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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Sensor Science and Technology
Journal Basic Information
Journal DOI :
The Korean Sensors Society
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Volume & Issues
Volume 25, Issue 4 - Jul 2016
Volume 25, Issue 3 - May 2016
Volume 25, Issue 2 - Mar 2016
Volume 25, Issue 1 - Jan 2016
Selecting the target year
Recognition of Falls and Activities of Daily Living using Tri-axial Accelerometer and Bi-axial Gyroscope
Park, Geun-chul ; Kim, Soo-Hong ; Kim, Jae-hyung ; Shin, Beum-joo ; Jeon, Gye-rok ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 79~85
DOI : 10.5369/JSST.2016.25.2.79
This paper proposes a threshold-based fall recognition algorithm to discriminate between falls and activities of daily living (ADL) using a tri-axial accelerometer and a bi-axial gyroscope sensor mounted on the upper sternum. The experiment was executed ten times according to the proposed experimental protocol. The output signals of the tri-axial accelerometer and the bi-axial gyroscope were measured during eight falls and eleven ADL action sequences. The threshold values of the signal vector magnitude (SVM_Acc), angular velocity (
), and angular variation (
) parameter were calculated using MATLAB. From the preliminary study, three thresholds (TH1, TH2, and TH3) were set so that the falls could be distinguished from ADL. When the parameter SVM_Acc is greater than 2.5 g (TH1),
is greater than 1.75 rad/s (TH2), and
is greater than 0.385 rad (TH3), these action sequences are recognized as falls. If at least one or more of these conditions is not satisfied, the sequence is classified as ADL.
Structural Design and Analysis for 3D Ultrasonic Anemometer
Kim, Kyung-Won ; Choi, Jae-Yeong ; Lee, Woo-Jin ; Lee, Seon-Gil ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 86~90
DOI : 10.5369/JSST.2016.25.2.86
A 3D ultrasonic anemometer measures the direction and velocity of wind in a 3D space. The 2D ultrasonic anemometers developed by different manufacturers do not differ significantly in terms of their form or structure. The 3D ultrasonic anemometers, on the other hand, have more diverse forms than their 2D counterparts depending on the measurement algorithms and methods. Designing and reviewing the structure at the initial stage and defining its performance objectives are time-consuming processes. The process can be made cost-effective and time-saving if the validity is tested by model design and structural interpretation, and the structure is designed to withstand high wind velocities. This study presents the results of a 3D ultrasonic anemometer on real sample data by using a 3D modeling program, CATIA, for ultrasonic anemometer modeling.
Railway Track Maintenance Scheduling using Artificial Bee Colony and Harmony Search
Kim, Ki-Dong ; Kim, Sung-Soo ; Nam, Duk-Hee ; Jeong, Hanil ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 91~102
DOI : 10.5369/JSST.2016.25.2.91
The objective of this paper is to propose a heuristic algorithm to optimize the railway track maintenance scheduling, a NP-hard problem, by reflecting conditions of the actual field more quickly and easily. We develop the mechanism based on Binary Artificial Bee Colony (BABC) and Binary Harmony Search (BHS), and verify their performance through simulation experiments. Our proposed BABC and BHS mechanisms were applied to problems composed of 30, 60, 100, and 200 operations for railway track maintenance scheduling to carry out experiments and analysis. On comparing it with the results solved by CPLEX, it is found that the mechanism could present an optimal solution within limited time by user.
Recent Trends of Light-enhanced Metal Oxide Gas Sensors: Review
Cho, Minkyu ; Park, Inkyu ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 103~109
DOI : 10.5369/JSST.2016.25.2.103
Recent light-enhanced metal oxide gas sensors are reviewed in this article. The basic mechanisms of a light-enhanced metal oxide gas sensor are discussed. Many literatures reveal that the standalone sensitivity and the response/recovery time enhancements enabled by the exposing light are not as high as the performance enhancement provided by external heating. Therefore, both optimal amount of external heating and exposed light intensity are necessary to increase the performance of these light-enhanced gas sensors. The development of highly light sensitive materials and structures is important to lower the overall power consumptions of the sensors.
