• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.305-307
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• 2016

We calculated Li ion migration energy barrier, applying three different models on Li ion insertion into $TiO_2$ nanolayers to elucidate the previously reported high rate of charge-discharge. With the existence of additional Li ion on the surface of $TiO_2$ structure, spontaneous insertion of Li ion into the second layer from the first layer was observed. Using this result, we showed the intrinsic property of $TiO_2$ structure and it has a contribution to the reported performance. In the end, we give a suggestion on the fabrication of $TiO_2-Graphene$ hybrid structure for Li ion battery electrode.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.98-100
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• 2004

In this study, PST thin films were etched with inductively coupled $Cl_2/(Cl_2+Ar)$ plasmas. The etch characteristics of PST thin films as a function of $Cl_2/(Cl_2+Ar)$ gasmixtures were analyzed by using quadrupole mass spectrometer (QMS). Systematic studies were carried out as a function of the etching parameters, including the RF power and the working pressure. The maximum PST film etch rate is 56.2 nm/min, because a small addition of $Cl_2$ to the $Cl_2$/Ar mixture increased the chemical effect. It was proposed that sputter etching is the dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• Journal of Information Processing Systems
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• v.10 no.4
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• pp.568-580
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• 2014

To enhance the utilization of the traffic channels of a network (instead of allocating radio channel to an individual user), a channel or a group of channels are allocated to a user group. The idea behind this is the statistical distribution of traffic arrival rates and the service time for an individual user or a group of users. In this paper, we derive the blocking probability and throughput of a subscriber station of Worldwide Interoperability for Microwave Access (WiMAX) by considering both the connection level and packet-level traffic under a complete partition scheme. The main contribution of the paper is to incorporate the traffic shaping scheme onto the incoming turbulent traffic. Hence, we have also analyzed the impact of the drain rate of the buffer on the blocking probability and throughput.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1713-1715
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• 2007

Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. We have advanced the framework of the multiple time scale congestion control and showed its effectiveness at enhancing performance for the rate-based feedback control. Our contribution is threefold. First, we define a modular extension of the TCP-a function called with a simple interface-that applies to various flavours of the TCP-e.g., Tahoe, Reno, Vegas and show that it significantly improves performance. Second, we show that a multiple time scale TCP endows the underlying feedback control with proactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of the three traffic control dimensions-tracking ability, connection duration, and fairness-on performance.

• Korean Institute of Interior Design Journal
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• no.5
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• pp.30-36
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• 1995

Light plays an important role in making a continuity of space and in determining the distinctive expression and char-acter of a space. Particularly, the introduction of natural light derives from our esthetic needs, as well as from the fundamental biologi-cal necessities of human beings. And also, adaptation to time and space is the vital factor of human survival and prosperity. Our visual recognition of light is usually formed not only by practical illumination but by analogy, expection and expe-rienced of lighting itself. As the forecase of natural light is (almost) impossible be-cause of variables such as changing weather, reflection rate of light and the patterns of shade, in designing the introduc-tion of daylight, there should be follow-ed careful considera-tion of the adaptation to such variety and the impet-us of light. The research was conducted to mane a contribution to cre-ate more rich and beautiful interior spaces by studying the characteristic of light which is one of the important factors of interior space design, and by inquiring the way to intro-duce light and its effect through the practical examples of Alvar Aalto, Le Corbusier and Louis I. Kahn.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.109-113
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• 1981

Most existing theories on ship waves and wave resistance are based on the perturbation of the flow field by a small pararr.eter which specifies the slenderness of the ship hull. Since however, ship hulls in practice are neither so slender nor thin enough to secure the validity of the linearized theory, the agreen:ent between the theoretical prediction and the experimental result is not generally satisfactory. The author pointed out that the contribution by the non-linear term in the free surface condition can be represented by sorr.e source distribution over the still water plane. This paper leads to a forrr.ula for the wave resistance of not slender ships at low Froude nurr.bers. and deals with the asynptotic expression. As a nurr.erical example, the wave resistance of Wigley model is calculated, and the result is compared with experimental values. It is concluded that the wave resistance coefficient varies in the rate of Fn6 at low speed limit in general. A comparison with the result derived from the linearized free surface condition shows that the non-linearity of the free surface is irr portant at low speed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.187-190
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• 2004

