• International conference on construction engineering and project management
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• 2015.10a
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• pp.289-293
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• 2015

The construction industry has been evolving with the development of information technology. According to this trend, the current industry changes from 2d drawings to Building Information Modeling(BIM). Current studies on the BIM-based estimation have problems such as Quantity Take-Off(QTO) specificity toward a particular software, the uncertainty of the amount in accordance with the model quality. These studies focus on QTO based on BIM rather than schematic estimation. In addition, studies on the connection with the QTO and unit cost for schematic estimation are insufficient. The purpose of this study is to propose schematic estimation process by utilizing construction codes and QTO in architectural object BIM libraries. Construction codes are classified in detail in order to input codes inside each. This study has connected unit cost and construction classification codes that obtain from BIM model. The results of this study will be helpful in decision-making and communication for schematic estimation of the design phase. It will improve the efficiency and reliability problems of existing schematic estimation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3183-3191
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• 2014

It is essential to effectively manage facilities because operating and maintenance cost for them accounts for more than 83% of lifecycle cost. This study developed BIM Object-based classification list to manage information required to operating and maintenance phase of them from design and construction phase. In order to develop this classification list, Construction Information Classification System, Design Criteria for Architectural Electrical Installations, commodity list classification of PPS(Public Procurement Service) were analyzed. and problems for consisting of object classification list were drawn. And each materials is classified that drawings discipline code (KSF 1540:2010 (Principle and criteria for CAD Drawing) was classified as level 1 to cover main areas and construction information classification system was classified as level 2 to cover elements also UNSPSC was classified as level 3 to cover objects for devices and equipments. this classification criteria was given code. This study is expected to be useful to exchange and share information in operating and maintenance phase by offering object point of view classification in design and construction phase. besides, it is looking forward to effective operating and maintenance of facilities by enabling management of devices and equipments by function, space, use.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.438-449
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• 2012

This paper presents new CRC-p codes for VHF band maritime wireless communication system based on performance analysis of various CRC codes. For this purpose, we firstly describe the method of determination of undetected error probability and minimum Hamming distance according to variation of CRC codeword length. By using the fact that the dual code of cyclic Hamming code and primitive BCH code become maximum length codes, we present an algorithm for computation of undetected error probability and minimum Hamming distance where the concept of simple hardware that is consisted of linear feedback shift register is utilized to compute the weight distribution of CRC codes. We also present construction of transmit data frame of VHF band maritime wireless communication system and specification of major communication parameters. Finally, new optimal CRC-p codes are presented based on the simulation results of undetected error probability and minimum Hamming distance using the various generator polynomials of CRC codes, and their performances are evaluated with simulation results of bit error rate based on the Rician maritime channel model and ${\pi}$/4-DQPSK modulator.

• Geotechnical Engineering
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• v.12 no.3
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• pp.73-82
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• 1996

Limit state design(LSD) principles employing load and resistance factor design(LRFD) are coming into use in geotechnical engineering community around the world. Current working (allowable) stress design principles are expected to be replaced by LRFH method in the near future. North America has recently adopted LRFD principles, and European community has also developed its own code called "Eurocode" based on partial safety factor design which is essentially the same as LRFD. Relevant review and analysis of new global design codes are prerequisites to adopting these codes in the Korean construction industry and in the Korean foundation design prac titre. This paper reviews geotechnical aspects of LRFD and Eurocode, and analyzes the geomaterial resistance factors in LRFD for the design of axially-loaded driven piles.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.835-843
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• 2009

Recently the more stable roadbed is required due to the high speed and design load. Therefore the reinforced roadbed was introduced as the solution. But the thickness and stiffness of reinforced roadbed in design code is being conservatively assessed by the foreign code without considering the domestic construction condition. In this paper, adequate Young's modulus, drain capacity, freezing depth, economical efficiency, bearing capacity, construction condition and 3-D finite element method were employed to determine the proper thickness of reinforced roadbed at the embankment section.

• Journal of Korean Society of Steel Construction
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• v.13 no.2
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• pp.123-131
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• 2001

The objective of this study is to investigate the criteria of the width-to-thickness ratio and to evaluate the buckling strength of high strength steel beam-columns and to compare their buckling strength with design codes, which are the Limit State Design code and the Allowable Stress Desogn code(drift). SM520TMC and SM570Q class steels are used for high strength steels. The coupon test and the stub column test were carried out to investigate the properties of high strength steels and the stress-strain curves of stub columns. The buckling strength of high strength steel beam-columns are assessed by numerical analysis used axial force, moment and curvature relationships.

