• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2010.05b
• /
• pp.103-108
• /
• 2010

The purpose of this study is to analyze of the risk factors for oversea plants construction projects. For this study, risk factors data from related literature review, research organization and construction company was researched and classified under each EPC phases. In addition, a questionnaire survey by plant experts was conducted for analysis of risk weight and costs and time impact on each EPC phases. The results of this study are as follows: First, a detail design errors(engineering phase), a equipment procurement plan(procurement phase), and exchange rate fluctuations(construction phase) were analyzed the highest weight factors. Second, a financing plan(engineering phase), quantity take-off bill(procurement phase), and exchange rate fluctuations(construction phase) were analyzed the highest cost impact factors. Third, detail design errors(engineering phase), a equipment procurement plan(procurement phase), and schedule management errors(construction phase) were analyzed the highest time impact factors.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.13 no.1
• /
• pp.367-378
• /
• 2021

This paper develops a dynamic regression model to quantify the contribution of key external factors to operational energy efficiency of ships. On this basis, kernel density estimation is applied to explore distribution patterns of fluctuations in operational performance. An empirical analysis based on these methods show that distribution of fluctuations in Energy Efficiency Operational Indicator (EEOI) is leptokurtic and fat tailed, rather than a normal one. Around 85% of fluctuations in EEOI can be jointly explained by capacity utilization and sailing speed, while the rest depend on other external factors largely beyond control. The variations in capacity utilization and sailing speed cannot be fully passed on to the energy efficiency performance of ships, due to complex interactions between various external factors. The application of the methods is demonstrated, showing a potential approach to develop a rating mechanism for use in the legally binding framework on operational energy efficiency of ships.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.1
• /
• pp.90-100
• /
• 2021

In the north and northeast of Cheonsu Bay, short-term fluctuations of surface water temperature are large owing to shallow water depth, weak current, and freshwater runoff. However, in the south of the bay, water temperature fluctuations are small owing to the inflow of offshore water by tidal currents. The water temperature in the north of the bay is higher in spring and summer than in the south of the bay, but lower in autumn and winter. During spring season, the fluctuation in the northern surface water temperature is the highest. The temperature fluctuations owing to tides are in phase with the tide in autumn and winter, and in the reverse phase with the tide in spring and summer. The dominant periods of water temperature fluctuations are half a day, daily, 15 days, and 1 month owing to the tide and 7 to 10 days, which are estimated based on atmospheric factors. Half a day and daily water temperature fluctuations are also highly correlated with air temperature and wind fluctuations. The sea area where water temperature fluctuations are highly correlated is divided into the north and south of the bay. The fluctuation phase is faster in the north of the bay than in the south or in the center.

• Neonatal Medicine
• /
• v.28 no.1
• /
• pp.7-13
• /
• 2021

Purpose: To evaluate the risk factors and effects of fluctuations in oxygen saturation on the occurrence and severity of retinopathy of prematurity (ROP). Methods: From January 1, 2013 to January 31, 2020, 260 patients hospitalized in the neonatal intensive care unit of Ajou University Hospital were retrospectively analyzed. Results: Sixty-six patients (25%) were diagnosed with ROP; of them 39 required treatment. In the multivariate regression analysis of ROP severity, the odds ratio (OR) of gestational age was 0.32 (95% confidence interval [CI], 0.22 to 0.47; P<0.0001). The OR of saturation of peripheral oxygen (SpO₂) fluctuations at the 4th week after birth was 1.02 (95% CI, 1.02 to 1.12; P=0.041). Conclusion: SpO₂ fluctuations in premature infants younger than 30 weeks' gestational age affects ROP severity, especially at the 4th week of life.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.5
• /
• pp.509-515
• /
• 2023

Despite the continued development of alternative energies, fuel consumption is increasing. In particular, the price of gasoline fluctuates greatly according to fluctuations in international oil prices. Gas stations adjust their gasoline inventory to respond to gasoline price fluctuations. In this study, news datasets is used to analyze the gasoline consumption patterns through fluctuations of the gasoline inventory. First, collecting news datasets with web crawling. Second, summarizing news datasets using KoBART, which summarizes the Korean text datasets. Finally, preprocessing and deriving the fluctuations factors through N-Gram Language Model and TF-IDF. Through this study, it is possible to analyze and predict gasoline consumption patterns.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.1 no.1
• /
• pp.8-16
• /
• 2013

