Hye-Sung Park

Comparing Project Performance of Design-Build and Design-Bid-Build Methods for Large-sized Public Apartment Housing Projects in Korea

The project delivery method has a great impact on project performance and construction quality. The numerous studies on the project performance of the two project delivery methods, design-bid-build (DBB) and design-build (DB), have found differing results depending on the project locations, the project types, and the project sizes. Since no previous studies have been conducted with regard to large-sized apartment housing projects, this paper presents the comparative analysis results for the project performance of the DB and DBB methods, focusing on the large-sized public apartment housing projects built in Korea. The project performances considered include cost, cost growth, construction duration, construction duration growth, and quality performance. The cost and schedule performance analysis results show that the cost growth of the DB method is about 5% lower than that of the DBB method and the construction duration is shortened by twelve days per floor. The quality performance analysis results demonstrate that the satisfaction with the DB method is higher in terms of the construction quality and efficiency of the DB method. This paper contributes to the growing body of research into the efficiency of project delivery methods, expanding the body of knowledge for large-sized public apartment housing projects.

Effects of Panax ginseng on Obesity in Animal Models: A Systematic Review and Meta-Analysis

Objective To determine the antiobesity effects of Panax ginseng in animals. Methods We conducted a systematic search for all controlled trials (up to March 2017) that assessed the antiobesity effects of P. ginseng in animal obesity models in the PubMed, EMBASE, Cochrane library, Web of Science, and Scopus databases. The primary outcome was final body weight measured at the longest follow-up time after administration of the intervention. The secondary outcome was the lipid profile. We assessed methodological quality using the SYRCLE risk of bias tool, and RevMan 5.3 was used to perform a meta-analysis. Finally, a subgroup analysis of parameters including intervention duration, animal models, and type of ginseng was performed. Result We identified 16 studies that met the inclusion criteria. Data from the meta-analysis indicated that the intervention group had a significantly lower body weight than the control group (SMD: −1.50, 95% CI: −1.90 to −1.11, χ2: 78.14, P < 0.0001, I2 = 58%). Final body weight was lower in an animal obesity model induced by high-fat diet than in genetic models. Also the intervention group had a significantly higher serum HDL level and lower serum LDL, TG, and TC level than the control group. Conclusion Our meta-analysis indicated that oral administration of P. ginseng significantly inhibits weight gain and improves serum lipid profiles in animal obesity models. However, causes of obesity and type of ginseng may affect treatment effects.

A Feasible Sales Price Decision Model of Apartment Housing Units Considering the Market Price and Buying Power

Abstract Sales price closely correlates with the market price of neighboring apartment-housing units, which reflects the real transaction price. In addition, sales price is dependent on goods including the apartment′s location, environment, traffic, residential conditions and housing characteristics. Studies on the sales price of apartment housing units mostly estimate the price in regard to the market price, the cost to build the apartments or a combination of both. Currently, there are studies in progress analyzing the factors that impact the sales price and the importance of purchase decision factors of consumers. However, the purchase decision factors of consumers and their importance are always changing. Thus, a sales price decision model that can account for the dynamic nature of purchase decision factors and market price is needed. In this regard, the purpose of this paper is to develop a feasible sales price decision model of apartment housing units considering market price and buying power. This model can be used as a decision-making tool in the initial phases of a project to help contractors′ achieve a reasonable sales price and improve their successes with apartment housing projects.

Regression Model of the Effect of Management Environment on the Contract Amount of Construction Firms

Abstract The growth potential of a corporation can be assessed in terms of its orders and sales. Because the management of a construction company starts with order-taking, orders received is directly related to corporate survival. New orders are impacted not only by construction business cycle, but also by a variety of external factors such as loan interest rate, legislation, and orders awarded in the public and private sectors, among other factors. These environmental factors have different impacts on companies and it is not easy to establish these relationships. However, it is possible to establish the impacts that particular environmental factors such as orders available from the public and private sectors have on orders received by companies in relative and qualitative terms, though it is still necessary to quantify such impacts. Nevertheless, no preceding research has attempted to quantitatively analyze the relationship between environmental changes and management performance of construction firms in Korea. Hence, the objective of this paper is to propose a regression model of the effect of management environment on contract amount of construction firms. The outcomes of this study will help forecast management performance in response to changes in business environment and provide basic inputs for corporate management strategies.

A Weight Analysis for Measuring the Management Performance of Strategic Business Units of Large Construction Companies

The business environment that affects the management performance can be characterized by each Strategic Business Unit (SBU) since construction companies win overseas contracts due to the fairly good construction situations while experience a decline in the local housing market. Environmental changes can alter the strategic importance of the SBU when measuring the management performance. However, large construction companies apply BSC (Balanced Score Card) for collective calculation to determine the management performance, making it difficult to reflect the strategic importance of SBU. This method may create a distorted image of management performance that fails to take environmental changes into consideration, and as such it needs to be improved. Yet, there are no studies on the weight of each SBU considering environmental changes. Thus, the current study intends to analyze the weight of SBU for company-wide measurement of the performance of large construction companies. In addition, a model for analysis of SBU importance is proposed to respond to the constantly changing environmental situations and to modify the weight. For analysis of SBU weight, a questionnaire was conducted with 23 experts and hands-on workers, and the questionnaire result was quantitatively analyzed by applying the FD-AHP method. It is expected that the result will enable a model to be proposed to calculate the weight per division in a manner that reflects environmental changes and minimizes strategic distortion when measuring the management performance of large construction companies.