• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.30-35
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• 2021

To operate an underwater robot in an environment with fluid flow, it is necessary to recognize the speed and direction of the fluid and implement motion control based on these characteristics. Fish have a lateral line that performs this function. In this study, to develop an artificial lateral line sensor that mimics a fish, we developed a method to measure the flow speed and the incident angle of the fluid using a pressure sensor. Several experiments were conducted, and based on the results, the tendency according to the change in the flow speed and the incident angle of the fluid was confirmed. It is believed that additional research can aid in the development of an artificial lateral line sensor.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.335-340
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• 2013

Purpose: This study was performed to develop a lateral flow strip sensor for the detection of pathogenic Escherichia coli O157:H7 in various samples. Also, feasibility of using an image analysis method to improve the interpretation of the strip sensor was evaluated. Methods: The lateral flow strip sensor has been fabricated based on nitrocellulose lateral-flow membrane. Colloidal gold and E. coli O157:H7 antibodies were used as a tag and a receptor, respectively. Manually spotted E. coli O157:H7 antibody and anti-mouse antibody on nitrocellulose membrane were used as test and control dots, respectively. Feasibility of the lateral flow strip sensor to detect E. coli O157:H7 were evaluated with serially diluted E. coli O157:H7 cells in PBS or food samples. Test results of the lateral flow strip sensor were measured with an image analysis method. Results: The intensity of the test dot started to increase with higher concentration of the cells were introduced. The sensitivities of the sensor were both $10^4$ CFU/mL Escherichia coli O157:H7 spiked in PBS and in chicken meat extract, respectively. Conclusions: The lateral flow strip sensor and image analysis method could detect E. coli O157:H7 in 20 min, which is significantly quicker than conventional plate counting method.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1391-1393
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• 1994

A silicon microbridge flow sensor has been developed. The heat transfer within silicon microbridge is modeled to predict the characteristics of the sensor. The flow sensor shows high sensitivity at small flow rate. This device is simple to fabricate, using standard IC and micromachining technology.

• Journal of Power System Engineering
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• v.7 no.3
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• pp.35-39
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• 2003

In this paper, the heat transfer phenomena in the sensor tube of a mass flow controller(MFC) were studied by experiments. In the sensor tube of MFC, the difference of temperature between inlet and outlet was necessary for calculating the mass flow rate. Therefore, the relations of flow rate, generated heat by heating wire, sensor location and tube thickness were investigated to find the optimized condition. Based on this study, static and dynamic characteristics of sensor can be used for mass flow controller.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1217-1222
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• 2012

A wall flow sensor has been used for feedback flow control and wall shear stress measurement. In this study, we developed a new wall flow sensor by combining the PIV algorithm and the micro image sensor used in an optical mouse. The feasibility of the wall flow sensor was investigated by using simulated fluid flow experiments. Compared with the quadrature signal from imaging devices, the accuracy of the wall flow velocity measurement was improved and the dynamic range increased. In addition, the depth information of particles was also measured by using the defocusing imaging technique.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.363-366
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• 2005

A micro flow sensor on silicon substrate allows the fabrication of small components where many different functions can be integrated so that the functionality of the sensors can be increased. Further more, due to the small size of the elements the sensors can be quite fast. A thermal mass flow sensor measures the asymmetry of temperature profile around the heater which is modulated by the fluid flow. In normal, a mass flow sensor is composed of a central heater and a pair of temperature sensing elements around the heater. A new 2-D wide range micro flow sensor structure with three pairs of temperature sensors and a central heater was proposed and numerically simulated by the Finite difference formulation to confirm the feasibility of the flow sensor structure.

• Tribology and Lubricants
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• v.40 no.4
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• pp.139-143
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• 2024

This study evaluates the sensitivity of a ferrous particle sensor in response to changes in viscosity in a gearbox. Composed of various gears, the gearbox typically occurs significant ferrous wear due to gear contact. Condition monitoring is primarily implemented by measuring the number of ferrous wear particles in the lubricant. Gearboxes are critical in many systems, including wind turbines, for facilitating changes in speed and torque. Therefore, technology to monitor ferrous particles in gearboxes is essential. In this study, a simplified gearbox is numerically modeled to assess sensor sensitivity based on viscosity and sensor position. Three sensor positions are considered: one directly beneath the gear and two at locations farther from the gear. Analyses are conducted using lubricants with low viscosity and gear oil. Sensor sensitivity is defined by the number of ferrous particles adhering to the sensor, where more particles indicated higher sensitivity. The evaluation reveals that the position directly beneath the gear exhibits the highest sensitivity due to direct influence from the main flow. To achieve optimal sensitivity, sensors should be installed in the main flow path as determined by flow analysis. Evaluation of sensor sensitivity with changes in viscosity shows that a higher viscosity results in a lower sensor sensitivity. Therefore, for ease of analysis, performing an analysis under low-viscosity conditions is useful for understanding the main flow and for identifying the optimal location for proper sensor position.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.393-399
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• 2011

In this paper, we designed and fabricated the novel air flow sensor using air drag force, which can be applied to the low air flow detection. To measure the low air flow, we should enlarge the air drag force and the output signal at the given air flow. The paddle structure is applied to the device, and the device is vertically located against the air flow to magnify the air drag force. We also adapt the corrugation structure to improve the output signals on the given air velocity. The device structure is made up of the silicon nitride layer and the output signal is measured with the piezoresistive layer. The output signals from the corrugated device show the better measurement sensitivity and the response time than that of flat one. The repeated measurement also shows the stabilized signals.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.308-313
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• 2003

Thermal mass flow meters (TMFMs) are most widely used for measuring mass flow rates in the semiconductor industry. A TMFM should have a short response time in order to measure the time-varying flow rate rapidly and accurately. Therefore it is important to study transient heat transfer phenomena in the sensor tube of a TMFM that is the most critical part in the TMFM. In the present work, a simple numerical model for transient heat transfer phenomena of the sensor tube of a TMFM is presented. Numerical solutions for the tube and fluid temperatures in a transient state are obtained using the proposed model and compared with experimental results to validate the proposed model. Based on numerical solutions, heat transfer mechanism in a transient state in the sensor tube is explained. Finally, a correlation for predicting the response time of a sensor tube is presented. The correlation is verified by experimental results.

• Journal of Navigation and Port Research
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• v.32 no.9
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• pp.717-722
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• 2008

We have proposed and demonstrated an gas-flow sensor using optical fiber bragg grating(FEG). The flow sensor has no electronics and no mechanical parts in its sensing part and the structure is th11s simple and immune to electromagnetic interference(EMI). The FEG sensor was consisted qf the sensing element and a coil heater. The metal coil was used to supply the current to the FEG. While some currents supply to the coil, the refractive index of the FEG under the coil is changed and thus the wavelength shift of fiber optic sensor was induced In this work, the wavelength shift according to flow-rate was experimentally studied and was used to evaluate the gas flow-rate in a gas tube. As a result, it was possible to measure the flow-rate in a linear range from 5 to $20{\ell}/min$ with a resolution of approximately $1{\ell}/min$ at the applied currents of 100 mA and 120 mA. The measured sensitivities were $15.3\;pm/\ell/min$ for 100 mA and $20.2\;pm/\ell/min$ for 120 mA.