• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.3
• /
• pp.43-50
• /
• 2010

DDC(Digital Down Converter) is a conversion technology to decimate to a lower sampling rate and DDC for the future development of communications technology has the necessary skills. So, it has been recognized in the wireless and the SDR(Software Defined Radio) system as essential components. In addition, research is underway on spectrum sensing for efficient communications environment due to the shortage of frequency resources. In this paper, the DDC systems were analyzed for CIC(Cascaded Integrator Comb) Filter, WDF(Wave Digital Filter), SRC(Sample Rate Conversion) each module. Moreover, we proposed a linkage effectively between DDC system and Spectrum Sensing for improve the efficiency of use of frequency by computer simulations. The simulation results of the DDC system was applied to the spectrum sensing capabilities. Also, performance and complexity of the results were derived and proposed system was the result of the check.

• KSBB Journal
• /
• v.22 no.6
• /
• pp.378-386
• /
• 2007

Bio-sensing devices, which are basically integrated and miniaturized assay systems consisted of bioreceptor and signal transducer, are advantageous in several ways. In addition to their high sensitivity, selectivity, simplicity, multi-detection capability, and real time detection abilities, they are both very small and require relatively inexpensive equipments. Two core technologies are required to develop bio-sensing devices; the fabrication of biological receptor module (both of receptor development and immobilisation of them) and the development of signal transducing instruments containing signal generation technique. Various biological receptors, such as enzymes, DNA/RNA, protein, and cell were tried to develop bio-sensing devices. And, the signal transducing instruments have also been extensively studied, especially with regard to electrochemical, optical, and mass sensitive transducers. This article addresses bio-sensing devices that have been developed in the past few years, and also discusses possible future major trends in these devices.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.3876-3881
• /
• 2012

In typical master/slave teleoperation systems, a human operator generally manipulates the master to control the slave through the visual information like camera image. However, the operator may get into trouble due to the limited visual information depending on the camera positions and the delay on the visual information because of low communication bandwidth. To cope with this inherit problem in the camera-based teleoperation system, this paper presents a teleoperation system using a reconstructed graphic model instead of the camera image. The proposed teleoperation system consists of a robot control module, a master module using a force-reflective joystick, and a graphic user interface (GUI) module. The graphic user interface module provides the operator with a 3D model reconstructed using a small set of sensing data received from the remote site. The proposed teleoperation system is evaluated through a peg-in-hole assembly task.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.6
• /
• pp.940-947
• /
• 2015

A Sitting posture is a very important issue for moderns who is mostly sedentary. Also, a wrong sitting posture causes back-pain and spinal disease. Many researchers have been proposed numerous approaches that classifying and monitoring for a sitting posture. In this paper, we proposed a real-time sitting posture monitoring system that was developed to measure pressure distribution in the human body. The proposed system consists of a pressure sensing module (six pressure sensors), data acquisition and processing module, a communication module and a display module for an individual sitting posture monitoring. The developed monitoring system can classify into five sitting postures, such as a correct sitting, sitting on forward inclination, leaning back sitting, sitting with a right leg crossed and a left leg crossed. In addition, when a user deviates from the correct posture, an alarm function is activated. We selected two kinds of chairs, one is rigid material and fixed form, the other one is a soft material and can adjust the height of a chair. In the experiments, we observed appearance changes for subjects in consequence of a comparison between before the correction of posture and after the correction of posture when using the proposed system. The data from twenty four subjects has been classified with a proposed classifier, achieving an average accuracy of 83.85%, 94.56% when the rigid chair and the soft chair, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.4
• /
• pp.1-8
• /
• 2008

Recently, there is developing various ubiquitous application services using sensor networks based on TinyOS represented the operating system of sensor node. These sensor networks perform the collection and the transmission of sensing data from sensor node to get the context information. In this paper, we proposes the sensor node control algorithm which converts a sensor node to sleep, active, power off mode according to monitoring result of the voltage state of sensor node. Also, we designs and implement the sensor control module on server, sink, sensor node of sensor networks using this algorithm. It designs a sensor voltage control module of sensor node, data receive and display module of USN server using a java language and TinyOS. And, it checks the voltage state of sensor node, and it changes one of the sleep or power off modes in case of high voltage loss. Accordingly, we effectively use the power of sensor nodes as changing control modes of sensor nodes.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.32 no.6
• /
• pp.375-381
• /
• 2019

