• 제어로봇시스템학회논문지
• /
• 제16권7호
• /
• pp.646-654
• /
• 2010

This paper describes an integrated chassis control for a maneuverability, a lateral stability and a rollover prevention of a vehicle by the using of the ESC and AFS. The integrated chassis control system consists of a supervisor, control algorithms and a coordinator. From the measured and estimation signals, the supervisor determines the vehicle driving situation about the lateral stability and rollover prevention. The control algorithms determine a desired yaw moment for lateral stability and a desired longitudinal force for the rollover prevention. In order to apply the control inputs, the coordinator determines a brake and active front steering inputs optimally based on the current status of the subject vehicle. To improve the reliability and to reduce the operating load of the proposed control algorithms, a multi-core ECU platform is used in this system. For the evaluation of this system, a closed loop simulations with driver-vehicle-controller system were conducted to investigate the performance of the proposed control strategy.

• 정보보호학회논문지
• /
• 제26권6호
• /
• pp.1561-1569
• /
• 2016

IoT환경에서 센서 디바이스의 사용이 증가함에 따라 보안에 대한 필요성도 중요해지고 있다. 센서 디바이스가 IEEE 802.15.4 기반 LoWPAN에 배치되는 경우 필수적으로 PAN Coordinator와의 가입 과정이 수행되고 후속적으로 디바이스 간 바인딩 과정이 진행된다. 가입 및 바인딩 과정에서는 사전 분배된 네트워크 키 또는 인증서를 이용해 디바이스의 인증 및 키 분배를 한다. 하지만, 기존 방식에서 사용하는 네트워크 키는 그룹인증에 한정된 역할을 하며 인증서의 발급에서도 개별식별이 이루어지지 않는 문제점이 있다. 본 논문에서는 사전 분배된 네트워크 키의 문제점을 보완한 LoWPAN 환경에서 디바이스의 안전한 가입 및 바인딩 프로토콜을 제안한다.

• 디지털콘텐츠학회 논문지
• /
• 제18권5호
• /
• pp.821-829
• /
• 2017

인터넷의 발달과 모바일 기기의 생활화로 인하여 쇼핑 시장에 큰 변화가 일어났다. 소비자들은 직접 방문해야하는 오프라인 쇼핑보다 직접 방문할 필요 없이도 옷을 구매할 수 있는 온라인 쇼핑에 더욱 편리함을 느껴 온라인 쇼핑을 더 많이 이용하게 되었다. 온라인으로 하는 쇼핑은 편리하고 쉽게 구매할 수 있다는 장점이 있지만 자신에게 어울리는 옷인지 판단하기 힘들고 옷을 잘못 살 수가 있다는 단점이 있다. 본 논문에서는 사용자의 전신사진을 이용하거나 신체 사이즈에 맞는 모델을 제공하여, 그 모델에 옷을 입어볼 수게 하는 앱을 제안한다. 제안하는 앱은 사용자가 가상으로 자신의 몸에 옷을 코디하는 것을 볼 수 있게 함으로써, 스마트한 구매를 유도할 수 있다.

• 자동차안전학회지
• /
• 제5권1호
• /
• pp.37-43
• /
• 2013

This paper describes an investigation into coordinated control of electronic stability control (ESC) and active roll control system (ARS). The coordinated control is suggested to improve the vehicle stability and agility features by yaw rate control. The proposed integrated chassis control algorithm consists of a supervisor, control algorithms, and a coordinator. The supervisor monitors the vehicle status and determines desired vehicle motions such as a desired yaw rate and desired roll motion based on control modes to improve vehicle stability. According to the corresponding the desired vehicle dynamics, the control algorithm calculated a desired yaw moment and desired roll moment, respectively. Based on the desired yaw moment and the desired roll moment, the coordinator determines the brake pressures and the ARC motor torques based on control strategies. Closed loop simulations with a driver-vehicle-controller system were conducted to investigate the performance of the proposed control strategy using CarSim vehicle dynamics software and the integrated controller coded using Matlab/Simulink.

• 한국병원경영학회지
• /
• 제14권3호
• /
• pp.104-131
• /
• 2009

This study analysed what effects conscious role conflict and conscious self-efficacy have on job satisfaction for hospital coordinators working in medical institutions. In order to study this issue, questionnaires were distributed to 154 hospital coordinators. The results from analysing the effects of role conflict and self-efficacy on job satisfaction are as follows: 1) Role conflict and job satisfaction are negatively correlated. The mean score for hospital coordinators' role conflict was 2.82, which was lower than average. Among subfactors for role conflict, personal role conflict had a significant effect on job satisfaction, while role ambiguity had no effect on job satisfaction. 2) The mean score for hospital coordinators' self-efficacy was 3.42, which was slightly higher than average. Other mean scores were as follows: job attitude 3.83, interpersonal skills 3.54, administrative knowledge 3.30, and medical treatment knowledge 3.02. Among subfactors for self-efficacy, job attitude and adminstrative knowledge had significant effects on job satisfaction, while interpersonal skills and medical treatment knowledge had no effect on job satisfaction (p < 0.01). In conclusion various hospital administration techniques, related job training and education needs to be given when introducing a hospital coordinator in order to strengthen the competitiveness of medical institutions. The hospital coordinators need to clearly understand their role so that they can settle into the system at the hospital and develop their job environment.

