• Asia pacific journal of information systems
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• 제20권2호
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• pp.63-86
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• 2010

Personalized services directly and indirectly acquire personal data, in part, to provide customers with higher-value services that are specifically context-relevant (such as place and time). Information technologies continue to mature and develop, providing greatly improved performance. Sensory networks and intelligent software can now obtain context data, and that is the cornerstone for providing personalized, context-specific services. Yet, the danger of overflowing personal information is increasing because the data retrieved by the sensors usually contains privacy information. Various technical characteristics of context-aware applications have more troubling implications for information privacy. In parallel with increasing use of context for service personalization, information privacy concerns have also increased such as an unrestricted availability of context information. Those privacy concerns are consistently regarded as a critical issue facing context-aware personalized service success. The entire field of information privacy is growing as an important area of research, with many new definitions and terminologies, because of a need for a better understanding of information privacy concepts. Especially, it requires that the factors of information privacy should be revised according to the characteristics of new technologies. However, previous information privacy factors of context-aware applications have at least two shortcomings. First, there has been little overview of the technology characteristics of context-aware computing. Existing studies have only focused on a small subset of the technical characteristics of context-aware computing. Therefore, there has not been a mutually exclusive set of factors that uniquely and completely describe information privacy on context-aware applications. Second, user survey has been widely used to identify factors of information privacy in most studies despite the limitation of users' knowledge and experiences about context-aware computing technology. To date, since context-aware services have not been widely deployed on a commercial scale yet, only very few people have prior experiences with context-aware personalized services. It is difficult to build users' knowledge about context-aware technology even by increasing their understanding in various ways: scenarios, pictures, flash animation, etc. Nevertheless, conducting a survey, assuming that the participants have sufficient experience or understanding about the technologies shown in the survey, may not be absolutely valid. Moreover, some surveys are based solely on simplifying and hence unrealistic assumptions (e.g., they only consider location information as a context data). A better understanding of information privacy concern in context-aware personalized services is highly needed. Hence, the purpose of this paper is to identify a generic set of factors for elemental information privacy concern in context-aware personalized services and to develop a rank-order list of information privacy concern factors. We consider overall technology characteristics to establish a mutually exclusive set of factors. A Delphi survey, a rigorous data collection method, was deployed to obtain a reliable opinion from the experts and to produce a rank-order list. It, therefore, lends itself well to obtaining a set of universal factors of information privacy concern and its priority. An international panel of researchers and practitioners who have the expertise in privacy and context-aware system fields were involved in our research. Delphi rounds formatting will faithfully follow the procedure for the Delphi study proposed by Okoli and Pawlowski. This will involve three general rounds: (1) brainstorming for important factors; (2) narrowing down the original list to the most important ones; and (3) ranking the list of important factors. For this round only, experts were treated as individuals, not panels. Adapted from Okoli and Pawlowski, we outlined the process of administrating the study. We performed three rounds. In the first and second rounds of the Delphi questionnaire, we gathered a set of exclusive factors for information privacy concern in context-aware personalized services. The respondents were asked to provide at least five main factors for the most appropriate understanding of the information privacy concern in the first round. To do so, some of the main factors found in the literature were presented to the participants. The second round of the questionnaire discussed the main factor provided in the first round, fleshed out with relevant sub-factors. Respondents were then requested to evaluate each sub factor's suitability against the corresponding main factors to determine the final sub-factors from the candidate factors. The sub-factors were found from the literature survey. Final factors selected by over 50% of experts. In the third round, a list of factors with corresponding questions was provided, and the respondents were requested to assess the importance of each main factor and its corresponding sub factors. Finally, we calculated the mean rank of each item to make a final result. While analyzing the data, we focused on group consensus rather than individual insistence. To do so, a concordance analysis, which measures the consistency of the experts' responses over successive rounds of the Delphi, was adopted during the survey process. As a result, experts reported that context data collection and high identifiable level of identical data are the most important factor in the main factors and sub factors, respectively. Additional important sub-factors included diverse types of context data collected, tracking and recording functionalities, and embedded and disappeared sensor devices. The average score of each factor is very useful for future context-aware personalized service development in the view of the information privacy. The final factors have the following differences comparing to those proposed in other studies. First, the concern factors differ from existing studies, which are based on privacy issues that may occur during the lifecycle of acquired user information. However, our study helped to clarify these sometimes vague issues by determining which privacy concern issues are viable based on specific technical characteristics in context-aware personalized services. Since a context-aware service differs in its technical characteristics compared to other services, we selected specific characteristics that had a higher potential to increase user's privacy concerns. Secondly, this study considered privacy issues in terms of service delivery and display that were almost overlooked in existing studies by introducing IPOS as the factor division. Lastly, in each factor, it correlated the level of importance with professionals' opinions as to what extent users have privacy concerns. The reason that it did not select the traditional method questionnaire at that time is that context-aware personalized service considered the absolute lack in understanding and experience of users with new technology. For understanding users' privacy concerns, professionals in the Delphi questionnaire process selected context data collection, tracking and recording, and sensory network as the most important factors among technological characteristics of context-aware personalized services. In the creation of a context-aware personalized services, this study demonstrates the importance and relevance of determining an optimal methodology, and which technologies and in what sequence are needed, to acquire what types of users' context information. Most studies focus on which services and systems should be provided and developed by utilizing context information on the supposition, along with the development of context-aware technology. However, the results in this study show that, in terms of users' privacy, it is necessary to pay greater attention to the activities that acquire context information. To inspect the results in the evaluation of sub factor, additional studies would be necessary for approaches on reducing users' privacy concerns toward technological characteristics such as highly identifiable level of identical data, diverse types of context data collected, tracking and recording functionality, embedded and disappearing sensor devices. The factor ranked the next highest level of importance after input is a context-aware service delivery that is related to output. The results show that delivery and display showing services to users in a context-aware personalized services toward the anywhere-anytime-any device concept have been regarded as even more important than in previous computing environment. Considering the concern factors to develop context aware personalized services will help to increase service success rate and hopefully user acceptance for those services. Our future work will be to adopt these factors for qualifying context aware service development projects such as u-city development projects in terms of service quality and hence user acceptance.

