• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.21-31
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• 2013

It is not easy to control the unstructured digital contents efficiently which are usually created while carrying out the wide scope of managerial activities. Moreover, besides the existing EDMS method, new methodologies including new-type servers and clients like SBC, VDI, thin client, zero client, etc are said to be more efficient for managing digital contents. Usually, digital contents has been created and stored in the dispersed individual computers like laptop or desktop. Today, due to the advent of new technologies and devices for computer systems and network capacity, it's possible to store whole digital contents within centralized storage like EDMS. In this paper, it is shown how digital contents can be controled through selection of which approaches are used for individual users and storage servers. For alternatives, we explained implementation, merits and demerits, selection criteria, etc. And a case of the implementation of digital contents control is shown for the reference of related systems.

• Progress in Medical Physics
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• v.17 no.2
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• pp.96-104
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• 2006

Experiments from several groups Including ours have demonstrated that $Ca^{2+}$ can enhance the inactivation of N-type calcium channels. However, it is not clear if this effect can be ascribed to a 'classic' $Ca^{2+}$-dependent inactivation (CDI) mechanism. One method that has been used to demonstrate CDI of L-type calcium channels is to alter the intracellular and extracellular concentration of $Ca^{2+}$. In this paper we replaced the external divalent cation to monovalent ion ($MA^+$) to test CDI. In the previous paper, we could separate fast (${\tau}{\sim}150ms$) and slow (${\tau}{\sim}2,500ms$) components of inactivation in both $Ba^{2+}$ and $Ca^{2+}$ using 5-sec voltage step. Lowering the external divalent cation concentration to zero abolished fast inactivation with relatively little effect on slow inactivation. Slow inactivation ${\tau}$ correspond very well with provided the $MA^+$ data is shifted 10 mV hyperpolarized and slow inactivation ${\tau}$ decreases with depolarization voltage in both $MA^+\;and\;Ba^{2+}$, which consistent with a classical voltage dependent inactivation (VDI) mechanism. These results combined with those of our previous paper lead us to hypothesize that external divalent cations are required to produce fast N-channel inactivation and this divalent cation-dependent inactivation is a different mechanism from classic CDI or VDI.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.903-915
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• 2011

Recently, anaerobic methane production of agricultural waste biomass has received increasing attention. Until now domestic BMP (Biochemical methane potential) studies concerned with agricultural waste biomass have concentrated on the several waste biomass such as livestock manure, food waste, and sewage sludge from WWTP (Waste water treatment plant). Especially, the lack of standardization study of BMP assay method has caused the confused comprehension and interpretation in the comparison of BMP results from various researchers. Germany and USA had established the standard methods, VDI 4630 and ASTM E2170-01, for the analysis of BMP and anaerobic organic degradation, respectively. In this review, BMP was defined in the aspect of organic material represented as COD (Chemical oxygen demand) and VS (Volatile solid), and the influence of several parameters on the methane potential of the feedstock was presented. In the investigation of domestic BMP case studies, BMP results of 18 biomass species generating from agriculture and agro-industry were presented. And BMP results of crop species reported from foreign case studies were presented according to the classification system of crops such as food crop, vegetables, oil seed and specialty crop, orchards, and fodder and energy crop. This review emphasizes the urgent need for characterizing the innumerable kind of biomass by their capability on methane production.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.5
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• pp.279-286
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• 2021

In this study, we investigated the behavior characteristics of the L-type flange bolt connection, which is used to connect upper and lower flanges having L-type ring sections, by bolts. This connection is mainly used in domestic wind turbine structures, wherein it is a vital component as any imperfection could cause the collapse of the entire structural system. Therefore, understanding the behavior characteristics of the L-type flange bolt connection is imperative. In this study, the connection's response to external force was simulated using finite element (FE) analysis and the FE model was idealized to behave as a single L-type bolt flange. The variation in the bolt tension and the L-type flange stress were analyzed to understand the behavior characteristics of the connection. Moreover, the bolt-load function models proposed by Petersen, Schmidt/Neuper and VDI 2230, theoretically expressing a relation between bolt tension and external force, were compared to evaluate the suitability of the FE analysis and analyze the significant behavior characteristics of the connection. Furthermore, the changes in the bolt-load curve due to the variations in the partial dimensions of the L-type flange bolt connection were analyzed.

