• Clean Technology
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• v.2 no.2
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• pp.44-50
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• 1996

"Pollution prevention" is an important and appropriate part of efforts to minimize the environmental impacts of industrial processes, but it is only a part. Even more important is to assess the environmental characteristics of processes across all stages of their lives. This paper presents a formalism for evaluating the environmental implications of processes at each life stage(a procedure termed "life-cycle assessment").

• Korean Journal of Computational Design and Engineering
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• v.18 no.1
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• pp.21-27
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• 2013

Presented in the paper is a log data based modeling method for effective construction of a virtual plant model which can be used for the virtual PLC (Programmable Logic Controller) simulation. For the PLC simulation, the corresponding virtual plant, consisting of virtual devices, is required to interact with the input and output symbols of a PLC. In other words, the behavior of a virtual device should be the same as that of the real device. Conventionally, the DEVS (Discrete Event Systems Specifications) formalism has been used to represent the behavior a virtual device. The modeling using DEVS formalism, however, requires in-depth knowledge in the simulation area, as well as the significant amount of time and efforts. One of the key ideas of the proposed method is to generate a plant model based on the log data obtained from the production system. The proposed method is very intuitive, and it can be used to generate the full behavior model of a virtual device. The proposed approach was applied to an AGV (Automated Guided Vehicle).

• Journal for History of Mathematics
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• v.30 no.4
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• pp.247-258
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• 2017

The goal of this essay is to examine metaphors for mathematics and to discuss philosophical problems related to them. Two metaphors for mathematics are well known. One is a tree and the other is a building. The former was proposed by Pasch, and the latter by Hilbert. The difference between these metaphors comes from different philosophies. Pasch's philosophy is a combination of empiricism and deductivism, and Hilbert's is formalism whose final task is to prove the consistency of mathematics. In this essay, I try to combine two metaphors from the standpoint that 'mathematics is a part of the ecosystem of science', because each of them is not good enough to reflect the holistic mathematics. In order to understand mathematics holistically, I suggest the criteria of the desirable philosophy of mathematics. The criteria consists of three categories: philosophy, history, and practice. According to the criteria, I argue that it is necessary to pay attention to Pasch's philosophy of mathematics as having more explanatory power than Hilbert's, though formalism is the dominant paradigm of modern mathematics. The reason why Pasch's philosophy is more explanatory is that it contains empirical nature. Modern philosophy of mathematics also tends to emphasize the empirical nature, and the synthesis of forms with contents agrees with the ecological analogy for mathematics.

• Journal for History of Mathematics
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• v.23 no.2
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• pp.59-74
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• 2010

Though considering of philosophy of mathematics can be optional to theoretical mathematicians, that of philosophy of mathematics-education is supposed to be indispensible to mathematics-educators. So it is natural for mathematics-educators to ask what kind of philosophy might be more desirable for mathematics-education. In this context, this essay reviews two kinds of major philosophy of mathematics, Platonism and formalism. However it shows that humanism could be more plausible alternative philosophy of mathematicseducation. In the course of entailing such a result it introduces an episode of lecture for Laplace-transformation as a speculative evidence from experience.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.253-258
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• 2002

This paper proposes a methodology for development of protocol models. The methodology attempts to employ two modeling environments in models development, NS2 and DEVSim++, which will interoperate during simulation. NS2 is a widely used network simulator in protocol research, which employs an informal modeling approach. Within the approach time and state information of protocol models are not explicitly described, thus being hard to validate model. On the other hand the DEVS formalism is a mathematical framework for modeling a discrete event system in a hierarchical, modular manner. In DEVS, model's time and state information is described explicitly, By using DEVS formalism, models can easily be validated and errors in the modeling stage can be reduced. However, the DEVS simulator, DEVSim++, supports a small amount of models library which are required to build simulation models of general communication network. Although NS2 employs an informal modeling approach and models validation is difficult, it supports abundant models library validated by experimental users. Thus, combination of DEVS models and NS2 models may be an effective solution for network modeling. Such combination requires interoperation between DEVSim++ simulator and NS2 simulator. This paper develops an environment for such interoperation. Correctness and effectiveness of the implemented interoperation environment have been validated by simulation of UDP and TCP models.