• 한국통신학회논문지
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• 제42권2호
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• pp.514-522
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• 2017

트래픽 오프로딩은 폭발적으로 증가하는 모바일 트래픽에 대응하기 위한 유망 솔루션이다. 오프로딩 방법 중, LIPA/SIPTO 오프로딩에서는 애플리케이션의 QoS 요구사항을 만족하면서 트래픽을 오프로딩할 수 있다. 또한, SNS로 인한 많은 트래픽때문에 social context를 이용한 트래픽 오프로딩이 필요하다. 그러므로, 본 논문에서는 social context를 이용하여 트래픽을 오프로딩하는 LIPA/SIPTO 오프로딩 알고리즘을 제안한다. 먼저, 애플리케이션 인기도를 social context로 이용하여 애플리케이션 선택확률을 정의한다. 그 다음, effective data rate 관점에서 소형셀 사용자의 QoS를 최대화하는 최적의 오프로딩 weighting factor를 찾는다. 마지막으로, 애플리케이션 선택확률과 오프로딩 weighting factor를 기반으로 각 애플리케이션의 오프로딩 비율을 정한다. 성능분석 결과, 제안한 알고리즘의 오프로딩 비율이 기존 알고리즘의 약 46%임에도 불구하고, 제안한 알고리즘의 effective data rate achievement ratio 값이 기존 알고리즘과 비슷한 것을 확인하였다.

