• Journal of Advanced Navigation Technology
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• v.20 no.3
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• pp.182-189
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• 2016

In this paper, we propose a buoy system based on multi-hop relay networks for ocean observation. The proposed system consists of various sensor modules, a gateway, wireless communication modules, and a remote monitoring site. The sensor modules are integrated with various communication interfaces and connected to the gateway of the proposed buoy system with an unified protocol based on controller area network (CAN)-bus. In order to communicate with the remote monitoring site and extend the coverage, the proposed system uses long-term evolution (LTE) router and XBee mesh network modules. The field test results show that the proposed system can extend the coverage using the proposed multi-hop relay network.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.59-67
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• 2012

In this study,the compact type solar thermal and ground coupled heat pump hybrid system for space heating/cooling and hot water supply has been developed. This hybrid system was installed in Zero Energy Solar House(ZeSH) in KIER for the demonstration. The thermal performance and operational characteristics of this hybrid system were analysed especially. The results are as follows. (1) This hybrid system was designed in order to address the existing disadvantages of solar thermal/ground coupled heat pump system. For this design, all parts except solar collector and ground coupled heat pump were integrated into a single product in a factory. The compact type unit includes two buffer tanks, an expansion tank, pumps, valves, a controller, etc. This system has an advantage of easy installation with simple plumbing work even in narrow space. (2) The thermal charging and discharging time of the buffer tanks and its characteristics by ground coupled heat pump, and heat pump COP according to geo-source temperature and buffer storage temperature have been studied. This system was found to meet well to the heat load without any other auxiliary heating equipment. (3) The operating hours of the ground coupled heat pump as a backup device of solar thermal can be reduced significantly by using solar heat. It was also found that the minimum heating water supply setting temperature and maximum cooling water supply setting temperature make an influence on the heat pump COP. The lower heating water and the higher cooling water temperature, the higher COP. In this respect, the hybrid system's performance can be improved in ZeSH than conventional house.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.219-225
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• 2014

This paper describes an IC for Power Factor Correction. It can use electrical appliances which convert power from AC to DC. The power factor can be influenced not only phase difference of voltage and current but also sudden change of current waveform. This circuit enables current wave supplied to load by close to sinusoidal and minimum phase difference of voltage and current waveform. A self oscillated 10[kHz]~100[kHz] pulse signal converted to PWM waveform and it chops rectified full wave AC power which flows to load device. The multiplier and zero current detector circuit, UVLO, OVP, BGR circuits were designed. This IC has been designed and whole chip simulation use 0.5[um] double poly, double metal 20[V] CMOS process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.610-617
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• 2017

In the recent weapon system trend, it is required to develop small and low cost guidance missile to track and strike the enemy target effectively. Controling the such small drone typed weapon demands a integrated electronic device that equipped with not only a wireless network interface, a high resolution camera, various sensors for target tracking, and position and attitude control but also a high performance processor that integrates and processes those sensor outputs in real-time. In this paper, we propose the android smartphone as a solution for that and implement the guidance and control application of the missile. Furthermore, the performance of the implemented guidance and control application is analyzed through the simulation.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.171-179
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• 2002

STEP-NC is the next generation CNC controller taking STEP-based data model as the interface scheme (or language) between CAM and CNC, and carrying out various intelligent functions. At the moment, efforts are being made worldwide to establish international standard for the new interface scheme formalized as ISO14649. As the new language is being established, increasing attention is being paid to the development of the new CNC. Korea STEP-NC is an integrated STEP-NC system taking ISO 14649 as an input, and carrying out various intelligent functions. It is composed of 5 modules: 1) Shop Floor Programming System (PosSFP), 2) Tool Path Generator (PosTPG), 3) Tool Path Viewer (PosTPV), 4) Man Machine Interface (PosMMI), and 5) CNC Kernel (PosCNC). Distinguished from other prototypes (of Europe and USA), the Korea STEP-NC is top-down designed, and bottom-up implemented comprehensively incorporating all the crucial components for realizing the full benefit of STEP-NC paradigm, without using any existing commercial CAD/CAM systems and CNC kernels. The Korea STEP-NC prototype was successfully demonstrated and evaluated in the ISO conventions Together with prototypes of Europe and USA, Korea STEP-NC will be used as a reference system fur the Triangular Conformance Test to be jointly carried out by ISO TC184 SC1, SC4, and IMS Project.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.4 s.310
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• pp.35-44
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• 2006

