• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.571-577
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• 2019

Since the introduction of digital cameras in an aerial-photogrammetry field on 2006, the technological paradigm related to the photogrammetry has been shifting from the analog types to digital types. However, current construction standard cost for the aerial-photogrammetry and the digital mapping are being mixed with analog-based concepts and digital-based methods. In the current standard cost, the monthly weather table is closely related to the calculation of the number of flying days in a taking of aerial photograph. The current monthly weather table uses the results calculated from the observation data of total cloud amount from 1999 to 2007. In this study, the monthly weather table was calculated using the total cloud data during ten years from 2009 to 2018. As a result, the newly calculated number of clear days for 29 stations was analyzed as 44 days decreased by 6 days. The maximum number of clear days decreased in Jinju as 23 days, and the highest decreased clearing days was February.

• Architectural research
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• v.15 no.1
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• pp.25-33
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• 2013

The amount of construction waste increased to 176,447 ton/day in 2008 from 28,400 ton/day in 2000, a 6-fold increase in just 10 years. Such dramatic increase in the waste of concrete, asphalt concrete, wood and metals was due to demolition of old buildings as well as a great number of building redevelopment projects and hurried city industrialization. Many buildings targeted for demolition today were built in line with the government policy to provide affordable housing to citizens in the shortest time possible and consequently, said buildings underwent rapid deterioration and required periodic repairs and reconstruction. Based on the above, we predict that construction waste will continue to increase for the foreseeable future. In particular, due to limited availability of suitable space to construct apartments and residential buildings in the city, old buildings are being torn down to make space for new development, further increasing construction waste. In light of that, efforts to recycle as well as reduce generated waste are urgently required.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.111-115
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• 2009

As shown in the accident analysis from 2007, it has been found that causes of accidents on large-scale projects are different from those found in general construction projects. A 300-question survey regarding systematic and practical aspects of safety problems at construction sites was distributed to ten (10) different companies. Participants were to respond subjectively, so that the results could be used to assemble the first formal questionnaire survey. They were collected and compiled by an advisory committee for this study. The resulting surveys were then sent to the division chiefs of the top 100 construction companies in Korea, in order to improve the response rate. The Department of Safety & Health Direction, and the :Ministry of Labor, ROK sent the same sheets to medium and small construction companies that placed within 101-200th of all Korea construction companies. The above safety engineers were classified into four (4) levels, from 1st to 4th, followed by the project dollar amount and risk level. Formulae were developed to assign safety engineers to construction sites by engineer level, the project dollar amount, and the project risk level. Conclusions are summarized as follows: 1) Reviewing the assignment system of experienced safety engineers to large scaled projects - The more experienced the engineers assigned to a project, the higher the level of accident prevention. 2) Enforcing the assignment of advanced level safety engineers to large-scaled sites - At least one advanced-level safety engineer should be assigned to construction sites with projects valued at $15million USD (15,000,000,000). 3) For assigning safety engineers by risk level - Twenty models have been developed to calculate the number of safety engineers to be assigned by risk level. In the future, risk level for each job should be established by the government (as is now the practice in Germany).

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.531-542
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• 2022

As buildings become taller, the strength of structural materials must increase and the amount of rebar reinforcement also increases while the application of an appropriate rebar splice method in the construction process become one of the essential factors. In this research, the current status of quality check for rebar coupler is identified by an expert questionnaire and an appropriate quality check method is proposed through a quality test on specimens similar to actual on-site construction. In the test results, it was revealed that, among the quality check methods for rebar coupler joints, the coupler tightening method and face to face degree of between upper and lower rebar did not affect the strength the specimen. Therefore, it is considered to be an appropriate way to check the coupler quality check to check whether the threads are completely assembled during on-site construction through manufacture the number of threads of rebar and coupler with a margin beyond the calculated thread number.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.67-68
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• 2022

Foreign countries stipulate that ventilation and smoke control facilities are installed in logistics warehouses. On the other hand, in Korea, the design guidelines and standards of ventilation and smoke control facilities for logistics warehouses are not clear even in the situation where the number of human casualties caused by smoke has increased until recently. Accordingly, the smoke descent time according to the vent was calculated. As a result, when there was no vent, the smoke descent time was 369s. On the other hand, when the vent was installed, smoke did not fall because the amount of smoke was greater than the amount of smoke generated.

