• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.157-164
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• 2005

The function of image in visual communication is increasing by development of information. It pursuits not only direct and concrete reappearance of information but also infinite possibility of image expression by image. It is also course of future image communication. Therefore, in this paper, if the images which pour out of rapid present society are communication means, it is formed to a point of view that improvement in function of communication will be performed excellently to interaction among consumers by recognizing meaning action process of methods of visual sign about user information processing which perceive Image of visual information.

• 전기의세계
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• v.26 no.2
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• pp.99-103
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• 1977

The object of this work is to study an optimal design problem of the proportional load-frequency controller for the single-control area power system. The selfservice power station is still a popular means as a power supplying source on ships or in a certain manufacturing area. The power system of this kind can be formulated as a single control-area system and it attracts a certain academic interest in controlling the system frequency under disturbances. In this paper, the single control-area system is mathematically formulated as a linear, time-invariant system in state-space under certain assumptions. The optimal proportional control law and the realization of the controller in closed loop-version is studied so that the final system designed can attain the system frequency to the nominal stationing value after the small load-disturbance. As in general cases of optimal design problems, the performance index is assumed to be quadratic in states and the control effort, and the infinite time control process is assumed in this work. The final control system realized depicts certain improvements in case study; in stability, transient responses and in steady-state frequency deviation, even though the steady state error did not attain the zero value.

• Water for future
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• v.21 no.4
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• pp.407-414
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• 1988

The purpose of this paper is to study the following ; (1) how the stability and sensitivity of a given stream water quality model can be analyzed theoretically by means of the stability theory and the sensitivity theory, and (2) point out that the results of this study prove that numerical analysis for the given stream water quality model is reliable, and the model is sensitive for the variations of parameters. A stability theory which is described by the infinite Fourier series is used to analyze the numerical scheme of the model. The numerical shheme is used a backward implicit scheme. a sensitivity theory which is described by the first order linear vector equation is used to analyze theoretically the effect of variations of water quality parameters such as BOD loads, flow rate, temperature. The results of sensitivity theory are of general applicability and are presented in a analytical form. The results of this study seems to be satisfactory for the reliability of stream water quality model with respect to the numerical scheme and the variations of the water quality parameters.

• Korean Business Review
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• v.11
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• pp.67-81
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• 1998

In this study, we discuss the possibility of applying the group technology to the service area. We analyze student service system to improve college student service and constructed new service cells using the group technology. To do so, we build service cells for the information technology support and related business in college student service with the standard of service cell formation process. This naturally leads us to the way to improve or to solve those problems such as waiting time and complexity of the related department to provide service to the student. The application of the group technology means the increase of the investment in the view point of the owner. However, to stand against the infinite competition and the open of the education market, university have to prepare. This preparation can be helped by applying the group technology for improving the college student service quality.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1195-1199
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• 1998

In this paper a design method of robust power system stabilizers is proposed by means of robust linear quadratic regulator design technique under power system's operating condition change, which is caused by inner structure uncertainties and disturbances into a power system. It is assumed that the uncertainties present in the system are modeled as one equivalent signal. In this connections an optimal LQR control input for disturbance rejection, the output feedback gain for eliminating the disturbance are calculated. In this case. PSS input signal is obtained on the basis of weighted ${\Delta}P_e$ and $\Delta\omega$. In order to stabilize the overall control of system. Pole placement algorithm is applied in addition. making the poles of the closed loop system to move into a stable region in the complex plane. Some simulations have been conducted to verify the feasibility of the proposed control method on a machine to infinite bus power system. From the simulation results validation of the proposed method could be achieved by comparisons with the conventional PSS with phase lag-lead compensation.

• Journal of Information Technology Services
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• v.16 no.1
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• pp.73-82
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• 2017

Recently in-memory data stream processing has been actively applied to various subjects such as query processing, OLAP, data mining, i.e., frequent item sets, association rules, clustering. However, finding regular periodic patterns of events in an infinite data stream gets less attention. Most researches about finding periods use autocorrelation functions to find certain changes in periodic patterns, not period itself. And they usually find periodic patterns in time-series databases, not in data streams. Literally a period means the length or era of time that some phenomenon recur in a certain time interval. However in real applications a data set indeed evolves with tiny differences as time elapses. This kind of a period is called as a pseudo-period. This paper proposes a new scheme called FPMH (Finding Periods using Multiple Hash functions) algorithm to find such a set of pseudo-periods over a data stream based on multiple hash functions. According to the type of pseudo period, this paper categorizes FPMH into three, FPMH-E, FPMH-PC, FPMH-PP. To maximize the performance of the algorithm in the data stream environment and to keep most recent periodic patterns in memory, we applied decay mechanism to FPMH algorithms. FPMH algorithm minimizes the usage of memory as well as processing time with acceptable accuracy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.70-73
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• 2004

