• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.396-401
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• 2017

In this paper, a device to analyze gait pattern was developed by using a 2-axis acceleration sensor attached to the foot. The 1st low-pass filter was adapted to limit the frequency band up to 5 Hz. An algorithm to detect the peak value exceeding the threshold voltage of an X-axis acceleration sensor and a Z-axis acceleration sensor was developed and normal and abnormal walking patterns were thus differentiated. Also, MCU and Bluetooth were combined to transfer the data to other MCUs to display on an LCD; the size of the device could then be reduced. The new algorithm and the device allowed the individual walking patterns to be easily measured at a low cost and with less restriction on activities compared to conventional multiple pressure sensors or motion camera system.

• Journal of Engineering Education Research
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• v.13 no.5
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• pp.36-40
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• 2010

The vehicle oriented block box system based on the u-healthcare and the human-free guard functions is developed in this paper. We also suggested the design philosophies, ideas, and analyzed the performance of the suggested system. The developed vehicle oriented black box system has some characteristics such as; 1) detects the dangerous situation by ultrasonic sensor in advance, and stores the situation information of the neighborhood of the vehicle to the imbedded SD memory card if the dangerous situation may be occurred in the parked vehicle; 2) detects the present location and speed information of the vehicle by GPS receiver and 3-axes acceleration sensor, and stores the information to the SD memory card periodically if the vehicle is running; 3) measures the dioxide carbon in the vehicle inside using $CO_2$ sensor, and forces the ventilation motor of the vehicle to operate and maintains the driver's health if the measured level is more than standard health requirements; 4) provides the stored vehicle's operating information to the driver by GUI (Graphical User Interface) based touch LCD monitor.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.1
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• pp.34-41
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• 2008

There are many researches to build up ubiquitous environment by the Ubiquitous Sensor Network(USN). These applications, such as home network, health care, natural environment and agricultural areas, are implemented by an embedded system. Their fields are gradually spreading. However the power consumption in its implementation plays an important role on the surrounding environment of the wireless network. In this paper, we design low power processor based sensor node platform for agricultural applications. We also compare its some performance with existing products.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.73-82
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• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.190-193
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• 2009

The most essential element in wireless sensor network is wireless sensor node which collects environmental information and transmits it to the user application systems. Recently, due to the technological advancement, wireless sensor nodes are become smaller, more intelligent and less power consuming. Especially, SoC(System-on-Chip) technology, which unifies the MCU, RF module, memory and other element inside one chip, plays an important part for miniaturization of sensor node, hence reduces the manufacturing expenses. In this paper, we have designed a miniaturized wireless sensor node for wireless sensor network using commercial SoC technology and discussed about some application scenario and additional considerations.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.1-10
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• 1997

It is well-known that rectangular bulk-Si sensors prepared by etch or epi etch-stop micromachining technology are already in practical use today, but the conventional bulk-Si sensor shows some drawbacks such as large chip size and limited applications as silicon sensor device is to be miniaturized. We consider a circular-shape SOI(Silicon-On-Insulator) micro-cavity technology to facilitate multiple sensors on very small chip, to make device easier to package than conventional sensor like pressure sensor and to provide very high over-pressure capability. This paper demonstrates the cross-functional results for stress analyses(targeting $5{\mu}m$ deflection and 100MPa stress as maximum at various applicable pressure ranges), for finding permissible diaphragm dimension by output sensitivity, and piezoresistive sensor theory from two-type SOI structures where the double SOI structure shows the most feasible deflection and small stress at various ambient pressures. Those results can be compared with the ones of circular-shape bulk-Si based sensor$^{[17]}. The SOI micro-cavity formed the sensors is promising to integrate with calibration, gain stage and controller unit plus high current/high voltage CMOS drivers onto monolithic chip.

• Journal of information and communication convergence engineering
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• v.8 no.2
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• pp.219-222
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• 2010

An ubiquitous sensor network (USN) system to monitor the bio information and the emergency of the elderly in the silver town is presented. The USN system consists of the sensor node platforms based on MCU of Atmage128L and RF Chip of CC2420 satisfying IEEE 802.15.4, which includes the bios sensor module such as the electrocardiogram (ECG) sensor and the temperature sensor. Additionally, when an emergency of the elderly is occurred in the silver town, the routing algorithm suitable to find and inform the location of the elderly is proposed, and the proposed routing algorithm is applied to the USN. To collect and manage the ECG data at the PC connected to the sink node, LabView software is used. The bio information and the emergency of the elderly can also be monitored at the client PC by TCP/IP networks in the USN system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.31-36
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• 2015

In this paper, an LED lighting system that is capable of automatic or maunal dimming control using a ultrasonic sensor and Bluetooth wireless communication technology is presented. The LED lighting system consists of a ultrasonic sensor, microcontroller unit, Bluetooth wireless communication, LED driver, and LED light source. By using the implemented LED lighting system sample, it is shown that the automatic and manual dimming control is realized. By using the ultrasonic sensor, the LED lighting is automatically brighter or dimmer depending on the distance between the sensor and an object. When using a smartphone that includes Bluetooth wireless communication function, one can not only manually control the brightness of the LED lighting from level 1 to 10, but also monitor the distance between the sensor and object on the smartphone.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.142-149
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• 2007

Wireless sensor network technology is an emerging technology consisting of small, low power, and low cost devices that integrate limited computation, sensing, and radio communication capabilities. An ad-hoc home network system based embedded system for home environment monitoring was fabricated and tested. The wireless sensor node consists of a MCU, RF transceiver and sensors (temperature, humidity and light). Wireless sensor nodes run application software for data sampling and wireless communication, that was developed using 'nesC language' which runs on TinyOS. In our tests, acquired sensors data were monitored on 6.4" TFT-LCD of base-station through IEEE802.15.4 standard wireless communication. Also, the sensor data can be monitored by client user at the terminal PC to monitor environmental status of home in real time.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.191-196
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• 2021

In this paper, we implemented an image sensor module possible of detecting color temperature in an indoor environment. The color temperature information in the video information acquired by the image sensor was matched with a color difference illuminometer to produce an LUT. An algorithm was developed so that color temperature information according to the received RGB values can be automatically calculated. As a result of measuring the color temperature with an image sensor indoors, an accurate result of less than 5.91% was obtained compared to the reference value. It was confirmed that the uniformity of 23.5% or more was excellent compared to the color temperature measurement result using a color sensor.