• Wind and Structures
• /
• v.12 no.4
• /
• pp.313-332
• /
• 2009

This paper numerically and experimentally investigates the control performance of the active mass damper (AMD) systems in a 26-story high-rise building in use. This is the first full-scale application of the AMD system for suppressing the wind-induced vibration of a building structure in Korea. In addition, the AMD system was installed on top of the building already in use, which may be the world's first implementation case. In order to simultaneously mitigate the transverse-torsional coupled vibration of the building, two AMD systems were applied. Moreover, the H-infinity control algorithm has been developed to utilize the maximum capacity of the AMD system. From the results of numerical simulation using the wind load obtained from the wind tunnel tests, it was found that the maximum acceleration responses of the building were reduced significantly. Moreover, the control performance of the installed AMD system was examined by carrying out the free and forced vibration tests. The acceleration responses on top of the building in the controlled case measured under strong wind loads were compared with those in the uncontrolled case numerically simulated by using the wind load deduced from the measured data and a structural model of the building. It is demonstrated that the AMD system shows good control performance in reducing the building accelerations.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.12
• /
• pp.615-623
• /
• 2001

In this paper, we study a series active power filter to compensate current harmonics and unbalanced source voltages. Conventional control methods for compensating unbalanced source voltages use source voltages to calculate compensation voltages, and in addition use load voltages to regulate load voltages. But the proposed control method uses load voltage to compensate unbalanced source voltages and regulate load voltages. And we propose a control method to reduce current harmonics which can calculate compensation voltages directly from source currents and load voltages. By well-matched operation of two control methods, the series active power filter can compensate current harmonics, unbalanced source voltages, and regulate load voltages. We compose a combined system of the series active power filter and parallel passive filters to confirm a validity of proposed control methods. The results from experiments are presented to demonstrate effectiveness of the proposed method.

• Journal of the Society of Naval Architects of Korea
• /
• v.41 no.4
• /
• pp.77-84
• /
• 2004

Active control is regarded as one of the most efficient and economic countermeasures to reduce excessive vibration of ship superstructure. However, it is difficult to find its practical application in real ships in spite that many studies on such systems have been done. In this study, for the practical use of an active control system to reduce ship superstructure vibration, we have developed an active vibration compensator consisting of a mechanical actuator having compact size and expected lifetime over 20 years, its control panel including exclusive signal processing and computing board, sensors to detect phase and vibration, and its operation software providing various user-interface functions. From the performance verification test of the system at a 5,500 TEU container carrier, we have confirmed the system could reduce ship superstructure vibration of a harmonic component of main engine rotating frequency up to 0.1 mm/s.

• The Research Journal of the Costume Culture
• /
• v.21 no.5
• /
• pp.765-779
• /
• 2013

This paper studied why middle-aged group is using active wear as casual wear. First, we can think of 'comfort', 'ideal body shape', 'trend', 'functionality', 'economy' for the reasons. We categorized the incentives as 'comfort/functionality pursuits', 'trend/economy pursuits', and 'ideal body shape pursuits'. Studies showed that statistically significant number of men pursue comfort and functionality, and statically significant number of women pursue trend and economy. Second, this study shows that the number of consumers who use the active wear in daily lives is greater than that of those who use it only for outdoor activities. The difference was statistically significant in T-shirts and pants. The most frequent usage was in social activities, and the next frequent usage was in cultural activities. The reason is that currently, middle-aged consumers are actively participating in social gatherings than any other activities. Especially, considering that the men wear active wear more than the women do, development of the product as men's casual wear that is compatible with other apparels will be necessary. We expect this study will be used as the preliminary data for a marketing strategy targeting the middle-ages.

• Journal of KIISE:Information Networking
• /
• v.29 no.5
• /
• pp.510-523
• /
• 2002

The routers in an active network perform customized computations on the messages flowing through them, while the role of routers in the traditional packet network, such as the Internet, is to passively forward packets as fast as possible. In contrast to the Internet, the processing in active networks can be customized on a per user or per application basis. Active networks allow users to inject information into the network, where the information describes or controls a program to be executed for the users by the routers as well as the end hosts. So the network users can realize the active networks by "programming" the network behavior via the programming interface exposed to them. In this paper, we devise a network protocol model and present a verification technique for reasoning about the correctness of an active application defined using the model. The technique is developed in a platform- and language-independent way, and it is algorithmic and can be automated by computer program. We give an example dealing with network auction to illustrate the use of the model and the verification technique.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1459-1464
• /
• 1996

