• Journal of the Korean Society for Library and Information Science
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• v.45 no.1
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• pp.189-210
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• 2011

This study aims to explore how users are tagging in order to utilize a folksonomy and whether they understand the social and interactive aspects of tagging in three different folksonomic systems, Connotea (www.connotea.org), Delicious(http://delicious.com), and CiteULike(www.citeulike.org). The study uses internet questionnaires, qualitative diary studies, and follow-up interviews to understand twelve participants' tagging activities associated with folksonomic interactions. The flow charts developed from the twelve participants showed that tagging was a quite complex process, in which each tagging activity was interconnected, and a variety of folksonomic system features were employed. Three main tagging activities involved in the tagging processes have been identified: item selection, tag assignment, and tag searching and discovery. During the tag assignment, participants would describe their tagging motivations related to various types of tags. Their perception of the usefulness of types of tags was different when their purpose was for social sharing rather than personal information management. While tagging, participants recognized the social potential of a folksonomic system and used interactive aspects of tagging via various features of the folksonomic system. It is hoped that this empirical study will provide insight into theoretical and practical issues regarding users' perceptions and use of folksonomy in accessing, sharing, and navigating internet resources.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.7
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• pp.1033-1038
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• 2013

Petrochemical complex has been a lot of research for the development of a more mature product and analysis for mid-process and finished products is essential in these process. But these analyzes are still by hand work samples being manufactured in many parts. Moreover they are exposed to hazardous chemical and such as the analysis is being made in a very poor working conditions. In this paper, in order to solve such problems the multi control system has been developed for the automated analysis. In addition, the organic behavior of these systems and the development of a program for the automated applied, and throughout the experiment to verify the reliability of this device for the accuracy of the dosing pumps for the standard solution prepared with a range of error of ${\pm}0.01m{\ell}$ was able to get a very good experimental results.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.105-113
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• 2009

To improve braced frame performance, the connection strength, stiffness, and ductility must be directly considered in the frame design. The resistance of the connection must be designed to resist seismic loads and to help provide the required system ductility. In addition, the connection stiffness affects the dynamic response and the deformation demands on the structural members and connections. In this paper, current design models for gusset plate connections are reviewed and evaluated usingthe results of past experiments. Current models are still not sufficient to provide adequate connection design guidelines and the actual stress and strain states in the gusset plate are very nonlinear and highly complex. Design engineers want simple models with beam and column elements to make an approximate estimation of system and connection performance. The simplified design models are developed and evaluated to predict connection stiffness and system behavior. These models produce reasonably accurate and reliable estimation of connection stiffness.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.286-286
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• 2009

A small PEM fuel cell has two different stack configurations such as active and passive stacks. The active stack has a distintion of high power density although it makes system complex by using alr blower and related BOPs resulting in large system volume. On the contrary, passive stack has an advantage of compact system because it doesn't need air supplying devices although it reveals relatively low stack power density. In this study we fabricated two 10W PEMFC stacks with different stack configurations, active and passive stacks, and tested their performance and stability. The active stack consists of 13cells with an active area of $5cm^2$. The passive stack has 12cells with an active area of $16cm^2$. When we compared the stack performance of those stacks, the active stack showed higher power density compared to the passive stack, particularly at high voltage regions. However, at low voltage and high current regions, the passive stack performance was comparable to the active stack. The stack stability was largely dependent on the fuel humidity, particularly for active stack. At low humidity conditions, the active stack performance was decreased continuously and the cell voltage distribution was not uniform showing seriously low cell voltage at center cells mainly due to the cell drying. The passive stack showed relatively stable behavior at low humidity and the stack performance was largely dependent on the atmospheric conditions.

• International Commerce and Information Review
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• v.15 no.2
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• pp.71-82
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• 2013

The automotive supply chain is increasingly complex as automakers seek more profitable solutions with global out-sourcing and manufacturing strategies. In the automotive industry, using returnable plastic containers (RPCs) is very common for domestic operations, but for internationally, it has not been considered by many companies because of issues such as overall distance and difficulty of control. The results of this simulation can help to analyze the interactive and coherent behavior of packaging and supply chain systems. The data obtained from the model can be applied to make substantial decisions for choosing the most profitable packaging types, at the same time as it can lead to designing an optimum supply chain for RPCs used in international supply chains.

• Tunnel and Underground Space
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• v.27 no.6
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• pp.343-350
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• 2017

Amid increasingly saturated ground space, development of underground space has been booming throughout the world and excavation has been underway near the structure above or under the ground level. But the ground subsidence caused by improper or poor construction technologies, underground water leakage, sudden changes of stratum and the problem with earth retaining system component has been emerged as hot social issue. To deal with such problems nationwide, establishment of preventive and proactive disaster management and rapid restoration system has been pushed now. In this study, collection of the data on technology development trend to secure the underground safety was made, taking into account of internal change elements (changing groundwater level, damage to underground utilities, etc) and external change elements (vehicle load, earthquake and ground excavation, etc) during excavation. Amid the growing need of ground behavior analysis, ground subsidence evaluation technology, safe excavation to prevent ground subsidence and reinforcement technology, improvement of rapid restoration technology in preparation for ground subsidence and development of independent capability, this study is intended to introduce the technology development in a bid to prevent the ground subsidence during excavation. It's categorized into prediction/evaluation technology, complex detect technology, waterproof reinforcement technology, rapid restoration technology and excavation technology which, in part, has been in process now.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1519-1526
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• 2010

