• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1149-1160
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• 2005

Generally, the network topology design problem, which is difficult to solve with the classical method because it has exponentially increasing complexity with the augmented network size, is characterized as a kind of NP-hard combinatorial optimization problem. The problem of this research is to design the highly reliable network topology considering the connection cost and all-terminal network reliability, which can be defined as the probability that every pair of nodes can communicate with each other. In order to solve the highly reliable network topology design problem minimizing the construction cost subject to network reliability, we proposes an efficient two phase approach to design reliable network topology, i.e., the first phase employs, a genetic algorithm (GA) which uses $Pr\ddot{u}fer$ number for encoding method and backtracking Algorithm for network reliability calculation, to find the spanning tree; the second phase is a greedy method which searches the optimal network topology based on the spanning ree obtained in the first phase, with considering 2-connectivity. finally, we show some experiments to demonstrate the effectiveness and efficiency of our two phase approach.

• Journal of Power Electronics
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• v.11 no.2
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• pp.120-131
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• 2011

This paper proposes two control strategies for the bidirectional Z-source inverters (BZSI) supplied by batteries for electric vehicle applications. The first control strategy utilizes the indirect field-oriented control (IFOC) method to control the induction motor speed. The proposed speed control strategy is able to control the motor speed from zero to the rated speed with the rated load torque in both motoring and regenerative braking modes. The IFOC is based on PWM voltage modulation with voltage decoupling compensation to insert the shoot-through state into the switching signals using the simple boost shoot-through control method. The parameters of the four PI controllers in the IFOC technique are designed based on the required dynamic specifications. The second control strategy uses a proportional plus resonance (PR) controller in the synchronous reference frame to control the AC current for connecting the BZSI to the grid during the battery charging/discharging mode. In both control strategies, a dual loop controller is proposed to control the capacitor voltage of the BZSI. This controller is designed based on a small signal model of the BZSI using a bode diagram. MATLAB simulations and experimental results verify the validity of the proposed control strategies during motoring, regenerative braking and grid connection operations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9C
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• pp.891-897
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• 2003

Partial response maxim likelihood (PRML) is a powerful and indispensable detection scheme for perpendicular magnetic recording channels. The performance of PRML can be improved by incorporating a noise prediction scheme into branch metric computations of Viterbi algorithm (VA). However, the systems constructed by VA have shortcomings in the form of high complexity and cost. In this connection, a new simple detection scheme is proposed by exploiting the minimum run-length parameter d=1 of RLL code. The proposed detection scheme have a slicer instead of Viterbi detector and a noise predictor as a feedback filter. Therefore, to improve BER performance, the proposed detection scheme is extended to dual detection scheme for improving the BER performance. Simulation results show that the proposed scheme has a comparable performance to noise-predictive maximum likelihood (NPML) detector with less complexity when the partial response (PR) target is (1,2,1).

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.273-278
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• 2014

Recent use of electricity during peak hours electricity supply-demand imbalance is inevitable that limit power use force. Therefore, in this paper, a circuit of parallel power operation equipment for peak power reduction which saves the power to electricity storage device during the non-peak power time and supply from the storage power during the expected power shortages time is designed Through this circuitry, the peak power of the commercial power supply with the parallel operation and connection of the commercial power supply and the power supply of the inverter from electricity storage that is a key feature of PRS(Peak power Reduction System) can be controlled. In addition, in order to increase the efficiency, a Transless Power Circuit DC-AC inverter is developed. Moreover, a variable impedance control is applied to the storage of electric power of an Uninterruptible Power Supply associated with a commercial power source.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.30-40
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• 2009

