• 대한기계학회논문집A
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• 제39권5호
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• pp.473-482
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• 2015

최근 과학 기술의 발전으로 첨단 자율 기능을 탑재된 차량의 출현이 가능하게 되었으며, 기존 차량에 추가된 첨단 운전자 지원 시스템(Advanced Driver Assistance Systems: ADAS)은 기존 차량에 추가된 이러한 자율 시스템들의 좋은 예라 할 수 있다. 이러한 시스템은 다수의 작동 모드를 가지는데 운전자들이 현재 수행중인 작동 모드를 잘못 인지하게 되면 교통사고가 일어날 수 있음이 관찰되고 있다. 본 연구에서는 적응 순항제어(Adaptive Cruise Control: ACC) 시스템을 장착한 자동화된 자동차의 운전자 인터페이스를 설계하고 이를 정형 기법을 통한 분석과 피실험자를 이용한 실험을 통해 모드 혼동 발생 여부를 검증하고 이를 개선하는 연구를 수행하였다. 이를 통해 모드 혼동을 방지하기 위해서는 시스템에 대한 심성 모델의 정확성과 간결성뿐만 아니라 인터페이스 구현시 디스플레이의 명확성이 또한 매우 중요하다는 것을 확인하였다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제7권4호
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• pp.103-110
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• 2018

Internet of Things(IoT) 기술이 발전하면서 다양한 IoT 기기들을 이용하여 사용자의 편의성을 높이기 위한 서비스가 늘어나고 있다. 또한, IoT 센서가 다양해지고 가격이 낮아지고 있어서 다양한 데이터를 수집 및 활용하여 서비스를 제공하는 사업자도 증가하는 추세이다. 스마트 IoT 홈 시스템은 IoT 기기를 이용하여 사용자의 편의성을 향상하는 대표적인 활용 사례이다. 본 논문에서는 스마트 IoT 홈 시스템의 사용자 편의성을 향상하기 위하여 데이터를 분석하여 연관 기기의 제어를 위한 방법을 제안한다. 스마트 IoT 홈 시스템의 센서에서 수집한 내부 환경 측정 데이터, 기기 제어 엑츄에이터에서 수집한 데이터 및 사용자의 판단 데이터를 학습하여 현재 홈 내부 상태를 분석하고 기기 제어 방법을 결정한다. 특히 기존 기술들과 다르게 최신 딥 러닝 기반의 심층 신경망을 도입하여 데이터를 분석하여 홈 내부 상태를 판단하고 최적의 홈 내부 환경 유지를 위한 정보를 제공한다. 실험에서는 실제 장기간 측정한 데이터와 추론 결과를 비교하여 제안한 방법의 판별 성능에 대한 분석을 수행하였다.

• 정보처리학회논문지C
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• 제17C권2호
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• pp.173-180
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• 2010

IT 기술의 발달에 힘입어 환자들의 위치에 상관없이 편리하게 진료가 가능한 유비쿼터스 헬스케어시스템이 개발되고 있다. 그러나 사용자의 수가 급증하고 다른 병원의 의사나 연구원 또는 환자의 가족들에게 의료 정보를 공개하도록 의료법이 개정되면서 사용자 관리와 프라이버시 침해라는 문제가 발생하였다. 이러한 문제를 해결하기 위하여 본 논문에서는 역할 기반 접근제어 모델에 기반한 사용자 접근 모델은 제안한다. RBAC 모델은 효율적인 사용자 관리 및 접근 제어를 제공하지만, 악의를 가진 사용자가 권한이 있는 역할을 가지고 정보를 유출하고자 할 경우 막을 방법이 없다. 이러한 RBAC의 취약점을 보완하기 위하여 "working status" 파라미터를 역할 속성과 연동하는 RBAC-WS 모델을 제안하였다. 역할에 working 속성을 연동함으로써 허가를 받은 사용자라 하더라도 업무 외 접근을 원천적으로 봉쇄함으로서 내부자에 의한 정보유출 문제를 해결하였다. 또한 RBAC을 위한 함수를 개발하여 도메인이 서로 다른 헬스케어 시스템에서도 유용하게 사용될 수 있도록 하였으며, RBAC-WS 모델의 기능 분석을 위하여 Healthcare 시스템 중 널리 사용되는 PACS에 적용하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권7호
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• pp.2631-2649
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• 2021