In this study, PST thin films were etched with inductively coupled $Cl_2/(Cl_2+Ar)$ plasmas. The etch characteristics of PST thin films as a function of $Cl_2/(Cl_2+Ar)$ gasmixtures were analyzed by using quadrupole mass spectrometer (QMS). Systematic studies were carried out as a function of the etching parameters, including the RF power and the working pressure. The maximum PST film etch rate is 56.2 nm/min, because a small addition of $Cl_2$ to the $Cl_2/Ar$ mixture increased the chemical effect. It was proposed that sputter etching is the dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• Membrane and Water Treatment
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• v.9 no.2
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• pp.129-136
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• 2018

In this contribution, the control of multivariable reverse osmosis (RO) desalination plant using proportional-integral-derivative (PID) controllers is presented. First, feed-forward compensators are designed using simplified decoupling method and then the PID controllers are tuned for flux (flow-rate) and conductivity (salinity). The tuning of PID controllers is accomplished by minimization of the integral of squared error (ISE). The ISEs are minimized using a recently proposed algorithm named as teacher-learner-based-optimization (TLBO). TLBO algorithm is used due to being simple and being free from algorithm-specific parameters. A comparative analysis is carried out to prove the supremacy of TLBO algorithm over other state-of-art algorithms like particle swarm optimization (PSO), artificial bee colony (ABC) and differential evolution (DE). The simulation results and comparisons show that the purposed method performs better in terms of performance and can successfully be applied for tuning of PID controllers for RO desalination plants.

• Bulletin of the Korean Chemical Society
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• v.3 no.1
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• pp.34-36
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• 1982

N-Methacryloyl-L-histidine and N-methacryloyl-L-histidine methyl ester were synthesized and polymerized to obtain polymeric catalysts with different functions. In the presence of each of these polymers the solvolytic reactions of p-nitrophenyl acetate (PNPA), 3-nitro-4-acetoxybenzoic acid(NABA), 3-acetoxy-N-trimethylanilinium iodide(ANTI) and 3-nitro-4-decanoyloxybenzoic acid(NDBA) were performed in 20% aqueous ethanol. For the purpose of comparison the low molecular weight analogs(LMWA's), L-histidine, L-histidine methyl ester and N-acetyl-L-histidine were also subjected to catalyze the solvolyses of above substrates. In the solvolysis of PNPA the polymeric catalysts exhibited lower activities than the LMWA's. However the ionic substrates, NABA and ANTI were solvolyzed at anomalous rate by polymeric catalyst, indicating that electrostatic effects are operative in the catalysis by polymers. Furthermore in the solvolysis of hydrophobic monomer NDBA, polymeric catalysts exhibited highly enhanced activities compared with the LMWA's implying that hydrophobic interaction can be the most important contribution to the high catalytic activity of imidazole-containing polymers.

• Computers and Concrete
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• v.8 no.4
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• pp.425-443
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• 2011

Most previous studies have generally overlooked the contribution of thermal stresses generated within the concrete mass when subjected to microwave heating and reported on pore-pressure as being the dominant cause of surface spalling. Also, the variation in electromagnetic properties of concrete and its effects on the microwave heating process have not been studied in detail. In this paper, finite element modeling is used to examine the simultaneous development of compressive thermal stresses and pore-pressure arising from the microwave heating of concrete. A modified Lambert's Law formulation is proposed to estimate the microwave power dissipation in the concrete mass. Moreover, the effects of frequency and concrete water content on the concrete heating rate and pattern are investigated. Results show high compressive stresses being generated especially in concrete with a high water content when heated by microwaves of higher frequencies. The results also reveal that the water content of concrete plays a crucial role in the microwave heating process.