• 한국ITS학회 논문지
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• 제21권6호
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• pp.299-310
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• 2022

자율주행시스템은 자율주행 센서, 판단 및 제어 알고리즘 등을 기반으로 스스로 자율주행할 수 있는 기능을 갖추고 있다. 자율주행의 안전성은 도로 네트워크의 운영 상태와 관련성이 높고 도로 인프라와의 협력이 필요하다. 자율주행의 안전한 운행을 위해서는 지속적으로 도로와 교통 조건이 적합한지를 모니터링 할 필요가 있다. 본 연구는 자율주행시스템의 ODD (Operational Design Domain) 특성에 따라 선정된 모니터링 항목을 관리할 수 있는 체계를 구축하기 위한 노드와 링크 체계를 제시하였다. 확장성을 고려하여 기존의 ITS 표준 노드링크 체계를 기반으로 하였으며, 모니터링 대상을 노드와 링크로 표출하는 방안을 제시하였다. 위험도를 5단계로 구분하고 관리하는 방안과 최적경로 탐색 및 통제 시 노드와 링크의 정보를 활용하는 방안을 제시하였다. 세종시를 대상으로 제시된 노드와 링크체계를 기반으로 한 시스템구축 사례를 소개하였다.

• International journal of advanced smart convergence
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• 제5권3호
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• pp.32-39
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• 2016

With the help of a small wearable device, patients reside in an isolated village need constant monitoring which may increase access to care and decrease healthcare delivery cost. As the number of patients' requests increases in simultaneously manner, the web service gateway located in the village hall encounters limitations for performing them successfully and concurrently. The gateway based RESTful technology responsible for handling patients' requests attests an internet latency in case a large number of them submit toward the gateway increases. In this paper, we propose the design tasks of the web service gateway for handling concurrency events. In the procedure of designing tasks, concurrency is best understood by employing multiple levels of abstraction. The way that is eminently to accomplish concurrency is to build an object-oriented environment with support for messages passing between concurrent objects. We also investigate the performance of event-driven architecture for building web service gateway using node.js. The experiments results show that server-side JavaScript with Node.js and MongoDB as database is 40% faster than Apache Sling. With Node.js developers can build a high-performance, asynchronous, event-driven healthcare hub server to handle an increasing number of concurrent connections for Remote Healthcare Monitoring System in an isolated village with no access to local medical care.

• 디지털산업정보학회논문지
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• 제7권4호
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• pp.15-22
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• 2011

U-Healthcare service is a real-time service using the vital signs which are continuously transferred from monitoring sensors attached to mobile patients under the wireless network environments. It should monitor the health condition of mobile patients everywhere at any time. In this paper, we have improved two features of the three layered mobile patient monitoring system with load balancing ability. First, the simulation process has been improved by allowing the number of related nodes to be changed. Secondly, we have modified S node to which queue is added to reduce the loss rate of collecting data from patients during the delay of S node process. And the data from the patient with high priority can be transferred to the server immediately through the filtering function. Furthermore, we have solved the problem of redundancy in sharing information among S nodes by differentiating process time to each S node. By performing a DEVS Java-based system simulation, we have verified the efficiency of this improved system.

• 한국전자통신학회논문지
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• 제7권1호
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• pp.195-201
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• 2012

센서노드와 관제시스템으로 구성된 환경정보모니터링시스템은 센서노드에서 실시간 정보를 수집하고 원격지의 관제시스템으로 수집된 데이터를 실시간 전송한다. 센서 노드에 설치되는 센서의 종류, 센서의 개수, 센서노드와 관제시스템 사이의 통신환경, 관제시스템 데이터 운영 환경에 따라 관제시스템의 운용성이 크게 저하될 수 있다. 따라서 본 연구에서는 운영 효율성을 증대하기 위하여 운용환경에 따라 적절한 컴포넌트를 이용하는 컴포넌트 기반 환경정보모니터링시스템을 제안하고 구현하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.281-286
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• 2009

The proposed technique uses cyclic frame structure, where three periods such as beacon period (BP), mesh contention access period (MCAP) and slotted period (SP) are in a data frame. This paper studies on a mechanism to allow communication nodes (6lowpan) in a PAN with different logical channel for global healthcare applications monitoring technology. The proposed super framework structure system has installed 6lowpan sensor nodes to communicate with each other. The basic idea is to time share logical channels to perform 6lowpan sensor node. The concept of 6lowpan sensor node and various biomedical sensors fixed on the patient BAN (Body Area Network) for monitoring health condition. In PAN (hospital area), has fixed gateways that received biomedical data from 6lowpan (patient). Each 6lowpan sensor node (patient) has IP-addresses that would be directly connected to the internet. With the help of IP-address service provider can recognize or analyze patient data from all over the globe by the internet service provider, with specific equipments i.e. cell phone, PDA, note book. The NS-2.33 result shows the performance of data transmission delay and data delivery ratio in the case of hop count in a PAN (Personal Area Networks).