Design of a Three-Axis Force Sensor for Finger Force Measuring System
Lee, Kyeong-Jun ; Kim, Gab-Soon ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 110~115
DOI : 10.5369/JSST.2016.25.2.110
This paper describes the design and fabrication of a three-axis force sensor with three parallel plate structures(PPSs) for measuring force in a finger force measuring system for a spherical object catch. The three-axis force sensor is composed of a Fx force sensor, Fy force sensor and a Fz force sensor, and the elements of Fx force sensor and Fy force sensor are a parallel plate structure(PPS) respectively and Fz force sensor is two PPS. The three-axis force sensor was designed using FEM(Finite Element Method), and manufactured using strain-gages. The characteristics test of the three-axis force sensor was carried out. As a test results, the interference error of the three-axis force sensor was less than 1.32%, the repeatability error of each sensor was less than 0.04%, and the non-linearity was less than 0.04%.
Study on the Fabrication and Evaluation of the MEMS Based Curved Beam Air Flowmeter for the Vehicle Applications
Park, Cheol Min ; Choi, Dae Keun ; Lee, Sang Hoon ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 116~123
DOI : 10.5369/JSST.2016.25.2.116
This paper presents the fabrication and evaluation of the novel drag force type air flowmeter using MEMS technologies for the vehicle applications. To obtain the air drag force, the flowmeter utilized the curved beam structure, which was realized by the difference of residual stress between the silicon oxide layer and the silicon nitride layer. The paddle structure was applied for the maximum air drag force, and the dual-beam was adapted to prevent distortion. The basic experiments were performed in the wind tunnel, and the stable outputs were obtained. The device was applied to the internal combustion engine, and the results were compared with the HI-DS output where the convection thermal flowmeter was used as the reference sensor. The results indicated that the comparable resolutions and response times were obtained under the various engine speeds.
Temperature Dependency of Non-dispersive Infrared Carbon Dioxide Gas Sensor by using Infrared Sensor for Compensation
Yi, SeungHwan ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 124~130
DOI : 10.5369/JSST.2016.25.2.124
gas sensor was built with ASIC implemented thermopile sensor which included temperature sensor and unique elliptical waveguide structures in this paper. The temperature dependency of dual infrared sensor module (
and reference IR sensors) has been characterized and its output voltage characteristics according to the temperature and gas concentration were proposed for the first time. NDIR
gas and reference IR sensors showed linear output voltages according to the variation of ambient temperatures from 243 K to 333 K and their slopes were 14.2 mV/K and 8.8 mV/K, respectively. The output voltages of temperature sensor also presented a linear dependency according to the ambient temperature and could be described with V(T)=-3.191+0.0148T(V). The output voltage ratio between
and reference IR sensors revealed irrelevant to the changes of ambient temperatures and gave a constant value around 1.6255 with standard deviation 0.008 at 0 ppm. The output voltage of
gas sensor at zero ppm
gas consisted of two components; one is caused by the HPB (half pass-band) of IR filter and the other is attributed to the part of
absorption wavelength. The characteristics of output voltages of
gas sensor could be accurately modeled with three parameters which are dependent upon the ambient temperatures and represented small average error less than 1.5% with 5% standard deviation.
Bio-Medical Data Transmission System using Multi-level Visible Light based on Resistor Ladder Circuit
An, Jinyoung ; Chung, Wan-Young ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 131~137
DOI : 10.5369/JSST.2016.25.2.131
In this study, a multilevel visible light communication (VLC) system based on resistor ladder circuit is designed to transmit medical data. VLC technology is being considered as an alternative wireless communication due to various advantages such as ubiquity, license free operation, low energy consumption, and no radio frequency (RF) radiation characteristics. With VLC even in places where traditional RF communication (e.g., Wi-Fi) is forbidden, significant bio-medical signal including the electrocardiography (ECG) and photoplethysmography (PPG) data can be transmitted. More lives could be saved anywhere by this potential advantage of VLC with a fast emergency response time. A multilevel transmission scheme is adopted to improve the data capacity with keeping simplicity, where data transmission rate can increase by log2m times (m is the number of voltage levels) than that of conventional VLC transmission based on on/off keying. In order to generate multi-amplitudes, resistor ladder circuit, which is a basic principle of digital to analog convertor, is employed, and information is transferred through LED (Light-Emitting Diode) with different voltage level. In the receiver side, multilevel signal is detected by optical receiver including a photo diode. Then, the collected data are analyzed to serve the necessary medical care to the concerned patient.
