• Earthquakes and Structures
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• v.5 no.1
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• pp.23-48
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• 2013

In this study, the effect of flexibility of superstructures and nonlinear characteristics of LRB (Lead Rubber Bearing) isolator on inelastic response of base isolated structures is investigated. To demonstrate the intensity of damage in superstructures, demand response modification factor without the consideration of damping reduction factor, demand RI, is used and the N2 method is applied to compute this factor. To evaluate the influence of superstructure flexibility on inelastic response of base isolated structures, different steel intermediate moment resisting frames with different heights have been investigated. In lead rubber bearing, the rubber provides flexibility and the lead is the source of damping; variations of aforementioned characteristics are also investigated on inelastic response of superstructures. It is observed that an increase in height of superstructure leads to higher value of demand RI till 4-story frame but afterward this factor remains constant; in other words, an increase in height until 4-story frame causes more damage in the superstructure but after that superstructure's damage is equal to the 4-story frame's. The results demonstrate that the low value of second stiffness (rubber stiffness in LRBs) tends to show a significant decrease in demand RI. Increase in value of characteristic strength (yield strength of the lead in LRBs) leads to decrease in the demand RI.

• Journal of the Korean Society of Food Culture
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• v.12 no.5
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• pp.469-475
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• 1997

The modification of rice powder was attempted by treatment of acetic acid and epichlorohydrin to improve the functional properties of baby food. The initial gelatinization temperature of rice powder determined by amylograph was decreased from $79.5^{\circ}C$ to $63^{\circ}C$ by modification. The apparent and maxium viscosity of rice paste at $95^{\circ}C$ before and after modification were increased from 92B.U. to 236B.U. and from 100B.U. to 202B.U., respectively. The light transmittance of modified rice paste was increased from the temperature of $60^{\circ}C$ and by increasing the degree of substitution at the fixed temperature, while decrease more or less by the treatment of epichlorohydrin. The degree of retrogradation of the paste was decreased from 28.7 to 18.0 upon modification. The rate of syneresis of modified rice powder was decreased with increasing the drgree of substitution and ,the extend of epichlorohydrin treatment. Syneresis was not observed when acetylated rice powder whose DS value is 0.048 was treated with 0.25% of epichlorohydrin for the formation of cross-linkage. The addition of modified rice powder in preparation of semi-solid type infant food could improve the quality without lowering overall digestibility.

• Journal of Korean Academy of Nursing
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• v.36 no.5
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• pp.751-760
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• 2006

Purpose: This study was to evaluate the effects of a comprehensive life style modification program on glycemic control and stress response in type 2 diabetes. Method: The participants(n=34) with type 2 diabetes were divided into either a usual care(control) or treatment(experimental) group. The experimental group(n=21) received a program that was based on a comprehensive life style modification protocol at a weekly meeting for 16 weeks. They also participated in individually prescribed exercise and diet along with stress management and self monitoring. The participants were followed for 6 months, during which postprandial glucose, HbA$_{1C]$, and stress response inventory were measured. Result: The experimental group showed a significant lower postprandial glucose and stress response compared to those of the control group. However, there was no significant change in the HbA$_{1C]$ value in either group. Conclusions: These results suggest that a type 2 diabetes comprehensive lifestyle modification program may lead to clinical improvement in glycemic control and reduce the stress response.

• Carbon letters
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• v.6 no.3
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• pp.166-172
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• 2005

The objective of this study was to investigate the possibility of application for water treatment using the zeocarbon. The zeocarbon was mixture of zeolite and activated carbon. In general, the application of commercial zeocarbon to water treatment is difficult because of weak strength in water and the high pH value of effluents after water treatment. Therefore, we have modified the surface of zeocarbon. For the surface modification, we used the acid treatment to make surface functional group. As a result of modification, was created functional group on zeocarbon surface and was formed mesopore in zeocarbon. The surface modified zeocarbon was applied to removal of nitrogen. In removal experiments of nitrogen, removal efficiency was very high. And, strength of zeocarbon after water treatment and pH of effluents were stabilized. This indicates that the surface modified zeocarbon was easy to recover and reuse. Consequently, our results were shown the possibility of application for water treatment using the surface modified zeocarbon.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.1
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• pp.48-58
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• 2002

There is a purpose of this study for the proposal of the optimum technique utilized for the vibration design initial step. The stiffened plate structure for the ship hull is made for analysis model. To begin with, dynamic characteristics of stiffened plate structure is analysed using FEM. Main vibrational mode of the structure is decided in the analytical result of FEM. The simplified equation on the natural frequency of the main vibrational mode is induced. Next, sensitivity analysis is carried out using the simplified equation, and rate of change of dynamic characteristics is calculated. Then, amount of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of panel, cross section moment of stiffener and girder become a design variable. The validity of the optimization method using simplified equation is examined. It is shown that the result effective in the optimum modification for natural frequency of the stiffened plate structure.

