• 한국소음진동공학회논문집
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• 제24권3호
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• pp.247-252
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• 2014

This paper presents a novel impact sensor which can be fabricated with smart paint made of grapheme. This smart nano paint can be easily installed on structures using a spray-on technique and that can make the sensor low cost and practical. The graphene effectively improves the piezoresistivity of the smart paint and that is available to achieve sensitive impact sensor with high gauge factor. The nano smart-paint can detect sufficient impact to cover the damaged energy range of the composite around 1~3J. The voltage outputs from the sprayed paints show fairly linear responses after signal processing. The impact makes deformation of the structure and it brings change of piezoresistivity of the paint and those converts into voltage output consequently by means of a simple signal processing system. The nano smart paint is lightweight and easily applied to the structural surface, and there is no stress concentration. The nano smart paint is expected to be a cost effective and sensitive multi-functional sensor for composites and other damage monitoring applications in the field of structural health monitoring.

• Smart Structures and Systems
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• 제4권5호
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• pp.565-582
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• 2008

This paper presents a feasibility study of flexible piezoelectric paint for use in wide-band low-profile surface-mount or embeddable ultrasonic sensor for in situ structural health monitoring. Piezoelectric paint is a piezoelectric composite with 0-3 connectivity. Because of its ease of application, piezoelectric paint can be readily fabricated into sensing element with complex pattern. This study examines the characteristics of piezoelectric paint in acoustic emission signal and ultrasonic guided wave sensing. A series of ultrasonic tests including pitch catch and pencil break tests were performed to validate the ultrasonic wave sensing capability of piezoelectric paint. The results of finite element simulation of ultrasonic wave propagation, and acoustic emission generated by a pencil lead break on an aluminum plate are also presented in this paper along with corresponding experimental data. Based on the preliminary experimental results, the piezoelectric paint appears to offer a promising sensing material for use in real-time monitoring of crack initiation and propagation in both metallic and composite structures.

• 항공우주시스템공학회지
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• 제13권2호
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• pp.43-50
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• 2019

위성 및 항공기 부속품 등은 온도 영향에 따라 미션의 가능성 및 안전에 큰 영향을 받게 된다. 또한 무인기를 위해 연구가 활발히 진행되고 있는 연료전지 분야에서도 효율성 및 안정성을 위해 온도는 필수적으로 확인되어야 한다. 본 논문은 큐리 온도 이상에서 저항이 급격히 변화하는 PTC 서미스터의 특성을 이용하기 위해 $BaTiO_3$와 세라믹 성분을 변화시킨 $SrTiO_3$를 이용하여 스마트 페인트를 제작하였으며, 박리를 방지하기 위하여 코팅제를 제작해 코팅 후 저항 변화를 확인하였다. 또한 코팅 전후 $BaTiO_3$ 와 $SrTiO_3$의 온도 변화에 따른 저항 변화를 측정하였다.

• 한국전기전자재료학회논문지
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• 제36권5호
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• pp.433-441
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• 2023

Piezoelectric ceramics play an important role in electrical and electronic devices such as sensors, actuators, and microelectronic devices. However, traditional ceramics are difficult to be used in various process industries due to their high brittleness and low flexibility. Therefore, piezoelectric paint sensors have been designed for application to the curved surfaces of complicated structures. Furthermore, recently, significant attention has been focused on the development of paint sensors that can be used as structure health monitoring sensors for vibration, impact, and acoustic emission. Several studies have successfully demonstrated the possibility that smart paint sensors can take the place of traditional ceramic sensors. In this review, we briefly introduce the concept of the piezoelectric paint sensors and the expected application field as well as their preparation and history.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.180-181
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• 2013

• 산업경영시스템학회지
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• 제46권3호
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• pp.23-31
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• 2023

In this study, a smart bench was developed and researched smart benches that can contribute to user convenience and satisfaction by installing them in parks, bus stops, and tourist attractions in line with the rapidly changing construction of smart cities. The smart bench is automatically operated by the control system according to the external temperature and provides additional functions such as charging, lighting, and advertising to improve general bench functions as well as heating in winter and cooling in summer, making it suitable for smart urbanization. The developed smart bench is designed to be strong enough to withstand loads of about 2,500 N. It minimizes the visible parts such as assembled bolts and 220V power supply wires, It can also give aesthetic effects. The development was carried out with the aim of waterproofing and dustproofing of IP44 grade in accordance with the climate of Republic of Korea, which has four seasons, and it is advantageous for long-term use because the paint was selected for the weather ability (discoloration) grade 3 or higher. If smart bench is commercialized, it is believed that various options can be provided to the smart bench market, where buyers had few product options, as the parts were developed in an assembled type so that all functions can be responded in an optional form according to the installation environment and the buyer's budget.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.15-22
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• 2020

With the need for efficient maintenance technology to reduce maintenance costs for steel bridges, repainting robots are being developed to automate the work in narrow and poor bridge spaces. The repainting robot is equipped with a blasting module to remove paint layers and contaminants. This study developed a prototype monitoring module to be mounted on the repainting robot. The monitoring module analyzes the condition of the painting surface through a camera installed in the front, guides the direction of movement of the robot, and provides the operator with a video to check the working status after blasting through a camera installed in the back. Various image visibility enhancement technologies were applied to the monitoring module to overcome worksite challenges where incomplete lighting and dust occurs.