Variation Factor Assessment of Radial Artery Pulse by the Tonometry Angle of the Pulse Pressure Sensor
Jung, Chang Jin ; Jo, Jung Hee ; Jun, Min-Ho ; Jeon, Young Ju ; Kim, Young-Min ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 138~142
DOI : 10.5369/JSST.2016.25.2.138
A pulse measurement by tonometry provides useful information for diagnosis, including not only blood pressure and heart rate but also parameters for estimating a condition of the cardiovascular system. Currently, various pulse measurement devices based on the tonometry have been developed. A reliability of these devices is determined by a positioning technic between the sensor and the blood vessel and a controlling technique of the pressurization level. An angle of the sensor for the pulse measurement seems to be highly related with a measured signal, however, the objective studies for this issue have been not published. In this paper, the variation of the pulse signals by tonometry direction was experimentally assessed according to the angle of the sensor. In order for guaranteeing the repeatability of the experiment, we used a pulse generator device, which can generate human pulse signal by using silicon tube and fluid pump, and developed a structure for precise adjustment of the angle and the pressurization level of the sensor. The angle of the sensor was acquired by an inclinometer, which was attached at the opposite side of the sensor. As results, a coefficient of variation (CV) of a maximum amplitude (MA) of the pulse wave was largely increased over the angle range of
. Furthermore, the changes of the pulse shape showed different aspects according to the sign of the angle tilted along the blood vessel. It is expected that the results of this study can be helpful for developing more precise pulse measurement devices based on the tonometry and applying in clinic.
Characteristics of Gold and Silver Based Bi- and Tri-metallic SPR Chip in the Intensity Measurement Mode
Kim, Hyungjin ; Kim, Chang-duk ; Sohn, Young-Soo ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 143~147
DOI : 10.5369/JSST.2016.25.2.143
Characteristics of the conventional gold (Au) surface plasmon resonance (SPR) chip, bi-metallic(Au/silver (Ag)) SPR chip, and tri-metallic(Au/Ag/Au) SPR chip were investigated and compared in the intensity measurement mode for the enhancement of SPR image sensor reactivity. Reflectance curves of the Au, bi- and tri-metallic SPR chips were acquired in phosphate-buffered saline (PBS) solution and were compared. The line width of the reflectance curve of the bi-metallic chip was the narrowest among the three different types of the chips. Also, the tangential slope of the bi-metallic chip was steeper than those of the other chips. Various concentrations of bovine serum albumin (BSA) were utilized in the SPR experiment. As a result, among the above three chips reflectance variation value of the bi-metallic chip was the largest.
Design of Force Sensors for the Ankle Rehabilitation Robot of Severe Stroke Patients
Kim, Han-Sol ; Kim, Gab-Soon ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 148~154
DOI : 10.5369/JSST.2016.25.2.148
This paper describes the design and fabrication of a two-axis force/torque sensor and an one-axis force sensor with parallel plate beams(PPSs) for measuring forces and torque in an ankle rehabilitation exercise using by a lower rehabilitation robot. The two-axis force/torque sensor is composed of a Fy force sensor and Tz torque sensor and the force sensor detects x direction force. The two-axis force/torque sensor and one-axis force sensor were designed using by FEM(Finite Element Method), and manufactured using strain-gages. The characteristics experiment of the two-axis force/torque sensor and one-axis force sensor were carried out respectively. As a test results, the interference error of the two-axis force/torque sensor was less than 1.56%, the repeatability error and the non-linearity of the two-axis force/torque sensor were less than 0.03% respectively, and the repeatability error and the non-linearity of the one-axis force sensor were less than 0.03% and 0.02% respectively.
Development of Charge Indicator Inspection System for Plug-in Hybrid Electric Vehicle
Kim, Jin Young ; Kang, Joonhee ;
Journal of Sensor Science and Technology , volume 25, issue 2, 2016, Pages 155~159
DOI : 10.5369/JSST.2016.25.2.155
In this work, we have developed a test system to examine whether the charge indicator of the plug-in hybrid electric vehicle (PHEV) works properly or not. In PHEV, the driver should charge the necessary electricity by plugging in manually and be able to know the charging status through the charge indicator conveniently located for the charging individual. Our system used the CAN bus to transmit the same commands from ECU to the indicator to test the proper operation of the indicator lights. It measured the electric current values during operation and analyzed to determine the quality of the indicators. The inspection items included the proper packaging, the electrical shorts, the LED lighting during charging, the LED lighting for charging failure, and the LED lighting when errors occur. We developed the system for the operators in the factory allowing them to approve the test results at the site. We developed the hardware, the control software, and the software to store the test results and the history of the products in the database. Serial numbers were given to the good quality products and the bar code labels were printed to trace the products afterwards. Through this work, we developed a system to inspect the electric parts in real time upon fabrication. We are planning to further improve our system to inspect the brightness of the indicator by adding the vision inspection in future.