• Asia pacific journal of information systems
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• 제18권3호
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• pp.123-145
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• 2008

Recently, as the information communication technology develops, the discussion regarding the ubiquitous environment is occurring in diverse perspectives. Ubiquitous environment is an environment that could transfer data through networks regardless of the physical space, virtual space, time or location. In order to realize the ubiquitous environment, the Pervasive Sensing technology that enables the recognition of users' data without the border between physical and virtual space is required. In addition, the latest and diversified technologies such as Context-Awareness technology are necessary to construct the context around the user by sharing the data accessed through the Pervasive Sensing technology and linkage technology that is to prevent information loss through the wired, wireless networking and database. Especially, Pervasive Sensing technology is taken as an essential technology that enables user oriented services by recognizing the needs of the users even before the users inquire. There are lots of characteristics of ubiquitous environment through the technologies mentioned above such as ubiquity, abundance of data, mutuality, high information density, individualization and customization. Among them, information density directs the accessible amount and quality of the information and it is stored in bulk with ensured quality through Pervasive Sensing technology. Using this, in the companies, the personalized contents(or information) providing became possible for a target customer. Most of all, there are an increasing number of researches with respect to recommender systems that provide what customers need even when the customers do not explicitly ask something for their needs. Recommender systems are well renowned for its affirmative effect that enlarges the selling opportunities and reduces the searching cost of customers since it finds and provides information according to the customers' traits and preference in advance, in a commerce environment. Recommender systems have proved its usability through several methodologies and experiments conducted upon many different fields from the mid-1990s. Most of the researches related with the recommender systems until now take the products or information of internet or mobile context as its object, but there is not enough research concerned with recommending adequate store to customers in a ubiquitous environment. It is possible to track customers' behaviors in a ubiquitous environment, the same way it is implemented in an online market space even when customers are purchasing in an offline marketplace. Unlike existing internet space, in ubiquitous environment, the interest toward the stores is increasing that provides information according to the traffic line of the customers. In other words, the same product can be purchased in several different stores and the preferred store can be different from the customers by personal preference such as traffic line between stores, location, atmosphere, quality, and price. Krulwich(1997) has developed Lifestyle Finder which recommends a product and a store by using the demographical information and purchasing information generated in the internet commerce. Also, Fano(1998) has created a Shopper's Eye which is an information proving system. The information regarding the closest store from the customers' present location is shown when the customer has sent a to-buy list, Sadeh(2003) developed MyCampus that recommends appropriate information and a store in accordance with the schedule saved in a customers' mobile. Moreover, Keegan and O'Hare(2004) came up with EasiShop that provides the suitable tore information including price, after service, and accessibility after analyzing the to-buy list and the current location of customers. However, Krulwich(1997) does not indicate the characteristics of physical space based on the online commerce context and Keegan and O'Hare(2004) only provides information about store related to a product, while Fano(1998) does not fully consider the relationship between the preference toward the stores and the store itself. The most recent research by Sedah(2003), experimented on campus by suggesting recommender systems that reflect situation and preference information besides the characteristics of the physical space. Yet, there is a potential problem since the researches are based on location and preference information of customers which is connected to the invasion of privacy. The primary beginning point of controversy is an invasion of privacy and individual information in a ubiquitous environment according to researches conducted by Al-Muhtadi(2002), Beresford and Stajano(2003), and Ren(2006). Additionally, individuals want to be left anonymous to protect their own personal information, mentioned in Srivastava(2000). Therefore, in this paper, we suggest a methodology to recommend stores in U-market on the basis of ubiquitous environment not using personal information in order to protect individual information and privacy. The main idea behind our suggested methodology is based on Feature Matrices model (FM model, Shahabi and Banaei-Kashani, 2003) that uses clusters of customers' similar transaction data, which is similar to the Collaborative Filtering. However unlike Collaborative Filtering, this methodology overcomes the problems of personal information and privacy since it is not aware of the customer, exactly who they are, The methodology is compared with single trait model(vector model) such as visitor logs, while looking at the actual improvements of the recommendation when the context information is used. It is not easy to find real U-market data, so we experimented with factual data from a real department store with context information. The recommendation procedure of U-market proposed in this paper is divided into four major phases. First phase is collecting and preprocessing data for analysis of shopping patterns of customers. The traits of shopping patterns are expressed as feature matrices of N dimension. On second phase, the similar shopping patterns are grouped into clusters and the representative pattern of each cluster is derived. The distance between shopping patterns is calculated by Projected Pure Euclidean Distance (Shahabi and Banaei-Kashani, 2003). Third phase finds a representative pattern that is similar to a target customer, and at the same time, the shopping information of the customer is traced and saved dynamically. Fourth, the next store is recommended based on the physical distance between stores of representative patterns and the present location of target customer. In this research, we have evaluated the accuracy of recommendation method based on a factual data derived from a department store. There are technological difficulties of tracking on a real-time basis so we extracted purchasing related information and we added on context information on each transaction. As a result, recommendation based on FM model that applies purchasing and context information is more stable and accurate compared to that of vector model. Additionally, we could find more precise recommendation result as more shopping information is accumulated. Realistically, because of the limitation of ubiquitous environment realization, we were not able to reflect on all different kinds of context but more explicit analysis is expected to be attainable in the future after practical system is embodied.

