• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1331-1332
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• 2015

본 논문은 CAN(Controller Area Network) 통신의 WCRT(Worst Case Response Time) 분석을 통해 IEEE1212 기반 RTU(Remote Terminal Unit)의 통신 신뢰성을 검증한다. RTU는 원격지에서 네트워크를 구성하여 각 모듈들로부터 획득한 정보를 서버로 전송하거나 원격지를 제어하는 역할을 한다. 본 논문에서 대상으로 하는 RTU의 네트워크는 물리계층과 데이터링크 계층은 CAN을 사용하고 응용계층은 IEEE1212 기반으로 통신한다. 즉, RTU를 구성하는 모듈은 각각메모리 영역을 가지고 있고, CAN ID에 메모리 주소를 포함하여 해당 영역을 쓰는 구조로 통신을 한다. 첫 번째로 이러한 응용계층을 고려하여 WCRT를 계산하는 방법을 제시하고, 두 번째로 CAN 메시지의 우선 순위를 최적화하는 방법을 고찰한다. 마지막으로 시험 환경을 구축하고 시뮬레이션을 통해 앞에서 선정한 우선순위에 따라 통신 신뢰성을 검증한다.

• Information Systems Review
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• v.20 no.2
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• pp.163-188
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• 2018

When people try to find restaurant information via search engine results, they look at posts not only from sites with solely restaurant reviews but also from sites with restaurant unrelated contents. This study aims to investigate whether relevance between post and blog type affects users' trust toward a review. This study also attempts to check if the above effects interact with age. We designed a restaurant review post for two different blogs: one featuring restaurant review and another that does not feature restaurant reviews. After our participants visited one restaurant review post, they answered our questionnaire. We conducted an online survey on 206 participants to test our research model. Results show that 1) the effect of relevance between post and blog type on message credibility, which is users' trust toward restaurant reviews, is not greater when posts are consistent with the theme of a blog. 2) Among users who are over 30 years old, relevance between post and blog type moderates the relationship between media skepticism, which is users' feeling of mistrust toward blog, and belief in expertise, that is, users' belief that the review post provides sufficient restaurant information. 3) Users' perceived value of the restaurant review post mediates the relationship between users' belief in the expertise in a post and users' intention to seek additional information.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.387-392
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• 2008

위치 기반 라우팅은 오직 지역적인 위치 정보를 기반으로 데이터를 전송한다. 이 기법은 소스가 목적지의 위치 정보를 알고 있다고 가정하면 에너지 효율적이고 단순하다. 그러나, 무선 센서 망에서 소스는 목적지인 싱크의 위치 정보를 알지 못한다. 따라서 위치 기반 라우팅의 장점을 살리기 위해서는 소스가 효율적으로 싱크의 위치 정보를 미리 획득하는 과정이 필요하다. 본 논문은 무선망에서 싱크의 위치정보 획득을 위한 제한적인 선형 플러딩 방안을 제안한다. 제안 방안에서 싱크와 소스는 각각 싱크 위치 획득을 위한 메시지를 정해진 방향으로 전송하며 두 메시지의 교차 지점에 위치한 노드는 소스에게 싱크의 위치 정보를 전송한다. 싱크의 위치 정보를 획득한 소스는 위치 기반 라우팅을 통해 싱크에게 데이터를 전송할 수 있다. 또한 망 내부에 가상 제한 플러딩 지역 구성이라는 추가 방안을 통해 두 메시지의 교차 지점 생성을 보장한다. 우리는 시뮬레이션을 통해 제안 방안이 지금까지의 방안보다 에너지 면에서 효율적이며 신뢰성 있다는 것을 증명한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.677-680
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• 2015

In this paper, we propsed scheme to mitigate conflict and loss of message in vehicle communication. And vehicles that exist in the moving direction, were grouping to the cluster form. Through, to select best relay vehicle, transmit a message to the destination. In addition, we applied the double rayleigh fading environment so that can applied in real-environments. Therefore, vehicle communication network applied proposed scheme, can be problem of mitigate conflict and loss of message. Thus, Increase the reliability of the received signal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.10
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• pp.1117-1130
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• 1992

