• KIEAE Journal
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• v.15 no.6
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• pp.63-68
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• 2015

Purpose: Most if buildings need various repair works for preventing or delaying the deterioration which gives rise to affect the living condition or function after constructed. Therefore, a long-term repair schedule should be planned and a repair cost is required. In this paper, it aimed at providing the statistical forecast model for a repair cost in roof water-proofing work and elevator work using statistical approach with three variables such as number of household, management area and a elapsed year. Data are collected in apartment housings which are located in Seoul area and conducted with interview and questionnaire sheet. Each analyzed work is divided into a partly work and fully work. Results of this study are shown that, first, the regression model takes a multiplying type like a Cobb-Douglas function and is changed into the log-linear type to include the three variable simultaneously. Second, the goodness-of-fit of the repair cost forecasting model has a good statistics in determinant's coefficient and Dubin-Watson value. Third, the management area is stronger factor than other the number of household and an elapsed year in roof water-proofing work and elevator work.

• Journal of KIBIM
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• v.11 no.2
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• pp.1-16
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• 2021

Since entering the 21st century, the construction industry has developed faster and faster, and more and more technologies have been applied in the construction industry. BIM technology (Building Information Modeling) was born in this environment. The application of BIM technology can greatly improve the efficiency of cost management and help achieve the goal of cost management. But through BIM to realize project cost management, there is still no good solution. In order to solve this problem, this paper puts forward the concept of WBS structure applied to construction projects by studying the BoQ (Bill of Quantities) list based on BIM, and proposes the numbering method of the structure. The WBS (Work Breakdown Structure) structure proposed in this paper divides more than 5000 cost objects into 133 projects according to the type of work and project schedule. This structure helps to realize the application of BIM in project cost management. Although this article has studied more than 5000 data of three projects, it does not think that it can cover all cost objects in the existing construction industry. The purpose of this article is to propose a solution for cost and Process Control using BIM-based BoQ data.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.193-198
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• 2009

It is an important issue in cost management to contract with the standard of cost estimate by the reasonable way in public construction projects. For the standard of cost estimate based on the Standard Estimating System, there is a difference of labor inputs between Standard Estimating System and actual quantities in construction projects. The duration of form work in multi-family housing depends on the manpower compared with other work, which is the critical path on the schedule management to be decided quality, and is the important to the cost management of construction projects. This study presented a simulation model of the productivity analysis for selecting the standard work type of form work in Multi-family housing construction projects.

• Korean Management Science Review
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• v.13 no.2
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• pp.25-48
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• 1996

Mixed Model Assembly Lines (MMALs) are increasingly used to produce differentiated products on a single assembly line without work-in-process storage, Usually, a typical MMAL consists of a number of (1) stations doing exactly the same operation on every job, (2) stations involving operations with different choices, and (3) stations offering operations that are not performed on every job, or that are performed on every job but with many options. For stations of the first type there is no sequencing problem at all. However, for the second type a set-up cost is incurred each time the operation switches from one choice to another. At the third type of stations, different models, requring different amounts and choices of assembly work, creates an uneven flow of work along the line and variations in the work load at these stations. When a subsequence of jobs requires more work load than the station can handle, it is necessary to help the operations at the station or to complete the work elsewhere. Therefore, a schedule which minimize the sum of set-up cost and utility work cost is desired. So this study has developed Fixed Random Ordering Rule (FROR), Fixed Ascending Ordering Rule (FAOR), Fixed Descending Ordering Rule, and Extended NHR (ENHR). ENHR is to choose optimal color ordering of each batch with NHR, and to decide job sequence of the batch with it, too. As the result of experiments, ENHR was the best heuristic algorithm. NHR is a new heuristic rule in which only the minimum addition of violations from both partial sequence and unassigned sequence at every branch could be considered. And this is a heuristic sequencing rule for the third type of stations at MMAL. This study developed one more heuristic algorithm to test the performance of NHR, which is named as Practical Heuristic Rule (PHR).

• IE interfaces
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• v.19 no.1
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• pp.34-42
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• 2006

This paper presents a scheme for a hierarchical production scheduling and control system for a refrigerator factory with mixed model assembly lines. The setting of the factory is as follows. There are three mixed-model assembly lines called main line A, B and C and two batch lines that supply parts to the main lines. For each of the main lines, three work-centers are dedicated to them. The sub-lines and work-centers produce parts in batch type. An incoming production order from the master planner is characterized by its product type, amount, and due date. Under this situation, the proposed scheme has several features to schedule and control the above mentioned factory; 1) select the starting time and the place (assembly line) for an order processing, 2) devise a way to control orders to be processed as scheduled, and 3) reschedule orders when something unexpected happen. Finally, this paper provides a case study where the proposed scheme is applied to.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.126-133
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• 2023