The most important parameter for hydraulic active suspension system is to sustain desirable vehicle maneuvering stability and ride comfort without increasing consumption power. The performance of hydraulic active suspension system depends on damping force of body damping valve and piston damping valve. Hydraulic actuator design and damping valve parameter selection are essential and basic procedure to design hydraulic active suspension system. This paper is on computer simulation with use of mathematical model that was delivered from dynamic characteristic of hydraulic actuator, as know basic damping characteristics of hydraulic active suspension system. The aim of this paper is to select the system parameter that affect mainly hydraulic active suspension, and identify the validity on the system parameter selection.

• Journal of the Korean Applied Science and Technology
• /
• v.26 no.3
• /
• pp.328-334
• /
• 2009

Recently, much interest on mesoporous carbon has been shown in their use for both hydrogen and methane storage and as an electrode material for electric double layer capacitors. The mesoporous active carbons by ion exchange were prepared and physical properties such as specific surface area and pore structure of active carbon were investigated using BET. In this study, active carbons with mesopore fraction of $60{\sim}90%$ were obtained. The Fe/Ca-exchanged active carbons showed a greater mesoporosity compared with Fe-exchanged carbons. The mean mesopore size in active carbons using Ca- and Fe-exchange was about $5.5{\sim}6.0nm$ and was approximately 1nm higher than that of the Fe-exchanged active carbon.

• Food Science and Biotechnology
• /
• v.16 no.5
• /
• pp.691-709
• /
• 2007

Concerns on environmental waste problems caused by non-biodegradable petrochemical-based plastic packaging materials as well as consumer's demand for high quality food products has caused an increasing interest in developing biodegradable packaging materials using annually renewable natural biopolymers such as polysaccharides and proteins. However, inherent shortcomings of natural polymer-based packaging materials such as low mechanical properties and low water resistance are causing a major limitation for their industrial use. By the way, recent advent of nanocomposite technology rekindled interests on the use of natural biopolymers in the food packaging application. Polymer nanocomposites, especially natural biopolymer-layered silicate nanocomposites, exhibit markedly improved packaging properties due to their nanometer size dispersion. These improvements include increased mechanical strength, decreased gas permeability, and increased water resistance. Additionally, biologically active ingredients can be added to impart the desired functional properties to the resulting packaging materials. Consequently, natural biopolymer-based nanocomposite packaging materials with bio-functional properties have huge potential for application in the active food packaging industry. In this review, recent advances in the preparation and characterization of natural biopolymer-based nanocomposite films, and their potential use in food packaging applications are addressed.

• Journal of Korea Society of Industrial Information Systems
• /
• v.8 no.2
• /
• pp.108-118
• /
• 2003

The purpose of this study is to understand what is ActiveX control and how to utilize it in developing dynamic web pages. For this purpose, some literature survey and experimental practices with PC were done to understand the differences among web programming technologies such as visual basic, java, XML web services. In order to scrutinize the functions of ActiveX controls and the comparison of their technology with currently introduced XML web service, a study on the history of Internet programming with a focused view on ActiveX control was also performed. With the knowledge of the fore mentioned, Actual design and building experiments of web pages using ActiveX control pad were implemented. The results show that Microsoft ActiveX controls, formerly known as OLE controls or OCX controls, developed to compete with java applet in internet battle fields, turn out to be useful in software reusability, cost-saving and time-saving etc. However, the use of ActiveX controls has been confined in window platform, Overall, this study was useful for understanding the usage of ActiveX controls in web pages.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.11 no.4
• /
• pp.214-220
• /
• 2008

The Ballast Water Management Convention provides that ballast water treatment systems which make use of active substances shall be approved from IMO according to the procedure developed by the IMO. The Convention described that active substance means a substance or organism, including a virus or a fungus, that has a general or specific action on or against harmful aquatic organisms and pathogens. The Marine Environment Protection Committee of IMO gave basic approval to 13 ballast water management systems and final approval to 4 systems until October 2008. This paper considered the matter of procedure and documents of the basic and final approval based on the "Procedure for approval of ballast water management systems that make use of Active Substances (G9)" and "The Methodology for information gathering and the conduct of work of the GESAMP-BWWG" and summarized the specifications of the treatment systems which was granted the basic or final approval from IMO and raised several points.