Device-to-Device (D2D) communication is one of the enabling technologies for 5G networks that support proximity-based service (ProSe) for wireless network communications. This paper proposes a power control algorithm based on the Nash equilibrium and game theory to eliminate the interference between the cellular user device and D2D links. This leadsto reliable connectivity with minimal power consumption in wireless communication. The power control in D2D is modeled as a non-cooperative game. Each device is allowed to independently select and transmit its power to maximize (or minimize) user utility. The aim is to guide user devices to converge with the Nash equilibrium by establishing connectivity with network resources. The proposed algorithm with pricing factors is used for power consumption and reduces overall interference of D2Ds communication. The proposed algorithm is evaluated in terms of the energy efficiency of the average power consumption, the number of D2D communication, and the number of iterations. Besides, the algorithm has a relatively fast convergence with the Nash Equilibrium rate. It guarantees that the user devices can achieve their required Quality of Service (QoS) by adjusting the residual cost coefficient and residual energy factor. Simulation results show that the power control shows a significant reduction in power consumption that has been achieved by approximately 20% compared with algorithms in [11].

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권5호
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• pp.423-443
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• 2009

We present the design and implementation of a unique sensing and actuation application -- the Illuminator: a sensor network-based intelligent light control system for entertainment and media production. Unlike most sensor network applications, which focus on sensing alone, a distinctive aspect of the Illuminator is that it closes the loop from light sensing to lighting control. We describe the Illuminator's design requirements, system architecture, algorithms, implementation and experimental results. The system uses the Illumimote, a multi-modal and high fidelity light sensor module well-suited for wireless sensor networks, to satisfy the high-performance light sensing requirements of entertainment and media production applications. The Illuminator system is a toolset to characterize the illumination profile of a deployed set of fixed position lights, generate desired lighting effects for moving targets (actors, scenic elements, etc.) based on user constraints expressed in a formal language, and to assist in the set up of lights to achieve the same illumination profile in multiple venues. After characterizing deployed lights, the Illuminator computes optimal light settings at run-time to achieve a user-specified actuation profile, using an optimization framework based on a genetic algorithm. Uniquely, it can use deployed sensors to incorporate changing ambient lighting conditions and moving targets into actuation. Experimental results demonstrate that the Illuminator handles various high-level user requirements and generates an optimal light actuation profile. These results suggest that the Illuminator system supports entertainment and media production applications.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.362-367
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• 2005

Control network adopted in the national power-plant or manufactory are mostly vendor-dependent products, which have their own special specification, components and individual communication methods. These systems not only raise installation cost, but also bring many difficulties to maintenance and extension. To overcome these problems, this paper introduces a development and application case of a new "PC/Ethernet-based fieldbus" architecture and protocol to be used in mid-level fieldbus. The designed system has a basic idea of "3 Layers fieldbus over Standard-LAN" and implemented on PCs. PC gives user friendly environment. By using an open standard Ethernet in layer 1,2, the system has low cost, wide communication bandwidth and high compatibility. Layer 3 protocol designed for large realtime data communication makes user bypass TCP/IP layer and gives user direct access to the Ethernet. This new protocol eliminates potential collision of Ethernet, and transmits large periodic/non-periodic control data by using long-frame/wide-bandwidth of Ethernet effectively, and offers simple API-Services to the upper layer. Since the system have installed in H-power plant simulator and U-nuclear power plant simulator in Korea, it have been proved to be efficient and stable without any trouble in realtime communication service for full-scope plant simulator that has a lot of control elements.