Structural health monitoring to determine structural conditions at an early stage and to efficiently manage the energy requirements of buildings using systems that collects relevant data, is under active investigation. Structural monitoring requires cutting-edge technology in which construction, sensing, and ICT technologies are combined. However, the scope of application is limited because expensive sensors and specialized technical skills are often required. In this study, a Raspberry Pi module, one of the most widely used single board computers, a Lora module that is capable of long-distance communication at low power, and a high-performance accelerometer are used to construct a wireless edge computing system that can monitor building response over an extended time period. In addition, the Raspberry Pi module utilizes an edge computing algorithm, and only meaningful data is obtained from the vast amount of acceleration data acquired in real-time. The raw data acquired using Wi-Fi communication are compared to the Laura data to evaluate the accuracy of the data obtained using the system.

• 한국HCI학회:학술대회논문집
• /
• 2008.02a
• /
• pp.319-325
• /
• 2008

In this paper, we develop the multi sensor system, to get the sufficient information of mobile robot's environment. Mobile robot user interface, based on multi sensor system, can choice a suitable sensor by low-cost multi sensors and then acquisition information from remote robot's workspace using auto sequencing user display function. This research of multi sensor system is consists of ultrasonic sensor, position sensing detector, and low-cost CMOS camera module.

• Journal of Digital Contents Society
• /
• v.15 no.4
• /
• pp.473-480
• /
• 2014

As the use of computer has been popularized these days, an active research is in progress to make much more convenient and natural interface compared to the existing user interfaces such as keyboard or mouse. For this reason, there is an increasing interest toward Microsoft's motion sensing module called Kinect, which can perform hand motions and speech recognition system in order to realize communication between people. Kinect uses its built-in sensor to recognize the main joint movements and depth of the body. It can also provide a simple speech recognition through the built-in microphone. In this paper, the goal is to use Kinect's depth value data, skeleton tracking and labeling algorithm to recognize information about the extraction and movement of hand, and replace the role of existing peripherals using a virtual mouse, a virtual keyboard, and a speech recognition.

• Journal of Digital Contents Society
• /
• v.18 no.7
• /
• pp.1451-1456
• /
• 2017

In this research we discuss an integrated actuator-control system for advanced control of a smart Shape Memory Alloy (SMA) actuator. Toward this goal, we designed and fabricated an actuator-control module combining two SMA actuating units with a single-chip microprocessor, two different sensing elements, and an actuator driver. In our proposed system, sensing elements include a 6-axis single-chip motion sensor for orientation measurement and a circuit for resistance measurement of SMA wires. We experimentally verified our proposed actuator-control system using actuator driving, sensor data readings, and communication tests.

• Korean Journal of Remote Sensing
• /
• v.16 no.4
• /
• pp.339-345
• /
• 2000

KOMPSAT-1 was launched on 21 December, 1999 and the main mission of the satellite is the cartography to provide the imagery from a remote earth view for the production of maps of Korean territory. For this purpose, the satellite has capability to tilt the spacecraft utmost $\pm$45 degrees to acquire stereo satellite imagery in different paths. This study aims to estimate the three dimensional positioning accuracy of stereo satellite imagery from EOC(electro-optical camera), a payload of KOMPSAT-1 satellite. For this purpose, the ground control points and check points were obtained by GPS surveying. The sensor modeling and the adjustment was performed by PCI software installed in KARI (Korea Aerospace Research Institute), which contained mathematical analysis module for KOMPSAT-1 EOC. The study areas were Taejon and Nonsan, placed in the middle part of Korea. As a result of this study, we found that the RMSE(root mean square error) value of three dimensional positioning KOMPST-1 stereo imagery can be less than 1 pixel (6.6 m) if we can use about 10 GCPs(ground control points). Then, a standarrd of FGDC (Federal Geographic Data Committee) of USA was applied to the result to estimate the three dimensional positioning accuracy of KOMPSAT-1 stereo imagery.