Objectives: This study was conducted to find out the prevalence and risk factors of anemia according to shift work. Methods: Data from the Korean National Health and Nutrition Survey (2016-2020) were used. 9,787 workers were divided into shift workers and non-shift workers. The work type between 6AM-6PM was defined as day work, and other work types were defined as shift work. A chi-square test was used to indicate the distribution of risk factors expected to affect shift work in both frequency and percentage. Multiple logistic regression analysis was performed to find out the relationship between anemia prevalence and shift work. Results: As a result of analysis, multiple logistic regression analysis of anemia prevalence and shift work, the OR (95% CI) of male workers on shift work was 2.186 (1.139 to 4.194) and there was a statistically significant difference. Conclusions: In conclusion, anemia in male shift workers should be considered a possibility of health problems. In the future, research based on various data collection should be conducted for research to reveal various causes or diseases of anemia in the future.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1254-1254
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• 2022

The Multi-family Residential is one of the most famous building types for a rental property in the US. Often times it includes multiple residential buildings and some amenity facilities, including a clubhouse or leasing office, swimming pool, dog park, and garages. Since the building type is built for rental purposes, the construction planning is phased and it makes the project complicated. Detailed planning and execution are important for successful construction management. This paper provides some management practices that are applied to one of the multi-family residential construction projects in Phoenix, AZ. The Front End Planning (FEP) process performed by both owner and contractor is the first key to a successful construction project. Specifically, the early review of phased turnover strategy, grading, fire/Americans with Disabilities Act (ADA) compliance, and Mechanical/ Electricity/Plumbing/Technology (MEPT) will provide absolute benefit to the project. Second, using a scheduling method to control short-term schedules and long-term can provide the ability to manage the issues with agility. Third, material delivery and procurement dominate the both project schedule and cost. With this COVID-19 circumstance, it is hard to expect the material, equipment, and labor forces to be delivered on time with the contracted price. Managing floats are more than important to managing construction productivity. Risk management should work to share the risks fairly. Lastly, turnover is directly linked with the profit of the project for both owner and contractor. The communication between the owner and contractor to re-schedule the proper turnover schedule is important for the phased construction project.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.409-416
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• 2020

This paper proposes a study measuring productivity improvement by using a type of technology called "Machine Guidance" through work sampling in earthwork. Earthwork is the activity typically on the critical path, indicating that productivity for the activity is critical for managing schedule on time. Thanks to the development of sensing and information system technologies, productivity for earthwork has been improved. While there have been many studies investigating the application of a certain type of technology to earthwork, few studies have measured the productivity improvement and presented how the technology leads to productivity improvement. Based on the thorough literature review, it is hypothesized that Machine Guidance contributes to improving productivity of earthwork by reducing indirect workhours spent for information waiting and inspection. In addition to the literature review, this paper presents a research model to test the hypothesis by using the work sampling technique. By proving and quantifying the productivity improvement from the technology use, this study can help practitioners justify the investment for technology use, which will contribute to the deployment of technology and more effective execution of earthwork.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.141-145
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• 2008

Because of world financial crisis, The Korea domestic construction industry has been damaged hugely on material supplying work. A current domestic material supply system can't react properly on a great rise of foreign exchange rate and raw material price, so the system has a problem which is not properly supplying material. To solve this problem, a more innovative material supply work system is seriously needed than ever. So this study wants to improve material supply system for supplying material right time, right place through applying a web-based system. Applying this, overall process of material-supply-work can be done on a web-based system for immediately understanding change of ordering and warehousing by material-supply-schedule to a domestic construction field.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.33 no.1
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• pp.2-15
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• 2022

Objectives: Children with attention-deficit/hyperactivity disorder (ADHD) tend to be noisy and violate rules with their disruptive behaviors, resulting in greater difficulties with off-task behaviors and being at risk for social refusal. The visual activity schedule (VAS) intervention program is a frequently used method to teach multiple skills involving on-task, use of schedules, transition behaviors, social initiation, independent play skills, classroom skills, and academic skills. The current systematic review aimed to examine the efficacy of using VAS intervention in reducing problem behaviors in children with ADHD between 5 and 12 years of age. Methods: Systematic searches were conducted using two electronic databases (PubMed and Scopus) to identify relevant studies published in English between 2010 and 2020. Four studies met the inclusion criteria: two studies examined the effect of schedule-based tasks and the use of an iPad on classroom skills, while the other two examined randomized clinical trials (RCTs) of psychosocial treatment for ADHD inattentive type and a cross-sectional study examined the impact of the group size on task behavior and work productivity in children with ADHD. Results: The findings indicate that the interventions used in all four studies could lead to increased satisfaction among participants and parents, as well as a reduction in problem behavior. In terms of the research indicators, the RCT had low quality, while the others were of high quality. Conclusion: A larger number of studies and the ADHD clinical population would help to increase the generalizability of future reviews of treatments in this context.