needs type. To validate the usefulness of our recommendation model. we collect the real-world data for mobile advertisements, and perform an empirical validation. Experimental results show that MAR-CF generates more accurate prediction results than other comparative models.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.4776-4798
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• 2015

The location selection of virtual machines in distributed cloud is difficult because of the physical resource distribution, allocation of multi-dimensional resources, and resource unit cost. In this study, we propose a multi-object virtual machine location selection algorithm (MOVMLSA) based on group information, doubly linked list structure and genetic algorithm. On the basis of the collaboration of multi-dimensional resources, a fitness function is designed using fuzzy logic control parameters, which can be used to optimize search space solutions. In the location selection process, an orderly information code based on group and resource information can be generated by adopting the memory mechanism of biological immune systems. This approach, along with the dominant elite strategy, enables the updating of the population. The tournament selection method is used to optimize the operator mechanisms of the single-point crossover and X-point mutation during the population selection. Such a method can be used to obtain an optimal solution for the rapid location selection of virtual machines. Experimental results show that the proposed algorithm is effective in reducing the number of used physical machines and in improving the resource utilization of physical machines. The algorithm improves the utilization degree of multi-dimensional resource synergy and reduces the comprehensive unit cost of resources.

• Journal of Information Processing Systems
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• v.10 no.4
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• pp.618-627
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• 2014

Nowadays mobile users are using a popular service called Location-Based Services (LBS). LBS is very helpful for a mobile user in finding various Point of Interests (POIs) in their vicinity. To get these services, users must provide their personal information, such as user identity or current location, which severely risks the location privacy of the user. Many researchers are developing schemes that enable a user to use these LBS services anonymously, but these approaches have some limitations (i.e., either the privacy prevention mechanism is weak or the cost of the solution is too much). As such, we are presenting a robust scheme for mobile users that allows them to use LBS anonymously. Our scheme involves a client side application that interacts with an untrusted LBS server to find the nearest POI for a service required by a user. The scheme is not only efficient in its approach, but is also very practical with respect to the computations that are done on a client's resource constrained device. With our scheme, not only can a client anonymously use LBS without any use of a trusted third party, but also a server's database is completely secure from the client. We performed experiments by developing and testing an Android-based client side smartphone application to support our argument.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.4869-4874
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• 2011

In this paper, we defined constructivism and ontology theory and associate it in Location Based Service ubiquitous learning. And this paper aims to provide a clear vision about location based service (LBS) ubiquitous learning. The typical ubiquitous learning involving the Context Aware Intelligent system was presented. Also the Architecture for learning environment including the key idea and technical concept is being presented in this paper. Guided with these principles and with the advancement of information and communication technology the context-awareness based on Artificial intelligence for Location based Service for ubiquitous Learning was conceptualized. U-learning for Location Based Service is presented here and the concept behind this new learning paradigm. The learning environment architecture which comprises the entire component is illustrated here.

• The Journal of Information Systems
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• v.21 no.2
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• pp.73-96
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• 2012

With emergence of smart technologies(e.g., smartphones), Location-Based Services(LBS) are expected to provide more enhanced values utilizing consumers' personal information than other smart services. However, in contrast to existing smartphone applications, LBS could raised severe consumer's privacy concerns because of rapidly changing information sensitive to consumers. In this context, the purpose of this study is to explore relationships among privacy concerns reduction, trust and intention to use LBS by examining the effect of precedence factors(social presence, reputation, mobile literacy, ability of information control) of privacy concern reduction. In addition, the study investigates the role of personal innovation as a moderating effect between privacy concern reduction and intention to use LBS. The results showed that the proposed precedence factors of privacy concerns with a exception of Mobile Literacy had a positive impact on privacy concerns reduction that then positively affected trust and intention to use LBS. In addition, the relationship between trust and intention to use LBS was significantly supported. Finally, personal innovation as a moderating effect significantly influenced the relationship between privacy concern reduction and intention to use LBS. This study is expected to be a reference for a subsequent study about the spread of LBS application of smartphone. Also, the finding of this study is meaningful for helping service direction to firms providing LBS.

• Journal of KIISE:Databases
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• v.37 no.5
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• pp.250-257
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• 2010

As the variant of skyline query processing, reverse skyline Queries have been studied. However, the existing methods for processing reverse skyline Queries have the limitation of service domains and spend high costs to provide various location-based services. In this paper, we propose a new reverse skyline Query processing method that efficiently processes a query with the objects in metric spaces. In addition, the proposed method also processes continuous reverse skyline queries efficiently. In order to show the superiority of the proposed scheme, we compare it with the previous reverse skyline 벼ery processing scheme in various environments. As a result, the proposed method achieves better performance than the existing method.