• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.8
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• pp.751-758
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• 2015

Mathematical models are actively used to reduce the experimental expenses required to understand physical phenomena. However, they are different from real phenomena because of assumptions or uncertain parameters. In this study, we present a calibration and validation method using a paper helicopter and statistical methods to quantify the uncertainty. The data from the experiment using three nominally identical paper helicopters consist of different groups, and are used to calibrate the drag coefficient, which is an unknown input parameter in both analytical models. We predict the predicted fall time data using probability distributions. We validate the analysis models by comparing the predicted distribution and the experimental data distribution. Moreover, we quantify the uncertainty using the Markov Chain Monte Carlo method. In addition, we compare the manufacturing error and experimental error obtained from the fall-time data using Analysis of Variance. As a result, all of the paper helicopters are treated as one identical model.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.116-126
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• 2019

The production volume and amount of non-timber forest products in Korea has been on the increase for the past five years. In particular, the production amount of wild vegetables (edible mountain plants) is approximately KRW 400 billion as of 2017, accounting for 14 % of the total production amount of non-timber forest products. Among wild vegetables, especially the production volumes and amounts of bracken, saw-wort (Saussurea), and thistle have grown steadily. Nevertheless, severe price competition with cheap imports and little changes in the pattern of wild vegetable consumption may negatively affect the prices of domestic wild vegetables. This, in turn, can decrease the overall consumption of wild vegetables. Recently, however, consumers have preferred healthy food with increases in their income and interest in health. Therefore, now is a crucial time for the wild vegetable market. Accordingly, this study analyzed consumers' purchase and consumption behavior related to wild vegetables through a consumer survey to contribute to establishing various strategies and policies for promoting the consumption of these vegetables. Also, this study identified consumers' awareness and intention regarding wild vegetables by analyzing social big data. Different from previous studies, this study investigated consumers' awareness and intention by analyzing SNS social big data, as well as conducting a survey. The results of the study will help prioritize strategies and policies for boosting the consumption of wild vegetables.

• Archives of design research
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• v.17 no.1
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• pp.89-98
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• 2004

A systemic approach to behavior on the basis of human psychology is needed for behavior-centered space design. Also, the recognition that human and environment, in all, have complementarity is needed- human and space shall be understood as a general phenomenon, supposing interaction. Design of behavior-oriented space means configuration and coordination of physical subjects as well as understanding, analysis and reflection of psychological and behavioral phenomena. It is analysis of a private individual as well as understanding of interaction between human groups, as well. In respect of space recognition, analysis not on material movement but on energy circulation and variable is important. It means that the understanding of user's behavior and psychology does not orient reasonable purpose just for convenience. That is, such understanding intends to understand behavioral patterns and psychological phenomena between space and human beyond the decomposition of structure of human and space into physical elements and the design based on standardized data. Thereby, more human-oriented space design might be implemented by the understanding of behavioral essence. Also, a user-centered design process from another viewpoint might be created, and the general amenity among man, space and environment - better environmental quality - might be produced. For this, the consciousness of human activity that is, activity system shall be ahead of it, and the approaches for design shall be implemented into a process not in predictive ideas but in semi-scientific system. On the basis of the above view, this study was attempted to investigate the orientation of design to recognize space as another life, and explore a process where it is drawn into a design language on the basis of human behavior. If the essence of space behavior and the activity system are analyzed through user observation and it is reflected upon a space design program and then developed into a formative language, a new design process on human and environment might be produced. In conclusion, the reflection of user's behavior and psychology into design, contrary to existing public space design based on physical data, can orient quality improvement of human life and ultimately be helpful to the proposition, 'humanization of space'.

• The Journal of Bigdata
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• v.5 no.1
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• pp.109-124
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• 2020

In Korea, despite much interest in real estate, it is not easy to predict prices. Because apartments are both residential spaces and investment materials. Key figures affecting the price of apartments vary widely, and there are also regional characteristics. This study was conducted to derive the factors and characteristics that affect the sale price of apartments in S City, Gyeonggi-do. In general, people diagnose that better subway accessibility leads to higher apartment sales price. Nevertheless, in the case of S City, the price was slightly lower as it was closer to Line 1, but the higher the subway accessibility at Shinbundang Line, the higher the price. The five-year average of government bonds and the price were inversely related, and it was found to be proportional to the M2 balance and the price. The floor area ratio and the total number of parking lots had a great influence on the price, and the presence of department stores and discount marts within 1.5 km were the most important factors in the area of cultural aspect.