The network induced transmission delay deteriorates the performance and stability of the real-time distributed control system on LonWorks over IP (LonWorks/IP) virtual device network (VDN). LonWorks/IP virtual device network is an integrated form of LonWorks device network and IP data network. The time delay in servo control on the LonWorks/IP-based VDN has highly stochastic nature. In the real-time distributed servo applications for predictive maintenance on the factory floor, timely response is essential.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.184-193
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• 2015

This paper proposes a cost-efficient and automatic method for large data acquisition from a test chip without expensive equipment to characterize random process variation in an integrated circuit. Our method requires only a test chip, a personal computer, a cheap digital-to-analog converter, a controller and multimeters, and thus large volume measurement can be performed on an office desk at low cost. To demonstrate the proposed method, we designed a test chip with a current model logic driver and an array of 128 current mirrors that mimic the random process variation of the driver's tail current mirror. Using our method, we characterized the random process variation of the driver's voltage due to the random process variation on the driver's tail current mirror from large volume measurement data. The statistical characteristics of the driver's output voltage calculated from the measured data are compared with Monte Carlo simulation. The difference between the measured and the simulated averages and standard deviations are less than 20% showing that we can easily characterize the random process variation at low cost by using our cost-efficient automatic large data acquisition method.

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.446-455
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• 2014

This study revealed the results related to the functionality of outdoor wear required when man and women in their 30s to 50s engage in outdoor activities. Based on the results of the survey, we proposed composition draft for a smart outdoor jacket with main functions of GPS device and light-emitting device using solar cell and EL. Absorption and release of sweat, functionality regarding rain and wind, and lightweightness, etc. from material functionalities of outdoor wear were found to be important. From function required in clothing for outdoor activity, location tracking, night glow, and lighting functions were found to be most important. For results investigating the necessity of the jacket's location tracking function and lighting function using solar cell, high scores of 3.9~4.0 were given. Purchase intentions for smart outdoor jacket with location tracking and lighting functions devised by this study were fairly positive and most responses indicated that the appropriate purchase price was between 200,000 to 300,000 won while possible problems of this smart outdoor jacket were listed in the order of washing inconvenience, high price, device weight, and discomfort in movement. The draft proposal to integrate with wearable devices for smart outdoor jacket prototype is as follows: Solar cell has been attached to the upper arm but placed inside a transparent pocket which has been detachable for washing convenience while the solar cell and controller have been integrated into a single unit. Using frequent movement exhibited by the arms, EL has been attached along the center line of the raglan sleeve for easy spotting when used as an emergency signal or for night lighting function during outdoor activity. GPS has been attached on the left sleeve so that the person can bend the left arm inward and operate the GPS screen with the right hand while walking or running outdoors.

• Journal of Korea Multimedia Society
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• v.9 no.3
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• pp.360-368
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• 2006

Recently, performance of the mobile phone has increased dramatically. Due to this, it is possible to integrate various biotechnology. There are many ventures to integrate biotechnology with mobile phone, because of increasement interest of peoples well-being. The transcutaneous electrical nerve stimulation can Improve the circulation of blood and suppress a pain. To integrate the transcutaneous electrical nerve stimulation with mobile phone, it is necessity to make small, low power, and safe module. In this paper, the transcutaneous electrical nerve stimulation module is designed and implemented by small boost convertor. The value of tank capacitor, which is the total stimulus energy to human, can be chosen to insure safe condition. The confirm the of operation of designed module, a small micro-controller is used to make system and test the module. The implemented system is small and consumes a low enough power to be integrated with mobile phone.

• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.7-14
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• 2015

This paper proposes the development model of the aerodrome traffic control simulator (ATCS) System for the domestic airport. The application of the ATCS is used as a OJT training function for the air traffic controller and research function for a new control procedure. In order to perform those functions, we classified the ATCS in three types such as education, research and integrated management system, and the ATCS types analysed by the working and OJT training condition in domestic airport. Therefore, we proposed the ATCS models such as uniform type, differential type, and center type, and analysed the merits and demerits of the proposed models. Also we looked up ATCS's application in terms of the building and maintenance costs, operational utilization and scalability. So, we proposed the differential type which was suitable for the developing ATCS for the domestic airports.