In this study, we propose a protocol for the communication between process groups required during message transfers. This is accomplished by an efficient process management of distributed systems connected by computer networks. For a single process group, a multicast protocol was proposed, which can control message flows while maintaining the order of messages sent or delivered. Through use of membership-related services, a member composing a process group may leave and join the current a membership anytime during execution. Moreover, message delivery can be delayed by using a logical vector time stamp. The functionality of the message delivery includes a virtual synchronization in response to a change in membership.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.3
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• pp.47-54
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• 2016

In this paper, we propose a new opportunistic routing scheme based on timed bargaining game. The proposed algorithm effectively formulates the opportunistic routing mechanism as an repeated bargaining model using timed learning method. Additionally, we formulate a new contention window adjusting scheme for reduce collision rate. Simulation results indicate that the proposed scheme has excellent performance than other existing schemes under widely diverse VANET environments.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.53-62
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• 2010

In VANETs (Vehicular Ad hoc NETwork), conditional anonymity must be provided to protect privacy of vehicles while enabling authorities to identify misbehaving vehicles. To this end, previous systems provide a mechanism to revoke the anonymity of individual messages. In VANET, if we can trace the movement path of vehicles, it can be useful in determining the liability of vehicles in car accidents and crime investigations. Although route tracing can be provided using previous message revocation techniques, they violate privacy of other vehicles. In this paper, we provide a route tracing technique that protects privacy of vehicles that are not targeted. The proposed method can be employed independently of the authentication mechanism used and includes a mechanism to prevent authorities from abusing this new function.

• Korean journal of communication and information
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• v.32
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• pp.209-245
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• 2006

This study examines primarily the effects of perceived risk and scarcity massage on consumers in CATV homeshopping. For consumers, the perceived risk is the cause of delaying purchase decision in CATV Homeshopping while scarcity message in the Ad facilitate purchasing intention in the CATV homeshopping. And another important characteristic of consumer which exerts impact on the response of consumer to the Ad and the product is the frequency of purchasing experience. Thus the purpose of this study is to test the effect of 3 factors on consumer's response to homeshopping Ad and product: one is perceived risk, another is scarcity message and the third is consumer's difference in purchasing. And these are defined as independent variables. The responses of the consumer, the dependent variables of this test are measured in three dimensions; 1) the purchasing intention of the product, 2) the attitude toward the Ad, and 3) the attitude toward product of the consumer. 110 housewives are sampled and assigned to 4 experimental groups. All the groups first watched a video-taped homeshopping Ad messages, and then filled up their responses on the administered questionnaire. The results of this study shows as follows: 1) Perceived risk has negative effect to consumer response. 2) Scarcity message has positive effect to consumers response. 3) But especially perceived risk has negative effect to high frequency purchasing experience group. 4) Scarcity message has also negative effect to high frequency purchasing experience group. 5) The interaction effect of perceived risk and scarcity message is most prominent to the consumers of high frequent purchasing experience.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.75-87
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• 2010

Secure communication has been one of the main challenges in vehicular ad hoc networks(VANET) since broadcast messages from nearby vehicles contain life-critical information for drivers and passengers. So far various secure communication schemes have been proposed to secure the communication in VANET, and they satisfy most security requirements. However most of them need to put trust on roadside units(RSUs), which are usually deployed in unattended area and vulnerable to compromise. In this paper, we propose a secure communication scheme, which does not need to put trust on RSUs. And we adopt a grouping technique to averagely divide the huge burden in the server without jeopardizing the anonymity of users. Moreover we design a complete set of protocols to satisfy common security requirements with a relatively lower hardware requirement. At last, we evaluate the scheme with respect to security requirements, communication overhead, storage overhead and network performance.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.141-148
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• 2009

This paper studies important factors of mobile phone marketing including experiences on entertainment, information, reliability and complaints by analyzing actual materials. The result shows that information, reliability, experiences are more significant than other factors. In case of information, the appropriate message is associated with marketing activities. Reliability and benefit on advertisement are significant. Also, experience has a positive effect on marketing activities. Therefore, this study suggests that mobile marketing should consider significant factors such as information, reliability, and experience.