• Science of Emotion and Sensibility
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• v.19 no.3
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• pp.81-88
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• 2016

The purpose of this research was to analyze several factors that can affect the respiration rate measurement using the Creative Senz3D depth camera. Depth error and noise of the depth camera were considered as affecting factors. Ambient light was also considered. The result of this study showed that the depth error was increased with an increase of the distance between subject and depth camera. The result also showed depth asymmetry in the depth image. The depth values measured in right region of the depth image was higher than real distance and depth values measured in left of the depth image was lower than real distance. The difference error of the depth was influenced by the orientation of the depth camera. The noise created by the depth camera was increased as the distance between subject and depth camera was increased and it decreased as the window size was increased which was used to calculate noise level. Ambient light seems to have no influence on the depth value. In real environment, we measured respiration rate. Participants were asked to breathe 20 times. We could find that the respiration rate which was measured from depth camera shows excellent agreement with that of participants.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.1-13
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• 2020

There are many factors that influence the image quality of CMOS camera images, among which the image exposure time is an important factor. If the image exposure time is long, the entire image on the screen becomes brighter. If the exposure time is shorter, the entire image becomes darker. When photographing a still image, real time is not required because the automatic exposure system is given sufficient time to obtain an appropriate exposure time. However, if the surroundings and environment change rapidly like the black box of a driving car, the exposure time should be applied in response to real time. To this end, a robust automatic exposure system for real-time performance and ambient light environment is required. An automatic exposure system that has real-time capability and is robust against the ambient light environment is required. we designed a real-time control sysem capable of parallel operation processing through the design of an embedded system using zynq's logic and ARM core, and developed a real-time CMOS automatic exposure system that is robust to noise and converges to a desired target value within 66 ms through PID control.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1668-1672
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• 2013

We developed a standoff Raman detection system for explosive molecules (EMs). Our system was composed of reflective telescope with 310 mm diameter lens, 532 nm pulse laser, and Intensified Charge-Coupled Device (ICCD) camera. In order to remove huge background noise coming from ambient light, laser pulses with nanosecond time width were fired to target sample and ICCD was gated to open only during the time when the scattered Raman signal from the sample arrived at ICCD camera. We performed standoff experiments with military EMs by putting the detector at 10, 20 and 30 m away from the source. The standoff results were compared with the confocal Raman results. Based on our standoff experiments, we were able to observe the peaks in the range of 1200 and $1600cm^{-1}$, where vibrational modes of nitro groups were appeared. The wave numbers and shapes of these peaks may serve as good references in detecting and identifying various EMs.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1244-1248
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• 2005

In this paper, we propose fuzzy c-means (FCM) to solve recognition errors in invariant range image, multi-pose face recognition. Scale, center and pose error problems were solved using geometric transformation. Range image face data was digitized into range image data by using the laser range finder that does not depend on the ambient light source. Then, the digitized range image face data is used as a model to generate multi-pose data. Each pose data size was reduced by linear reduction into the database. The reduced range image face data was transformed to the gradient face model for facial feature image extraction and also for matching using the fuzzy membership adjusted by fuzzy c-means. The proposed method was tested using facial range images from 40 people with normal facial expressions. The output of the detection and recognition system has to be accurate to about 93 percent. Simultaneously, the system must be robust enough to overcome typical image-acquisition problems such as noise, vertical rotated face and range resolution.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1241-1248
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• 2019

In this paper, an auxiliary device was implemented to help blind people more safely from obstacles or risk factors while walking. The ultrasonic sensors detect obstacles in the front, so that the noise gap and the vibration intensity of the buzzer can be heard differently by distance and angle, and so the situation can be perceived by pedestrians. When the ambient light becomes darker than the light intensity set using the CdS resistance value of the light sensor, the LED automatically turns on, makes it easier for pedestrians to recognize the position of the auxiliary device through buzzer if the pedestrian misses the aid using the gyro sensor's slope. Moreover, the location and situation of the blind were transmitted to the caregiver to check safety and behavior using GPS and Bluetooth.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.1
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• pp.16-23
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• 2019

