• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.579-580
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• 2021

다양한 센서에서 발생하는 데이터를 효과적으로 수집하기 위해서는 각 센서에서의 임베디드된 플랫폼을 활용하는 방법이 가장 대표적이다. 하지만 임베디드된 플랫폼은 다양한 종류의 센서마다 모두 구현이 다르게 되어있어 한번에 적용하기 어렵게 되어있다. 이에 본 논문에서는 다양한 센싱 데이터를 하나의 플랫폼에서 쉽게 수집하고 관리할 수 있는 웹 기반의 데이터 수집 플랫폼을 제안하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.451-453
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• 2007

This paper describes the design of an asynchronous implementation of a sensor network processor. The main purpose of this work is the reduction of power consumption in sensor network node processors and the research presented here tries to explore the suitability of asynchronous circuits for this purpose. The Handshake Solutions toolkit is used to implement an asynchronous version of a sensor processor. The design is made compact, trading area and leakage power savings with dynamic power costs, targeting the typical sparse operating characteristics of sensor node processors. It is then compared with a synchronous version of the same processor. Both versions are then compared with existing commercial processors in terms of power consumption.

• 한국해양공학회지
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• 제36권3호
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• pp.153-160
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• 2022

Moored floating platforms have great potential in ocean engineering applications because a mooring system is necessary to keep the platform in station, which is directly related to the operational efficiency and safety of the platform. This paper briefly introduces the technical and operational details of an optical sensor for measuring the tension of mooring lines of a moored platform in waves. In order to check the performance of optical sensors, an experiment with a moored floating platform in waves is carried out in the wave tank at Changwon National University. The experiment is performed in regular waves and irregular waves with a semi-submersible and triangle platform. The performance of the optical sensor is confirmed by comparing the results of the tension of the mooring lines by the optical sensor and tension gauges. The maximum tension of the mooring lines is estimated to investigate the mooring dynamics due to the effect of the wave direction and wavelength in the regular waves. The significant value of the tension of mooring lines in various wave directions is estimated in the case of irregular waves. The results show that the optical sensor is effective in measuring the tension of the mooring lines.

• Journal of Positioning, Navigation, and Timing
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• 제9권3호
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• pp.175-182
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• 2020

This paper introduces a study to estimate the user altitude in need of rescue in an emergency. The altitude is estimated by using the barometric pressure sensor embedded in the smartphone. Compared to GPS, which is degraded in urban or indoor environments, it has the advantage of not having spatial restrictions. With the endless development of smartphone hardware, it is possible to estimate the absolute altitude using the measured value if only the bias of the embedded barometric pressure sensor is applied. The altitude information of the person in need of rescue in an emergency is a great help in reducing rescue time. Since time is tight, we propose online calibration that provides the barometric pressure sensor bias used for altitude estimation through database. Furthermore, experiments were conducted to understand the characteristics of the barometric pressure sensor, which is greatly affected by wind. At the end, the altitude estimation performance was confirmed through an actual field tests in various floors in the building.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권2호
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• pp.247-268
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• 2011

Due to the application-specific nature of wireless sensor networks, the sensitivity to such a requirement as data reporting interval varies according to the type of application. Such considerations require an application-specific, parameter tuning paradigm allowing us to maximize energy conservation prolonging the operational network lifetime. In this paper, we propose a reporting interval adaptive, sensor control platform for energy-saving data gathering in wireless sensor networks. The ultimate goal is to extend the network lifetime by providing sensors with high adaptability to application-dependent or time-varying, reporting interval requirements. The proposed sensor control platform is based upon a two phase clustering (TPC) scheme which constructs two types of links within each cluster - namely, direct link and relay link. The direct links are used for control and time-critical, sensed data forwarding while the relay links are used only for multi-hop data reporting. Sensors opportunistically use the energy-saving relay link depending on the user reporting, interval constraint. We present factors that should be considered in deciding the total number of relay links and how sensors are scheduled for sensed data forwarding within a cluster for a given reporting interval and link quality. Simulation and implementation studies demonstrate that the proposed sensor control platform can help individual sensors save a significant amount of energy in reporting data, particularly in dense sensor networks. Such saving can be realized by the adaptability of the sensor to the reporting interval requirements.

