• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.417-424
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• 2003

In this paper, we introduce and analyze a feedback control model of TCP/AQM dynamics. Then, we propose the Pro-active Queue Management (PAQM) mechanism, which can provide proactive congestion avoidance and control using an adaptive congestion indicator and a control function for wide range of traffic environments. The PAQM stabilizes the queue length around a desired level while giving smooth and low packet loss rates independent of the traffic load level under a wide range of traffic environment. The PAQM outperforms other AQM algorithms such as Random Early Detection (RED) [1] and PI-controller [2]

• 지식경영연구
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• 제15권4호
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• pp.171-187
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• 2014

The social network services (SNS) like Facebook, have gained an enormous amount of popularity. However, side-effects of Facebook usage are occasionally reported such as sense of alienation and cyber-bullying. Among these potential factors threatening to the success of SNS, this research focused on alienation and intends to investigate possible factors that affect SNS alienation and how it affects on SNS attachment and proactive use of SNS. Through extensive literature reviews regarding online and offline alienation, SNS characteristics, and SNS usage, we generated the research model and hypotheses. We surveyed 142 Facebook users and empirically proved that among SNS characteristics, complexity increases SNS alienation, and interactivity and social presence positively affect SNS attachment. Offline alienation, one of the personal attributes, increases both SNS alienation and SNS attachment at the same time while the number of SNS friends have no significant effects. In addition, SNS alienation decreases proactive use of Facebook while SNS attachment increases it. Theoretical and practical implications are discussed based on research findings, and we also suggest future research directions to minimize negative consequences due to SNS users' sense of alienation.

• 전자공학회논문지CI
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• 제44권3호
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• pp.8-13
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• 2007

상황 인식 환경에서는 물리적인 환경, 상황 등을 시스템이 인식하고 이를 기반으로 사용자와의 상호작용을 지원하는 상황 인식 기술이 중요한 요소로 자리잡고 있다. 온톨로지 기반의 상황 정보 모델은 상황정보의 공유와 재사용의 이점을 제공하기 때문에 최근 널리 사용되고 있다. 본 논문에서는 상황 인식 환경에서 온톨로지를 이용한 새로운 프로액티브 검색 기법을 제안한다. 제안된 기법은 온톨로지의 계층적 개념 트리를 이용하여 사용자의 상황에 맞는 정보의 개념 수준을 결정함으로써 보다 효율적인 검색이 가능하다. 이를 위해 제안된 기법을 설명하고, 실험을 통해 기존 기법보다 제안 기법이 우수함을 보인다.

• 한국통신학회논문지
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• 제32권12A호
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• pp.1226-1237
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• 2007

이 논문은 IEEE 802.16 기반의 무선 메쉬 네트워크를 위한 QoS 메쉬 라우팅 프로토콜을 제안한다. 본 논문에서 제안하는 QoS 메쉬 라우팅 프로토콜은 테이블 관리 (Table-driven or Proactive) 방식의 홉 간 (Hop-by-Hop) QoS 라우팅 프로토콜이다. 제안하는 라우팅 프로토콜의 목표는 송신 노드에서 목적지 노드까지 경로를 찾는 것 뿐만 아니라, 대역폭과 지연의 관점에서, QoS 요구사항을 만족시키는 최적 경로를 찾는 것이다. 이 논문에서, 우리는 먼저 이동 Ad Hoc 라우팅 프로토콜과 관련된 연구를 바탕으로, 라우팅 프로토콜의 유형을 분석하고, 테이블관리 방식의 홉 간 라우팅 프로토콜이 무선 메쉬 네트워크에 가장 적합함을 보인다. 그리고 나서, 본 논문에서 주목하는 IEEE 802.16 기반의 무선 메쉬 네트워크의 네트워크 모델을 소개하고, 테이블 관리 방식의 홉 간 라우팅 프로토콜을 기반으로 하는 QoS 메쉬 라우팅 프로토콜을 제안한다. 시뮬레이션을 통해서, 제안하는 라우팅 프로토콜이 QOLSR 프로토콜에 비하여 단대단 지연 (End-to-End Delay)이 낮고, 패킷 전달률 (Packet Delivery Ratio)이 높으며, 라우팅 오버헤드 패킷 량이 적음을 보였다.

• Geomechanics and Engineering
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• 제37권1호
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• pp.21-29
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• 2024

The effective management of damage in tunnels is crucial for ensuring their safety, longevity, and operational efficiency. In this paper, we propose an educational management model tailored specifically for addressing damage in tunnels, utilizing numerical solution techniques. By leveraging advanced computational methods, we aim to develop a comprehensive understanding of the factors contributing to tunnel damage and to establish proactive measures for mitigation and repair. The proposed model integrates principles of tunnel engineering, structural mechanics, and numerical analysis to facilitate a systematic approach to damage assessment, diagnosis, and management. Through the application of numerical solution techniques, such as finite element analysis, we demonstrate the efficacy of the proposed model in simulating various damage scenarios and predicting their impact on tunnel performance. Additionally, the educational component of the model provides valuable insights and training opportunities for tunnel management personnel, empowering them to make informed decisions and implement effective strategies for ensuring the structural integrity and safety of tunnel infrastructure. Overall, the proposed educational management model represents a significant advancement in tunnel management practices, offering a proactive and knowledge-driven approach to addressing damage and enhancing the resilience of tunnel systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2052-2072
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• 2012

