• 센서학회지
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• 제5권6호
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• pp.15-24
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• 1996

본 연구에서는 광섬유센서를 지능형 복합재 구조물에 적용하기 위한 기초적 연구의 일부로서, 구조물내에서의 광섬유센서의 건전성 평가와 주조물에 유발된 변현 및 손상에 대한 광섬유센서의 신호검출 거동을 연구 검토하였다. 첫째로, 최약체결파손이론에 거한 광섬유센서의 누적파손분포를 비교하고 수정계수를 도입함으로써, 굽힘시험이 인장시험을 대신할 수 있음을 보였다. 실험에 의해 Weibull 파라미터를 얻고, 굽힘시험에서 유도된 누적파손분포에 적용될 수정계수를 구했다. 열처리한 강섬유센서와 열처리하지 않은 광섬유센서의 인장강도 평균값을 비교함으로써 복합재료 적층관의 경화 사이클 동안 열처리에 의해 야기되는 광섬유센서의 건전성을 평가하였다. 둘째로, 직교적층판과 일방향적층판의 인장시험에서 측정된 시편의 응력-변형률과 삽입된 광섬유센서를 통과한 레이저신호 세기와의 관계를 검토하고, 광섬유센서를 이용한 효과적 손상검출 가능성을 연구 검토하였다.

• 한국지진공학회논문집
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• 제10권6호
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• pp.137-145
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• 2006

최근 건설기술이 발달함에 따라 점차적으로 더욱 높은 정확성과 신뢰성을 바탕으로 구조물의 상태를 파악 또는 예측 할 수 있는 기술적인 체제가 요구되고 있는 시점에서, 광섬유센서는 내구성과 높은 분해능, 전자기파 노이즈 저항성, 절대값의 측정, 다중화 등의 가지고 있는 여러 장점 때문에 미국 등 선진국의 경우 교량, 터널 그리고 건물 등에 변위와 변형률 측정에 많은 설치가 진행되어 왔고, 광섬유 센서를 이용한 시스템이 구조물의 안정성과 잔존수명을 판단하는 기준으로 중요한 역할을 할 것으로 기대되고 있다. 본 논문에서는 이러한 광섬유센서 중에서 일반적으로 가장 많이 사용하고 있는 광섬유격자 센서의 응용의 폭을 확대하기 위하여 여러 가지 응용분야에 적용하고자 하였으며, 특히 전단응력이 많이 걸려 foil형 스트레인 게이지를 사용하기 어려운 보 기둥 접합부에 적용하여 광섬유격자 센서가 일반적으로 사용되는 전자식 변위 센서들과 정밀도가 대단히 차이가 나고 있음을 보여주고 있고, 복합재료와 콘크리트 접합 구조물에 적용하여 흔히 발생하는 결함인 delamination을 측정하는데 광섬유격자 센서가 유효적절함을 보여주고 있으며, 원자력발전소 격납구조물과 같은 대형구조물에 적용하여 변위를 측정함에 있어서 광섬유격자 센서가 시공도 용이하고 데이터도 양호함을 보여 주고 있어, 기존의 어떤 구조물도 광섬유센서를 적용하여 쉽게 광섬유 스마트구조물화 할 수 있음을 보여준다.

• Smart Structures and Systems
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• 제7권3호
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• pp.223-228
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• 2011

An understanding of biomaterials' smart properties and how biocomposite materials are manufactured by cells provides not only bio-inspiration for new classes of smart actuators and sensors but also foundational technology for smart materials and their manufacture. In this case study, I examine the unique smart properties of bone, which are evident at multiple length scales and how they provide inspiration for novel classes of mechanoactive materials. I then review potential approaches to engineer and manufacture bioinspired smart materials that can be applied to solve currently intractable problems such as the need for "smart" body armor or decor cum personal safety devices.

• 한국콘텐츠학회논문지
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• 제9권12호
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• pp.477-484
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• 2009

스마트 의류가 고객 중심으로 다변화 되어가는 생활환경 속에서 날씨정보를 제공하는 것은 서비스 전략의 중요한 성공요소가 되고 있다. 최근에는 스마트 의류의 다양한 어플리케이션이 연구자와 개발자에 의해 제시되고 있다. 그 중 센서 기반의 스마트 의류는 시장에서 가장 수요가 높을 것으로 기대된다. 본 논문에서는 웨어러블 기반의 스마트 모자를 이용한 생활기상지수 모니터링 시스템을 제안하였다. 제안된 스마트 모자를 착용하여, 기상상태를 수집하고 신호를 UMPC로 무선 전송되어 이를 실시간으로 모니터링 할 수 있도록 고안하였다. 센서에 따른 생활기상지수를 제공하기 위해서, 기상지수를 6가지 요소(열지수, 식중독지수, 불쾌지수, 자외선지수, 체감온도지수, 동파가능지수)에 따라 분석하였다. 생활기상지수 모니터링 시스템을 개발하여 논리적 타당성과 유효성을 검증하기 위해 실험적인 적용을 시도하고자 한다. 따라서 스마트 의류에서 서비스의 만족도와 질을 향상시켰다.

