• Journal of Korean Society of Steel Construction
• /
• v.26 no.4
• /
• pp.299-309
• /
• 2014

HSA800 is a new high strength steel (HSS) plate for building structures developed by POSCO and RIST in 2011. It has upper and lower bounds for yield ($F_y$) and tensile ($F_u$) strength as of 650-770MPa and 800-950MPa, respectively, with yield ratio ($F_y/F_u$) limit as of 0.85 which make steel quality more reliable and enhance the seismic resistance of structures. As made by TMCP, it has a good weldability without increasing carbon percentage. The objective of this study is to provide alternative design of mega-structural members of the Lotte World Tower (555m, 123 story), a first super-tall building in Korea, using HSS considering structural safety, constructability, and cost-effectiveness. Steel outrigger trusses, belt-trusses and steel exterior columns were selected and analyzed to evaluate the structural performance between original and alternative designs using HSS. The results show that HSS can be applied to the members which do not affect lateral stiffness of a building and, in this study, approximately 1100tons of steel were saved. It implies that HSS can save overall construction costs - manufacturing, delivery, and erection costs - by reducing mega structural member size. HSA800 was very first applied to the Lotte World Tower based on the results of this study.

• Journal of the Korean Society of Safety
• /
• v.20 no.4 s.72
• /
• pp.162-170
• /
• 2005

The effective development of event product for a successful event is first started with figuring out the participation motive of event. Second, what level of expectation before participating event for participant will have. Third, what level of satisfaction and safety satisfaction based on figured out motive and expectation will participant have. Fourth, what level of revisit based on satisfaction will have. The study is needed for these low items. Therefore, this investigation started as an exploratory study for a successful event to analysis the relationship among expectation satisfaction, safety satisfaction and revisit. The results indicated that participated motive is positively influenced on expectation. The expectation is positively influenced on safety satisfaction. The satisfaction is positively influenced on revisit. Finally, the safety satisfaction is positively influenced on revisit. The unique characteristics of this study is considered a safety satisfaction as m event safety and as an important factor when terror becomes often these days.

• Science of Emotion and Sensibility
• /
• v.9 no.spc3
• /
• pp.287-297
• /
• 2006

Human-being's craving for wealthy life and a change of a culture to consume have created mega discount, stores. Therefore, a convenience for use has been required when people shop at the stores. There is tome inconvenience that customers have to find out goods and to purchase them by themselves. This is the fundamental elements for this study about a Robot design which is able to resolve that kinds of problems when shopping at mega discount stores. This study proposes guidelines for Robot design to help shopping business service. It is based on research material by analysis of consumer behavior and its questionnaire.

• The Research Journal of the Costume Culture
• /
• v.12 no.5
• /
• pp.792-804
• /
• 2004

Sportism is continuously expressed in every season in a different theme and established as a Mega-Trend of the early 21 th century fashion. This study was conducted to research the social and cultural sources of the sportism expressed in the early 21th century fashion. This study focused on hybrid as one of the post-modem phenomena. By analysing social and cultural sources of the sportism, three aspects were found; first, many different fashion trends are coincides in post-modem society, which is possible and accelerated by hybrid each other. Second, the complicated and competitive society urge the people to review the past and the originality. Third, youth-oriented and individualistic lifestyle was brought by the development of the technology and economic surplus. Hybrid of the TPO was analysed which made the sportism mega-trend. 'Formal wear was mixed with casual wear, casual wear with active sportswear, hi-fashion with street fashion, and hi-fashion influenced formal and casual wear again'. The sportism prevalent in 21th century fashion can be explained by this system of hybrid. Results of the analysis in this study can be categorized into four aesthetic values based on hybrid of the styles, which are glamorous sportism, romantic sportism, minimal sportism, and heritage sportism.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.554-563
• /
• 2009

The trend of current urban redevelopment and new city development project shows that the superstructure of building is getting larger and higher in consequence of a limited plottage condition. For this reason, it is definitely required to extend pile diameter and install more deep foundation(Mega foundation) to support superstructure. The existing precast pile construction method causes construction-related problems such as increasing quantities, difficulty of storage & transportation material and decreasing design load while construct pile in deep foundation. The drilled shaft method has applied to minimize those problems. This article will be presented construction case study of design & construction of R.C.D method for a large building foundation work on the inside and outside of the country.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2009.05b
• /
• pp.119-122
• /
• 2009

