• Korean Journal of Construction Engineering and Management
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• v.19 no.1
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• pp.43-53
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• 2018

Modular construction can improve construction quality and accuracy through manufacturing process, and it allow massive production and cost savings by repeatedly producing the same unit. In particular, it is possible to reduce the time because the on-site work and the manufacturing process can be carried out at simultaneously. However, according to the modular construction project survey report, there is no significant difference regarding the average construction period between modular construction and conventional construction. This is due to schedule delay problems that occur during construction phase. Therefore, it is necessary to select alternatives to prevent schedule delay during on-site construction progressing. Especially, in case of large-scale modular construction project, on-site module assembly and manufacturing process are performed concurrently. Hence, identification of alternatives should be done at the co-occurrence by taking both manufacturing and on-site work process in to account. In this research, the management factors of large-scale modular construction project were identified through the IDEF0 modeling, and the quantity management model for manufacturing and assembly is developed. This will reduce the schedule delay problem that occurs in the progression on-site work of a large scale modular construction.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.110-119
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• 2012

The Plan and equipment of vertical lifting are very important in high-rise building construction site, and unmanned lifts usage is increasing for financial and efficient reason. However if lift stop position error occur, It can be accumulated. And the lift can not be available during an engineer fix the problem. So loss of time and cost will occur when lifts have problems. This paper reports an improved lift stop position sensing device for preventing loss of time and cost from lift stop position error. The result of tests showed that the system has a correction function of lift stop position error, and the accuracy of device which was developed in this paper was about 9.75mm better than existing equipment.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.53-66
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• 2012

Gangform compared with conventional wood and steel form is systemized form which has a capability to install and dismantle form at a time without repeating to assembly and disassembly small members. Gangform compared with ACS has some problems such as 1) Tower Crane load increase, 2) increase in safety incidence during climbing Gangform, 3) decrease in detachment operation productivity, 4) stop work due to climate impacts, and 5) decrease in labor cost, productivity, quality. A conceptual design model of automated Gangform climbing system is suggested for apartment housing construction to show its technical/economic feasibility and workers' safety while increasing operation productivity and concrete quality.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.194-201
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• 2004

Core-wall construction method is applied in many high-rise building constructions. This is caused by the advantages of the method such as the effect of saved construction cost and shortened period. However, the analysis study of planning practice for core-wall construction shows matters take place during core-wall construction, such as increasing in construction cost and period. These matters result from the limited work space leading to low productivity, the activity interference leading to increasing in period, additional temporary work cost and time, and delayed concrete pour activity. A large part of these can be prevented taking place by very detailed and most careful core-wall construction plan. Therefore, this study suggests improvement directions of core-wall construction planning process focused on the cooperation system of a contractor between a sub-contractor and the process.

• Korean Journal of Construction Engineering and Management
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• v.20 no.5
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• pp.3-11
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• 2019

This study is designed to examine the stock price of construction firms which are affected by the deregulation of new apartment sales price. As empirical methodology, it uses the traditional event study analysis to test the influence of the deregulation of new apartment sales price and the regression analysis to test which variables are related. The results of this study are summarized as follows : First, the cumulative abnormal return of stock is positive when government announced the deregulation of new apartment sales price. The cumulative abnormal return of stock for 21 trading day before -10 to +10 day is 25.51% which is significant different from zero at 1 percent level. This result suggests that the deregulation of new apartment sales price conveys good information to stock market that the firms performance will be good in the future. Second, in the regression analysis this study shows that the cumulative abnormal return of stock is related to firm's profit margin ratio.

• Journal of the Korean GEO-environmental Society
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• v.12 no.2
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• pp.15-22
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• 2011

In this study, the effect of surface coating on iron-sulfide mineral for preventing the product acid mine drainage(AMD) was progressed by oxidation process of sulfide minerals abandoned mine Area. Three abandoned mines, Yongdong coal mine, Sil Lim mine, and Il Koang mine were selected as a sulfide mineral resource due to higher contamination rate. Six coating agents, apatite, limestone, mangnite, dolomite, bentonite, and cement were used for preventing the AMD with $H_2O_2$ and NaClO as a oxidizing agent helping for oxidizing process on sulfide minerals. Experimental results showed that sulfide mineral surface was coated effectively. Cement has a higher ability of preventing AMD when the ratio of cement to mineralis 1:1 and experimental condition is maintaining 4Days.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.249-256
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• 2014

Advancing health screening and treatment of cancer techniques, they contribute to grow the probability of survival of cancer patients for a long time. So health behavior and quality of life of the patients are getting important. This study analysed correlation between healthy person and cancer patient's EQ-5D index, social demographic characteristics, health behavior and so on by the multiple regression analysis. The result was that EQ-5D index of cancer patients is lower than healthy persons. Patients of cervical cancer and lung cancer had very low the index especially. In conclusion, cancer have a bad influence on the quality of life. For cancer patients, smoking and drinking are a major factors of correlation. The number of non-smokers among the patients is lower than the number of smokers among healthy persons. This conclusion means that the importance of health behaviors and quality of life for cancer patients is established so that this will be used for basic reference of PHR models and service enhancing quality of life.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.123-131
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• 2014

The demand of the real-time data was promoted by significant development of network and IT technology. In particular, the entry of an aging society and income growth increase the demand for personal health related data which attempt to provide various and evolutional healthcare services by several healthcare institutions. Especially the presentation of the medical examination result is the most basic healthcare services which should be expressed to maximize understanding in personal health records for their own health. However according to absence of systematic visualization framework and visualization model, intuitive understanding of healthcare related data is difficult. Cosequently In this study, customized visualization representation based on the results of medical examination was provided to aviod consistent format for health examinee and establish a variety of data representations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.705-717
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• 2011

The number of horizontal tower cranes, major hoisting machineries for lifting approximately 50% of entire materials in construction projects, is rapidly increasing, but a number of accidents related to the tower cranes are being continuously occurred in construction sites as well. In particular, telescoping works in the horizontal tower cranes have showed the greatest safety concerns such as falls and collapses. It is due to the fact that tasks inserting a new mast in the space made after raising telescoping cage by fluid pressure and ascending it to the required height in the telescoping works include a series of dangerous factors in safety aspects, and might cause very serious and unexpected accidents in construction sites. The primary objective of this research is to propose two conceptual models for automating the telescoping work in horizontal tower crane and conduct their technical feasibility analyses. In this study, a design concept, a position control system using hydraulic cylinders is suggested as a better alternative for automating the telescoping work. Its potential safety improvement rate compared to the conventional method is also analyzed and presented in this study.

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.407-413
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• 2014

Appropriate selection of lifting equipments for a high-rise building construction project is one of the important factors to the project's success. Proper position of a tower crane on a construction site is so important to be determined by an expert or an experienced construction manager who draws working range of a tower crane and moves it over 2D(dimensional) site layout plan. 3D CAD, BIM, and virtual reality are is used for building design and construction, but it is not usual to use them for temporary facility planning or selection of a tower crane. This study proposes a suitable method to use augmented reality to select proper position of tower cranes. An augmented reality prototype is implemented by Vuforia and Unity 3D on a smart device to verify the practicability of the proposed method. The prototype application installed on a smart device shows several tower cranes on different markers in a real architectural drawing to locate the proper tower crane.