• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.249-252
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• 1997

The resolution of analog sensor is determined by its sensitivity and amplitude of noise. This paper presents modeling of inductive gap sensor base on equivalent magnetic circuit and analysis of sensitivity. The model of inductive gap sensor is verified by the experimental results. Then we can simulate static characteristic of inductive gap sensor using this model. Computer simulation show that sensor's sensitivity and linearity are affected by magnetic flux's leakage and fringing, and that they are affected by shape of sensor probe.

• Smart Structures and Systems
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• v.1 no.2
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• pp.121-140
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• 2005

This paper presents a systematic investigation of the effect of sensor location on the data quality and subsequently, on the effectiveness of machine health monitoring. Based on an analysis of the signal propagation process from the defect location to the sensor, numerical simulations using finite element modeling were conducted on a bearing test bed to determine the signal strength at several representative sensor locations. The results showed that placing sensors closely to the machine component being monitored is critical to achieving high signal-to-noise ratio, thus improving the data quality. Using millimeter-sized piezoceramic plates, the obtained results were evaluated experimentally. A comparison with a set of commercial vibration sensors verified the developed structural dynamics-based sensor placement strategy. It further demonstrated that the proposed shock wave-based sensing technique provided an effective alternative to vibration measurement, while requiring less space for sensor installation.

• Korean Journal of Remote Sensing
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• v.30 no.1
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• pp.75-81
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• 2014

Until recently, photogrammetric applications for processing the satellite images and remotely sensed data have been used in different structure of functions and interfaces for sensor modeling by each developer. Thus, a standardized utilization procedure was necessary to solve the problems, such as expandability, cost, inefficiency of sources which were resulted from different approaches. Therefore, National Geospatial Intelligence Agency (NGA) provided unified interfaces by developing Community Sensor Model (CSM) to sensor models in same way. In this study, we suggested the method of design and analyzed main functions needed modeling for the frame sensor using CSM Application Program Interface (API) provided by NGA. We also applied the designed structure to the modeling. The implemented CSM was verified by groundToImage and imageToGround. In the future, the active R&D is expected with using CSM due to the cost saving effect of software development and remarkable expandability of sensor.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.6
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• pp.490-495
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• 2016

Pulsed eddy current (PEC) testing signals have typically been obtained from the electromotive force induced in a sensor coil. However, an increasing number of studies have elected to incorporate the Hall plate as a sensor. Thus, accurate numerical modeling of the Hall sensor signal is necessary. In this study, a PEC probe is designed and a numerical modeling program is written so that Hall sensor signals and coil sensor signals can be calculated simultaneously. First, a step current is used as the input current. The predicted Hall sensor signals show similar characteristics to those of the experimental signals reported by other researchers. The characteristics of the two types of signals are then analyzed and compared as the thickness of test object changes. The results show that the Hall sensor signal provides less information for evaluating the thickness of the test object than the coil sensor signal. The response signals from a pulsed input current are also calculated, and it is confirmed that an equivalent reversed signal pattern appeared after the pulse width at both signals.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.49-55
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• 2016

Nowadays there are magnetic sensors in a wide variety of equipment such as computers, cars, airplanes, medical and industrial instruments. In many of these applications the magnetic sensors offer safe and non-invasive means of detection and are more reliable than other technologies. The electric current in a conductor generates a magnetic field detected by this type of sensor. This work aims to define a package dedicated to an electrical current sensor using a MTJ (Magnetic Tunnel Junction) as a sensing device. Four different proposals of packaging, three variations of the chip on board (CoB) package type and one variation of the thin small outline package (TSOP) were analyzed by COMSOL modeling software by simulating a brad range of current injection. The results obtained from the thermal and magnetic analysis has proven to be very important for package improvements, specially for heat dissipation performance.

• Journal of the Korea Society of Computer and Information
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• v.25 no.5
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• pp.57-64
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• 2020

In this paper, based on the building's 3D modeling, a digital twin-based building control system using the collection information of wireless sensor box is proposed. The proposed system applies wireless sensors, making sensor modules more expandable and usable, and more intuitive building control possible through three-dimensional modeling. In addition, effective control and visual representation are possible through BIM data. Sensor boxes have been designed for general purpose so that a variety of sensor modules can be added and have been implemented for actual university buildings to demonstrate high availability. The results of this paper could be used to implement a digital twin control platform in the future.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.539-543
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• 2005

The research presented in this paper enables real-time 3D modeling to help make construction processes ultimately faster, more predictable and safer. Initial research efforts used an emerging sensor technology and proved its usefulness in the acquisition of range information for the detection and efficient representation of static and moving objects. Based on the time-of-flight principle, the sensor acquires range and intensity information of each image pixel within the entire sensor's field-of-view in real-time with frequencies of up to 30 Hz. However, real-time working range data processing algorithms need to be developed to rapidly process range information into meaningful 3D computer models. This research ultimately focuses on the application of safer heavy equipment operation. The paper compares (a) a previous research effort in convex hull modeling using sparse range point clouds from a single laser beam range finder, to (b) high-frame rate update Flash LADAR (Laser Detection and Ranging) scanning for complete scene modeling. The presented research will demonstrate if the FlashLADAR technology can play an important role in real-time modeling of infrastructure assets in the near future.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.187-195
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• 2008

Generation of accurate ground coordinates from high resolution satellite image are becoming increasingly of interest. The primary focus of this paper is to compute satellite direct sensor model (DSM) and rational function model (RFM) for accurate generation of ground coordinates from high resolution satellite images. Being based on this we presented an algorithm to be able to efficiently ground coordinates about large area with introducing RFM(rational function model) method applied to rigorous sensor modeling standing on basis of satellite orbit dynamics and collinearity equation, and sensor modeling of high-resolution satellite data like IKONOS, QuickBird, KOMPSAT-2 and others. The general high resolution satellite measures the position, velocity and attitude data of satellite using star, gyro, and GPS sensors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.371-376
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• 1994

This paper presents an on-line modeling method approach for the machine condition. the machine condition is continuously monitored with a sensor such as, a vibration, a current, an acoustic emission (AE) sensor. In this study, neural network modeling by radial basis function is designed for analysis a prediction error. An on-line learning algorithm is designed using the RLS(recursive least square) estimation and the existing clustering method of Kohonen neural network. Experimental results show that the proposed RBNN modeling is suitable for predicting simulated data.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.42-49
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• 2005

Our purpose is to develop a precision magnetic displacement sensor that has sub-micron resolution and small size probe. To achieve this, we first have tried to establish mathematical models of a magnetic sensor in this paper. The inductance model that presents basic measuring principle of a magnetic sensor is based on equivalent magnetic circuit method. Especially we have concentrated on modeling of magnetic flux leakage and magnetic flux fringing. The induced model is verified by experimental results. The model, including the magnetic flux leakage and flux fringing effects, is in good agreement with the experimental data. Subsequently, based on the augmented model, we will design magnetic sensor probe in order to obtain high performances and to scale down the probe.