• 한국통신학회논문지
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• 제36권4B호
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• pp.354-361
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• 2011

스마트 홈 분야에 대한 관심의 증가와 기술적인 발전은 상황인지 서비스와 베이시안 네트워크 알고리즘, 트리 구조 알고리즘 그리고 유전자 추측 알고리즘과 같은 예측 알고리즘에 대한 연구가 활발히 이루어지고 있다. 상황 인지 서비스는 개별적인 사용자의 패턴을 고려한 맞춤형 서비스를 제공하는 것은 사용자의 삶의 질을 향상시키는 데 도움 주는 것을 의미한다. 하지만 상황인지 서비스를 구현 하는 것은 상황정보와의 부합성 문제와 예외적인 상황 처리가 고려하는데 어려움을 겪고 있다. 이 문제를 해결하기 위해서, 본 연구에서는 지능형 순차적 매칭 방식 알고리즘(Intelligent Sequential Matching Algorithm : ISMA)을 제안하고, 페트리 넷에 시간 개념을 추가하여 시간 페트리 넷(Timed Petri-net : TPN)으로 모델링한다. 제안한 지능형 순차적 매칭 알고리즘의 유효성을 증명하기 위하여 시나리오를 제시하고, 그것을 모델링 한다. 또한 동일한 실험 조건 아래, 기존의 예측 알고리즘과 비교를 통하여 과 제안된 알고리즘의 예측 정확도가 4~6% 우수함을 보인다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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• pp.281-285
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• 2000

This paper proposes context-based coding methods for variable length coding of inter-frame DCT coefficients. The proposed methods classify run-level symbols depending on the preceding coefficients. No extra overhead needs to be transmitted, since the information of the previously transmitted coefficients is used for classification. Two entropy coding methods, arithmetic coding and Huffman coding, are used for the proposed context-based coding. For Huffman coding, there is no complexity increase from the current standards by using the existing inter/intra VLC tables. Experimental results show that the proposed methods give ～ 19% bits gain and ～ 0.8 dB PSNR improvement for adaptive inter/intra VLC table selection, and ～ 37% bits gain and ～ 2.7dB PSNR improvement for arithmetic coding over the current standards, MPEG-4 and H.263. Also, the proposed methods obtain larger gain for small quantizaton parameters and the sequences with fast and complex motion. Therefore, for high quality video coding, the proposed methods have more advantage.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.97-99
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• 2013

Various display devices become widespread now. Endeavoring to provide high-quality user experience, sharing contents becomes a hot issue in recent years. In this paper, a Contents Sharing System based on Users Context is proposed, which can provide pervasive contents sharing services on multiple devices with disregard for the device differences. This system supporting automatical contents sharing according to users' context, and intelligent content-fault recovery to provide an intelligent platform for users sharing service seamlessly without additional manual operations. Also we points out the problems and considerations about this proposed system which will be improved in the later research.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.547-549
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• 2010

본 논문에서는 실내 환경에서 반도체 장비 주변에 배치된 다수의 센서로부터 정보를 취득하고 취득된 정보를 바탕으로 반도체 장비의 상황을 인지하는 시스템을 제안한다. 제안하는 반도체 장비 상황인지 시스템은 가속도, 압력, 온도, 가스 센서로부터 정보를 취득하고 서버로 전송한다. 그리고 서버로 전송된 데이터는 단일이벤트와 다중이벤트의 상황인지 알고리즘을 통해 알람을 발생시킨다. 그 결과 불필요한 알람이 줄어 수준 높은 실시간 감시가 가능하고 주위의 정보를 한 번에 알 수 있어 효율적인 관리가 가능하다.