• Journal of Welding and Joining
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• v.32 no.6
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• pp.22-28
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• 2014

Most publications on friction stir welding describe phenomena or results with given process parameters like feed rate, rotation speed, angle and depth of penetration. But without a complete documentation of tool design, the results under the same process parameters are completely different. For this purpose, the Institute of Cutting and Joining Manufacturing Processes (tff), University of Kassel investigated the influence of tool roughness on the friction stir welding process. Therefore a defined surface finish was produced by turning and die sinking. As basis of comparison the constant parameters were rotation speed, feed rate, tilt angle and a heel plunge depth. Sound butt-welds were produced in aluminium alloy 6082 (AlMgSi1) with 1.5 mm sheet thickness with a turned reference tool with a surface of $Ra=0.575{\mu}m$ in position controlled mode. The surfaces are manufactured from a very fine to a very rough structure, classified by the VDI-classes with differences in the arithmetical mean roughness. It can be demonstrated with the help of temperature measures, that less heat is generated at the surfaces of the shoulder and the pin by the higher roughness due to lower active friction contact surface. This can also be seen in the resulting wormhole defects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.482-488
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• 2012

Desktop is offered to each individual in Educational environments of school or academy, as the users are increasing, the more Desktop is required for each person. Huge Desktop accession resulted in many problems including difficulty of management, Software and Hardware cost rising, cramped places, power consumption increasing and etc. To solve those problems, we focus into uprising technology solution, such as Multi Computer, Desktop Virtualization, and DaaS(Desktop as a Service). In this paper, existing problems that can dramatically improve the private cloud computing for desktop virtualization with the requirements of the system were analyzed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1871-1890
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• 2021

The transition toward a contactless society has been rapidly progressing owing to the recent COVID-19 pandemic. As a result, the IT environment of organizations and enterprises is changing rapidly; in particular, data security is expanding to the private sector. To adapt to these changes, organizations and companies have started to securely transfer confidential data to residential PCs and personally owned devices of employees working from home or from other locations. Therefore, organizations and companies are introducing streaming data services, such as the virtual desktop infrastructure (VDI) or cloud services, to securely connect internal and external networks. These methods have the advantage of providing data without the need to download to a third terminal; however, while the data are being streamed, attacks such as screen shooting or capturing are performed. Therefore, there is an increasing interest in prevention techniques against screen capture threats that may occur in a contactless environment. In this study, we analyze possible screen capture methods in a PC and a mobile phone environment and present techniques that can protect the screens against specific attack methods. The detection and defense for screen capture of PC applications on Windows OS and Mac OS could be solved with a single agent using our proposed techniques. Screen capture of mobile devices can be prevented by applying our proposed techniques on Android and iOS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.747-749
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• 2017

To protect financial services against danger of financial accidents and customer information leakage caused by malware, injection attack and so on, Financial Services Commission announced "Financial Networks Security Enhancement Comprehensive Plan", which suggests the guideline of protecting customer information and providing secure financial services by separating network topology and then makes the financial company use network partitioning system. In consequence of this policy, financial companies respectively chose between the physical partitioning mechanism or the logical partitioning mechanism according to their IT environment. This paper suggests an efficient infrastructure configuration plan for making the logical network partition, by comparison of a construction of traditional general equipment and an integrated HCI(Hyper Converged Infrastructure) through 'Hyper Converged' which is one of virualization techniques for developing currently, and the case study of the integrated HCI method.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.384-401
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• 2016

The vegetation assessment indicator has been developed recently as a biological part of the integrated assessment system for river environment to improve the efficiency of river restoration projects. This study carried out to test the vegetation assessment indicator and to reset its grade criteria on experimental streams. We classified and mapped vegetation communities at the level of physiognomic-floristic composition by each assessment unit. A total of 204 sampling quadrats were set up on the 68 assessment units at 5 experimental streams. By analyzing the vegetation data collected, we examined the appropriate numbers of sampling quadrats, the criteria of vegetation index score, classification of vegetation community, and grade criteria for vegetation assessment. The developed vegetation assessment indicator composed with the vegetation complexity index (VCI), the vegetation diversity index (VDI), and the vegetation naturalness index (VNI) was proved to reflect the current conditions of the streams sufficiently. The contribution of vegetation naturalness index to grading by vegetation assessment indicator was larger, but three indexes were closely correlated to each other. Also there was more clearer discrimination of grading with the application of adjusted criteria of vegetation assessment indicator and the standardized classification of vegetation community, but the stream segment type did not influence the vegetation assessment grade significantly.

• KIISE Transactions on Computing Practices
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• v.21 no.7
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• pp.506-511
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• 2015

IOV is a technology that supports one or more virtual desktops, and can share a single physical device. In general, the virtual desktop uses the virtual IO devices which are provided by virtualization SW, using SW emulation technology. Virtual desktops that use the IO devices based on SW emulation have a problem in which service quality and performance are declining. Also, they cannot support the high-end application operations such as 3D-based CAD and game applications. In this paper, we propose a physical network separation system using Virtual Desktop Service based on HW direct assignments to overcome these problems. The proposed system provides independent desktops that are used to access the intranet or internet using server virtualization technology in a physical desktop computer for the user. In addition, this system can also support a network separation without network performance degradation caused by inspection of the network packet for logical network separations and additional installations of the desktop for physical network separations.