• English Language & Literature Teaching
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• v.16 no.4
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• pp.223-238
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• 2010

This article analyzes and discusses M.M. Bakhtin's dialogics with the perspectives of what it emphasizes and how it makes the Russian Formalism and the Marxist literary theory together in his dialogics. This article considers conversion in the literary texts the central idea of dialogics, and it takes place through satire and parody. As Bakhtin stresses in his works, this article also examines the novel as the dominant genre in the nineteenth and twentieth centuries. Such satire and parody shows the ambivalence of the Russian Formalism and the Marxist literary theory. Bakhtin states that novel per se is very conversing. It has turned over the position that has been occupied by epics (poetry) and play for thousands years, and taken it over in the nineteenth century. Thus, novel is a literary genre in which a variety of conversing struggles occur throughout the texts, which makes it different from epics and play. Throughout such analyses and discussions, this paper considers Bakhtin's dialogics a complex of semantic, pragmatic, and semiotic elements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1435-1443
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• 2009

In this paper, an energy harvesting sensor network system is modeled and simulated by using the DEVS (Discrete Event System Specification) formalism. The system is composed of a sink (master) node, which is battery or mains powered, and a set of sensor (slave) nodes, each of which harvests ambient energy and converts it into electrical energy. For simulation, (i) the behavior of energy harvesting and storing circuits of the slave node is partitioned into a set of piecewise continuous segments and then each segment is represented as a discrete state; (ii) the interaction among the master node and components of the slave node is investigated preciously; and (iii) the investigated result is modeled and simulated by using the DEVS formalism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.5
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• pp.2186-2203
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• 2020

Security administrators of companies and organizations need to come up with proper countermeasures against cyber-attacks considering infrastructures and security policies in their possession. In order to develop and verify such countermeasures, the administrators should be able to reenact both cyber-attacks and defenses. Simulations can be useful for the reenactment by overcoming its limitations including high risk and cost. If the administrators are able to design various scenarios of cyber-attacks and to develop simulation models from their viewpoints, they can simulate desired situations and observe the results more easily. It is challenging to simulate cyber-security issues, because there is lack of theoretical basis for modeling a wide range of the security field as well as pre-defined basic components used to model cyber-attacks. In this paper, we propose a modeling method for cyber-security simulations by developing a basic component and a composite model, called Abstracted Cyber-Security Unit Model (ACSUM) and Abstracted Cyber-security SIMulation model (ACSIM), respectively. The proposed models are based on DEVS(Discrete Event systems Specification) formalism, a modeling theory for discrete event simulations. We develop attack scenarios by sequencing attack behaviors using ACSUMs and then model ACSIMs by combining and abstracting the ACSUMs from a security perspective. The concepts of ACSUM and ACSIM enable the security administrators to simulate numerous cyber-security issues from their viewpoints. As a case study, we model a worm scenario using ACSUM and simulate three types of simulation models based on ACSIM from a different security perspective.

• Journal of architectural history
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• v.16 no.4
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• pp.57-75
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• 2007

Bulguk Temple, one of the national temples, sublimated the high formalism and symbolism into lovely art, and thus be called the pinnacle of Korean architecture. Of many characteristic structures of Bulguk Temple, the stone stereobate and stairs have a great importance in that we can read out the purpose of the architect through their relics. Especially, the stone stairs are noteworthy for they structuralize the intentional space division. The objects of this observation are Yeonwhagyo and Chilbogyo bridges at the entrance of Keungnakjeon precinct, and Cheongwoongyo and Baekwoongyo stairs at the entrance of Daewoongjun precinct. All these relics are the structures that divide the precinct areas on the basis of Buddhist theory and have strong symbolic meanings as well. Although the diverse studies have made on the structures, there are many insufficient aspects for the manifestation of the meanings. In this study, I considered the Buddhist dogmatic meanings of the structures in the formalistic view of the Buddhist architecture. The study was proceeded in the way that the establishments of former studies were fully reflected in it. Through the study, I could confirm that the objects of consideration have the double formalistic meanings and they are strongly structuralizing the symbolism.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.3 s.258
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• pp.365-372
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• 2007

Revisited in this paper are Green's functions for unit concentrated forces in an infinite orthotropic Kirchhoff plate. Instead of obtaining Green's functions expressed in explicit forms in terms of Barnett-Lothe tensors and their associated tensors in cylindrical or dual coordinates systems, presented here are Green's functions expressed in two quasi-harmonic functions in a Cartesian coordinates system. These functions could be applied to thin plate problems regardless of whether the plate is homogeneous or inhomogeneous in the thickness direction. With a composite variable defined as $z=x_1+ipx_2$ which is adopted under the necessity of expressing the Green's functions in terms of two quasi-harmonic functions in a Cartesian coordinates system Stroh-like formalism for orthotropic Kirchhoffplates is evolved. Using some identities of logarithmic and arctangent functions given in this paper, the Green's functions are presented in terms of two quasi-harmonic functions. These forms of Green's functions are favorable to obtain the Newtonian potentials associated with defect problems. Thus, the defects in the orthotropic plate may be easily analyzed by way of the Green's function method.