• Nuclear Engineering and Technology
• /
• v.53 no.9
• /
• pp.2839-2846
• /
• 2021

In this study, experiments of downward-facing flow boiling were conducted to investigate material effects on CHF. Experiments were conducted using aluminum, copper, and carbon steel. It was found that different materials had different CHFs. Aluminum has the biggest CHF while copper has the lowest CHF for each mass flux. After experiment, surface wettability increased and surface became rougher, which was probably due to the oxidation process during nucleate boiling. The CHF difference is likely to be related to the surface wettability, roughness and thermal effusivity, which influences the bubble behavior and in turn affects CHF. Further studies are needed to determine which factor is dominant.

• Korea Journal of Hospital Management
• /
• v.26 no.2
• /
• pp.17-26
• /
• 2021

Purposes: This study aims to identify factors affecting dental university hospitals' profitability and understand recent their business condition. Methodology: Data from 2016 to 2019 was collected from financial statement, public open data in 8 dental university hospitals. For the study, multiple regression test with stepwise selection was applied. Findings: First of all, 9 out of 19 independent variables were selected by stepwise selection. As a result of multiple regression test with selected independent variables and the dependent variable(operating profit margin ratio), the factors affecting hospitals' profitability were the number of dental unit chair, hospital location, debt ratio, total capital turnover ratio, employment cost rate, material cost rate, management expense rate, the number of patient per a dentist. Practical Implication: To improve dental university hospitals' profitability, hospitals specifically analysis and manage their cost such as employment, material and management cost and seek effectiveness by managing the proper number of patient per a dentist.

• International Journal of Quality Innovation
• /
• v.9 no.1
• /
• pp.68-93
• /
• 2008

The steel bars account for a high percentage of material costs for the current construction projects. At the present time, most of the construction projects for the factories of thin-film transistor liquid crystal display (TFT-LCD) complete the transactions of steel bars when the suppliers ship the steel bars to the temporary storage/processing sites. This paper applies the buy-in concept in the Theory of Constraint (TOC) on the supply chain of steel bars. In this study, suppliers are required to establish warehouses at the construction sites and complete the transactions when the formed and processed steel bars are shipped into the factory sites. The aim is to find a win-win solution to meet with the expectations from constructors as they hope that there is no need to build up inventories but supply is ready at any time. Also, this paper compares and analyzes the traditional supply/inventory model of steel bars and the Demand-Pull (D-P) model under the TOC framework. It is proved that Vendor Management Inventory (VMI) in the D-P model is able to more effectively manage steel bars as a material.

• Journal of Family Resource Management and Policy Review
• /
• v.2 no.1
• /
• pp.15-31
• /
• 1998

The purpose of study is to understand the home management strategy to cope with rapid changing environments and to verify that how personal value orientation affect home management strategy. The research results are summarized below. First, variables that affect the value orientation of Korean urbanite are sex, area of dwelling, degree of information using and degree of stress recognition in case of material orientation, degree of information using in case of environmental orientation, academic career, sex, degree of information using, degree of stress recognition in cases of fate control orientation, number of children, sex, degree of information using in case of equilibrium orientation, sex, degree of stress recognition in case of present orientation and academic career, degree of stress recognition in case of individualistic orientation. Second, value orientation variables that affect overall home management strategy of Korean urbanite are material orientation, environmental orientation, fate control orientation and individualistic orientation. Third, variables that affect overall home management strategy of Korean urbanite are age, academic career, degree of information using, degree of stress recognition, perception level of living relative to others, environmental orientation and fate control orientation and it is shown that degree of information using is domineering variable.

• Journal of Family Resource Management and Policy Review
• /
• v.2 no.2
• /
• pp.1-19
• /
• 1998

The purpose of study is to understand the home management strategy to cope with rapid changing environments and to verify that how personal value orientation affect home management strategy. The research results are summarized below. First, variables that affect the value orientation of Korean urbanite are sex, area of dwelling, degree of information using and degree of stress recognition in case of material orientation, degree of information using in case of environmental orientation, academic career, sex, degree of information using, degree of stress recognition in cases of fate control orientation, number of children, sex, degree of information using in case of equilibrium orientation, sex, degree of stress recognition in case of present orientation and academic career, degree of stress recognition in case of individualistic orientation. Second, value orientation variables that affect overall home management strategy of Korean urbanite are material orientation, environmental orientation, fate control orientation and individualistic orientation. Third, variables that affect overall home management strategy of Korean urbanite are age, academic career, degree of information using, degree of stress recognition, perception level of living relative to others, environmental orientation and fate control orientation and it is shown that degree of information using is domineering variable.

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

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.6
• /
• pp.127-134
• /
• 2009

This study aims to provide an optimal model for the layout of multiple tower cranes and material stockyards which have multiple candidate positions. In a high-rise building construction, the positional allocation of tower cranes and material stockyard has an effect on the travel time of material hauling. In addition, in case of using multiple tower cranes, specific location of a tower crane allocated to each material determines the efficiency of the works. Current optimal model limited to the optimization of position of single tower crane and material stockyards. This study suggests optimal model both for the positions of multiple tower cranes and material stockyards. Layout of multiple tower cranes requires additional allocation of each crane to each material hauling and control on the minimum distance between tower cranes. This optimization model utilizes genetic algorithm to deal with complex interaction on the candidate positions of multiple tower cranes, material stockyards, and types of materials. In order to identify its utility, case study was performed.

• International conference on construction engineering and project management
• /
• 2011.02a
• /
• pp.213-220
• /
• 2011

In the current construction industry where various stakeholders take part, BIM Data exchange using standard format can provide a more efficient working environment for related staffs during the life-cycle of the building. Currently, the formats used to exchange the data from 3D-CAD application to structure energy analysis at the design stages are IFC, the international standard format provided by IAI, and gbXML, developed by Autodesk. However, because of insufficient data compatibility, the BIM data produced in the 3D-CAD application cannot be directly used in the energy analysis, thus there needs to be additional data entry. The reasons for this are as follows: First, an IFC file cannot contain all the data required for energy simulation. Second, architects sometimes write material names on the drawings that are not matching to those in the standard material library used in energy analysis tools. DOE-2.2 and Energy Plus are the most popular energy analysis engines. And both engines have their own material libraries. However, our investigation revealed that the two libraries are not compatible. First, the types and unit of properties were different. Second, material names used in the library and the codes of the materials were different. Furthermore, there is no material library in Korean language. Thus, by comparing the basic library of DOE-2, the most commonly used energy analysis engine worldwide, and EnergyPlus regarding construction materials; this study will analyze the material data required for energy analysis and propose a way to effectively enter these using semantic web's ontology. This study is meaningful as it enhances the objective credibility of the analysis result when analyzing the energy, and as a conceptual study on the usage of ontology in the construction industry.

• Proceedings of the Safety Management and Science Conference
• /
• 2000.05a
• /
• pp.369-374
• /
• 2000

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1999.04a
• /
• pp.304-305
• /
• 1999