Purpose: The objective of this paper is to identify and assess the contribution of budgetary, monetary and institutional shocks affecting the Tunisian economy over the period 1976-2003. The methodology used is vector autoregressive models and structural recent techniques for the analysis of time series related. The empirical results show a significant relationship between the supply shock and institutions on the one hand, and between institutional shocks and economic activity on the other hand. Research Design, Data and Methodology: As part of this section we will try to identify and assess the contribution of various shocks to macroeconomic variables' fluctuations for the Tunisian economy. The study period is: 1976-2003 and observations are annual. Results: The real business cycle theory argues that fluctuations in aggregate economic activity are the result of the interaction of the only real factors namely agents' preferences, technological opportunities, factor endowments and possibly certain institutional constraints. Conclusions: The lowest contribution to the variability of these rights is the monetary shock. As for "civil liberties", the largest share of their variability is the shock relating to the "political rights" during the first four periods .

• Wind and Structures
• /
• v.4 no.1
• /
• pp.73-84
• /
• 2001

Analysis of pressures measured on the roof of the full-scale Texas Tech building and a 1/50 scale model of a typical house showed that the pressure fluctuations on cladding fastener and cladding-truss connection tributary areas have similar characteristics. The probability density functions of pressure fluctuations on these areas are negatively skewed from Gaussian, with pressure peak factors less than -5.5. The fluctuating pressure energy is mostly contained at full-scale frequencies of up to about 0.6 Hz. Pressure coefficients, $C_p$ and local pressure factors, $K_l$ given in the Australian wind load standard AS1170.2 are generally satisfactory, except for some small cladding fastener tributary areas near the edges.

• Journal of Korean Society of Rural Planning
• /
• v.24 no.3
• /
• pp.25-31
• /
• 2018

This study analyzed factors influencing cultivation area of two major apple cultivars, Fuji and Hongro, applying the panel SUR model to survey data from farms. Characteristics of farms, distribution factors, and weather factors were the independent variables of the model. The analysis indicated that characteristics of farms, distribution factors, and weather factors influence the cultivation area of Hongro and Fuji. The independent variables were also found to have different levels of influence on increase and decrease of the cultivated area. Helping predict changes in cultivation area of Hongro and Fuji, the research results can be used as primary data to support efforts to prevent price fluctuations due to changes in supply.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.6
• /
• pp.624-635
• /
• 2012

Construction projects, including housing, are carried out over long periods of time. According to changes to the construction period, the cost of input materials and wages also changes. Therefore appropriate management is important in order to minimize cost risks caused by fluctuations in prices. In Korea, housing units are usually sold in lots prior to construction completion. Therefore, careful management of input elements such as materials and equipment that are sensitive to price fluctuations is very important. This study deals with how the price fluctuation of materials, labor, and equipment influences the change of housing cost and seeks a way for cost management through identifying key resources sensitive to price fluctuation. As a result, a change to the housing cost index multiplies depending on cost changes of materials and labor together. Labor costs are a major factor on the housing cost index. In addition, certain types of materials and labor input to housing construction greatly influence price fluctuations. Thus, it is found that managing those main cost factors is the key for effective cost management.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.3
• /
• pp.148-160
• /
• 2023

The air transport industry is experiencing unprecedented fluctuations in aviation demand through the Covid-19 pandemic, and is more focused than ever on maintaining and generating business profitability. During the pandemic, demand for air cargo has soared, and the conversion business from passenger aircrafts to freighters(P2F) is drawing attention as a new business in the aviation maintenance industry. This study derives important factors to be considered in order to successfully carry out the P2F project through a wide range of cases and related literature, and analyzes the relative importance of each factor using the analytic hierarchy process. Through a survey of 33 aviation maintenance experts with more than 20 years of field experience, the importance of main factors and their sub factors was determined and implications were drawn. As a primary result, in order to succeed in the P2F project, the main factors were identified in the order of skill, finance, and location. The most important sub factors for each main factors were identified in order of securing airframe modification skill, securing infrastructure construction cost, and creating P2F business complex and district. The quantified success factors suggested the critical direction for the successful development of Korea's P2F business, and presented viable and specific business strategies and implementation plans for each factors.