Employing the Numata-type life form, the paper analyzed changes of plants for 4 years at the Human-made Wetlands along Boknaecheon of Juam Lake since its creation. The number of the species planted at the Human-made Wetlands along Boknaecheon of Juam Lake, which was completed in December 2002, were 15 in total including, 10 families, 13 genera, 12 species and 3 varieties. As for the three-featured life forms of the planted species, there were 6 perennial hydatophytes, recording the biggest number of species in dormancy form; species each of $R_5$, $R_3$, $R_{2-3}$ respectively in radicoid from; 20 species of geomantic dissenminule form ($D_1$) in disseminule form and erecred type(e) existed the most in growth form. With regard to the 3 features of life form identified during the final year of the monitoring that lasted 5 years after the completion of the Wetlands, the number of species and individuals was found to have increased but there was no significant change of tendency as against the composition ration(%) of life form. There were 43 species of therophytes (Th) that covered 24.29% in dormancy form, while $R_5$ was prevalent in radicoid form and $D_4$, $D_1$, and $D_{1,4}$ comprosed 77.39% of the whole disseminule form. Growth form was surveyed in the order of erected type (e), bunch type (t), temporal rosette type (pr), branch type (b) and straight rosette type (ps) and these species comprised 64.97% of the whole flora. Consequently, in case of the artificial wetlands along the Boknaecheon of Juam Lake, it turned out that the vegetation type in which pioneer species of succession, or gradually stabilized perennial vegetation favoring Wetlands because the higher dormancy form has its perennial plants' composition ratio getting, the more its succession is progressing. Even though single grained plants ($R_5$) belonging to radicoid in breeding form, succession is predicted to take place considering the fact that they actually belong to ~ plants like Phragmites japonica that form a connection on the surface of the earth. In addition, it is judged that geomantic disseminule form ($D_1$) conveyed by water and gravitational disseminule form favored by the development of waterside woody plants ($D_4$) seem to be better fit to this area in desseminule form. As for growth form, bunch type (t) is judged to become prevalent on the Wetlands while a good variety of phanerophytes will coexist on the earth due to artificial as well as natural disturbances.

• Korean Institute of Interior Design Journal
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• v.23 no.6
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• pp.87-94
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• 2014

Today, the growing number of international architects enters the open market of South Korean architecture and interior from exhibition spaces such as art galleries to buildings of major companies. Establishing new local landmarks, their works have a considerable influence on the development of architecture. Among many, French architect Jean-Michel Wilmotte has worked consistently in South Korea. The purpose of this study is to analyze and put together the expression characteristic of the interior design in his exhibition spaces including Gana Art Gallery. Jean-Michel Wilmotte has designed based on the history, culture, society, and arts in France and other European countries, and is influenced by architects like Charles Rennie Mackintosh, Josef Hoffmann, and Carlo Scarpa. Such an influence is shown in the form of contrast between verticality and horizontality as well as the fortification in his modern classical characteristic, which is one of his expression characters. In his work of improving the ancient architecture, Wilmotte is good at creating a modern space through contextual expression, and the textural contrast between materials of the past and the present. Thus I performed an analysis of the expression characteristic of the interior design in National Museum of Contemporary Art of Chiado in Lisbon, Cognac Hennessy Museum in France, Gana Art Gallery in Korea, Mus$\acute{e}$e du Pr$\acute{e}$sident Jacques Chirac in Sarran, France, Ullens Center for Contemporary Art (UCCA) in Beijing, and lastly Mus$\acute{e}$e d'Orsay in Paris. The results show that he maintains the spatial context by applying contemporary design to the preserved existing structure, continues the flow of exhibition through the lightings in the corridors and on the ceiling, and seeks for a balance by adding vertical or horizontal elements to the elevation. In the interior, the staircase and exhibition structure are turned into objects, and the contrasting texture of the wall vitalizes the space. Wilmotte redesigns the space of the past and the present by using indirect joint that allows an organic connection of the old and new structures, and by minimizing the conflict between the two elements through prefabrication. The expression character of his interior design will be potential resources for architects and interior designers to develop their own design languages.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.171-185
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• 2006

A sophisticated reliability analysis method is proposed to evaluate the reliability of real nonlinear complicated dynamic structural systems excited by short duration dynamic loadings like earthquake motions by intelligently integrating the response surface method, the finite element method, the first-order reliability method, and the iterative linear interpolation scheme. The method explicitly considers all major sources of nonlinearity and uncertainty in the load and resistance-related random variables. The unique feature of the technique is that the seismic loading is applied in the time domain, providing an alternative to the classical random vibration approach. The four-parameter Richard model is used to represent the flexibility of connections of real steel frames. Uncertainties in the Richard parameters are also incorporated in the algorithm. The laterally flexible steel frame is then reinforced with reinforced concrete shear walls. The stiffness degradation of shear walls after cracking is also considered. The applicability of the method to estimate the reliability of real structures is demonstrated by considering three examples; a laterally flexible steel frame with fully restrained connections, the same steel frame with partially restrained connections with different rigidities, and a steel frame reinforced with concrete shear walls.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.33-42
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• 2016