As architectures have recently become high-risers and mega-structured, stable high strength products have been ensured. Accordingly, use of precast concrete accouplement has been increased in order to facilitate air compression and rationalize construction. Since not only external heating but a1so internal temperature rise caused by the accumulation of cement hydration heat in manufacturing process, precast concrete members with large cross-section used for high-rise mega-structure's columns and beams may exhibit different temperature history compared to the precast concrete members for wall and sub-floor with relatively small cross-sections. Therefore, this study aims to elucidate the characteristics of temperature history of mass concrete members cast with high-strength concrete fur precast concrete application. In this study, large cross-sectional precast concrete mock-up, unit cement quantity, and temperature histories in manufacturing precast concrete member under different curing condition were inclusively investigated.

• Proceedings of KOSOMES biannual meeting
• /
• 2004.05b
• /
• pp.99-105
• /
• 2004

• The Journal of the Korea Contents Association
• /
• v.13 no.3
• /
• pp.511-519
• /
• 2013

The purpose of this paper is to examine how European textbooks reflect Seoul nowadays. The study focuses on the trend of textbooks in main European countries, such as England, France, Spain, Italy, and Germany. They tend to describe Seoul as one of the mega cities with urban problems, and introduces the city as an economic center which is responsible for interaction with other mega cities. Besides, Seoul is also described as less competitive city compared to others, and its history and cultural resources are not paid attention. Despite everything, it is fortunate that there are very few errors in descriptions of Seoul. In future I expect that descriptions of Seoul in European textbooks are enhanced in not only economic aspects of Seoul but also historic and cultural aspects of Seoul and then European textbooks get more reliable contents to inform Korea.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.649-652
• /
• 2005

The camera cellular phone has a large portion of cellular phone market in recent year. The variety of a customer demand makes a fast model change and the spatial resolution is changed from VGA to multi-mega pixel. The 1.3 mega pixel (MP) camera cellular phone was first released into the Korean market in October 2003. The major cellular phone companies released a 2MP camera cellular phone that supports zoom function and a 2MP camera cellular phone is settled down with the Korea cellular phone market. It makes a keen competition in price and demands automation for phone camera module. There is an increasing requirement for the automatic assembly to correspond to a fast model change. The hard automation techniques that rely on dedicated manufacturing system are too inflexible to meet this requirement. Therefore in this study, this system is designed with the flexibility concept in order to cope with phone camera module change. The system has a same platform that has X-Y-Z motion or X-Z motion with ${\mu}m$order accuracy. It has a special gripper according to the type of a component to be put together. If the camera model changes, the gripper may be updated to fit for the camera module. The controller of this system acquires the data sets that have the information about the assembly part by the tray. This information is obtained ahead of an inspection step. The controller excludes an inferior part to be assembled by using this information to diminish the inferior goods. The assembly jig used in this system has a function of self adjustment that reduces the tact time and also diminish the inferior goods. Finally, the intelligent assembly system for phone camera module will be designed to get a flexibility to meet model change and a high productivity with a high reliability.

• Earthquakes and Structures
• /
• v.19 no.5
• /
• pp.347-359
• /
• 2020

The Mega-Sub Controlled Structure System (MSCSS), an innovative vibration passive control system for building structures, is improved by adding lead rubber bearings (LRBs) on top of the substructure. For the new system, a genetic algorithm is used to optimize the dynamic parameters and distributions of dampers and LRBs. The program uses various seismic performance indicators as optimization objectives, and corresponding results are compared. It is found that the optimization procedure for maximizing the energy dissipation ratio yields the best solutions, and optimized models have consistent seismic performances under different earthquakes. Seismic performances of optimized MSCSS models with and without LRBs, as well as the traditional Mega-Sub Structure model, are evaluated and compared under El Centro wave, Taft wave and 20 other artificial waves. In both elastic and plastic analysis, the model with LRBs shows significantly smaller story drift and horizontal acceleration than those of the other two models, and fewer plastic hinges are developed during severe earthquakes. Energy analysis also shows that LRBs installed in proper locations increase the deformation and energy dissipation of dampers, thereby significantly reduce the kinetic, potential, and hysteretic energy in the structure. However, LRBs do not have to be mounted on all the additional columns. It is also demonstrated that LRBs at unfavorable locations can decrease the energy dissipation for dampers. After LRBs are installed, the optimal damping coefficient and the optimal damping exponent of dampers are reduced to produce the best damping effect.