• 대한예방한의학회지
• /
• 제16권3호
• /
• pp.75-87
• /
• 2012

Objectives : This study was performed to investigate the knowledge on contacting experiences to foreign patients, the equipments and requirements to make the vitalization method for the oriental medical tourism for foreign patients. Methods : We adopted the focusing group interviews on the oriental medical doctors, nurses and personnels who had the experiences to deal with the oriental medical tourism. Results : For 3 parts, translation into each country's language in program, hospital information, treatment information and homepage should be done and consideration into each country's culture is very important part to know medical tourism patients and prepare the adequate products, and lastly the translater or medical coordinator plays a very important role to connect the hospital personnels with medical tourism patients. Conclusions : Translation in to each country's language concerning medical tourism material and understanding on one's country's culture and a medical coordinator are very important constituents for a successful medical tourism.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권12호
• /
• pp.3152-3165
• /
• 2012

Wireless sensor networks (WSN) often employ asynchronous MAC scheduling, which allows each sensor node to wake up independently without synchronizing with its neighbor nodes. However, this asynchronous scheduling may not deal with collisions due to hidden terminals effectively. Although most of the existing asynchronous protocols exploit a random back-off technique to resolve collisions, the random back-off cannot secure a receiver from potentially repetitive collisions and may lead to a substantial increase in the packet latency. In this paper, we propose a new collision resolution algorithm called Transient Coordinator (TC) for asynchronous WSN MAC protocols. TC resolves a collision on demand by ordering senders' transmissions when a receiver detects a collision. To coordinate the transmission sequence both the receiver and the collided senders perform handshaking to collect the information and to derive a collision-free transmission sequence, which enables each sender to exclusively access the channel. According to the simulation results, our scheme can improve the average per-node throughput by up to 19.4% while it also reduces unnecessary energy consumption due to repetitive collisions by as much as 91.1% compared to the conventional asynchronous MAC protocols. This demonstrates that TC is more efficient in terms of performance, resource utilization, and energy compared to the random back-off scheme in dealing with collisions for asynchronous WSN MAC scheduling.

• 한국산학기술학회논문지
• /
• 제11권11호
• /
• pp.4543-4552
• /
• 2010

리더는 그룹 내의 여러 프로세스 중에서 조정자 역할을 하는 특별한 프로세스이다. 분산 시스템에서 하나의 조정자를 선출하는 과정을 리더선출이라 하며 이는 결함허용 분산시스템을 구축하기 위한 매우 중요한 문제이다. 현재 정상 작동하고 있는 두 개의 모바일 ad hoc 네트워크 그룹들이 병합되면 두 개의 리더가 존재하게 된다. 이것은 안전성 속성에 위배되므로 이를 감지하고 처리할 수 있는 메커니즘이 필요하다. 본 논문에서는 모바일 ad hoc 분산 컴퓨팅 시스템에서 그룹 멤버십 탐지 기반의 리더 경쟁 프로토콜을 제안하고 이를 시제논리로 검증하고자 한다.

• 한국멀티미디어학회논문지
• /
• 제19권9호
• /
• pp.1698-1709
• /
• 2016

These days, anyone can easily product and share their own content through a web service such as blogs and SNS. However, contents are being operated separately because of the space limitation in individual SNS. Therefore, it is hard to search contents efficiently in individual SNS. To solve this problem, this paper propose a "Private Contents Management and Sharing Service with Voluntary Sharing Economy System." The system is in part [Input], [Save] and it provides a way to collect the content that are scattered on the Internet based on the creation of personal index. It also proposes a more systematic content management and sharing by creating and updating the website standard index by introducing an index Coordinator concept. Furthermore in [Use] section, by providing a portion of the index as the primary search results, it avoid unclassified content list which was simply collected by users. In conclusion, unlike previous studies, this system will contribute to the acquisition and management of interspersed content and ultimately contribute to the shared activation by preventing secondary processing and unauthorized processing to the original article.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권12호
• /
• pp.4385-4399
• /
• 2021

The Internet of Things (IoT) eHealth systems composed by Wireless Body Area Network (WBAN) has emerged recently. Sensor nodes are placed around or in the human body to collect physiological data. WBAN has many different applications, for instance health monitoring. Since the limitation of the size of the battery, besides speed, reliability, and accuracy; design of WBAN protocols should consider the energy efficiency and time delay. To solve these problems, this paper adopt the end-edge-cloud orchestrated network architecture and propose a transmission based on reinforcement algorithm. The priority of sensing data is classified according to certain application. System utility function is modeled according to the channel factors, the energy utility, and successful transmission conditions. The optimization problem is mapped to Q-learning model. Following this online power control protocol, the energy level of both the senor to coordinator, and coordinator to edge server can be modified according to the current channel condition. The network performance is evaluated by simulation. The results show that the proposed power control protocol has higher system energy efficiency, delivery ratio, and throughput.