• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.117-126
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• 2005

In this paper, it was suggested method to recognize the motion of a person(lying, sitting, walking, running) using fuzzy inference and wireless biologic signal processing system. These are to Perceive the motion of the person. Furthermore, the information of motion is indispensable parameter for Context Awareness (CA). In the present study, ADXL 202JE accelerometer sensor was used to measure for checking the continuance motion, biological quantify of motion, and motion pattern of a Person. The measured data was transmitted to CA server by Radio Frequency(RF). From the present result, we confirmed that it is difficult to decide the motion of walking and running with only the magnitude of the Longitudinal Accelerometer Average Value(LAAV) and moreover the covariance of LAAV in any block is very useful for CA of walking and running.

• Fire Science and Engineering
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• v.30 no.2
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• pp.43-48
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• 2016

One of the main problems with gaseous fire extinguishers is the decrease in fire suppression capability due to the leakage of the fire extinguishing agents, either naturally or caused by obsolete equipment. Therefore, in this study, a real-time detector module for monitoring pressure leakages was developed and an assessment on its performance was carried out. Currently, there are no domestic or global standards for testing pressure leakage detection systems. Therefore, similar global standards, such as ISO 7240 and FM 1421, and the domestic law on "Receiver type-approval and technical standards for product inspection" were used as a reference for assessing the performance of the newly developed module. Its basic performance was assessed by applying compressed air to the module, and, as a result, the minimum working pressure was identified as 0.3 bar. Its environmental qualification was carried out to confirm the proper functioning of the module in different climates and the module was confirmed to function properly at both high ($50^{\circ}C$) and low ($-10^{\circ}C$) temperatures.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.5
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• pp.515-523
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• 2015

In this paper, we fabricated and evaluated the gas sensor for the detection of CO gas and $NO_X$ gas among the vehicle exhaust emission gasses. The $SnO_2$ (tin dioxide) layer is used as the detection material, and the thin-film type and the nano-fiber type layers are deposited with various thicknesses using sputtering method and electro spinning method, respectively. The experiments are performed in the chamber where the gas concentration is controlled with mass flow controller. The fabricated devices are applied to the CO and $NO_X$ gas, where the device with the thinner $SnO_2$ layer shows better sensitivity. The nano-fiber has the larger surface area, and the shorter response time and recovery time are obtained. From the experimental results, both types of gas sensors successfully detect CO and $NO_X$ gases, which can be applied to measure those gases from the vehicle emissions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.52-60
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• 2003

In aviation navigation using GPS, requirements on availability and integrity must be absolutely satisfied. Current study on accomplishing this integrity includes RAIM(Receiver Autonomous Integrity Monitoring), monitoring integrity internaIly in GPS receiver itself. Parity space technique as one of RAIM techniques has shown the advantages in fault detection and isolation due to each use of its magnitude and direction under the assumption of one fault. ln case of multiple fault, as biases in errors interact decreasing the effect of multiple fault in parity space, the exact fault detection and identification(FDI) may be difficult to be conducted. This paper focuses on FDI study on two faults and explains why parity space techniques applied on single fault is not adequate to the application of multiple fault case and shows that extended parity space technique may improve the performance of RAIM on two faults.

• The Journal of the Korea Contents Association
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• v.6 no.10
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• pp.126-133
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• 2006

Application software streaming is a virtualization technology that enables users to use applications without installation on her/his computer. With application streaming service, a client immediately starts and uses the application as if it were installed. The application can be executed while executable codes for the application may still be streamed. Since the software streaming is based on networks, its service is affected by network failures. Network failures may cause the streamed application to stop, and to make it worse, also the system may crash because executable codes for the application can't be streamed from the streaming server. Using the Pareto principle (80 vs. 20 rule), users can be served continuously with the minimum functions that are frequently used, pre-fetched and cached if we provide a more intelligent and fault-tolerant streaming technique. This paper proposes the concept and technique named Evergreen. Using the Evergreen technique, users can continue using the streamed application while a network failure occurs, although user can access only the streamed code. We also discuss the implementation of Evergreen technique in details.

• Journal of Satellite, Information and Communications
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• v.8 no.3
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• pp.15-19
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• 2013

Lithium-ion batteries have been used for high density energy storage system due to the features such as low self-discharge rate. And the unit cell battery with the voltage less than 4V is recommended to use the series connections for a high voltage charger. When batteries are charged or discharged with series connection, there may be an explosion or degradation of unit cell battery owing to undistributed internal resistance of cell battery. therefore, the voltages of unit cell batteries should be monitored to prevent an overcharging and a deep discharging. This paper introduces the implementation of CVM (Cell Voltage Monitoring) system that can transmit the 12 channel's information including voltages and temperatures with the 12-bits resolutions and the transmission speed of 192 kbps.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.34-39
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• 2010

This paper proposes S/W Watch-Dog method between Dual CPU using the different OS. The proposed watch-dog method performs that it distinguishes the status of channel between dual CPU and status of processor itself. We find out the ideal value of threshold and priority for load test task. and we evaluate the accuracy of the proposed S/W Watch-Dog Method at the result of evaluation. We figure out that the accuracy of proposed method is higher than the accuracy of general S/W Watch-Dog Method in case of variable data rate. Therefore we confirm that the proposed Method has high accuracy of watch-dog function with the ideal value of threshold and priority for load test task through the performance evaluation.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.313-320
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• 2018

The importance of sensors on a self-driving vehicle has rising since it act as eyes for the vehicle. Lidar sensors based on laser technology tend to yield better image quality with more laser channels, thus, it has higher detection accuracy for obstacles, pedistrians, terrain, and other vechicles. However, incorporating more laser channels results higher unit price more than ten times, and this is a major drawback for using high channel lidar sensors on a vehicle for actual consumer market. To come up with this drawback, we propose a method of integrating multiple low channel, low cost lidar sensors acting as one high channel sensor. The result uses four 16 channels lidar sensors with small form factor acting as one bulky 64 channels sensor, which in turn, improves vehicles cosmetic aspects and helps widespread of using the lidar technology for the market.

• The KIPS Transactions:PartB
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• v.19B no.2
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• pp.127-134
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• 2012

Video digital door lock(VDDL) system detects people who access to the door and acquires the human image. Design considerations is that current consumption must be minimized by applying fast human detection algorithm because of battery-based operation. Since the digital door lock takes an image through a fixed camera, detection of a person based on background image leads to high degree of reliability. This paper deals with a single human detection algorithm suitable for VDDL with fulfilling these requirements such that it detects a moving object in an image, then identifies whether the object is a person or not using image processing. The proposed image processing algorithm consists of two steps: Firstly, it detects the human image region using both background image and skin color information. Secondly, it identifies the person using polar histogram based on proportional information of human body. Proposed algorithm is implemented in VDDL and is verified the performance through experiments.

• Fire Science and Engineering
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• v.21 no.4
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• pp.65-71
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• 2007

This paper is studied on a protective control system for electrical fire and electrical faults by using electrical and thermal characteristics of PTC thermistor. The PTC thermistor has characteristic or positive resistivity temperature coefficient according to the temperature variation, which is construction of a regular square and cube demarcation with $BaTiO_3$ Ceramics of positive temperature coefficient. Also PTC thermistor shows the phenomenon which is rapidly increased in the resistivity if the temperature is increased over Curie temperature point. This paper is proposed on a protective control system used PTC thermistor which is protected from electrical fire due to electric short circuit faults or overload faults. Some experimental results of the proposed electric safety control apparatus are confirmed to the validity of the analytical results.