• Explosives and Blasting
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• v.28 no.1
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• pp.1-10
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• 2010

In blasting for lighting, fatigue behaviors of pillars such as destruction and deformation may occur due to blasting vibration and flyrock, which may cause collapses of cavities. This study aims to identify dynamic behavior of pillars to maintain efficient safety of cavities in large drafts. when they collide with flyrocks under blasting for the excavation. For the purpose, we compared ground vibration around pillar when flyrock collided with the pillar and that when explosive blast happened for the excavation. we conducted fragmentation analysis of the flyrock and compared impact vibration obtained from empirical equation with ground vibration obtained from regression analysis of real vibration data. also we compared those with results analyzed from numerical analysis.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.683-687
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• 2007

Hydroelastic deformation of pontoon type floating structure in waves is critical in structural design. Therefore, it is necessary to develop additional technology that make to dissipate the wave energy as the submerged horizontal plate. In this study, we investigate the characteristics of hydrodynamic interaction effect by the submerged plate affecting to the radiation forces on a pontoon type floating structure using numerical analysis. We have developed the numerical method based on the composite grid system that consists of moving and fixed grid to compute the radiation forces due to the heaving motion of pontoon type floating structure and submerged plate. The numerical simulations based on the finite difference method are carried out to solve the fully nonlinear free surface involving the breaking waves and compared with the experimental data to confirm the reliability of the numerical method. Then, we discuss the interaction effects on the hydrodynamic forces that could influence on the hydroelastic response of floating structure.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.423-436
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• 2011

Many of the theoretical studies have considered herd behavior as a source of the volatility in financial markets, but there have been few empirical studies on the dynamic herding due to the technical difficulty of detecting herd behavior with time-series data. In this context, this paper proposes a new method for measuring time-varying herd behavior based on QR-GARCH model. Using daily data of KOSPI stocks, this paper provides some empirical evidence for strong and volatile herding among traders of stocks of medium firms, and shows that time-varying herd behavior in traders of some stocks has persistent autocorrelation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.31-37
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• 2012

In this paper, we present a smart grid monitoring system connected with electric vehicle charging system using anti-islanding method. Electric vehicles can be charged through remote control of smart grid monitoring system and the charging process may be more stable and more efficient by wireless communication between the Local Area Module and End Modules. It is illustrated by some experiments that electric vehicle charging process may not be interrupted without any serious fault even though the islanding phenomena occurred in the grid if the presented monitoring system was applied to the smart grid system.

• Archives of design research
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• v.11 no.1
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• pp.73-80
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• 1998

Recently, the importance of cultural design has been increasing due to the globalization. However the cultural design is mainly focusing on the shape or color stereotype of different cultures, ignoring another important aspects of cultural design: the way of peoples' interacting with product. The study aims to develop usability test program for cultural user-interface design that operates in the world wide web. The study begins with discussing the nature of culture through defining culture and reviewing the depth and variables of culture. Based on the findings the structure of the usability testing program on the WWW design methods is identified. The usability testing program on the WWW comprises of five different modules: module for identifying users' demographic characteristics, module for cultural variables, module for population stereotype, module for usability testing, and module for data storage and analysis. Finally findings are summarized and further research prospects are outlined.

• Spatial Information Research
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• v.11 no.2
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• pp.185-201
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• 2003

The purpose of this study is to seek the methods of constructing a cultural information system based on GIS. It is impossible for regional culture to be formed apart from its surrounding space, so a study of culture should be based on realizing the features of its space. It is important to note that the elements composing a culture complicatedly interact with each other in their function and continuously change. Also they are interrelated in space and plentiful in their amount. Nevertheless, those studies practised so far in relation to culture and constructing cultural database are too limited in establishing cultural area or community life area required to recognize the regional identity So it is now essential that we should study the methods of cultural expression surpassing objective historical and cultural site maps instead of simple maps depicting historical remains or sites. From this viewpoint, this study tries to find various cultural phenomena in relation to their space through seeking the methods of constructing the cultural database model using XML. In addition, this study tries to construct a base for increasing the utilization of information in making the cultural contents.