• Journal of the Korea Society for Simulation
• /
• v.31 no.3
• /
• pp.23-34
• /
• 2022

Due to the characteristics of the railway system, a fleet consists of multiple railway vehicles, and a project contract is made by supplying multiple fleets to the customer. If the project fails to meet the due date, the manufacturer must compensate for the delay to the customer. In this paper, we analyze the operation strategies of the railway vehicle manufacturing factory using simulation, in which the layout adopts the concept of the flow lines, and when shortages of parts are considered. If there is a shortage of parts, the subsequent assembly process cannot proceed due to the nature of the assembly process. Thus, in order to overcome this problem, three strategies for performing assembly work are presented when the events of shortages are occurred. We also compare the strategies with respect to reduce the total cost which includes labor costs and compensation costs for delay.

• Journal of the Korea Convergence Society
• /
• v.9 no.9
• /
• pp.263-270
• /
• 2018

The purpose of this study is to investigate the correlation between the demographic characteristics of Korean men and the preference of women's grading such as age, education, marital status, occupation, monthly income, and residence. After the questionnaire distribution, 333 questionnaires were analyzed statistically. Through this study, we will investigate the preference of men according to the step length of women's graduation cuts, and contribute to the establishment of the most preferred type of graduation cuts. As a result of the questionnaire analysis, 51.1% of all males preferred the gradation type with a large step of the cut length, and it was found that there was a difference in the preference for the step according to demographic characteristics (p <0.05) It is possible to conduct various studies on the style of the graduation cut among the hairstyles of women who are visually preferred and beautiful. In addition, it will be possible to derive the importance of customer satisfaction in hair salons, and it will be a basic index for searching for changes in the gradation cuts that can be applied in various ways while maximizing the aesthetic image of women.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.20 no.4
• /
• pp.337-347
• /
• 2018

Weather causes much of the risk of agricultural activity. For efficient farming, we need to use weather information. Modern agriculture has been developed to create high added value through convergence with state-of-the-art Information and Communication Technology (ICT). This study deals with the quality control algorithms of weather monitoring equipment through Ubiquitous Sensor Network (USN) observational equipment for efficient cultivation of cabbage. Accurate weather observations are important. To achieve this goal, the Korea Meteorological Administration, for example, developed various quality control algorithms to determine regularity of the observation. The research data of this study were obtained from five USN stations, which were installed in Anbandegi and Gwinemi from 2015 to 2017. Quality control algorithms were developed for flat line check, temporal outliers check, time series consistency check and spatial outliers check. Finally, the quality control algorithms proposed in this study can also identify potential abnormal observations taking into account the temporal and spatial characteristics of weather data. It is expected to be useful for efficient management of highland cabbage production by providing quality-controlled weather data.

• The Korean Journal of Applied Statistics
• /
• v.32 no.4
• /
• pp.607-618
• /
• 2019

A new and interesting task in statistics is to effectively analyze functional data that frequently comes from advances in modern science and technology in areas such as meteorology and biomedical sciences. Functional linear regression with scalar response is a popular functional data analysis technique and it is often a common problem to determine a functional association if a functional predictor variable affects the scalar response in the models. Recently, Kong et al. (Journal of Nonparametric Statistics, 28, 813-838, 2016) established classical testing methods for this based on functional principal component analysis (of the functional predictor), that is, the resulting eigenfunctions (as a basis). However, the eigenbasis functions are not generally suitable for regression purpose because they are only concerned with the variability of the functional predictor, not the functional association of interest in testing problems. Additionally, eigenfunctions are to be estimated from data so that estimation errors might be involved in the performance of testing procedures. To circumvent these issues, we propose a testing method based on fixed basis such as B-splines and show that it works well via simulations. It is also illustrated via simulated and real data examples that the proposed testing method provides more effective and intuitive results due to the localization properties of B-splines.