• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.27-38
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• 2017

Packet classification is one of the essential functionalities of Internet routers in providing quality of service. Since the arrival rate of input packets can be tens-of-millions per second, wire-speed packet classification has become one of the most challenging tasks. While traditional packet classification only reports a single matching result, new network applications require multiple matching results. Ternary content-addressable memory (TCAM) has been adopted to solve the multi-match classification problem due to its ability to perform fast parallel matching. However, TCAM has a fundamental issue: high power dissipation. Since TCAM is designed for a single match, the applicability of TCAM to multi-match classification is limited. In this paper, we propose a cost- and energy-efficient multi-match classification architecture that combines TCAM with a tuple space search algorithm. The proposed solution uses two small TCAM modules and requires a single-cycle TCAM lookup, two SRAM accesses, and several Bloom filter query cycles for multi-match classifications.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.312-318
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• 2011

USN technology will be applied to various fields such as logistics, transportation, government, health, welfare and environment and will be settled down by basic infrastructure of a future society. In this study, we analyzed sensor networks structure based on IEEE 802.15.4 and implemented the sensor monitoring system using Zigbee modules. For implementation of real-time sensor monitoring system, we designed Linux-based development environment and the sensor-specific component. The result of this paper may be utilized in such areas lighting system, intrusion detection, fire detection, detection and notification of abnormal conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.327-327
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• 2010

In this paper, an investigation of factors affecting piezoelectric transformers is presented by ATILA software. These transformers are multi-layer piezoelectric transformers in square shape $28\;{\times}\;28\;mm$ and operate in first vibration mode for step-down function. The piezoelectric transformers were modeled in 3D-dimension and analyzed using finite element method in ATILA software, a popular software in piezoelectric analysis. Modal and harmonic modules were used in this process. Effective factors to the properties of piezoelectric transformers including different input electrode patterns, directions of polarization, sizes of connective comer, number of layers were examined on the simulated model using input voltage of 20 V and load resistance of $100\;{\Omega}$. Moreover, thermal analysis was also obtained with conditions of input voltage of 5 V and no-load.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.109-113
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• 2020

A power device is a component used as a switch or rectifier in power electronics to control high voltages. Consequently, power devices are used to improve the efficiency of electric-vehicle (EV) chargers, new energy generators, welders, and switched-mode power supplies (SMPS). Power device designs, which require high voltage, high efficiency, and high reliability, are typically based on MOSFET (metal-oxide-semiconductor field-effect transistor) and IGBT (insulated-gate bipolar transistor) structures. As a unipolar device, a MOSFET has the advantage of relatively fast switching and low tail current at turn-off compared to IGBT-based devices, which are built on bipolar structures. A superjunction structure adds a p-base region to allow a higher yield voltage due to lower R_DS (on) and field dispersion than previous p-base components, significantly reducing the total gate charge. To verify the basic characteristics of the superjunction, we worked with a planar type MOSFET and Synopsys' process simulation T-CAD tool. A basic structure of the superjunction MOSFET was produced and its changing electrical characteristics, tested under a number of environmental variables, were analyzed.

• Korean Journal of Construction Engineering and Management
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• v.5 no.3 s.19
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• pp.166-173
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• 2004

This research develops a preliminary system prototype of construction data warehouse of a construction industry application to provide the construction manager with electronic decision supporting information. Construction data warehouse technology is a contractor-focused concept that provides electronic information analyzed from the separately stored database by management dimension, management subject, and data warehouse technology modules. First the authors reviews the characteristics of data warehouse technology and reviewed the conceptually designed architecture of previous study, then propose the architecture of construction data warehouse system and real application alternatives of each technology module to confirm the construction adaptability of the data warehouse technology through a case study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.13-20
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• 2010

The development of the console for exterior advertizing LCD Panel(LCD Console) is the purpose of this study with regard to importance of display industry. In this study, the most important point is to develop the cooling system for LCD Console. It is developed by using systematic application techniques and statistical tests and analysis to integrate commercial components, cooling fan, heat sink, thermo electronic modules etc, of it. This study, at first, shows design/manufacturing process of the cooling system and the setting process of control factors to control through experimentation. Next, after constructing the complete console, 46 inch LCD Panel and the cooling system are built in, the performance test of it is shown through experimentation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.6
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• pp.510-514
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• 2005

We have investigated the excitation-light source dependence of photo-catalytic efficiency for the benzene removal. The photo-catalytic module for the benzene removal is fabricated by a combination of GaN-based ultraviolet light-emitting diode (UV GaN-LED) and $TiO_2$ thin film coated on an aluminum plate. The benzene reduction rates of 365 nm and 375 nm modules at 60 mA junction current are approximately $8.95\;\%/Hr$ and $9.2\;\%/Hr$, respectively, which indicates that 365 nm GaN-LED is more effective than 375 nm GaN-LED. The benzene reduction efficiency is also noticeably dependent on the excitation wavelength and excitation-light power, as well as it is increased with the shorter wavelength and higher excitation power. This result exhibits that UV GaN-LED is useful to remove the volatile organic compounds (VOCs) existing in the environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.342-345
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• 2002

As the size of chip components and module decreases, new patteming method for fine line and geometry is needed. So far, in LTCC(Low Temperature Cofired Ceramic) process, screen printing method has been used generally. But screen printing method has some disadvantages as follows. First, the geometry including line, vias, etc. smaller than $100{\mu}m$ can't be evaluated easily. Second, the patterned dimension is different from designed value, which makes distortion in charactersitics of not only chip components but also modules. Thick film lithography has advantages of thick film screen printing process, low cost and thin film process, fine line feasibility. Using this method, the line with $30{\mu}m$ width and the geometry with expected dimension can be evaluated. In this study, the fine line with $35{\mu}m$ line/space is formed and the embedded capacitor with very small tolerance is developed using thick film lithography.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.3-4
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• 2008

Photovoltaic module consists of serially connected solar cell which has low voltage characteristics. But, the other way, the whole current flow of PV module is restricted by lowest current of one solar cell. For the experiment, we make PV module composing the solar cells that have short circuit current difference of 0%, 1%, 3% and 5%. Using Light I-V and Dark I-V measurements, electrical characteristic parameters like Isc(short-circuit current), Voc(open-circuit voltage), Rs(series resistance), Rsh(shunt resistance) are analyzed. PV module of low current characteristics has electrical stress from other modules. And, such a module has a tendency of hot-spot suffering which leads degradation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.1
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• pp.12-16
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• 2009

Current sensing in power semiconductors involves sensing of over-current in order to protect the device from harsh conditions. This technique is one of the most important functions in stabilizing power semiconductor device modules. The sense FET is very efficient method with low power consumption, fast sensing speed and accuracy. In this paper, we have analyzed the characteristics of proposed sense FET and optimized its electrical characteristics to apply conventional 450 V power MOSFET by numerical and simulation analysis. The proposed sense FET has the n-drift doping concentration $1.5{\times}10^{14}cm^{-3}$, size of $600{\um}m^2$ with $4.5\;{\Omega}$, and off-state leakage current below $50{\mu}A$. We offer the layout of the proposed sense FET to process actually. The offerd design and optimization methods are meaningful, which the methods can be applied to the power devices having various breakdown voltages for protection.