• 한국IT서비스학회지
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• 제13권1호
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• pp.1-21
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• 2014

In IT service quality research, the relationship between the service quality and clients' satisfaction was the focus of many studies while in relationship quality research, the influence of trust and conflict on relationship commitment seems to be the focus. In this study, these two research streams are integrated and a theoretical research model is proposed consisting of IT service quality, satisfaction, trust and relationship commitment with conflict as a moderator for the overall psychological mechanism. As satisfaction represents emotional response while trust cognitive response, this research model integrated both emotional and cognitive aspects of relationship maintenance in the IT service context. Analysis of data collected from 262 employees of global IT service firm revealed the differential effects of reliability, responsiveness, assurance and empathy on satisfaction and trust. Also, depending upon the level of conflict, the effects of reliability and assurance were found to be moderated. Further analysis revealed more profound mechanism at work relating emotional and cognitive aspects in the psychology of relationship maintenance in IT service context. Practical implications are further discussed in the conclusion.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2008년도 춘계학술대회
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• pp.1072-1077
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• 2008

This study is aimed at proposing a new approach to designing UDSS (Ubiquitous Decision Support System) which allows context-awareness and connectivity. In the previous studies, the need to design UDSS and analyze its performance empirically was raised. However, due to the complexity of empirical approaches, there is no study attempting to tackle this research issue so far. To fill this research void, this study proposes a Mobile Delivery System (MDS) as a form of UDSS, empirically analyzing how users perceive its context-awareness and connectivity functions. Especially, to add more rigor to the proposed approach to know how much it works well in the decision-making contexts, we considered three decision making phases (intelligence, design, choice) in the research model. With the valid questionnaires collected from 340 users of the MDS, we induced statistically proven results showing that both context-awareness and connectivity of the proposed UDSS (or MDS) influence the decision making steps positively and then contribute to improving the decision making quality.

• 한국ITS학회 논문지
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• 제10권3호
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• pp.95-100
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• 2011

정보통신 기술의 급속한 성장 및 발전에 따라 유비쿼터스 네트워크 컴퓨팅 및 이용자 맞춤 서비스에 대한 관심이 증폭되고 있다. 또한 최근 스마트폰(Smartphone)을 매개체로 모바일 관련 기술들이 급속도로 발전하며 큰 각광을 받고 있다. 이러한 환경 및 인프라의 발전에 따라 최근 모바일에서 각 종 정보 및 서비스를 제공하는 다양한 응용소프트웨어들이 출시되고 있는 추세이나 그 대부분이 공급자 위주의 정보시스템으로 단순히 다량의 정보들을 불특정 다수의 이용자들에게 제공하는데 목적을 두고 있으며 이용자 개개인에 대한 맞춤화 혹은 개인화된 정보 및 서비스의 제공은 거의 이루어지지 않고 있다. 이에 따라 본 연구에서는 모바일환경에서 개인화 및 맞춤화를 위한 추천시스템을 설계 및 구현 한다. 각 종 정보필터링 기법의 장점만을 결합한 하이브리드 필터링(Hybrid Filtering)을 이용하여 추천 시스템을 구성하며 추천의 질을 향상시키기 위해 정보 필터링 단계에 앞서 사용자의 목적행위, 위치의 상황정보(Context-information)를 이용하여 추천대상 아이템의 범위를 결정함으로써 이용자 상황에 따른 효과적인 정보의 추천을 가능하도록 한다.