• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2999-3004
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• 2013

Smartphone subscribers exceeded 30 million people, Smart Korea is up on this track, and leaping to 'Smart powerful nation from 'IT powerful nation. Of course, the popularization of the smart phone called 'PC in the hands' has brought a revolutionary change to nation livelihood, and also to business and government, too. The current usage of Smartphone is not just a simple function call, people can communicate anytime, anywhere with it. The current usage of Smartphone is not just a simple function call, people can communicate anytime, anywhere with it. And it has become the culture of the terminal type in the hands whenever and wherever. However, the screen size and the existing flash or video files do not run when trying to access to the homepage for PC with Smartphone. and it may gives the inconvenience to people who use mobile devices. Therefore, in this paper, it is a study for the provision of an efficient service for Smartphone users through the establishment of website for mobile in mobile circumstances.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.6
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• pp.879-888
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• 1999

A Study on the ARQ scheme of data error control is important for more reliable information transmission. Since performance difference is large by the long transmission delay time in satellite communication, the performances of SR ARQ and conventional type-I hybrid ARQ with fixed code rate are investigated by using the parameters of packet length, channel capacity, BER, and transmission delay time especially. BCH code is used in type-I hybrid ARQ for FEC method. This paper presents the throughput analyses according to such various parameters as BCH code rate, window size, data rate and round-trip delay time. Especially we derive a performance equation of type-I hybrid ARQ with the factor of the transmission delay time using the equation of SAW ARQ. Also, the performance of type-I hybrid ARQ specially considering transmission delay time is analyzed through numerical analysis and computer simulation so we can get a important characteristics variation.

• Structural Engineering and Mechanics
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• v.66 no.2
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• pp.203-215
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• 2018

A large body of experiments have been conducted to date to evaluate the punching shear strength of flat slab-column connections, but it is noted that only a few of them have been considered for the development of the ACI Code provisions. The limited test results used for the development of the code provisions fall short of predicting accurately the punching shear strength of such connections. In an effort to address this shortfall and to gain an insight into the factors that control the punching shear strength of flat slab-column connections, we report a qualified database of 650 punching shear test results in this article. All slabs examined in this database were tested under gravity loading and do not contain shear reinforcement. In order to justify including any test result for evaluation punching shear database, we have developed an approved set of criteria. Carefully established set of criteria represent the actual characteristics of structures that include minimum compressive strength, effective depths of slab, flexural and compression reinforcement ratio and column size. The key parameters that significantly affect the punching shear strength of flat slab-column connections are then examined using ACI 318-14 expression. The results reported here have paramount significance on the range of applicability of the ACI Code provision and seem to indicate that the ACI provisions do not sufficiently capture many trends identified through regression of the principal parameters, and fall on the unsafe side for the prediction of the punching shear strength of flat slab-column connections.

• Nuclear Engineering and Technology
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• v.41 no.7
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• pp.945-952
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• 2009

The Three Mile Island Unit 2 (TMI-2) accident provides unique full scale data, thus providing opportunities to check the capability of codes to model overall plant behavior and to perform a spectrum of sensitivity and uncertainty calculations. As part of the TMI-2 analysis benchmark exercise sponsored by the Organization for Economic Cooperation and Development Nuclear Energy Agency (OECD NEA), several member countries are continuing to improve their system analysis codes using the TMI-2 data. The Republic of Korea joined this benchmark exercise in November 2005. Seoul National University has analyzed the TMI-2 accident as well as the currently proposed alternative scenario along with a sensitivity study using the Modular Accident Analysis Program Version 4.03 (MAAP4.03) code in collaboration with the Korea Hydro and Nuclear Power Company. Two input files are required to simulate the TMI-2 accident with MAAP4: the parameter file and an input deck. The user inputs various parameters, such as volumes or masses, for each component. The parameter file contains the information on TMI-2 relevant to the plant geometry, system performance, controls, and initial conditions used to perform these benchmark calculations. The input deck defines the operator actions and boundary conditions during the course of the accident. The TMI-2 accident analysis provided good estimates of the accident output data compared with the OECD TMI-2 standard reference. The alternative scenario has proposed the initial event as a loss of main feed water and a small break on the hot leg. Analysis is in progress along with a sensitivity study concerning the break size and elevation.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.1
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• pp.97-107
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• 2017