• Journal of Korean Society of Steel Construction
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• v.28 no.4
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• pp.271-280
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• 2016

The need to accurate quantification of blast pressure loading in the near field is important because the focus of security design of critical infrastructure, buildings and bridges is for near-field detonations. Incident and reflected pressures for near-field detonations are very difficult to be measured by commercially available pressure transducers due to the high pressure and temperature, which requires a verified and validated computational fluid dynamics code to reasonably predict the near-field pressures and impulses. This paper presents numerical studies to verify and validate a CFD code for calculations of incident and reflected overpressures and impulses. The near field is emphasized and recommendations for mesh sizes to optimally simulate the near-field detonation are provided.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.1-5
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• 2008

Optical code division multiple access(OCDMA) systems make the active users to share the bandwidth by simply assigning distinct optical orthogonal codeword to each active user. An optical orthogonal code(OOC) is a collection of binary sequences with good correlation properties which are important factors of determining the capacity of OCDMA systems. Recently, 2-D OOC construction method is frequently researched which is able to support more users than 1-D OOC. In this paper, a combinatorial construction of simple multi-weight 2-D OOC with autocorrelation 0 and crosscorrelation 1 is proposed and the bound on the size of these codes is derived.

• Earthquakes and Structures
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• v.10 no.1
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• pp.1-23
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• 2016

Steel plate shear walls (SPSWs) have been shown to be efficient lateral force-resisting systems, which are increasingly used in new and retrofit construction. These structural systems are designed with either stiffened and stocky or unstiffened and slender web plates based on disparate structural and economical considerations. Based on some limited reported studies, on the other hand, employment of low yield point (LYP) steel infill plates with extremely low yield strength, and high ductility as well as elongation properties is found to facilitate the design and improve the structural behavior and seismic performance of the SPSW systems. On this basis, this paper reports system-level investigations on the seismic response assessment of multi-story SPSW frames under the action of earthquake ground motions. The effectiveness of the strip model in representing the behaviors of SPSWs with different buckling and yielding properties is primarily verified. Subsequently, the structural and seismic performances of several code-designed and retrofitted SPSW frames with conventional and LYP steel infill plates are investigated through detailed modal and nonlinear time-history analyses. Evaluation of various seismic response parameters including drift, acceleration, base shear and moment, column axial load, and web-plate ductility demands, demonstrates the capabilities of SPSW systems in improving the seismic performance of structures and reveals various advantages of use of LYP steel material in seismic design and retrofit of SPSW systems, in particular, application of LYP steel infill plates of double thickness in seismic retrofit of conventional steel and code-designed SPSW frames.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2157-2169
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• 2023

In order to handle the problem that puncture patterns will change the position distribution of original information bits and frozen bits in polar codes, which affects performance of puncture polar codes further, a minimum row weight and polar spectrum based puncture polar codes construction algorithm (called PA-MRWP) is proposed in this paper. The algorithm calculates row weight of generator matrix and sorts the row weight in ascending order first. Next, the positions with the minimum row weight are selected as initial puncture positions. If the rows with the same row weight cannot all be punctured, polar spectrum based auxiliary puncture scheme is used. In sub-channels with the same row weight, rows corresponding to the polarized sub-channels with higher reliability are selected as puncture positions to construct puncture vector, and the reliability is calculated based on polar spectrum. It is actually a two-step selection strategy, the proposed minimum row weight puncture (MRWP) algorithm is used for primary selection and polar spectrum based auxiliary puncture is used for adjustment. Simulation results show that, compared with worst quality puncture (WQP) algorithm, the proposed PA-MRWP algorithm and Gaussian approximation-aided minimum row weight puncture (GA-MRWP) algorithm provide gains of about 0.46 dB and 0.29 dB at bit error rate (BER) of 10^-4, respectively when code length N=400, code rate R=1/2. In addition, the proposed puncture algorithms improve the BER performance significantly with respect to quasi-uniform puncture (QUP) algorithm.