• 연구논문집
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• 통권24호
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• pp.129-140
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• 1994

Design and implementation of monitoring and control system using dual-microprocessor node is presented for real time process. The proposed system is implemented with 2 of the single chip microprocessors in tightly coupled mode and results in speed up of $s_p=1.74.$ Under the assumption that the nodes are interconnected in multidrop. the overall system performance such as average throughout-delay characteristics and effective throughput are analyzed using M/G/1 gueueing model, and results show that the proposed node can be used to medium sized distributed monitoring and control system.

• International Journal of Advanced Culture Technology
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• 제4권3호
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• pp.13-19
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• 2016

The growth of mobile devices in Internet of Things (IoT) leads to a number of remote and controlling system related IoT applications. For instance, home automation controlling system uses client system such web apps on smartphone or web service to access the home server by sending control commands. The home server receives the command, then controls for instance the light system. The web service gateway responsible for handling clients' requests attests an internet latency when an increasing number of end users requests submit toward it. Therefore, this web service gateway fails to detect several commands, slows down predefined actions which should be performed without human intervention. In this paper, we investigate the performance of a web server-side platgorm based event-driven, non-blocking approach called Node.js against traditional thread-based server side approach to handle a large number of client requests simultaneously for remote and controlling system in IoT remote monitoring applications. The Node.JS is 40% faster than the traditional web server side features thread-based approach. The use of Node.js server-side handles a large number of clients' requests, then therefore, reduces delay in performing predefined actions automatically in IoT environment.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.661-673
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• 2010

This paper presents recent developments in an extremely compact, wireless impedance sensor node (the WID3, $\underline{W}$ireless $\underline{I}$mpedance $\underline{D}$evice) for use in high-frequency impedance-based structural health monitoring (SHM), sensor diagnostics and validation, and low-frequency (< ~1 kHz) vibration data acquisition. The WID3 is equipped with an impedance chip that can resolve measurements up to 100 kHz, a frequency range ideal for many SHM applications. An integrated set of multiplexers allows the end user to monitor seven piezoelectric sensors from a single sensor node. The WID3 combines on-board processing using a microcontroller, data storage using flash memory, wireless communications capabilities, and a series of internal and external triggering options into a single package to realize a truly comprehensive, self-contained wireless active-sensor node for SHM applications. Furthermore, we recently extended the capability of this device by implementing low-frequency analog-to-digital and digital-to-analog converters so that the same device can measure structural vibration data. The compact sensor node collects relatively low-frequency acceleration measurements to estimate natural frequencies and operational deflection shapes, as well as relatively high-frequency impedance measurements to detect structural damage. Experimental results with application to SHM, sensor diagnostics and low-frequency vibration data acquisition are presented.

• 한국강구조학회 논문집
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• 제22권1호
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• pp.21-31
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• 2010

본 연구에서는 구조 케이블의 인장력 모니터링을 위한 무선 임피던스 센서노드를 개발하였다. 이를 위해 다음과 같은 연구가 수행되었다. 첫째, 경제적이고 자동화된 구조 케이블의 인장력 모니터링을 위한 무선임피던스 센서노드를 설계/제작 하였다. 둘째, 자동화된 인장력 모니터링을 위해 임피던스 기반 모니터링 기법을 무선 센서노드에 내장하였다. 셋째, 측정 범위가 제한적인 무선임피던스 센서노드의 한계점을 극복하기 위하여 인터페이스 와셔를 이용하는 구조케이블 인장력 모니터링 기법을 제안하였다. 마지막으로 내장형/외장형 텐던을 가지는 모형 프리스트레스트 콘크리트 거더에 대하여 무선임피던스 센서노드와 인터페이스 와셔를 이용하는 모니터링 기법의 적용성을 평가하였다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.535-538
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• 2007

클러스터 시스템을 관리하기 위하여 모니터링 툴(S/W)이 필요하지만, 소규모 클러스터 시스템에 적합하고 관리자가 필요로 하는 기능을 갖춘 모니터링 툴을 결정하는 것은 쉽지가 않다. 본 문서는 인피니밴드 네트워크 스위치를 사용한 소규모 SMP 클러스터 시스템을 위하여 개발한 모니터링 툴의 설계와 구현 내용을 기술하였다. 모니터링 툴의 기능은 계산노드, 인피니밴드 스위치 그리고 작업관리 스케쥴러(PBS)의 작업을 모니터링한다.