• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.305-312
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• 2017

This paper presents a laboratory investigation into the effects of fillers using industrial by-product such as coal ash, IGCC slag on properties of hot-mixed asphalt concrete variation with filler content. For comparison, existing mixture with lime and dust have also been considered. Marshall and flow test has been considered for the purpose of mix design as well as evaluation of mixture. Other performance tests such as indirect tensile strength test, tensile strength ratio(moisture susceptibility), dynamic stability have also been carried out variation with filler content. It is observed that the mixes with industrial by-product exhibit conform with quality standard. Therefore, it has been recommended to utilize industrial by-product based on fly ash wherever available, not only reducing the produce cost but also partly solve the industrial by-product utilization and disposal problem.

• Journal of Korea Multimedia Society
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• v.7 no.9
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• pp.1329-1338
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• 2004

The purpose of data mining is to extract multi-dimensional information from a large database. The only information that we can extract from a large database is the column name, data type or simple comments included in the columns of database tables. With such unstructured and scarce information, it is very difficult and time taking to collect and to cleanse data by analyzing the purpose, characteristic and schema of the column during the data preparation step. In order to solve this problem, we propose solutions for reducing the time spent data preparation step in a relational database environment in this paper. That is, we propose useful elements to be considered during the data preparation step and then these elements are organized to constitute MDR(Metadata Registry) which is becoming the international standard of ISO/IEC : ll179. Finally, we propose a XML-based distributed MDR retrieval system that is convertible among heterogeneous systems and heterogeneous DBMSS.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.142-150
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• 2014

In this paper, the performance analysis results of time/frequency synchronization and cell search algorithm are presented for aeronautical mobile airport communication systems (AeroMACS). AeroMACS is based on IEEE 802.16e mobile WiMAX standard and uses the aeronautical frequency band of 5GHz with the bandwidth of 5MHz. The simulation model of AeroMACS is designed and the performance evaluation is conducted with the various airport channel models such as apron (APR), runway (RWY), taxiway (TWY), and park (PRK). The proposed synchronization unit was designed in hardware description language (HDL) and implemented on FPGA. Also, the real-time operation was verified and evaluated using FPGA test system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.1
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• pp.1-8
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• 2004

Nowadays the soccer becomes one of the best spot lighting sports in the world Especially the 2002 Korea-Japan World Cup was deeply impressed on all the korean. One goal of illuminating engineering should be the design of lighting system that can provide consistently high task visibility regardless of where a task might be located within a working space. The television broadcasting on the soccer has been an important role in the media. The standard of FIFA(The Federation Internationale do Football Association) requires recommended illuminance levels for artificial lighting for a player, an audience, TV broadcasting, as well as everybody in the stadium. This paper has proposed an algerian to select the suboptimal lighting tower position for watching and TV broadcasting a soccer game within a pleasant environment and an optimum illuminance distribution. The position using the software Philip's Calculux was chosen based an the calculations of a horizontal illuminance, vertical illuminance, uniformity, glare, and so on by changing lighting tower positions.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.921-929
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• 2011

This paper describes an analysis of the decoding performance and decoding convergence speed of layered LDPC(low-density parity-check) decoder for mobile WiMAX system, and the optimal design conditions for hardware implementation are searched. A fixed-point model of LDPC decoder, which is based on the min-sum algorithm and layered decoding scheme, is implemented and simulated using Matlab model. Through fixed-point simulations for the block lengths of 576, 1440, 2304 bits and the code rates of 1/2, 2/3A, 2/3B, 3/4A, 3/4B, 5/6 specified in the IEEE 802.16e standard, the effect of internal bit-width, block length and code rate on the decoding performance are analyzed. Simulation results show that fixed-point bit-width larger than 8 bits with integer part of 5 bits should be used for acceptable decoding performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.778-784
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• 2012

A symmetric block cryptosystem uses an identical cryptographic key at encryption and decryption processes. HIGHT cipher algorithm is 64-bit block cryptographic technology for mobile device that was authorized as international standard by ISO/IEC on 2010. In this paper, block cipher HIGHT algorithm is designed using Verilog-HDL. Four modes of operation for block cipher such as ECB, CBC, OFB and CTR are supported. When continuous message blocks of fixed size are encrypted or decrypted, the desigend HIGHT core can process a 64-bit message block in every 34-clock cycle. The cryptographic processor designed in this paper operates at 144MHz on vertex chip of Xilinx, Inc. and the maximum throughput is 271Mbps. The designed cryptographic processor is applicable to security module of the areas such as PDA, smart card, internet banking and satellite broadcasting.

• The Transactions of the Korea Information Processing Society
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• v.5 no.9
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• pp.2248-2255
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• 1998

The property of connectivity between DBMS and application system developed in java is very important under the distributed object environments with heterogeneous systems. In these days, mostly used JDBC 3-tier model, which supports the connectivity, has two problems: the one is the restricted connectivity needed for the Java applet as application programs and the other is the additional efforts to design and implemtnt in linking any application program with the middleware from being deficit of standard protocol. In order to solve these problems, we have worked on Enlarging the properties of JDBC 3 tier model by applying CORBA distributed object environments. Thus, the enlarged 3-tier model has an ORB-JDBC sub protocol for the client sub-protocol and a middleware whose property is supported by CORBA.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.666-670
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• 2015

This paper presents radiation pattern reconfigurable antenna for Fitbit Flex wristband which detects vital signal. Also, the paper presents Specific Absorption Rate (SAR) from the loop-dipole radiation pattern reconfigurable antenna based on the position of human body. The proposed loop-dipole radiation pattern reconfigurable antenna produces two opposite side direction radiation pattern using two RF switches. The resonant frequency of the radiation pattern reconfigurable antenna is Bluetooth communication bandwidth (2.4 - 2.485 GHz) and the maximum gain of the proposed antenna is 1.96 dBi. The proposed antenna satisfied the standard SAR value of 1.6 W/kg in 1 g tissue of the human body when the Bluetooth communication input average power of 0.04 W is excited to five parts of human body (head, chest, stomach, back, wrist). The maximum SAR value of in this simulation is presented in the part of head.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.820-828
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• 2014

This study was done to identify factors influencing suicidal ideation in middle school students. Data were collected by questionnaires from 673 middle school students in D metropolitan city. Measures were daily life stress, problem of life, social support, depression, and suicidal ideation. Data were analyzed using frequencies, means and standard deviation, t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression analysis with SPSS/WIN 19.0 version. The mean score for suicidal ideation of the participants was 1.22, out of a possible 5. There were significant differences in suicidal ideation according to religion, record, family structure, experience of school violence, and economy status. Suicidal ideation correlated positively with daily life stress, problem of life and depression and negatively with social support. According to the research, factors influencing suicidal ideation in middle school students were problem of life, depression, social support, daily life stress, and experience of school violence. Based on the outcomes of this study, it is necessary to design an intervention program that emphasizes the reducement of problem of life, depression, daily life stress, school violence and enhancement social support in order to prevent suicidal ideation in middle school students.