• Smart Structures and Systems
• /
• 제5권4호
• /
• pp.397-413
• /
• 2009

Composite bridges offer many advantages compared to current steel and aluminum bridges. This paper presents the results of a comprehensive on-going research program to develop innovative Diagnostic Prognostic System (DPS) and a structural evaluation of Composite Army Bridge (CAB) system. The DPS is founded on three technologies: optical fiber sensing, remote data transmission, and virtual testing. In developing this system, both laboratory and virtual test were used in different damage scenarios. Health monitoring with DPS entailed comparing live strain data to archived strained data in various bridge locations. For field repairs, a family of composite chords was subjected to simple ramp loads in search of ultimate strength. As such, composite bridge specimens showcased their strengths, heralded the viability of virtual testing, highlighted the efficacy of field repair, and confirmed the merits of health monitoring.

• Smart Structures and Systems
• /
• 제5권2호
• /
• pp.139-152
• /
• 2009

Globally, civil infrastructures are deteriorating at an alarming rate caused by overuse, overloading, aging, damage or failure due to natural or man-made hazards. With such a vast network of deteriorating infrastructure, there is a growing interest in continuous monitoring technologies. In order to provide a true distributed sensor and control system for civil structures, we are developing a Structural Nervous System that mimics key attributes of a human nervous system. This nervous system is made up of building blocks that are designed based on mechanoreceptors as a fundamentally new approach for the development of a structural health monitoring and diagnostic system that utilizes the recently developed piezo-fibers capable of sensing and actuation. In particular, our research has been focused on producing a sensory nervous system for civil structures by using piezo-fibers as sensory receptors, nerve fibers, neuronal pools, and spinocervical tract to the nodal and central processing units. This paper presents up to date results of our research, including the design and analysis of the structural nervous system.

• Smart Structures and Systems
• /
• 제6권9호
• /
• pp.1079-1105
• /
• 2010

Railway transport of goods and passengers is effective in terms of energy conservation and travel time savings. Safety and ride quality have become important issues as train speeds have increased. Due to increased speeds, minor damage to railway structures and abnormal interactions between trains and structures have given rise to increasingly serious accidents. Therefore, structural health and operational conditions must be monitored continuously in all service environments. Currently, various health and operation management systems are being developed and these are reducing both maintenance frequency and costs associated with disassembly. In this review, major damage and malfunctions and their locations are first analyzed based on numerous references. Then advanced train health and operation management technologies are classified into wayside detection methods and advanced integrated sensor methods and their operating principle and functions are reviewed and analyzed.

• Smart Structures and Systems
• /
• 제6권9호
• /
• pp.1007-1023
• /
• 2010

This paper describes the development and evaluation of an innovative TDR distributed moisture sensor. This sensor features advantages of being responsive to the spatial variations of the soil moisture content. The geometry design of the sensor makes it rugged for field installation. Good linear calibration is obtained between the sensor measured dielectric constant and soil physical properties. Simulations by the finite element method (FEM) are conducted to assist the design of this sensor and to determine the effective sampling range. Compared with conventional types of moisture sensor, which only makes point measurement, this sensor possesses distributed moisture sensing capability. This new sensor is not only easy to install, but also measures moisture distribution with much lower cost. This new sensor holds promise to significantly improve the current field instruments. It will be a useful tool to help study the influence of a variety of moisture-related phenomena on infrastructure performance.

• 한국태양에너지학회 논문집
• /
• 제28권6호
• /
• pp.58-63
• /
• 2008

It is essential to investigate the structure and the main characteristic of Home USN (Ubiquitous Sensor Network) technologies in built ubiquitous environment while designing bio-sensors. For this study, Thermistor elements and Thermopile black body have been selected to implement ubiquitous technologies for bio-sensors and wireless network such as WiBro has been used to transfer sensing data to the BSN (Bio-Sensor Network) gateway. It is certain that efficiency of ubiquitous space design is improved if main components of each specific sensor network are analyzed precisely in digital way and corresponding communication modules are prepared accordingly. Ubiquitous technology, in conclusion, has to be applied not only with systematical mechanism or electronic setting but in human-centered atmosphere as well, keeping with deep consideration for bio-housing service factors in eco-friendly surrounding.

• 전자통신동향분석
• /
• 제33권5호
• /
• pp.76-85
• /
• 2018

In recent years, automobiles have evolved from simple transportation to convergence devices, and have combined the Internet of things, high-speed communications, and artificial intelligence technologies to provide people with social and cultural benefits. To provide services such as a smart traffic analysis, autonomous driving, and unmanned driving, automobiles applying these technologies are required to perform various types of sensing and image analyses for vehicle recognition and distance measurements. addition, there has been a rapid increase in the need to introduce an automotive Ethernet, that can provide a wide bandwidth to support. such technologies. In this article, we survey the latest trends in automotive Ethernet based automobiles and their security threats, and analyze the status and prospects of security technologies applied to cope with them.

• 한국안전학회지
• /
• 제26권6호
• /
• pp.64-70
• /
• 2011

In this study, the applicability of PVDF films for measurements of dynamic strain in a structure was investigated. A relationship between the strain and the voltage response of a PVDF film was analytically derived. Free vibration test on a steel cantilever beam was performed and vibration response of the beam was measured both by a convential foil strain gauge and a PVDF film. Strain-voltage relationship obtained from the experiment was compared with the analytic relationship. Good agreement between the analytic and experimental relationships was observed. It was found that a tailored PVDF film can measure the dynamic strain of a structure as accurate as a conventional foil strain gauge.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2017년도 춘계학술대회
• /
• pp.603-604
• /
• 2017

본 논문은 농작물의 생육환경에 있어 날씨와 기온 등 농작물 재배에 최적의 환경에 적합한 비닐하우스 자동 제어 시스템을 제안한다. 제안 시스템은 일광, 개폐, 온습도, 차폐와 비닐하우스 내 외부의 기온차를 이용한 계절별(동절기, 하절기) 수막 가동 및 개폐 자동제어 기능 및 원격 모니터링 기능을 구현한다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.409-412
• /
• 2007

A lot of research for system-on-panel(SOP) have been done to integrate display systems including data driver, gate driver, timing controller, DC-DC converter, and smart functions such as embedded touch screen, ambient brightness sensing and luminance control, finger printing on the glass. Recently, the cost of an one-chip driver IC with various functions has decreased rapidly, and new mobile display interface technologies have been introduced. So it is necessary to examine the feasibility of SOP for practical mobile applications. In this paper, we will re-examine LTPS technologies for mobile displays in terms of various aspects and discuss the practical limitations on SOP technology and future technology trend of mobile displays.

• Smart Structures and Systems
• /
• 제17권6호
• /
• pp.1055-1065
• /
• 2016

An anisotropic ultrasonic transducer is proposed for Lamb wave applications, such as passive damage or impact localization based on ultrasonic guided wave theory. This transducer is made from a PMNPT single crystal, and has different piezoelectric coefficients $d_{31}$ and $d_{32}$, which are the same for the conventional piezoelectric materials, such as Lead zirconate titanate (PZT). Different piezoelectric coefficients result in directionality of guided wave generated by this transducer, in other words, it is an anisotropic ultrasonic transducer. And thus, it has different sensitivity in comparison with conventional ultrasonic transducer. The anisotropic one can provide more information related to the direction when it is used as sensors. This paper first shows its detailed properties, including analytical formulae and finite elements simulations. Then, its application is described.