In this research, reduced graphene oxide/polypyrrole (rGO/PPy) particles were synthesized and used to measure the amount of dopamine (DA) electrochemically. The obtained rGO/PPy particle was characterized by Fourier Transform Infrared Spectrophotometer (FTIR), UV–Visible Spectrophotometer (UV–Vis), and X-Ray Diffraction Diffractometry (XRD). To investigate the DA sensor performance, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to acquire electrochemical measurements of the sensor. Current values of 1.65 and 5.9 mA were observed in the CV at 0.2 mM and 1.2 mM concentrations of target molecule, respectively. Under optimized conditions, the linear calibration plots were found to exhibit significant sensitivity in the linear range of 0.2 and 1.2 mM, with a corresponding detection limit of 0.061 μM for DA. The results obtained were similar to the sensor results of DA made using precious metals. This work was a demonstration of the feasibility of high-sensitivity electrochemical analysis with conductive carbon materials without the use of precious metals. It was also observed that the cost-effective rGO/PPy exhibited a very high potential for DA detection.

The purpose of this study is to analyze the effect of temperature and humidity on the measured Particulate Matter (PM) concentrations recorded by PMS5003T, a low-cost light scattering type measuring tool. A regression analysis was performed on the ratio of PM concentrations measured by the light scattering method and the beta-ray absorption method according to temperature and humidity in an outdoor environment. As the temperature decreased, the PM concentration ratio increased, and this tendency intensified below 0oC. As the humidity increased, the PM concentration ratio increased, but the effect was less than the temperature effect. The coefficients of determination for temperature and humidity were R2 = 0.325 and 0.003, respectively, and the effects of temperature and humidity on the measured values w ere formulated and compensated for. As a result of the compensation, R2, relative precision, accuracy and RMSE improved from 0.927 to 0.958, from 91.183% to 96.651%, from 31.383% to 74.058%, and from 13.517 μg/m³ to 6.690 μg/m³, respectively. Finally, results from this study indicate that the reliability of the low-cost light scattering type PM sensor can be improved by applying the temperature and humidity compensation method.

센싱 기술의 발달로 다양한 종류의 매체를 이용한 우수한 차량 검지장비들이 개발되고 있는 요즘, 간단한 구조의 저가형 검지장비 또한 적은 예산으로 여러 곳에 설치할 수 있다는 장점 때문에 지속적인 연구가 이루어지고 있다. 본 연구에서는 저가형 차량 검지장비로서 센서를 사선으로 설치하여 좌우 및 전후 바퀴의 통과시간 간격과 차량의 윤거값을 적용하여 차량속도를 추정하는 방법을 제안하였다. 출고된 차량의 제원조사에서 얻어진 대표 윤거값을 축거와 뒤윤거의 비율에 따라 소형과 대형 차량으로 구분하여 적용하므로 기존의 연구보다 정확한 속도추정이 가능하도록 개선하였다. 특히, 소형과 대형차량을 구분하는 파라미터를 통하여 조사지점의 차종구성 비율을 고려한 정확도 보정이 가능하다. 간단하고 저가로 개발된 본 연구의 사선형 센서를 이용한 검지장비는 적은 비용으로 교통상황을 설명하는데 효율적으로 활용될 것으로 기대된다.

We have tested the measuring system that can monitor the dynamic behaviour of floating structure by various sensors. In this paper, we present a initial result using a low-cost GPS sensor, which showed the inaccurate position and insufficient frequency for a floating structure.