• 비파괴검사학회지
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• 제24권5호
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• pp.465-475
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• 2004

본 논문은 두 편으로 구성된 스마트 능동 레이어(smart active layer, SAL) 센서 개발에 관한 첫 번째 논문으로, 구조 내에 발생하는 균열 및 손상에 의한 탄성파 검출을 위한 SAL 센서의 이론 및 개념을 연구하였다. 본 SAL 센서의 개발을 위해, 첫째, 탄성파의 기본 이론을 고찰하였고, 둘째, 이론적 토대 위에 단일 압전 disc의 유한요소해석법(finite element analysis, FEA)을 이용하여 탄성파 검출 센서로서의 가능성을 검증하였고, 셋째, 몇 종류의 압전 disc 센서와 상용 음향방출(acoustic emission, AE) 센서를 연필심 파괴시험을 통해 상호 성능을 비교하여 실험적으로 그 가능성을 확인하였다. 또한 수 개의 센서를 일정한 거리로 분포시켜서 구조물 결함의 효과적 검출 및 위치 표정이 가능한 스마트능동레이어 센서의 개념연구를 수행하였다.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.423-438
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• 2010

Wireless smart sensors enable new approaches to improve structural health monitoring (SHM) practices through the use of distributed data processing. Such an approach is scalable to the large number of sensor nodes required for high-fidelity modal analysis and damage detection. While much of the technology associated with smart sensors has been available for nearly a decade, there have been limited numbers of fulls-cale implementations due to the lack of critical hardware and software elements. This research develops a flexible wireless smart sensor framework for full-scale, autonomous SHM that integrates the necessary software and hardware while addressing key implementation requirements. The Imote2 smart sensor platform is employed, providing the computation and communication resources that support demanding sensor network applications such as SHM of civil infrastructure. A multi-metric Imote2 sensor board with onboard signal processing specifically designed for SHM applications has been designed and validated. The framework software is based on a service-oriented architecture that is modular, reusable and extensible, thus allowing engineers to more readily realize the potential of smart sensor technology. Flexible network management software combines a sleep/wake cycle for enhanced power efficiency with threshold detection for triggering network wide operations such as synchronized sensing or decentralized modal analysis. The framework developed in this research has been validated on a full-scale a cable-stayed bridge in South Korea.

• International journal of advanced smart convergence
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• 제8권3호
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• pp.184-192
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• 2019

The existing digital signage systems inside the elevators are a lack of tailored contents appropriate to the space and environment inside or outside the elevators. Also, they almost impossible to flexibly respond to various contents disclosure according to the demand of the consumers or the elevator markets. Therefore we design and implement an IoT(Internet of Things)-based smart digital signage system for the safety of elevator passengers.. In order to provide IoT-based information to the smart digital signage within the elevator, we propose an IoT system as a set-top box with gyroscope sensor, acceleration sensor, RFID(Radio-Frequency Identification), fine dust sensor, etc., which processes various data collected by the sensors and provides the elevator passengers with various tailored contents such as elevator driving information, environmental information inside and outside the elevator, and disaster information in addition to simple advertisement information. The proposed IoT system is a set-top box that operates the smart digital signage and has an independent information control processor based on the IoT sensors that do not depend on the elevator control system. For the proposed smart digital signage, it supports an operating system that is independent of the elevator driving service as well as the media service. So the smart signage system has a characteristic that it does not depend on the elevator control system since it is a stand-along IoT-based information control system. With the proposed system providing intuitive content for the surge, steep descent, and radical movements of an elevator due to an emergency situation, the elevator passengers should be able to recognize the situation quickly and respond accordingly. In the near future, the proposed system will expand the market of digital signage applied in conjunction with the development of contents in the disaster, safety and environment fields, and expect expected to revitalize related industries associated with signage.

• 한국의류산업학회지
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• 제18권6호
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• pp.733-745
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• 2016

This paper provides a review of wearable textile strain sensors that can measure the deformation of the body surface according to the movements of the wearer. In previous studies, the requirements of textile strain sensors, materials and fabrication methods, as well as the principle of the strain sensing according to sensor structures were understood; furthermore, the factors that affect the sensing performance were critically reviewed and application studies were examined. Textile strain sensors should be able to show piezoresistive effects with consistent resistance-extension in response to the extensional deformations that are repeated when they are worn. Textile strain sensors with piezoresistivity are typically made using conductive yarn knit structures or carbon-based fillers or conducting polymer filler composite materials. For the accuracy and reliability of textile strain sensors, fabrication technologies that would minimize deformation hysteresis should be developed and processes to complement and analyze sensing results based on accurate understanding of the sensors' resistance-strain behavior are necessary. Since light-weighted, flexible, and highly elastic textile strain sensors can be worn by users without any inconvenience so that to enable the users to continuously collect data related to body movements, textile strain sensors are expected to become the core of human interface technologies with a wide range of applications in diverse areas.

• International journal of advanced smart convergence
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• 제3권2호
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• pp.14-17
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• 2014

Precision agriculture relies on information technology, whose precondition is providing real-time and accurate information. It depends on various kinds of advanced sensors, such as environmental temperature and humidity, wind speed, light intensity, and other types of sensors. Currently, it is a hot topic how to collect accurate information, the main raw data for agricultural experts, monitored by these sensors timely. Most existing work in WSNs addresses their fundamental challenges, including power supply, limited memory, processing power and communication bandwidth and focuses entirely on their operating system and networking protocol design and implementation. However, it is not easy to find the self-localization capability of wireless sensor networks. Because of constraints on the cost and size of sensors, energy consumption, implementation environment and the deployment of sensors, most sensors do not know their locations. This paper provides maximum likelihood estimators for sensor location estimation when observations are time-of arrival (TOA) range measurement.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.938-942
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• 2007

The proposed algorithm tries to localize damage in a structure by monitoring abnormal increases in strain measurements from a group of wireless sensors. Initially, this clustering technique provides an effective sensor placement within a structure. Sensor clustering also assigns a certain number of master sensors in each cluster so that they can constantly monitor the structural health of a structure. By adopting a voting system, a group of wireless sensors iteratively forages for a damage location as they can be activated as needed. Numerical simulation demonstrates that the newly developed searching algorithm implemented on wireless sensors successfully localizes stiffness damage in a plate through the local level reconfigurable function of smart sensors.