• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1257-1264
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• 2019

The traditional cuff-based method for BP(Blood Pressure) measurement is not suitable for continuous real-time BP measurement techniques. For this reason, the previous studies estimated various blood pressures by fusion with the electrocardiography (ECG) and photoplethysmogram (PPG) sensor signals. However, conventional techniques based on PPG bio-sensing measurement face many challenging issues such as noisy supply fluctuation, small pulsation, and drifting non-pulsatile. This paper proposed a novel BP estimation methods using PPG and ECG sensors, which can be derived from the relationship between PPG and ECG using PTT(Pulse Transit Time) and PWV(Pulse Wave Velocity). Unlike conventional height ratio features, which are extracted on the basis of the peaks in the PPG and ECG waveform. The proposed method can be reliably obtained even if there are missing peaks among the sensed PPG signal. The increased reliability comes from periodical estimation of the peak-to-peak interval time using ECG and PPG. After 250,000 times trials of the blood pressure measurement, the proposed estimation technique was verified with the accuracy of ±28.5% error, compared to a commercialized BP device.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.465-472
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• 2015

In order to improve the performance of TCAS it should improve the performance of the sensor, which transmits a variety of information. In this paper, To improve the performance of the existing radar sensors such as being used in behalf of the next generation air traffic control system, ads-b the applied. In addition, ADS-B in a high precision by using information from the correction GPS system, SBAS assume would be able to apply an improved location accuracy for TCAS and analyzed TCAS and ADS-B. Played the simulation results, TCAS equipment receives the help of these ADS-B can calculate a CPA to determine the position of the aircraft in advance, and it was confirmed that it is possible to reduce the unnecessary RA operation, also, the pilot reduction and the workload, it has advantages such as fuel consumption and time associated with the reduced operation unnecessary RA was confirmed.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.165-169
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• 2014

Digital load is increasing suddenly for various reasons, such as easy control and management. Accordingly, a consumption pattern of load is becoming DC. However, the power supply is supplied by AC power. The load power supply substantially needs DC power. AC power has to be converted to DC power. Renewable energy sources like solar, wind, fuel cells are DC power generation, but the transfer needs to through by AC power, thus DC power has to be converted to AC power. Resultantly, a multi-stage conversion loss is constantly increasing. The power distribution system of DC-based is required for effective use of these energy sources. This requires a DC load, as well as is necessary to develop DC ELCB which are able to detect DC leakage current for implementing protection. In this study, it realize detection algorithm about DC leakage current to verify the performance of the sensor and apply it to the ELCB which is based on DC. Therefore, it is expected to protect operating of DC power distribution system.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.128-133
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• 2014

This paper is the study of BNWAS based on TLC. The functionality of BNWAS and its operations are investigated through its international standard. But the BNWAS to be used currently in the ship have difficulty in monitoring. Several kinds of data are generated from many equipments in BNWAS, such as NMEA-0183 data or NMEA-2000. Although these data are mainly used for the safe navigation of ship, their usability may be enhanced if they are managed to control the BNWAS equipment with sensors. The purpose of this system is prevent the marine accidents on sailing voyages due to drowsiness of watchers. On Night sailing, watcher is collected the navigation information from multiple devices and he determines the safe operation of the ship through continuous monitoring.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.121-127
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• 2014

The functionality of BNWAS and its operations are investigated through its international standard. But the BNWAS is being used currently in the ship had difficulty in monitoring. Several kinds of data are generated from many equipments in BNWAS, such as NMEA-0183 data or NMEA-2000. In this paper, we have proposed a method of the multimedia data transmission using a communication protocol based on slower NMEA-0183, which is mainly used in BNWAS. Data compression techniques are needed for smooth streaming services of the multimedia data in the low data rate over the NMEA-0183 interface. Although these data are mainly used for the instruments of ship, their efficient transmission may be needed if they are managed to control the BNWAS equipment with sensors.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.508-512
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• 2014

This paper suggests the control system and algorithm for auto and manual control of the streetlight using RF system. There are two control system in this auto control algorithm. One is group control, the other individual control. In case of group control, if a car is detected by the object detecting sensor of the system installed on the streetlight, it will turn on the light per group by transmitting the RF signal. The streetlight turns on separately when it detects people or a car parked on the shoulder in accordance with the individual control. Also, there is manual control algorithm that manager can check surrounding environment and condition of the streetlight by RF signal and various sensors. So, not only the proposed system reduce meaningless energy consumption, but also it offers convenience regarding maintenance and control of the streetlight.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.1017-1023
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• 2015

The amount of smart phones has increased exponentially. Due to the periodic release of high-performance smart phones and upgraded operating system, new smart phones become out-dated over 1 or 2 years. In order to solve environmental constraints of these smart phones, virtualization technology using Thin-Client terminal has been developed. However, in the case of Virtual Machine(VM), the applications associated with sensors and a GPS device can not run because they are not included. In this paper, by implementing the device driver for Android running in a virtual machine in the x86-based systems, it is to provide Android virtualization capabilities such as using the latest smart phones in the virtual machine environment. It would like to propose a method that the virtual device driver receives sensors and GPS information from the old Android smart phones(Thin-Client) that actually work and run as if the real device exists.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1993-1999
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• 2011

This paper describes a design of area-efficient/low-power cryptographic processor for HIGHT block cipher algorithm, which was approved as standard of cryptographic algorithm by KATS(Korean Agency for Technology and Standards) and ISO/IEC. The HIGHT algorithm, which is suitable for ubiquitous computing devices such as a sensor in USN or a RFID tag, encrypts a 64-bit data block with a 128-bit cipher key to make a 64-bit cipher text, and vice versa. For area-efficient and low-power implementation, we optimize round transform block and key scheduler to share hardware resources for encryption and decryption. The HIGHT64 core synthesized using a 0.35-${\mu}m$ CMOS cell library consists of 3,226 gates, and the estimated throughput is 150-Mbps with 80-MHz@2.5-V clock.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.581-588
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• 2005

The performance of mobile devices and wireless networks is improved rapidly and Mobility management skills such as Mobile IP and ad-hoc technology were developed. So the requirement of processing the distributed computing is highly increased in any place and any time or in the state of movement. Therefore we studied the mobile grid system to process the distributed applications properly in wireless networks. In addition to typical computational resources, Mobile Grid brings new resources such as sensor, mobile devices or other wireless devices to distributed computing for the purpose of resource-sharing. In this paper, we design and implement the mobile grid system in wireless lan network environment for the providing the grid service. Also, we evaluate the performance of mobile grid system using the processing the distributed applications in implemented mobile grid environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.73-79
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• 2001

In this paper, the transmitted noise reduction performance of piezoelectric smart panels is experimentally studied. The proposed piezoelectric smart panels are comprised of plate structure on which piezoelectric sensor/actuators are bonded and sound absorbing material is provided. It is a combination of passive and active approaches utilizing a passive effect at high frequencies and an active effect at low frequencies. To prove the concept of piezoelectric smart panels, an acoustic measurement experiment is performed. An acoustic tunnel is designed and its acoustic characteristics are tested. Below 800Hz, the tunnel exhibits a plane wave guide characteristics. When an absorbing material is bonded on a single plate, a remarkable transmitted noise reduction in mid frequency range is observed except the first resonance frequency. By enabling the active control of single smart panel with negative feedback control. about 10dB noise reduction is achieved at the resonance frequencies. The double smart panel got 4dB at the first resonance frequency and has more potential to reduce the transmitted noise in a wide range frequency. Piezoelectric smart panels incorporating passive absorbing material and active piezoelectric devices is a promising technology for noise reduction in a wide range frequency.