The behavior of peptide or protein solutes in saline aqueous solution is a fundamental topic in physical chemistry. Addition of ions can strongly alter the thermodynamic and physical properties of peptide molecules in solution. In order to study the effects of added ionic salts on protein conformation and dynamics, we have used the molecular dynamics (MD) simulations to investigate the behavior of Staphylococcus aureus Hfq protein under two different ionic concentrations: 0.1 M NaCl and 1.0 M NaCl in presence and absence of RNA (a hepta-oligoribonucleotide AU5G). Hfq, a global regulator of gene expression is highly conserved and abundant RNA-binding protein. It is already reported that in vivo the increase of ionic strength results in a drastic reduction of Hfq affinity for $Q{\beta}$ RNA and reduces the tendency of aggregation of Escherichia coli host factor hexamers. Our results revealed the crucial role of 0.1 M NaCl Hfq system on the bases with strong hydrogen bonding interactions and by stabilizing the aromatic stacking of Tyr42 residue of the adjacent subunits/monomers with the adenine and uridine nucleobases. An increase in RNA pore diameter and weakened compactness of the Hfq-RNA complex was clearly observed in 1.0 M NaCl Hfq system with bound RNA. Aggregation of monomers in Hfq and the interaction of Hfq with RNA are greatly affected due to the presence of high ionic strength. Higher the ionic concentration, weaker is the aggregation and interaction. Our results were compatible with the experimental data and this is the first theoretical report for the experimental study done in 1980 by Uhlenbeck group for the present system.

• The KIPS Transactions:PartD
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• v.15D no.2
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• pp.271-284
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• 2008

Self-healing is an approach to evaluating constraints defined in target system and to applying an appropriate strategy when violating he constrains. Today, the computing environment is very complex, so researches that endow a system with the self-healing's ability that recognizes problem arising in a target system are being an important issues. However, most of the existing researches are that self-healing developers need much effort and time to analyze and model constraints. Thus, this paper proposes an automated approach to determine problem arising in external and internal system environment. The approach proposes: 1) Specifying the target system through the models created in design phase of target system. 2) Automatically creating constraints for external and internal system environment, by using the specified contents. 3) Deriving a dependency model of a component based on the created internal state rule. 4) Translating the constraints and dependency model into code evaluating behaviors of the target system, and determinating problem level. 5) Monitoring an internal and external status of system based on the level of problem determination, and applying self-healing strategy when detecting abnormal state caused in the target system. Through these, we can reduce the efforts of self-healing developers to analyze target system, and heal rapidly not only abnormal behavior of target system regarding external and internal problem, but also failure such as system break down into normal state. To evaluate the proposed approach, through video conference system, we verify an effectiveness of our approach by comparing proposed approach's self-healing activities with those of the existing approach.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.4
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• pp.51-63
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• 2002

This paper presents a hybrid control strategy for seismic protection of a benchmark cable-stayed bridge, which is provided as a testbed structure for the development of strategies for the control of cable-stayed bridges. This benchmark problem considers the cable-stayed bridge that is scheduled for completion in Cape Girardeau, Missouri, USA in 2003. Seismic considerations were strongly considered in the design of this bridge due to the location of the bridge in the New Madrid seismic zone and its critical role as a principal crossing of the Mississippi river. Based on detailed drawings of this cable-stayed bridge, a three-dimensional linearlized evaluation model has been developed to represent the complex behavior of the bridge. A set of eighteen evaluation criteria has been developed to evaluate the capabilities of each control strategy. In this study, a hybrid control system is composed of a passive control system to reduce the earthquake-induced forces in the structure and an active control system to further reduce the bridge responses, especially deck displacements. Conventional base isolation devices such as lead rubber bearings are used for the passive control design and Bouc-Wen model is used to simulate the nonlinear behavior of these devices For the active control design, ideal hydraulic actuators are used and on $H_2$/LQG control algorithm is adopted. Numerical simulation results show that the performance of the proposed hybrid control strategy is quite effective compared to that of the passive control strategy and slightly better than that of the active control strategy. The hybrid control method is also more reliable than the fully active control method due to the passive control part. Therefore, the proposed hybrid control strategy can effectively be used to seismically excited cable-stayed bridges.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.147-156
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• 2023

Because the behavior of cable bridges is dominated by dynamic response and is relatively complex, short- and long-term field monitoring are often required to evaluate the bridge condition. If a permanent SHMS (Structural Health Monitoring System) is not installed, a portable monitoring system is needed for the checking of bridge condition. In this case, it can be difficult to operate the portable monitoring system due to limited conditions such as power and communication according to the location and type of the bridge. In this study, the portable-based smart structural response monitoring system is developed that can be effectively used for short- and long-term monitoring of cable bridges in Korea and Southeast Asia. The developed system is a multi-channel portable data acquisition and analyzer that can be operated for a long time in the field using its own power supply system, and is included with the automated analysis algorithm for the dynamic characteristics of cable bridges using real-time data. In order to evaluate the field applicability of the developed system, field demonstration was conducted on cable bridges in Korea and Vietnam. Through the demonstration, the reliability and efficiency of field operation of the developed system were confirmed, and additionally, the possibility of application to overseas markets was confirmed in cable bridge monitoring field.