• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.51-61
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• 2000

This paper reviews fundamentals of a pseudo-static seismic design/analysis method for soil-reinforced segmental retaining walls. A comparative study on NCMA and FHWA seismic design guidelines, which are one of the most well known design guidelines for mechanically stabilized earth walls, was also performed. The results demonstrate that there exist significant discrepancies in the results of external stability analysis despite the same calculation model used in the two guidelines, due primarily to different seismic coefficient selection criteria. It is also demonstrated that the internal stability calculation model for NCMA guideline tends to yield larger seismic reinforcement force in the shallower reinforcement layers, resulting in an increased number of reinforcement layers at the top of reinforced wall and increased reinforcement lengths to ensure adequate anchorage capacity. The internal stability calculation model adopted by FHWA guideline, however, leads to redistribution of dynamic force to the lower reinforcement layers and thus results n an opposite trend of NCMA guideline. Findings from this study clearly demonstrate a need for more in-depth studies to develop a generally acceptable design/analysis method.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.160-169
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• 2006

This paper describes the data structure for program analysis and optimization of bytecode level. First we create an extended CFG(Control Flow Graph). Because of the special properties of bytecode, we must adaptively extend the existing control flow analysis techniques. We build basic blocks to create the CFG and create various data that can be used for optimization. The created CFG can be tested for comprehension and maintenance of Java bytecode, and can also be used for other analyses such as data flow analysis. This paper implements CTOC's CTOC-BR(CTOC-Bytecode tRanslator) for control flow analysis of bytecode level. CTOC(Classes To Optimized Classes) is a Java bytecode framework for optimization and analysis. This paper covers the first part of the CTOC framework. CTOC-BR is a tool that converts the bytecode into tree form for easy optimization and analysis of bytecode in CTOC.

• Journal of the Korean Geotechnical Society
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• v.24 no.9
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• pp.23-32
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• 2008

This paper presents the global stability of geosynthetic reinforced segmental retaining walls in tiered configuration. Four design cases of walls with different geometries and offset distances were analyzed based on the FHWA and NCMA design guidelines and the discrepancies between the different guidelines were identified. A series of global slope stability analyses were conducted using the limit-equilibrium analysis and the continuum mechanics based shear strength reduction method with the aim of identifying failure patterns and the associated factors of safety. The results indicated among other things that the FHWA design approach yields conservative results both in the external and internal stability calculations, i.e., lower factors of safety, than the NCMA design approach. It was also found that required reinforcement lengths are usually governed by the global slope stability requirement rather than the external stability calculations. Also shown is that the required reinforcement lengths for the upper tiers are much longer than those based on the current design guidelines.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.9-16
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• 2022

In this paper, we propose a plan to design and utilize the RDBS(Record Block Data file management System) so that data can be recovered when data files in the Combat Management System are mismatched. The CMS(Combat Management System) manages the same files in multiple IPN(Infomation Processing Node) repositories to support multiplexing. However, mismatches in data files can occur due to equipment maintenance or user immaturity. The existing CMS does not manage the history of changes in data files, and when a mismatch occurs, data file were synchronized based on the latest date. But, It is difficult to say that files with the latest date have the highest reliability, and once the file synchronization has progressed, it cannot be recovered with pre-synchronization data. To solve this problem, data was stored and synchronized in units of record blocks using RDBS proposed in this paper, and the Rsync algorithm was used to reduce the overhead of file synchronization due to units of record blocks. SW applied with RDBS was tested for performance in a simulated environment, and it was confirmed that it could be applied to CMS through normal operation confirmation.

• Korean journal of communication and information
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• v.31
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• pp.113-165
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• 2005

The research focused on the return of class analysis of the media soctor. It is told that class is a determining factor of media industry. This article is divided in to four sections that represent class analysis of media. In this study, I claimed that class analysis is necessary of understanding the nature of media industrial capital and its nature. With their domination of the media, big corporations seek to control political power and information. This article has demonstrated that the media power of corporations should be curved.

• Explosives and Blasting
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• v.32 no.1
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• pp.1-9
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• 2014

TNT was blasted on the surface of steel plates and concrete block to study the effect of separation distance between object and charge. The equation of US Army Corps of Engineers turned out to be rather conservative. Effect of separation distance is larger for steel plate than concrete block. Steel plate cannot be cut by standard or more charge in the case of 2 cm separation while the concrete block can be crushed with the same distance.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.515-525
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• 2011

In this study, Urban maglev is applied to inductive-loop speed and position detection system for the top-level classification system for the entire system, and performed functional analysis On-board signal equipment, Wayside-signal equipment divided by the reliability, availability, maintainability, and safety through analysis of the proposed formula. RDB and by applying a system service for each device was calculated to availability, safety analysis. The PHA, FMEA, HAZOP over the Top Event of the FTA is performed by presenting the results. This also shows approach methods and relative activities for project to accomplish and ensure the system requirements.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.9
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• pp.55-61
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• 2002

Using the carry-select adder scheme, an adder with small number of stages can be operated as fast as an adder with large number of stages. In this paper, a 4-block 5-stage 32-bit pipelined carry-select adder is designed and implemented. The proposed adder operates as fast as a conventional 16-stage 32-bit pipelined adder while the number of registers required is nearly same as a conventional 4-stage pipelined adder. This adder is operated at 1.67GHz clock frequency in a standard 0.25um CMOS technology with 2.5 V supply voltage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1451-1459
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• 2004

In this paper, a low-power 32-point IMDCT structure is proposed for MP3. Through re-odering of IMDCT matrices, we propose the systolic structure operating with 16, 8, 4, 2, and 1 cycle, respectively. To reduce power consumption, multiplication of each sub blocks are implemented by add and shift operation with CSD(Canrmic sigled digit) form coefficients. To reduce, furthermore, the number of adders, we utilize the common sub-expression sharing techniques. With these techniques, the relative power consumption of the proposed structure is reduced by 58.4% comparison to the conventional structure using only 2's complement form coefficient. Validity of the proposed structure is proved through Verilog-HDL coding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3685-3691
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• 2015

We developed the platform safety step system for the passenger to avoid misstep accident and secure the pedestrian safety. In this study, we classify platform safety step system into hierarchy system and predict the failure rate of each part and calculate the failure rate & MTBF(Mean Time Between Failure) of each module(sub-system) by means of RBD(Reliability Block Diagram) & FTA(Fault Tree Analysis). Finally, we will propose the reliability analysis results for RAMS analysis of platform safety step system.