Utilization of cultural contents is more and more increasing as it is believed to improve local problems and provide historical values. This kind of business is positive in terms of the fact that it attracts visitors into local areas and activate local commercial areas. Under this trend, the construction of specialized streets is required to be approached with first priority to solve problems of cities. So to speak, it's more important to solve intrinsic problems found in local communities and then approach cultural contents step-by-step rather than constructing new spaces with first priority. Moreover, cultural contents should accompany economic aspects which result in local community-friendly and sympathetically concentrated values. Under this sentiment, the efforts to suggest economic ripple effects for government local government's businesses using cultural contents are very important. This study analyzed how much economic ripple effects is yielded by reflecting cultural contents. As the result of analysis, specialized street with cultural contents applied are proved to be more concentrated on multiplier of expediting employment, income and tax and tourism industry than service industry. On the contrary to this, service industry showed more concentrated multiplier of expediting production, income, added values and chain reaction effect (coefficients for influence and sensitivity for front and rear side of tourism industry. Based on these results, construction of specialized streets with cultural contents applied is proved to help synergy effects for local economy.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.5-5
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• 1999

The Principal deficiency of the existing notion about the sintering-mixtures consists in the fact that almost no attention is focused on the Phenomenon of alloy formation during sintering, its connection with dimensional changes of powder bodies, and no correct ideas on the driving force for the sintering process in the stage of establishing chemical equilibrium in a system are available as well. Another disadvantage of the classical sintering theory is an erroneous conception on the dissolution mechanism of solid in liquid. The two-particle model widely used in the literature to describe the sintering phenomenon in solid state disregards the nature of the neighbouring surrounding particles, the presence of pores between them, and the rise of so called arch effect. In this presentation, new basic scientific principles of the driving forces for the sintering process of a two-component powder body, of a diffusion mechanism of the interaction between solid and liquid phases, of stresses and deformation arising in the diffusion zone have been developed. The major driving force for sintering the mixture from components capable of forming solid solutions and intermetallic compounds is attributed to the alloy formation rather than the reduction of the free surface area until the chemical equilibrium is achieved in a system. The lecture considers a multiparticle model of the mixed powder-body and the nature of its volume changes during solid-state and liquid-phase sintering. It explains the discovered S-and V-type concentration dependencies of the change in the compact volume during solid-state sintering. It is supposed in the literature that the dissolution of solid in liquid is realised due to the removal of atoms from the surface of the solid phase into the melt and then their diffusicn transfer from the solid-liquid interface into the bulk of liquid. It has been shown in our experimental studies that the mechanism of the interaction between two components, one of them being liquid, consist in diffusion of the solvent atoms from the liquid into the solid phase until the concentration of solid solutions or an intermetallic compound in the surface layer enables them to pass into the liquid by means of melting. The lecture discusses peculimities of liquid phase formation in systems with intermediate compounds and the role of the liquid phase in bringing about the exothermic effect. At the frist stage of liquid phase sintering the diffusion of atoms from the melt into the solid causes the powder body to grow. At the second stage the diminution of particles in size as a result of their dissolution in the liquid draws their centres closer to each other and makes the compact to shrink Analytical equations were derived to describe quantitatively the porosity and volume changes of compacts as a result of alloy formation during liquid phase sinteIing. Selection criteria for an additive, its concentration and the temperature regime of sintering to control the density the structure of sintered alloys are given.

• Korean journal of communication and information
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• v.56
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• pp.237-256
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• 2011

The goal of this study is to examine consumers' cognition for the corporate social responsibility(CSR) and opinion to practical use of CSR on advertising (ex. corporate PR) in situation that CSR is treated with long-term and continuous activity in strategic marketing. The results of survey in this study are, first, the best effective method of CSR to introduce is TV or radio program placed first, internet came second, and followed by advertising. But the cognition process of CSR is internet palaced first in frequency. Thus it is very important to use of new media as a internet with regard to CSR. Second, respondents have thought positively about CSR and to practical use of CSR on advertising. But respondents answered that CSR is not enough though it's importance. Therefore marketers of companies is needed to transfer direction of CSR accord with consumers' liking and taste. Third, consumers have recognized that CSR in connection with characteristics core business of the companies. It is, image of company is not detached with CSR, more effective that CSR reflected characteristics of the company. Fourth, consumers have thought to active for CSR that the companies they like. Finally, these results are showed that is important brand management and corporate image management in strategic and macroscopic level include CSR.