• 한국군사과학기술학회지
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• 제25권5호
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• pp.522-529
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• 2022

In this paper, an experimental study on the control of the plume deflection panel(PDP) with a support jack of the ground launching platform using a tilt angle sensor is described. To overcome the disadvantages of the existing PDP control without a support jack using a limit sensor, the control algorithm using a tilt angle sensor and the ferroelectric RAM in the Launcher Control Unit for recognizing the contact with the ground in an abnormal operation is proposed to control the PDP in various operation environments. Finally, the proposed algorithm can be well applied for not only heavy-load launching platforms but also any other similar systems.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.441-448
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• 2014

USN(Ubiquitous Sensor Network) 응용 소프트웨어는 다양한 대상 운영체제의 핵심모듈들을 기반으로, 다양한 종류의 센서 노드들을 유기적으로 제어하는 복잡한 특징을 가진다. 이에 따라, 현재 USN 응용 분야에서는 효율적으로 소프트웨어를 개발하기 위한 다양한 연구가 진행되고 있다. 본 논문에서는 센서 네트워크 환경에서 하나의 모델로 부터 여러 플랫폼에 맞는 노드 소프트웨어를 효율적으로 개발하기 위한 속성 기반 개발을 지원하는 속성 설계 기법을 제시한다. 제시된 기법에서는 Platform Independent Model과 Platform Specific Model을 만들기 위한 속성을 설계하는 방법을 기술한다. 본 논문에서 제시하는 기법을 사용하면, 속성 값의 선택을 통하여 멀티 플랫폼을 위한 노드 소프트웨어를 손쉽게 디자인함으로써 소프트웨어 개발 생산성은 증대된다. 또한 운영체제의 변화에 따라 속성 변경을 통하여 노드 소프트웨어를 쉽게 재생성할 수 있으므로, 소프트웨어의 유지보수성이 향상된다.

• 한국정보통신학회논문지
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• 제13권5호
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• pp.1022-1029
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• 2009

최근 화두가 되는 유비쿼터스(Ubiquitous)는 "언제, 어디서나 존재하는"을 의미하는 라틴어로 사용자가 네트워크나 컴퓨터를 의식하지 않고 장소에 상관없이 자유롭게 네트워크에 접속할 수 있는 정보통신 환경을 말한다. 본 논문에서 구현한 시스템은 크게 두 부분으로 나누어진다. 한 부분은 환경정보를 감지하여 무선으로 대상 플랫폼에 데이터를 전송이 가능한 센서부로 Gas Sensor와 저전력 Zigbee Module을 사용하여 구현하였으며 센서 노드의 역할 수행한다. 나머지 한 부분은 센서부로부터 얻은 데이터를 수신하여 LCD에 표시하는 플랫폼으로 Sink 노드의 기능을 수행한다. 본 논문에서 구현한 플랫폼은 ARM11기반의 프로세서에 공개소스 기반의 OS(Operating System)인 리눅스를 포팅하여 구현하였다. 또한, 리눅스상의 윈도우 매니저인 Qtopia를 포팅하여 사용 함으로써 사용자 중심의 응용프로그램을 작성하기에 유연하게 하였다.

• 대한임베디드공학회논문지
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• 제7권3호
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• pp.151-156
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• 2012

When mounting the sensor device in the way of Plug&Play, sensor device drivers need to be loaded and linked dynamically. Since a sensor node platform is based on small 8 bit MCU, dynamic loading and linking technique used in Windows and Linux can not be applied. In this paper, we present how to link and load dynamically sensor device drivers for sensor device Plug&Play. We implement a prototype and evaluate it to make sure that there is no performance degradation like sensor device driver connection speed and memory usage. Connection speed overhead increases to 0.2ms. Memory usage overhead increases to hundreds byte. It shows that there is no heavy influence in running the actual program.

• ETRI Journal
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• 제30권4호
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• pp.516-525
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• 2008

This paper proposes a compact, energy-efficient, and smart gas sensor platform technology for ubiquitous sensor network (USN) applications. The compact design of the platform is realized by employing silicon-on-insulator (SOI) technology. The sensing element is fully integrated with SOI CMOS circuits for signal processing and communication. Also, the micro-hotplate operates at high temperatures with extremely low power consumption, which is important for USN applications. ZnO nanowires are synthesized onto the micro-hotplate by a simple hydrothermal process and are patterned by a lift-off to form the gas sensor. The sensor was operated at $200^{\circ}C$ and showed a good response to 100 ppb $NO_2$ gas.