• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.600-603
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• 2008

In this paper, a new circuit design named memory-in-pixel for low power consumption of the liquid crystal display (LCD) is presented. Since each pixel has a memory, it is able to express 8 color grades using the data saved in the memory without the operation of the gate and source driver ICs so that it can reduce the power consumption of the LCD panel. A memory circuit consists of modified S-R flip-flop (NAND-type) implemented in the pixel, which can supply AC bias for operating the liquid crystal (LC) with the interlocking clocks (CLK_A and CLK_B). This circuit is more complex than the inverter-type memory circuit, but it has lower power consumption of approximately 50% than the circuit. We have investigated the power consumption both NAND and inverter-type memory circuit using a Smart SPICE for the resolution of $96{\times}128$. The estimated power consumption of the inverter-type memory was about 0.037mW. On the other hand, the NAND-type memory showed power consumption of about 0.007mW.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.1
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• pp.1-12
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• 1997

The acousto-optical spectrometer as a new type backend of the receiver system for radio astronomical observations is manufactured for radio signal analysis. We studied on the effect of Acousto-Optic and Acousto-Optic devices and designed the optics system. We manufactured the optical mount and the CCD detector for deflected beam and interface card. This acousto-optical spectrometer consisted of a laser, optics, acousto-optic deflector, CCD detector and Interface card. This system use He-Ne laser as a light source and use optics to get parallel beam and to focus the deflected beam. Acousto-optic deflector converts IF signal to ultrasonic wave and deflect the laser beam according to the Bragg deflection. The ultra wide band acousto-optic deflector has 1 GHz bandwidth and a total of 2,048 channel Charge Coupled Device for signal detection. In this study, we discuss the theoretical description on the effect of Acousto-optics, the design of the optics, manufacture of optical mount, CCD detector, interface card and we presented the results of experiment. As a result of measurement, we have 1,000 channels bandwidth from CCD channels.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.681-684
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• 2006

A new packet extraction program is presented to extract communication packet between a server and clients. The extracted packet source is used to develope a special driver to access general clients to the server. The proposed scheme employs a relay server to take a specified packet among a large number of packets on the same network. The proposed method is tested in PMS (Plant Management System) sewer and ProDAS (Process Data Aquisition and Analysis System) in a combined cycle power plant. The developed scheme can be applied for extracting a specified communication packet between the general server and client.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.71-76
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• 2022

Since brightness is proportional to the operating current, a method of connecting several LEDs in series and driving with a constant current source is widely used for driving circuits of LED lights. Because several LEDs are connected in series, if some LEDs open due to a fault, the current path is broken and all other LEDs connected in series are turned off. In this paper, we designed a circuit to solve this problem by connecting a Zener diode having a breakdown voltage of about 0.4V higher than the LED operating voltage in parallel with each LED to create a current bypass in case of LED failure. Through simulations and experiments, it was confirmed that the current of the Zener diode hardly flows when the LED is operating normally, and that the Zener diode stably operates as a current bypass when the LED fails.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.159-167
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• 2009

The vehicles play a significant role in modern people's life as economy grows. The development of car navigation system(CNS) provides various convenience because it shows the driver where they are and how to get to the destination from the point of source. However, the existing map-based CNS does not consider any environments such as traffic congestion. Given the same starting point and destination, the system always provides the same route and the required time. This paper proposes a path planning method with traffic prediction by applying historical driving information to the Fuzzy theory and Bayesian update. Fuzzy theory classifies the historical driving information into groups of leaving time and speed rate, and the traffic condition of each time zone is calculated by Bayesian update. An ellipse area including starting and destination points is restricted in order to reduce the calculation time. The accuracy and practicality of the proposed scheme are verified by several experiments and comparisons with real navigation.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.28-33
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• 2016

Batteries are used for main power engine in the fields such as mobiles, electric vehicles and unmanned submarines, for starter and lamp driver in general automotive, for emergency electric source in ship. These days, lead-acid and the lithium ion batteries are increasingly used in the fields of the secondary battery, and the lead-acid battery has a low price and safety comparatively, The lithium ion battery has a high energy density, excellent output characteristics and long life, whereas it has the risk of explosion by reacting with moisture in the air. But Recently, due to the development of waterproof, fireproof, dustproof technology, lithium batteries are widely used, particularly, because their usages are getting wider enough to be used as a power source for hybrid ship and electric propulsion ship, it is necessary to manage more strictly. Hybrid ship has power supply units connected to the packets to produce more than 500kWh large power source, and therefore, A number of the communication modules and wires need to implement the wire inspection and monitor system(WIIMS) that allows monitoring server to transmit detecting voltage, current and temperature data, which is required for the management of the batteries. This paper implements a low price type wireless inspection and monitoring system(WILIMS) of the lithium ion battery for hybrid vessels using BLE wireless communication modules and power line modem( PLM), which have the advantages of low price, no electric lines compared to serial communication inspection systems(SCIS). There are state of charge(SOC), state of health(SOH) in inspection parts of batteries, and proposed system will be able to prevent safety accidents because it allows us to predict life time and make a preventive maintenance by checking them at regular intervals.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.921-929
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• 2015

Road conditions which obstruct the driver from seeing road markings, such as in the evening or in the rain, due to the lack of a light source gives way to increasing the risk of traffic accidents. In order to increase road safety, the Korea Expressway Corporation set up a pilot project which used high-quality materials along a section of the Gyeongbu Expressway between Daejeon and Pangyo. There is little research on high-quality materials in the field of pavement marking. This study introduces high-quality materials used in pavement materials, presents the results of a survey conducted to examine the effect of the pilot project and analyzes traffic accident data from before and after the implementation of the pilot project. The survey results show that 87% of the respondents were highly satisfied with the pilot project. With the goal of evaluating the effect of the pilot project, this study used traffic accident data provided by the Korea Expressway Corporation accident data and performed a before-after study of the number of traffic. The results of data analysis show that there were 62 and 48 traffic accidents before and after the implementation of the pilot project. In addition, the result of Emperical Bayes Method indicates that there is an 41.7% decrease in the number of traffic accidents as an effect of High-quality Pavement Marking Materials.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.

• Journal of the Korean Society for Library and Information Science
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• v.38 no.2
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• pp.239-259
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• 2004

The purpose of this study is to review the established research practices and managerial methods on the range of Knowledge that have been independently studied from the conventional information system (libraries) and the managerial information system (MIS, DSS and EIS) within the quantitative and the non-quantitative perspective. The information systems were developed through their own purpose since the 1950s and these days the corporate environments have become integrated due to the rapid creation and expansion of information. Therefore, to make fast decisions in this situation it is appropriate that these two systems, Library and the managerial information system, should be dealt within the same category. In other words, not only the quantitative data that become main sources of DSS or EIS, but also the qualitative data such as the text documents, video and audio data, which have been managed in the libraries and information centers and not extracted from the former, can be used as the new knowledge source. Also BSS/EIS can provide the splendid infrastructure for Knowledge Management(KM) while libraries/information centers manage the comprehensive range of explicit and tacit knowledge, which can be a facilitator or main driver for KM.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.490-499
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• 2002

Recently, gamma radiographic equipments have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of $0.4{\sim}1.2m/s$ by BLDC motor of 24V 200W which has output of $54kgf{\cdot}cm$, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use.