• Journal of the Korean BIBLIA Society for library and Information Science
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• v.26 no.4
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• pp.105-121
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• 2015

PDA model is new collection development method not only corresponding user's demand, but also expensing acquisition budget effectively. In the PDA model, when the trigger that indicates user's demand reaches up to treshold, e-book is automatically purchased without librarian's interrogation. This study examines concept, basic principles, and current condition of operation about PDA and finds a way that could applicate to Korean university library foreign E-book consortium. Current model of university library e-book acquisition pursuit reduction of budget and utility value, but the selected collection is not based on user's demand. Therefore, it could be considerable to apply PDA or evidence based purchase model to foreign e-book acquisition consortium.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.497-500
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• 2002

When one is interested in the dynamics of a mechanical system with electric motors, the force generated by the motor is generally considered as only an applied torque or force independent of mechanical state variables such as velocity. For a system operated in non-steady dynamic conditions, however, the usual analysis approach may fail to predict some characteristics in the dynamic behaviors because of electromechanical coupling effects. In this paper, we propose dynamics analysis model in which dc motor dynamics with the electromechanical coupling effects are embedded to mechanical dynamics models. The do motor is modeled based on its equivalent circuit model and included in the dynamics solving algorithm which we developed before, called generalized recursive dynamics formula. The developed dynamic analysis model is effective and realistic for analysis of electromechanical dynamics of a system with do motors. The developed model is evaluated by constructing and simulating the flexible antennas of an artificial satellite driven by do motors.

• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.8-16
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• 2005

In an effort to encourage the development of value added engineered applications for small diameter round timber, research is being conducted to develop and verify design guidelines for connections with specific application to round timbers. The objective of this research is to provide potential users with a number of viable connection options applicable in the fabrication of engineered, round wood structural components and systems. Target uses include trusses, built up flange beams and space frames. This paper presents information on a mortised steel plate connection fabricated using powder driven nails in 6 cm diameter Japanese Larch. The design load for PDN connections are around 1.3 kN per nail with strip and 0.8 kN per nail without stripe. The design model for PDN connectors could be chosen by the number of nails. If the number of nails are more than the critical number between nail bearing and wood failure, the wood failure model could be the way to design the structure safely. The wood failure model needs to be studied more but the model could be the tensile and cleavage mixed failure model.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.1-6
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• 2005

The purpose of this paper is to propose a novel modeling approach called Services Ecosystem that applies the concept of ecosystems in ecology to Service-Oriented Software Development and Integration. For this purpose, an ecological system for software systems is proposed for the emerging Service-Oriented Computing paradigm, describing how participants interact with each other within their environments. Three emerging concepts, Service-Oriented Programming, Software Factories, and Service Grid, are employed to explain biotic and abiotic environments. Based upon the Services Ecosystem model, we demonstrate Services Ecosystem Model transformations by using a case example. The Services Ecosystem model is a novel approach for envisioning the Service-Oriented Computing paradigm in terms of an ecosystem in which the roles/perspectives of each participant and their relationships/interactions to environments are clearly described with a holistic view.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.496-500
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• 2015

International construction projects are inherently more risky than domestic projects with multi-dimensional uncertainties that require complementary risk management at both the country and project levels. However, despite a growing need for systematic country evaluations, most studies have focused on project-level decisions and lack country-based approaches for firms in the construction industry. Accordingly, this study suggests data-driven approaches for evaluating countries using two quantitative models. The first is a two-stage country segmentation model that not only screens negative countries based on country attractiveness (macro-segmentation) but also identifies promising countries based on the level of past project performance in a given country (micro-segmentation). The second is a multi-criteria country segmentation model that combines a firm's business objective with the country evaluation process based on Kraljic's matrix and fuzzy preference relations (FPR). These models utilize not only secondary data from internationally reputable institutions but also performance data on Korean firms from 1990 to 2014 to evaluate 29 countries. The proposed approaches enable firms to enhance their decision-making capacity for evaluating and selecting countries at the early stage of corporate strategy development.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.4
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• pp.375-382
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• 1987

Accurate solar radiation data are fundamental to the design of HVAC systems and solar driven devices. Unfortunately, the total radiation data on a horizontal surface has been only reported by meteorological office. Consequently, there is interest in development of model to estimate the solar radiation data. Based on the statistically estimated TAC data which were obtained from measured hourly values collected over a period of ten years at Seoul, the solar radiation model was determined. Atmospheric transmittance for this model was presented in the form of polynominal.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.4
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• pp.195-204
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• 2013

The embedded software has been developed in the forms of various versions that provides similar service based on product family. For increase usefulness of product family, software must has well-structured and reusable properties. Software architecture is important to improve adaptability in model-based development of embedded software mounted onto product family. In this paper, we proposed a technique of ADD(Attribute-Driven Design)-based software architecture design for low power software development. This technique provides a chance to consider the power consumption issue in design phase of software, and makes possible to develop low power embedded software.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.421-428
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• 2014

For the analysis of water supply network, demand-driven and pressure-driven analysis methods have been proposed. Of the two methods, demand-driven analysis (DDA) can only be used in a normal operation condition to evaluate hydraulic status of a pipe network. Under abnormal conditions, i.e., unexpected pipe destruction, or abnormal low pressure conditions, pressure-driven analysis (PDA) method should be used to estimate the suppliable flowrate at each node in a network. In order to carry out the pressure-driven analysis, head-outflow relationship (HOR), which estimates flowrate at a certain pressure at each node, should be first determined. Most previous studies empirically suggested that each node possesses its own characteristic head-outflow relationship, which, therefore, requires verification by using actual field data for proper application in PDA modeling. In this study, a model pipe network was constructed, and various operation scenarios of normal and abnormal conditions, which cannot be realized in real pipe networks, were established. Using the model network, data on pressure and flowrate at each node were obtained at each operation condition. Using the data obtained, previously proposed HOR equations were evaluated. In addition, head-outflow relationship at each node was analyzed especially under multiple pipe destruction events. By analyzing the experimental data obtained from the model network, it was found that flowrate reduction corresponding to a certain pressure drop (by pipe destruction at one or multiple points on the network) followed intrinsic head-outflow relationship of each node. By comparing the experimentally obtained head-outflow relationship with various HOR equations proposed by previous studies, the one proposed by Wagner et al. showed the best agreement with the exponential parameter, m of 3.0.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.1079-1080
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• 2005

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.517-527
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• 2021

While the two principles of lean manufacturing and time-driven activity-based costing (TDABC) have been established out of multiple incentives and do not follow the same particular targets, there is substantial commonality between them. In these conditions, the supply management of a multi-product system needs a rigorous production model to minimize costs. In this sense, this paper proposes an interactive model with the consideration of optimizing product-mix decisions using both lean development tools and TDABC. This paper proposes a qualitative approach using the case study of the Iraqi state company for battery production. The suggested model decreased manufacturing time and costs, along with some substantial reduction in idle production capacity by 26 percent in 2019, based on the findings of the case study. On the other hand, the proposed model gives two side advantages: an efficient division of costs on goods due to the use of time spent as a cost factor for products and cost savings due to the introduction of the lean manufacturing approach that reduces all additional costs and increases product-mix decisions. Furthermore, the analytical data gathered here suggests that the incorporation of lean management concepts and TDABC has a strong and important influence on product-mix decisions.