• Earthquakes and Structures
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• v.8 no.5
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• pp.1091-1111
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• 2015

Base isolation is an effective method for protecting structures against earthquake hazard. It elongates the period of vibration and introduces supplemental damping to the structural system. The stiffness, damping and displacement are coupled forcing the code seismic design procedure to be unnecessarily complicated. In addition, the force reduction factor -a key parameter in the design procedurehas not been well addressed by seismic design codes at the high levels of damping due to the pronounced difference between pseudo and actual accelerations. In this study, a comparison has been conducted to evaluate eight different methods, in the literature, for calculating the force reduction factor due to damping. Accordingly, a simplified seismic analysis procedure has been proposed based on the well documented N2 method. Comprehensive analysis has been performed for base-isolated structure models for direct application and verification of the proposed procedure. The results have been compared with those of the European code EC8, the nonlinear time history analysis and investigations in the literature, where good agreement has been reported. In addition, a discussion has been elaborated for the resulted response of the base-isolated structure models with respect to the dynamic characteristics of the base isolation system.

• Health Policy and Management
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• v.2 no.1
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• pp.66-79
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• 1992

The code of the International Classification of Disease(ICD) is seriously questioned on its effectiveness in identifing an independent disease entity from similar conditions at general practitioner's offices. This study has attempted to show individual coding variations in ICD for similar ambulatory care conditions. It has been assumed that a following outpatient visit is regarded as the sane kind of visit owing to the same disease if a visit to the different source of care would be mad within an interval of less than two days. The 'D' health insurance association was selected for this analysis. The 'D' association had 153,298 members and made claims of 642,605 outpatient care in 1990. Out of the total outpatient claims, 8.6%(55,102 claims) were counted as the same disease which could meet the above assumption. Percent of conditions classified as the 10 leading causes of frequent visits which were matched accurately to the subsequent ICD diagnostic code found to be 15.8% on the average. The URI was noted for the highest concurrence rate of 20.4%. This proportion was even decreased to 11.6% on the case of chronic disease. Despite the fact that the assumption underlying the definition of the above same disease is rather rough and inappropriate, this study reveals that the code of ICD currently in use has weaknesses in seperating a certain independent disease from similar conditions at the outpatient setting. Thus, efforts need to be elaborated to meet the need of a new system of classification for conditions and diseases encountering at ambulatory care.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.3
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• pp.27-33
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• 2001

The aim of the present work is to propose a model for Computer Aided programming of numerical Control lathe. This model is based on the concept by features. It has been developed in an Artificial Intelligence environment, that offers a rapidity as well as a precision for NC code elaboration. In this study a pre-processor has been elaborated to study the geometry of turning workpiece. This pre-processor is a hybrid system which combine a module of design by features and a module of features recognition for a piece provided from an other CAD software. Then, we have conceived a processor that is the heart of the CAD/CAM software. The main functions are to study the fixture of the workpiece, to choose automatically manufacturing cycles, to choose automatically cutting tools (the most relevant), to simulate tool path of manufacturing and calculate cutting conditions, end to elaborate a typical manufacturing process. Finally, the system generates the NC program from information delivered by the processor.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.846-854
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• 1996

In this paper, we propose a solution to the software maintenance problem that is a primary factor of software crisis. We surveyed and analyzed the current software maintenance problems through questionnaires and interviews. As a result, we defined the software maintenance management life cycle and established a fundamental strategies to solve the software maintenance problems efficiently. We also designed a software maintenance management support systems to construct an automated software maintenance management tool. Furthermore, tp improve the formalization and reliability of the software maintenance management procedure, we defined acost predictive model using a fixed-single parameter based on comprehensive program size for the source code and delivered effort(person/month). We elaborated the model by considering an experience level of maintainer, a skill- level defined by the manager, and a reliability level required by the model of maintenance management.

