• Convergence Security Journal
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• v.10 no.1
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• pp.9-17
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• 2010

Internet network routing system is used to prevent spread and distribution of malicious data traffic. The penetration of malicious code and the function of security blocking are performed on the same course of traffic pathway. The security architecture is the concept to distinguish the architecture from the group handling with the traffic on the structure of network which is performed with the function of penetration and security. The security architecture could be different from the criterion of its realm and function, which requires the development and the application of security mechanism for every architecture. For the establishment of security architecture it is needed to show what criterion of net work should be set up. This study is based on analysis of diagnostic weakness structure in the network security architecture and research the criterion for topology factor, security architecture structure map selection, and blocking location and disinfection net. It is shown to increase the effective rate blocking the virus with the proposed method in this paper rather than the traditional network architecture.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.8
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• pp.1015-1028
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• 2013

This study analyzed the relationship among swimming experiences, swimsuit selection criteria, swimsuit purchase satisfaction level, and the physical self-concept of female consumers. This study was based on a descriptive survey method using a questionnaire. The survey was conducted from June 15 through July 20, 2012, and the sample consisted of 330 female consumers in their 20s and 30s residing in the Seoul and Gyeonggi area. Factor analysis and Cronbach's ${\alpha}$ coefficients, ANOVA, Duncan's Test, and multiple regression analysis were employed for the data analysis. The results revealed that individual self-concepts on health, sports competence, and fitness were influenced by swimming experiences. There was a tendency for those with a longer period of swimming experience to have a higher level of brand consideration as a swimsuit selection criterion; in addition, they showed a higher satisfaction level with swimsuits. Individual physical self-concept influenced the consideration given to each swimsuit selection criterion as well as swimsuit purchase satisfaction level. The findings of the study reflect the possibility of utilizing swimming experiences as a criterion for swimsuit market segmentation. Attention to the quality of swimsuits as well as to the physical self-concept of consumers are required for marketing activities.

• Structural Engineering and Mechanics
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• v.32 no.5
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• pp.609-620
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• 2009

In this paper the results of a series of experimental tests upon three-point bending specimens made of polystyrene and containing re-entrant corners are firstly described. Tests involved different notch angles, different notch depths and finally different sizes of the samples. All the specimens broke at the defect, as expected because of the material brittleness and, hence, the generalized stress intensity factor was expected to be the governing failure parameter. Recorded failure loads are then compared with the predictions provided by a fracture criterion recently introduced in the framework of Finite Fracture Mechanics: fracture is assumed to propagate by finite steps, whose length is determined by the contemporaneous fulfilment of energy balance and stress requirements. This fracture criterion allows us to achieve the expression of the generalized fracture toughness as a function of the tensile strength, the fracture toughness and the notch opening angle. Comparison between theoretical predictions and experimental data turns out to be more than satisfactory.

• Journal of Korean Clinical Nursing Research
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• v.20 no.3
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• pp.372-383
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• 2014

Purpose: The purpose was to determine the content validity of a semantic revision of items on a reliable and valid instrument, the Sieloff-King Assessment of Group Outcome Attainment (Power) within Organizations in Korea (K-SKAGOAO). Methods: The target population for research was chief nurse officers (CNOs) of all hospital within Korea. A sample of 303 hospitals from across the Korea was selected through a stratified random sampling process. A total of 174 CNOs comprised the final sample. Psychometric evaluation of the K-SKAGOAO included: (a) criterion-related validity (b) factor analysis and (c) internal consistency reliability using Cronbach's alpha coefficients. Results: The Convergent validity and criterion-related validity were supported. Cronbach's alpha coefficient for the K-SKAGOAO was .95. Subscale alphas ranged from .60 to .86. Conclusion: The K-SKAGOAO and related subscales show validity and internal reliability. A nursing group of any size can use the K-SKAGOAO to both assess the group's level of outcome attainment and develop strategies to further improve that level.

• Geomechanics and Engineering
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• v.9 no.4
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• pp.513-530
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• 2015

Commonly, the base stability of sheeted excavation pits against seepage failure by heave is evaluated by using two-dimensional groundwater flow models and Terzaghi's failure criterion. The objective of the present study is to investigate the effect of three-dimensional groundwater flow on the heave for sheeted excavation pits with various dimensions. For this purpose, the steady-state groundwater flow analyses are performed by using the finite element program ABAQUS 6.12. It has been shown that, in homogeneous soils depending on the ratio of half of excavation width to embedment depth b/D, the ratio of safety factor obtained from 3D analyses to that obtained from 2D analyses $FS_{(3D)}/FS_{(2D)}$ can reach up to 1.56 and 1.34 for square and circular shaped excavations, respectively. As failure body, both an infinitesimal soil column adjacent to the wall (Baumgart & Davidenkoff's criterion) and a three-dimensional failure body with the width suggested by Terzaghi for two-dimensional cases are used. It has been shown that the ratio of $FS_{(Terzaghi)}/FS_{(Davidenkoff)}$ varies between 0.75 and 0.94 depending on the ratio of b/D. Additionally, the effects of model size, the shape of excavation pit and anisotropic permeability on the heave are studied. Finally, the problem is investigated for excavation pits in stratified soils, and important points are emphasized.