• 생물환경조절학회지
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• 제32권3호
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• pp.197-204
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• 2023

본 연구에서는 육계사에 차열 페인트와 히트펌프의 적용에 따른 내부 온도 변화를 분석 하였다. 이를 위하여 환기율, 환기 방법, 시간별 환기 변화에 따른 실험 조건을 설정하였으며 육계사 외부 및 내부 기온을 측정하였다. 그 결과, 차열 페인트를 도포한 육계사에서는 최대 1-2℃ 실내 기온 상승을 억제하는 효과가 나타났으며 히트펌프를 가동한 육계사에서는 외기 온도의 영향을 제일 적게 받는 환기율 0%일 때 내부 기온 감소가 제일 크게 나타났다. 계사 내부의 온도가 외기 온도보다 높을 경우에는 환기율을 높게 설정하여 환기팬을 이용한 냉방이 더욱 효과적이나 계사 내부 온도가 외기 온도와 유사하거나 낮을 경우에는 히트펌프를 이용하는 것이 가장 효과적일 것으로 판단된다. 히트펌프 가동 시 외기 온도의 영향이 적은 환기율을 0%로 설정하였을 때 내부 기온이 가장 큰 폭으로 감소하였으나 실제 육계사에서는 분진, 이물질, 암모니아 등을 고려하여 최소환기율 정도로 환기율을 설정한 후 히트펌프를 가동하는 것이 가장 효율적일 것으로 판단된다. 본 연구는 실험 기간이 짧아 데이터가 많지 않으며 실제 육계가 사육되고 있는 환경에서 실험을 진행한 것이 아니라는 한계가 있다. 향후 후속 연구로 실제 닭이 사육되고 있는 환경에서의 히트펌프 효과 분석과 히트펌프의 전력사용량, 냉방부하, 환기팬 가동시간 등 다양한 환경인자를 포함한 연구가 진행되어야 할 것으로 판단된다.

• 대한인간공학회지
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• 제33권6호
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• pp.543-551
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• 2014

Objective: The purpose of this study is to identify visual perception of and satisfaction with the orange peel effect of surface. The orange peel effect is a type of finish on painted or coated surface. Background: Gloss paint sprayed on a smooth surface (such as car body, smart phone, and electric home appliances, etc.) should also dry into a smooth surface. Then, a surface resembling the texture of an orange peel can be caused by some factors. The orange peel effect can degrade user's satisfaction with a product. Method: Visual perception and emotional satisfaction were subjectively evaluated using Likert scale. The significance of orange peel effect on visual perception and satisfaction were then analyzed by the analysis of variance. The correlation between visual perception and satisfaction was also analyzed. Results: Surface roughness significantly influenced visual perception and emotional satisfaction. The level of visual perception increased and emotional satisfaction decreased with the increase of orange peel effect. Emotional satisfaction decreased with the increase of visual perception level. Conclusion: It was identified that orange peel phenomenon on surface was a very important factor for emotional satisfaction. The orange peel effect on the surface of a product should be minimized to improve the emotional satisfaction of the product. Application: The result of this study can be applied to the texture design of the body of a car, smart phones, and electric home appliances, etc.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.745-751
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• 2011

내부식성이 강화된 새로운 방청안료를 개발하기 위한 연구의 일환으로, 본 연구에서는 높은 내부식성을 제공하는 아연 및 세륨 이온 교환된 제올라이트를 도입하였다. 그리고 이온교환 제올라이트를 이용하여 프라이머 도료 제조 및 도장을 수행한 후, 그것의 방식성능을 측정하였다. 도장을 위한 금속 기재는 아연도금(galvanized, GI) 강판이었고, 도장된 강판의 방식성능은 electrochemical impedance spectroscopy(EIS)와 scanning vibrating electrode technique(SVET)으로 측정되었다. EIS 및 절단면의 내부식성을 확인하기 위한 SVET 측정으로부터 세륨이온 교환된 제올라이트가 가장 높은 효율을 제시하였고, 아연 및 세륨 이온 교환된 제올라이트의 경우 GI 강판에 대하여 cathodic 부식 방지제로 기여함을 확인할 수 있었다.