• Journal of the Korean Institute of Navigation
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• v.5 no.1
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• pp.1-23
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• 1981

As far as transportation problems are concerned, the minimization of transportation cost is the most prevailing object. But in some cases, the cargo delivery time is the utter problem rather than the cost. For instance, we may imagine the case that the delivery of the construction materials is delayed behind the schedule and this makes the construction cost increased because of idle time of other materials and man power, in addition to the indemnity. Therefore the allocation of ships, in marine transportation which is now the main route of overseas trade, to the needed area on the required time is to be appropriately performed. However, there are several restrictions for cargo delivery to meet the demand, such as ship's size, number to be employed and cargo handling capacity of the ports, etc. And there are some other factors to be considered, that is, the degree of necessities of commodities, on their kinds, amount, and the time of arrival, etc. This paper deals with the problem of optimum allocation of ships emphasizing the cargo delivery time adopting Linear Programming technique with those cargo delivery restrictions and factors transformed by introducing the multi-speed conception, the conversion of multi-commodity to a single commodity, allowable delivery time, weight penalty number and nominating priority. This paper presents a case of optimum allocation of ships in the light of cargo delivery time for a construction company which has two different construction places and analyzes the result. This study will give a planner a good tool for optimum planning of maring transportation and be used for decision of schemes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.48-49
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• 2020

Recently the diversification of construction market and the continuous reduction of construction amount are raising the need of alternative delivery method in the construction industry. The foreign advanced companies actively adopted the CM at Risk delivery method where they perform the service of agent CM in the design phase, and agree GMP(Guaranteed Maximum Price) with the client at the time of 50~80% completion of design. Even in Korea they began to apply that method to pilot projects. In CM at Risk, through the early participation of builder, the level of design completion can be improved and the change order and construction period delay can be minimized. On the other hand, GMP is usually calculated when the design is about 80% complete, so there is uncertainty in the construction cost. Therefore, in this research, the increased amounts of construction cost are analyzed in a number of public construction projects, and GMP calculation process is proposed using the analysis results and CBR(Case-Based Reasoning) technique to reduce the construction cost increase in the construction phase.

• KIEAE Journal
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• v.10 no.5
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• pp.181-186
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• 2010

Research on construction waste unit was in progress in the 1995 when 'Proper Disposal and Recycling Measures for Construction Waste' was made by the Seoul Development Institute. Such an effort has been made in order to cope with the lack of natural resources in Korea and to utilize the reusable resources. Furthermore, these efforts have also increased due to the improved standing of Korea in the international community. A large number of residential buildings were built in the response to the government's policy by increasing the supply of houses between the 1970's and 1980's. In 2000, more reconstruction and redevelopment was done because of the aged buildings and change of use for those buildings. And the project has been actively promoted until now, which caused a sharp increase in the generation volume of construction waste. In Korea, 8 kinds of construction waste unit, including the standard construction manpower and materials estimation, are introduced. Currently, they provide standards to different building categories and waste properties while for construction sites different standards are applied. This study aims to measure the actual amount of construction waste after sample buildings are dismantled and analyzes the estimation of the waste quantity by using various standard units. Through comparison, this study will figure out the differences among the standard units in order to find out how to apply the standard units properly. Moreover, this research will provide practical measures to apply such units to construction sites.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1087-1093
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• 2017

The purpose of this study is to present an empirical analysis of determinants of the amount of orders received in construction technology engineering industry sector. Regression model was applied for 5 years from 2010 to 2014 to find out how the factors affecting the amount of orders received each year are different and what trends are observed. Although common significant variables were identified that there is a difference in the impact on their orders received. Specifically, the increase in the number of orders received while reducing the impact on orders received from 2010 to 2013, 2014 showed a slight tendency to increase. And increase in the number of employees shows that the influence of order received is higher in 2014 than in 2010. In addition, the gap between the metropolitan area and the non-metropolitan area has doubled in 2014 compared to 2010, but it is also confirmed that the metropolitan area is still strong. On the other hand, in the case of licensed technology, the only statistically significant variable was the negative correlation between the amount of orders received. Although the influence declined in 2014 compared to 2011, it still had a large impact on the amount of orders received.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.175-176
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• 2012

In this study, coupler on the safety of meeting the requirements and construction and economy to satisfy the number of parts to minimize an LK-DK coupler has been developed, affordability existing reinforcing bar joint, welded joint, mechanical joints, compared with a favorable one to the understanding, and also facilitate the construction and logistics, etc. I've found that there is no additional pay because the amount of product performance through the tensile test after test, if commercialization is expected to be greater ramifications.