The packaging of the integrated circuits requires knowledge of ceramics and metals to accommodate the fabrication of modules that are used to construct subsystems and entire systems from extremely small components. Composite ceramics (Al$_2$O$_3$-SiO$_2$) were tested for substrates. A stress analysis was conducted for a linear work-hardening metal cylinder embedded in an infinite ceramic matrix. The bond between the metal and ceramic was established at high temperature and stresses developed during cooling to room temperature. The calculations showed that the stresses depend on the mismatch in thermal expansion, the elastic properties, and the yield strength and work hardening rate of the metal. Experimental measurements of the surface stresses have also been made on a Cu/Al$_2$O$_3$-SiO$_2$ceramic system, using an indentation technique. A comparison revealed that the calculated stresses were appreciably larger than the measured surface stresses, indicating an important difference between the bulk and surface residual stresses. However, it was also shown that porosity in the metal could plastically expand and permit substantial dilatational relaxation of the residual stresses. Conversely it was noted that pore clusters were capable of initiating ductile rupture, by means of a plastic instability, in the presence of appreciable tri-axiality. The role of ceramics for packaging of microelectronics will continue to be extremely challenging.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.308-312
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• 2003

The packaging of the integrated circuits requires knowledge of ceramics and metals to accommodate the fabrication of modules that are used to construct subsystems and entire systems from extremely small components. Composite ceramics ($Al_2O_3-SiO_2$) were tested for substrates. A stress analysis was conducted for a linear work-hardening metal cylinder embedded in an infinite ceramic matrix. The bond between the metal and ceramic was established at high temperature and stresses developed during cooling to room temperature. The calculations showed that the stresses depend on the mismatch in thermal expansion, the elastic properties, and the yield strength and work hardening rate of the metal. Experimental measurements of the surface stresses have also been made on a $Cu/Al_2O_3-SiO_2$ ceramic system, using an indentation technique. A comparison revealed that the calculated stresses were appreciably larger than the measured surface stresses, indicating an important difference between the bulk and surface residual stresses. However, it was also shown that porosity in the metal could plastically expand and permit substantial dilatational relaxation of the residual stresses. Conversely it was noted that pore clusters were capable of initiating ductile rupture, by means of a plastic instability, in the presence of appreciable tri-axiality. The role of ceramics for packaging of microelectronics will continue to be extremely challenging.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.572-577
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• 2006

The physiochemical interactions of 1-methylcyclopropene (1-MCP) and adsorbing agents can be described using a very powerful tool, inverse gas chromatography (IGC). Sorption behavior of 1-MCP on various adsorbing agents was assessed using the profile peaks of 1-MCP at an infinite dilution concentration using the IGC technique. Chromatogram peaks of 1-MCP adsorption were not observed for the adsorbing agent activated carbon. The forms of sorption isotherms followed Henry's law, and behaved according to the binding site theory. Specific retention volume and distribution coefficients for 1-MCP on the adsorbing agents were determined at 50, 60, 70, and $80^{\circ}C$, respectively. Silica gel had a much higher number of binding sites for 1-MCP compared to Tenax-TA and activated clay agents. Meanwhile, activated carbon proved to be a very strong binding agent for 1-MCP based on 1-MCP efficiency experiments on the selected adsorbing agents. However, as a proper means of delivering 1-MCP molecules to fresh food products, activated carbon is not fit for the binding and release of 1-MCP gas under dry or high humidity conditions because activated carbon has a strong affinity for 1-MCP, even when treated with distilled water.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.4
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• pp.25-36
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• 2019

Contemporary architecture is showing its deconstruction and departure from modern architecture based on rationality, such as reductionism or virtualism. This means a shift from a mechanistic and ecological world view to an organic and ecological view, from a deterministic reason to a reason for a possible secret static. This study examines the potential of fractals, a scientific theory of complexity that is emerging as a new paradigm in the 21st century, as an appropriate alternative to contemporary complexity architecture. The method and scope of this study were understood and its features were identified through literature and data research and prior study review. Based on the organic nature of fractal geometry, we analyzed the works of contemporary architects(Frank Gehry, Bernard Tschumi, Steven Holl, Zaha Hadid, Rem Koolhaas, Daniel Libeskind, Zvi Hecker, Ito Toyo) and studied the possibility of architectural design using the principle of fractal. As a result, fractal geometry, similar to the patterned order of nature, has an infinite set of organizational functionalities in architecture and can be applied in various aspects of design analysis. Architectural designs based on the fractal theory will require more research and development to realize dynamic design representation using digital computers.