• Steel and Composite Structures
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• v.45 no.4
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• pp.513-533
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• 2022

This study presents similarities and differences between Turkish Building Code for Steel Structures, which are TS 648 and SDCCSS (Specification for Design, Calculation and Construction of Steel Structures) in terms of the design of the members. Hot-rolled I-shaped steel sections for symmetrical and U-shaped steel sections (i.e., channels) for monosymmetric sections were elaborated in detail. The design strength of tension members under tensile load, compression members under axial load and flexural members under flexure and shear were examined separately. Connection details for tension members, slenderness for compression members and distance between lateral supports for flexural members were considered as prime variables. Analysis results revealed the design strength of the tension members where at least one of the cross-sectional parts is not connected to the connection plates, I-shaped compression members where a slenderness ratio is below 39 (𝛌<39), U-shaped compression members and flexural members where L_b is between L_p and L_r (L_pb≤L_r) designed based on TS 648 are greater than those designed based on SDCCSS 2018. Strength differences between the specification can reach 79% for tensile members, 13% for compression members and 9% for flexural members.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.133-140
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• 2023

The origin of texts we refer to as literary or artistic may be imagination, but many are based on experiences. In fact, experiences can be the source of artistic imagination since imagination often builds upon experiences. Therefore, the act of verbalizing human experiences using them as raw material can become a great form of art. Transforming past experiences into stories and infusing them with vitality inevitably requires a creative process of reconstruction, which is essentially a literary process. As such, 'Personal Narrative' holds significance as a literary process that weaves facts into stories and shapes them into forms. Individual experiences are stored as personal memories, and these 'personal memories' continuously generate stories. Collections of individual stories are stored as multiple memories, which gradually form 'collective memories' with distinct social and cultural inclinations through the passage of time and invisible yet potent societal and cultural censorship. The problem lies in the fact that individuals may tend to align their own memories with the inclinations of collective memory rather than simply recalling what they personally experienced. In the context of actual history, personal memories and collective memories communicate with each other, producing non-fictional content close to reality and sometimes manifesting as fiction content enriched with imagination. 'Personal Narrative' holds a significant genre as one genre of non-fiction content within our culture.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.5
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• pp.197-209
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• 2020

Evidence of liquefaction during the 2017 Pohang earthquake has highlighted the urgent need to evaluate the current seismic design standard for liquefaction in Korea, particularly the liquefaction triggering standard. With the simplified method, which is the most popular method for evaluating liquefaction triggering, the factor of safety for liquefaction triggering is calculated via the cyclic stress ratio (CSR) and the cyclic resistance ratio (CRR). The parameters in the CSR and CRR have undergone changes over time based on new research findings and lessons learned from liquefaction case-histories. Hence, the current design standard for liquefaction triggering evaluation in Korea should also reflect these changes to achieve seismic safety during future earthquakes. In this study, liquefaction susceptibility criteria were discussed initially and this was followed by a review of the current liquefaction triggering codes/guidelines in other countries and Korea. Next, the parameters associated with the CSR such as the maximum ground acceleration, stress reduction factor, magnitude scaling factor, and overburden correction factor were discussed in detail. Then, the evaluation of the CRR using the SPT N-value and CPT qc-value was elaborated along with overburden and clean-sand correction factors. Based on this review of liquefaction triggering evaluation standards, recommendations are made for improving the current seismic design standard related to liquefaction triggering in Korea.

• Geomechanics and Engineering
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• v.17 no.1
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• pp.31-45
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• 2019

In this study the spatial variability of soils is substantiated physically and numerically by using random field theory. Heterogeneous samples are fabricated by combining nine homogeneous soil clusters that are assumed to be elements of an adopted random field. Homogeneous soils are prepared by mixing different percentages of kaolin and bentonite at water contents equivalent to their respective liquid limits. Comprehensive characteristic laboratory tests were carried out before embarking on direct shear experiments to deduce the basic correlations and properties of nine homogeneous soil clusters that serve to reconstitute the heterogeneous samples. The tests consist of Atterberg limits, and Oedometric and unconfined compression tests. The undrained shear strength of nine soil clusters were measured by the unconfined compression test data, and then correlations were made between the water content and the strength and stiffness of soil samples with different consistency limits. The direct shear strength of heterogeneous samples of different stochastic properties was then evaluated by physical and numerical modelling using FISH code programming in finite difference software of $FLAC^{3D}$. The results of the experimental and stochastic numerical analyses were then compared. The deviation of numerical simulations from direct shear load-displacement profiles taken from different sources were discussed, potential sources of error was introduced and elaborated. This study was primarily to explain the mathematical and physical procedures of sample preparation in stochastic soil mechanics. It can be extended to different problems and applications in geotechnical engineering discipline to take in to account the variability of strength and deformation parameters.