In this study, the validity and applicability of the multipurpose fishway which has been constructed for the upstream migration of fish at Chuksan river in Uljin is assessed and analyzed by a commercial software. The upper slab types of fishway in this investigation are reinforced concrete slab (S1 type) and reinforced concrete slab with steel plate (S2 type). The three different sizes of subway passage ($0.8m{\times}0.1m$, $0.8m{\times}0.2m$, $0.8 m{\times}0.3m$) and velocities (0.6 m/s, 1.2 m/s, 1.8 m/s) of Chuksan fishway was investigated and compared for the Chuksan in government design code. The analysis showed that the maximum stress and bending moment of S1 type decreased 1~21 % and 12~27 % compared to the Chuksan in government design code, respectively. Also, the maximum stress of and bending moment of S2 type decreased 11~32 % and 27~39 %. From the numerical analysis, it was found that the S2 type was greatly effective and the subway passage size of $0.8m{\times}0.2m$ was most safe. This result can be utilized to be the basic data for design of the Multipurpose fishway.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.198-204
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• 2012

Tracking and recognition of robots are required for the cooperation task of robots in various environments. In the paper, a tracking control system of moving robot using stereo image processing, code-book model and fuzzy controller is proposed. First, foreground and background images are separated by using code-book model method. A candidate region is selected based on the color information in the separated foreground image and real distance of the robot is estimated from matching process of depth image that is acquired through stereo image processing. The open and close processing of image are applied and labeling according to the size of mobile robot is used to recognize the moving robot effectively. A fuzzy tracking controller using distance information and mobile information by stereo image processing is designed for effective tracking according to the movement velocity of the target robot. The proposed fuzzy tracking control method is verified through tracking experiments of mobile robots with stereo camera.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.994-1004
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• 2000

In this paper, bitstreams are composed of using H.263 for a moving picture coding in the band-limited and error-prone environment such as wireless environment. EREC sub-frames are implemented by applying the proposed EREC algorithm in order to be UEP for the real data parts of implemented bitstreams. Because those are able to do resynchronization with a block unit, propagation of the error can be minimized, and the position of the important bits such as INTRADC and MVD can be known. Class is separated using the position of these important bits, and variable puncturing tables are designed by the class informations and the code rates of turbo codes are differently designed in according to the class. Channel coding used the turbo codes, and an interleaver to be designed in the turbo codes does not eliminate redundancy bits of the important bits in applying variable code rates of EREC sub-frames unit and is always the same at the transmitter and the receiver although being variable frame size. As a result of simulation, UEP with the code rate similar to EEP is obtained a improved result in the side of bit error probability. And the result of applying it to image knows that the subjective and objective quality have been improved by the protection of important bits.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.520-528
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• 2000

he speed of microprocessor getting faster, the data transfer width between the microprocessor and the memory becomes a critical part to limit the system performance. So the study of the computer architecture with the high code density is cmerged. In this paper, a tentative Bi-Length Instruction Set Computer(BISC) that consists of 16 bit and 32 bit length instructions is proposed as the high code density 32 bit microprocessor architecture. The 32 bit BISC has 16 general purpose registers and two kinds of instructions due to the length of offset and the size of immediate operand. The proposed 32 bit BISC is implemented by FPGA, and all of its functions are tested and verified at 1.8432MHz. And the cross assembler, the cross C/C++ compiler and the instruction simulator of the 32 bit BISC are designed and verified. This paper also proves that the code density of 32 bit BISC is much higher than the one of traditional architecture, it accounts for 130~220% of RISC and 130~140% of CISC. As a consequence, the BISC is suitable for the next generation computer architecture because it needs less data transfer width. And its small memory requirement offers that it could be useful for the embedded microprocessor.

• Convergence Security Journal
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• v.19 no.1
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• pp.11-17
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• 2019

Recently, the abuse of Internet technology has caused economic and mental harm to society as a whole. Especially, malicious code that is newly created or modified is used as a basic means of various application hacking and cyber security threats by bypassing the existing information protection system. However, research on small-capacity executable files that occupy a large portion of actual malicious code is rather limited. In this paper, we propose a model that can analyze the characteristics of known small capacity executable files by using data mining techniques and to use them for detecting unknown malicious codes. Data mining analysis techniques were performed in various ways such as Naive Bayesian, SVM, decision tree, random forest, artificial neural network, and the accuracy was compared according to the detection level of virustotal. As a result, more than 80% classification accuracy was verified for 34,646 analysis files.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.2
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• pp.179-188
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• 2012

Packing techniques, one of malicious code detection and analysis avoidance techniques, change code to reduce size and make analysts confused. Therefore, malwares have more time to spread out and it takes longer time to analyze them. Thus, these kind of unpacking techniques have been studied to deal with packed malicious code lately. Packed programs are unpacked during execution. When it is unpacked, the data inside of the packed program are changed. Because of these changes, the entropy value of packed program is changed. After unpacking, there will be no data changes; thus, the entropy value is not changed anymore. Therefore, packed programs could be unpacked finding the unpacking point using this characteristic regardless of packing algorithms. This paper suggests the generic unpacking mechanism using the method estimating the unpacking point through the variation of entropy values.