Fine particulate matter known as PM 2.5 refers to the atmospheric particulate matter that has a diameter less than 2.5 micrometer identified as dangerous element for human health and its concentration can provide us a clear picture about air dust concentration. Humans stay indoor almost 90% of their life time and also there is no official indoor dust concentration data, so our study is focused on measuring the indoor air quality. Indoor dust data monitoring is very important in hospital environments beside that other places can also be considered for monitoring like classrooms, cements factories, computer server rooms, petrochemical storage etc. In this paper, visible light communication system is proposed by Manchester encoding technique for electromagnetic interference (EMI)-free indoor dust monitoring. Important indoor environment information like dust concentration is transferred by visible light channel in wide range. An average voltage-tracking technique is utilized for robust light detection to eliminate ambient light and low-frequency noise. The incoming light is recognized by a photo diode and are simultaneously processed by a receiver micro-controller. We can monitor indoor air quality in real-time and can take necessary action according to the result.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.4
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• pp.313-319
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• 2001

The development of ozone SRP (Standard Reference Photometer) designated as a G-7 project by the Korean Ministry of Environment began 1997 and is now nearly completed. With the completion of the ozone SRP we will not only acquire a qualification to participate in the international ozone calibration system but also enhance calibration credibility of ozone similarly to that of other ambient air pollution monitors. As the ozone SRP uses highly cleaned blank air that can be distinguished from general ozone analyzer, it is possible to reduce errors associated with the determination of ozone via elongation of the absorption length as long as 1 meter In addition, gas chopping method hat been adopted to cut down interference of other substances and time drift. Furthermore, the system has also been modified to minimize the strayed ultra-violet noise along the light path. In this paper, a new method for uncertainty evaluation has been introduced, which is guided by the ISO (International Standard Organization) GUM (Guide to the Expression of Uncertainty in Measurement) through assessments of the uncertainty type B (that was impossible to estimate before) as well as the uncertainty type A (based on statistics).

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.31-37
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• 2024

In this study, we propose a machine vision-based pedestrian signal detection algorithm that operates efficiently even in computing resource-constrained environments. This algorithm demonstrates high efficiency within limited resources and is designed to minimize the impact of ambient lighting by sequentially applying HSV color space-based image processing, binarization, morphological operations, labeling, and other steps to address issues such as light glare. Particularly, this algorithm is structured in a relatively simple form to ensure smooth operation within embedded system environments, considering the limitations of computing resources. Consequently, it possesses a structure that operates reliably even in environments with low computing resources. Moreover, the proposed pedestrian signal system not only includes pedestrian signal detection capabilities but also incorporates IoT functionality, allowing wireless integration with a web server. This integration enables users to conveniently monitor and control the status of the signal system through the web server. Additionally, successful implementation has been achieved for effectively controlling 50W LED pedestrian signals. This proposed system aims to provide a rapid and efficient pedestrian signal detection and control system within resource-constrained environments, contemplating its potential applicability in real-world road scenarios. Anticipated contributions include fostering the establishment of safer and more intelligent traffic systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.68-74
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• 2003

This paper describes the design and the test results of the receiver-downconverter module for a Ka-band Satellite Payload. The developed module is not only a downconverter that convert the signal of 30.6 GHz∼31.0 GHz to the signal of 20.8 GHz∼21.2 GHz but also is a receiver that has the function of low noise amplification in the front stage. It has been fabricated and tested by the qualified satellite component manufacturing process and it shows the best performance of the receiver-downconverter modules operating at Ka-band frequency up to date. The module has the performance of 1.9 dB-NF, 55 dB-Gain, and 58 dBc-C/I3 fur the two tone signals of -59 dBm input power respectively at ambient temperature. It is a small and light module with the size of 93 mm${\times}$84 mm${\times}$26 mm and the weight of 240 g.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.726-728
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• 2013

Optoelectronic arc discharge sensor was used to detect arc discharge inside power distribution panel. Arc discharge is fatal to power system once it begins, thus preventive detection is necessary before power failure occurs. Optoelectronic detection method was used to avoid direct electrical contact to power apparatus inside power distribution panel. 180 degree detection angle and detection range far exceeding 6m, which was sufficient for monitoring purpose, was achieved using the photodiode having $7.5mm^2$ of active surface area and flash source with $0.4cal/cm^2$ energy density, which is equivalent to 1.9J with $2.16cm^2$ emitting area. The response speed of arc discharge sensor was measured to be below 1 msec. The above optoelectronic arc discharge sensor was measured to be sensitive enough to detect 0.94 pC charge.