• ETRI Journal
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• 제21권4호
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• pp.23-28
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• 1999

In this paper, we analyze the performance benefits of broadband ATM networks when the call control and management flows are separated from user data flows. The virtual path tunneling concept for control and management flows are applied to the same physical ATM networks. The behaviors of channel throughput and transfer delay are analyzed. It results that the proposed virtual short-cut paths can maintain the network being stable with acceptable bandwidth. They are very useful to provide the stable control and management capabilities for Internet and mobile applications in the broadband ATM networks. In our numerical results, the effective throughputs of the proposed virtual shout-ut channel are about three times than those of end-to-end user data channels with hop distances of 10, and about two times than those with hop distance of 5 when the link blocking probability increases to 0.1. It concludes that the effective channel bandwidth are greatly reduced down while physical links are not stable and user traffic flows are occasionally overflowed.

• Imaging Science in Dentistry
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• 제44권2호
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• pp.155-160
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• 2014

Purpose: The purposes of this study were to develop a workstation computer that allowed intraoperative touchless control of diagnostic and surgical images by a surgeon, and to report the preliminary experience with the use of the system in a series of cases in which dental surgery was performed. Materials and Methods: A custom workstation with a new motion sensing input device (Leap Motion) was set up in order to use a natural user interface (NUI) to manipulate the imaging software by hand gestures. The system allowed intraoperative touchless control of the surgical images. Results: For the first time in the literature, an NUI system was used for a pilot study during 11 dental surgery procedures including tooth extractions, dental implant placements, and guided bone regeneration. No complications were reported. The system performed very well and was very useful. Conclusion: The proposed system fulfilled the objective of providing touchless access and control of the system of images and a three-dimensional surgical plan, thus allowing the maintenance of sterile conditions. The interaction between surgical staff, under sterile conditions, and computer equipment has been a key issue. The solution with an NUI with touchless control of the images seems to be closer to an ideal. The cost of the sensor system is quite low; this could facilitate its incorporation into the practice of routine dental surgery. This technology has enormous potential in dental surgery and other healthcare specialties.

• 인터넷정보학회논문지
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• 제14권4호
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• pp.43-51
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• 2013

고도의 보안 시스템에서 사용자 인증과 접근제어는 두 가지 중요한 요소이다. 최근 Chen & Yeh는 이 두 가지 보안 요소를 원활하게 잘 통합한 방법을 제안하였다. 그러나 Chen-Yeh 방법은 원격 서버에 스마트 카드 ID 자료를 유지하기 때문에 SVA(stolen verifier attack: 도난 검증자 공격)에 취약하다는 단점을 가지고 있다. 따라서 본 논문에서는 Chen & Yeh 방법의 이런 단점을 개선하고, 장점은 그대로 유지하는 새로운 사용자 인증 및 접근제어 방법을 제안한다. 보안 분석 결과에 의하면, 기존 방법들에 비하여 제안 방법은 여러 가지 다양한 보안 침해 공격에 강인하면서, 사용자 인증 및 접근제어에 도움이 되는 많은 좋은 특징을 보유하고 있는 것으로 입증되었다.

• 성인간호학회지
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• 제14권2호
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• pp.184-193
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• 2002

Purpose: The purpose of this study was to assess the characteristics of the user of complementary alternative therapies(CAT) and to identify the important predictive factors associated with them. Method: This study included 142 patients attending outpatient rheumatology clinics of D Hospital in Busan between July and August in 2001. The multiple logistic regression model was developed to estimate the likelihood of user or nonuser of CAT. Result: The duration of illness and chance score of health locus of control were found to be significant factors through the estimated coefficients of using CAT. Duration of illness is longer and chance score of health locus of control is higher in patients who have used CAT in past than that of nonuser. When the model performance was evaluated by comparing the observed outcome with predicted outcome, the model correctly identified 95% of user of CAT and 31% of nonuser. Conclusion: In this survey, duration of illness and chance score of health locus of control are found to be significant factors in predicting utilization of CAT. Nurses who care for rheumatoid arthritis patients should take consideration into health locus of control in planning health education programs.