• Korean Journal of Mathematics
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• v.26 no.3
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• pp.537-544
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• 2018

There is a standard construction of lifting cyclic codes over the prime finite field ${\mathbb{Z}}_p$ to the rings ${\mathbb{Z}}_{p^e}$ and to the ring of p-adic integers. We generalize this construction for arbitrary finite fields. This will naturally enable us to lift codes over finite fields ${\mathbb{F}}_{p^r}$ to codes over Galois rings GR($p^e$, r). We give concrete examples with all of the lifts.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.17-18
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• 2016

Today, many kind of buildings are higher than those of previous generations, and Curtain Wall is adapted broadly as an outer wall material. But weather and environmental condition could cause problems in curtain wall construction in most construction projects. High wind speed and unplanned lifting equipment's allocation could cause construction delay and cost increase. To solve these problems, we suggest using a curtain wall mullion as a rail to lift curtain wall which is less affected wind speed. And we would like to show a preliminary data of its economic advantage evaluation.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.97-104
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• 2007

Recently, the demand of the large span structures has been increasing. The large span structures include such a large scaled structures such as: the shell structure, the space frame structure, the membrane structure and the cable structure, etc. The large span structures are supposed to be confirmed and issued carefully at the initial process of the design besides the construction engineering aspects because of the structural specific cause that should solve and accomodate those large and wide space without columns. In the field of the large span structure construction, the erection construction method has been regarded as a major affected aspects on the construction cost, construction term, and stability. In the field of the large span structure construction, there are various construction method and system could be applied depends on the condition of the construction site and other circumstances such a major construction method as: the element method, the block method, the sliding method, the lift-up method and complexed method, etc. In this study, as the case study of the erection construction method of the large span structures, after survey and study that those existing large span structures construction cases which had applied and adopted the election construction method and analysis and classify into the Uoups by the size, span, ceiling height, structural system in odor to supply and suggest the data for the enhancement and development in the field of the erection construction method as a efficient structural solution of the large span structure construction.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.64-71
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• 2019

We herein propose a systematic design method of hydraulic pipes used in heavy construction equipment. We found that even though many design studies have been conducted regarding major hydraulic components such as pumps, cylinders, and control valves, studies regarding the optimal design of hydraulic pipes are scarce. In this study, the design of four types of pipes is considered: two high-pressure and two low-pressure pipes. First, fluid flow analysis was conducted based on oil flow and pressure for various radii of curvature. For a check-valve pipe, we considered the location of an inlet pipe. We could visualize fluid flow inside the pipe according to the flow velocity and pressure distribution. Based on fluid flow analysis, we conducted a structural analysis that revealed the stress distribution and concentration for each pipe design. We selected the best design parameters for each pipe design, fabricated the pipes, and subsequently tested them for validity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.109-112
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• 2007

As buildings become higher, larger, and more complex, safety issues for construction workers working at such environments become more important. We analyzed 140 critical accident cases reported to the KOSHA(Korea Occupational Safety & Health Agency) for construction cranes and lifts by types of cranes and by patterns of accidents and causes. By finding out the accident's types and causes, we expect to develop an efficient measure for preventing similar accidents in the near future. The cases will be studied further and reexamined using the FMEA(Failure Mode and Effect Analysis) as a quantitative analysis method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.75-76
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• 2023

The construction industry's lack of experience and expertise makes it difficult for projects to realize the full benefits of implementing modular construction. Such project performance-hindering elements are often labeled as modular challenges. The added requirement for the transportation of the finished volumetric module is one aspect of the 'module transportation logistics,' the under-researched modular challenge that can prevent projects from incurring maximum cost and productivity benefits. The typical module transportation phases include lifting, transporting, and offloading. From conducting a literature review, this paper aims to investigate the equipment commonly adopted to lift and offload the module and validate its economic efficiency by comparing it with the alternative lifting/offloading equipment used in the two case projects. The results showed that hydraulic jacks are an economic alternative to the crane for lifting/offloading the module. The increase in single-module projects with smaller budgets made crane usage economically undesirable, and this study suggested a viable option for a more economical alternative.

• Journal of the Korean Society of Safety
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• v.28 no.6
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• pp.64-72
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• 2013

Construction machinery has been utilized to carry out construction works effectively. Using construction machinery enables a builder to reduce the time and the cost needed for the construction, but the fatal accident caused by it has been increased. This study is intended to identify risk magnitude of accident by kind of construction machinery through interviews with experts. Construction machineries surveyed in this research are excavator, tower crane, lift, mobile crane and forklift, those are the machinery which accident occurs more often than the other machinery. To evaluate the risk of the accidents identified, risk category was determined according to the US DOD system safety program (MIL-STD-882B) considering the risk degree and intensity. As a result, accident occurred in the process of material transport & handling was found to be the most dangerous. On the other hand, the accidents caused by the defective machinery and the poor safety gear were considered to be less dangerous relatively. The risk category by type of construction machinery suggested in this study is expected to provide the basic data in developing the safety guidance for construction project.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.97-105
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• 2005

As construction project is becoming larger, construction progress and works are more various and complex according to recent Korean construction tendency. The growth of construction induces much pollution on the progress of construction and the problems due to the construction pollution are raised into social problem strongly, because it is increasing the need on the quality of lift and the desire of clean environment. This study aimed to seek far the effective solving plan of the construction popular complaints by surveying the real condition of construction popular complaints and analyzing the cause and tansaction period of popular complaints. For this study, the laws related and popular complaints were analysed focusing on the documents in low district offices of Gwangju from 2000 to 2004. As a result, the types of construction popular complaints were divided into 17 and the causes were as follows in order: crack and subsidence of ground(14.90%), infringement of private life(11.55%), noise(10.80%), infringement of a right to sunshine(10.07%) and breakdown(6.7%). Consequently, it is considered that these complaints are occurred by physical and environmental causes.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.627-628
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• 2015

Construction defect which can causes economic damage such as schedule delay, cost overrun is a considerably important factor in construction industry. In general, a construction defect features a difficulty to find out causes precisely because it occurs when several interrelated causes combine. Yet, studies have tried to understand the interrelationships between factors are limited. In addition, despite of a tremendous amount of construction data, it's not still enough to analyze them, but tends to depend on experience or know-how of practitioners. Thus, it is necessary to identify underlying causes in influential factors by utilizing related data. This paper analyses Interrelationships between causal factors using Association Rule Mining to discover root causes of construction defects. Confidence and Lift that can be used for presenting the interrelationships of the causes were extracted from 1241 cases in 30 projects in Korea. It is expected that this paper allows the construction managers to discover key factors and make right decisions to reduce occurrence of construction defects. Furthermore, analysis of interrelationships can improve understanding of structural patterns of construction defects.

• Proceedings of the Korean Magnestics Society Conference
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• 1991.11a
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• pp.12-16
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• 1991

The advantage of the controlled permanent magnet system for magnetic levitation is the considerable improvement in levitation force to weight ratio and the reduced rating of the on-board power supply. A combined support and guidance technique with selfstable guide behaviour reduce the expense of control and power electronics. An important feature of this system is the simplified mechanical construction of track and the vehicle does not embrace the guide way. Therefore surface mounted as well as elevated tracks are possible. The magnet was designed to provide a lift force of 750kg for a 3 ton prototype vehicle with 4 magnets by KERI and built by Dae-Bo Magnetic Co., LTD. The paper also describes the assembling technology for permanent magnets, the experimental setup and test results for lift force, guidance force and flux distribution.