• Computers and Concrete
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• v.20 no.3
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• pp.329-338
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• 2017

A new simple and practical strut-and-tie model (STM) for predicting the shear strength of RC pile caps is proposed in this paper. Two approaches are adopted to take into account the concrete softening effect. In the first approach, a concrete efficiency factor based on compression field theory is employed to determine the effective strength of a concrete strut, assumed to control the shear strength of the whole member. The second adopted Kupfer and Gerstle's biaxial failure criterion of concrete to derive the simple nominal shear strength of pile caps containing the interaction between strut and tie capacity. The validation of these two methods is investigated using 110 RC pile cap test results and other STMs available in the literature. It was found that the failure criterion approach appears to provide more accurate and consistent predictions, and hence is chosen to be the proposed STM. Finally, the predictions of the proposed STM are also compared with those obtained by using seven other STMs from codes of practice and the literature, and were found to give better accuracy and consistency.

• Geomechanics and Engineering
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• v.16 no.1
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• pp.35-47
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• 2018

This paper investigates the mechanisms of tunnel spalling and massive tunnel failures using fracture mechanics principles. The study starts with examining the fracture propagation due to tensile and shear failure mechanisms. It was found that, fundamentally, in rock masses with high compressive stresses, tensile fracture propagation is often a stable process which leads to a gradual failure. Shear fracture propagation tends to be an unstable process. Several real case observations of spalling failures and massive shear failures in boreholes, tunnels and underground roadways are shown in the paper. A number of numerical models were used to investigate the fracture mechanisms and extents in the roof/wall of a deep tunnel and in an underground coal mine roadway. The modelling was done using a unique fracture mechanics code FRACOD which simulates explicitly the fracture initiation and propagation process. The study has demonstrated that both tensile and shear fracturing may occur in the vicinity of an underground opening. Shallow spalling in the tunnel wall is believed to be caused by tensile fracturing from extensional strain although no tensile stress exists there. Massive large scale failure however is most likely to be caused by shear fracturing under high compressive stresses. The observation that tunnel spalling often starts when the hoop stress reaches $0.4^*UCS$ has been explained in this paper by using the extension strain criterion. At this uniaxial compressive stress level, the lateral extensional strain is equivalent to the critical strain under uniaxial tension. Scale effect on UCS commonly believed by many is unlikely the dominant factor in this phenomenon.

• KIEE International Transactions on Power Engineering
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• v.3A no.1
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• pp.35-41
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• 2003

To ensure resource adequacy in restructured electricity markets, policymakers have adopted installed capacity (ICAP) markets in some regions of the United States. These markets ensure that adequate generation exists to satisfy regional Loss of Load Probability(LOLP) criterion. Since the incentives created through ICAP mechanisms directly impact new generation and transmission investment decisions we examine one important factor that links ICAP markets with LOLP calculations;, determining the amount of ICAP credit assigned to particular generation units. First, we review and critique the literature on electric power systems' market failure resulting from demand exceeding supply. We then summarize the method of computing (the LOLP) as a means of assessing reliability and relate this method to ICAP markets. We find that only the expected value of available generation is used In current ICAP markets while ignoring the second and higher order moments, which tends to mis-state the ICAP value of a specific resource. We then consider a proposal whose purpose is to avoid this ICAP assignment issue by switching from ICAP obligations to options. We find that such a proposal may fail to not provide the benefits claimed and suffers from several practical difficulties. Finally, we conclude with some policy recommendations and areas for future research.

• Water for future
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• v.26 no.1
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• pp.51-62
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• 1993

The most significant factor in estimating annual runoff must be the precipitation. But in the previous study, the watershed area instead of precitation was included as an independent variable in regression model in the process of checking accurate data. The criterion of accurate data was the runoff ratio in the range of 20% to 100%. In this study the valid range of evapotranspiration was adopted as a criterion of accurate data and the same data were reexamined. It came up with following model which has a high coefficient of determination and conforms to hydrologic theory. R=-518.25+0.8834P where, R: runoff depth(mm) P: precipitation(mm) This regression model was found to be stable by cross-validation and is proposed as annual runoff estimation model applicable to ungaged small and medium watersheds in Korea.

• Journal of Hydrogen and New Energy
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• v.20 no.1
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• pp.79-85
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• 2009

In this paper, we investigated impact factors by brainstorming and survey research and calculated the weights of them using the Analytic Hierarchy Process(AHP) method in order to evaluate alternatives for supplying Liquefied Natural Gas(LNG). AHP is a useful method for evaluating multi-criteria decision making problems. We selected 3 criteria and 9 sub-criteria. According to the result in this study, the most important sub-criterion is the Government's Policy, and the second is the Province's Policy. The other side, the lowest important sub-criterion is the Investment Cost. This study may provide basic data to select the optimal alternative for supplying LNG.