Access control is an essential security component in protecting sensitive data and services from unauthorized access to the resources in mission-critical Cyber-Physical Systems (CPSs). CPSs are different from conventional information processing systems in such that they involve interactions between the cyber world and the physical world. Therefore, existing access control models cannot be used directly and even become disabled in an emergency situation. This paper proposes an adaptive Access Control model for Emergences (AC4E) for mission-critical CPSs. The principal aim of AC4E is to control the criticalities in these systems by executing corresponding responsive actions. AC4E not only provides the ability to control access to data and services in normal situations, but also grants the correct set of access privileges, at the correct time, to the correct set of subjects in emergency situations. It can facilitate adaptively responsive actions altering the privileges to specific subjects in a proactive manner without the need for any explicit access requests. A semiformal validation of the AC4E model is presented, with respect to responsiveness, correctness, safety, non-repudiation and concurrency, respectively. Then a case study is given to demonstrate how the AC4E model detects, responds, and controls the emergency events for a typical CPS adaptively in a proactive manner. Eventually, a wide set of simulations and performance comparisons of the proposed AC4E model are presented.

• Asia pacific journal of information systems
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• 제15권2호
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• pp.195-218
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• 2005

The emergence of ubiquitous computing environment will change the service architecture of business information systems such as Decision Support System(DSS), which will be a new application. Recent mobile DSSs allow the decision makers to be benefited from web and mobile technology. However, they seldom refer to context data, which are useful for proactive decision support. Meanwhile, ubiquitous applications so far provide restricted personalization service using context and preference of the user, that is, they do not fully make use of decision making capabilities. Hence, this paper aims to describe how the decision making capability and context-aware computing are jointly used to establish ubiquitous applications. To do so, an amended DSS paradigm: CKDDM(Context-Knowledge-Dialogue-Data-Model) is proposed in this paper. What will be considered for the future decision support systems when we regard ubiquitous computing technology as an inevitable impact that enforces the change of the way of making decisions are described. Under the CKDDM paradigm, a framework of ubiquitous decision support systems(ubiDSS) is addressed with the description of the subsystems within. To show the feasibility of ubiDSS, a prototype system, CAMA-myOpt(Context-Aware Multi Agent System-My Optimization) has been implemented as an illustrative example system.

• 한국안전학회지
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• 제33권6호
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• pp.93-101
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• 2018

Various leading indicators of safety culture have been advocated for proactive actions as lagging indicators have limitations in reflecting the attitudes and behaviors due to their reactivity and low sensitivity. This study proposes a model of incident-reporting culture (IRC) and determines the influence of the components on incident-reporting rate (IRR) in order to develop proactive indicators of safety culture. A questionnaire survey was administered to 614 workers at a chemical company in Korea, and the internal psychological aspects were explored by using perceptions, attitude, and backgrounds. The relationship between these factors and IRR was quantitatively confirmed. The workers are more reluctant to report injury than property damage, the perception of severity is the most influencing factor, and most property damages are reported regardless of worker's willingness. These features should be prioritized when improving IRC, and the criteria of IRC need to be aligned with safety culture.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.324-329
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• 2009

Proactive computing의 핵심 기술인 손동작 인식 (Hand Motion Recognition, HMR) 기술은 인간과 컴퓨터 사이의 상호작용(Human Computer Interaction, HCI) 분야에서 많은 연구가 진행되고 있다. 본 연구에서는 3축 가속도 센서를 부착한 data glove를 제작하고, 3차원 손 모델을 구현한 후, 이를 이용한 손동작 인식 기술을 개발하였다. Data glove는 가상현실에 대한 입력 장치로써 본 논문에서는 3축 가속도 센서를 사용하여 획득된 신호를 wireless communication으로 PC에 전송할 수 있도록 구현하였다. 손 모델링은 ellipsoid를 이용한 kinematic chain 이론 바탕의 3차원 손 모델을 구현하였으며, data glove에서 얻어진 가속도 정보에 rule 기반의 알고리즘을 적용하여 구현된 3차원 손 모델을 통하여 간단한 손동작(가위, 바위, 보)을 인식하였다.

• Journal of Information Processing Systems
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• 제12권4호
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• pp.577-590
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• 2016

We studied the current state-of-the-art of Smart TV, the challenges and the drawbacks. Mainly we discussed the lack of end-to-end solution. We then illustrated the differences between Smart TV and IPTV from network service provider point of view. Unlike IPTV, viewer of Smart TV's over-the-top (OTT) services could be global, such as foreign nationals in a country or viewers having special viewing preferences. Those viewers are sparsely distributed. The existing TV service deployment models over Internet are not suitable for such viewers as they are based on content popularity, hence we propose a community based service deployment methodology with proactive content caching on rendezvous points (RPs). In our proposal, RPs are intermediate nodes responsible for caching routing and decision making. The viewer's community formation is based on geographical locations and similarity of their interests. The idea of using context information to do proactive caching is itself not new, but we combined this with "in network caching" mechanism of content centric network (CCN) architecture. We gauge the performance improvement achieved by a community model. The result shows that when the total numbers of requests are same; our model can have significantly better performance, especially for sparsely distributed communities.