• Polymer(Korea)
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• v.31 no.5
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• pp.436-441
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• 2007

In this work, the multiwalled carbon nanotubes(MWNTs) were functionalized with sodium dodecylbenzene sulfonate(SDBS) and then MWNTs/Lyocell composite fibers were prepared. The properties of MWNTs, the functionlization on the surface of MWNTs and their dispersion in the cellulose matrix were characterized by TEM, SEM, WAXD and FT-IR. The results showed that SDBS has been coated successfully onto the surface of the MWNTs by functionlization. This can improve effectively the dispersion uniformity of MWNTs in NMMO aqueous solution and is helpful to prepare a spinnable spinning dope. Moreover, the resultant MWNTs/Lyocell composite fibers still have cellulose II crystal structure, and their tensile strength and initial modulus increased with the increasing draw ratio and reached the optimal value with adding 1 wt% MWNTs. The thermal stability of the composite fiber was also improved by the addition of the MWNTs.

• Polymer(Korea)
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• v.33 no.5
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• pp.420-428
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• 2009

In this study, the composites containing carbon black (CB) or carbon fibers were prepared, and the microwave absorbing properties and the absorption mechanism of them were investigated and discussed in the frequency range of 2-18 GHz, respectively. The optimum mass fraction of CB has been found as 6%, and the carbon fibers were discovered to absorb radar wave either under parallel or vertical polarization, the suitable gap distance between each bundle of which was 5 mm. According to the results of the single constitute absorber samples, the structured composites with the two kinds of absorbers combination were fabricated and studied at 2-18 GHz. The top layer absorbers affect the absorption performance a lot; the maximum reflection loss of composites with CB as top layer absorbers was -31.8 dB with the frequency range of 2.4 GHz below -10 dB, and the other type with CFs as the top layer absorbers obtained the reflection loss peak value of -31.4 dB with 2 GHz below-10 dB.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.115-118
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• 1999

One of the typical methods to design a codebook is K-means algorithm. This algorithm has the drawbacks that converges to a locally optimal codebook and its performance is mainly decided by an initial codebook. D. Lee's method is almost same as the K-means algorithm except for a modification of a distance value. Those methods have a fixed distance value during all iterations. After many iterations. because the distance between new codevectors and old codevectors is much shorter than the distance in the early stage of iterations, the new codevectors are not affected by distance value. But new codevectors decided in the early stage of learning iterations are much affected by distance value. Therefore it is not appropriate to fix the distance value during all iterations. In this paper, we propose a new algorithm using each different distance value between codevectors for a limited iterations in the early stage of learning iteration. In the experiment, the result show that the proposed method can design better codebooks than the conventional K-means algorithms.

• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.72-80
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• 2005

The number of apartments has been increased, and it is time to activate the remodeling or reconstruction. Recently remodeling has been preferred to reconstruction, because reconstruction might cause many problems. At this point of time, remodeling could save resources, preserve environment, and expand the construction market places. However, most research for remodeling is aimed to improve the financial value, and structural effects being caused by floor plan modification has not been done yet quantitatively. Remodeling naturally brings to floor plan modification, and it can cause serious problems of structural side. So we made apartments an object of study, then analyzed stress variation of structural elements according to the removal of shear wall, supposing the floor plan modification. For this purpose, we selected a sample of universal apartment floor plan and extracted floor plan modification factors. Then we applied the factors to sample floor plan and organized the results of stress variation of structural elements. As results, walls are most harmful when the independent walls are removed, and in case of slabs, it is most critical when continuous walls are removed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.11
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• pp.919-927
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• 2013

In this paper, we present a perception-based tone mapping technique using histogram modification for displaying high dynamic range image. HDR (high dynamic range) tone mapping algorithms are used to display HDR image on LDR (low dynamic rnage) devices. Although perception-based tone mapping methods provides better performance, it dose not always produce good results for a wide variety of images. The proposed method reduces dynamic range by using the perception-based tone mapping function and histogram modification. A derivative of perception-based tone mapping function is used as constraint function of histogram and additional compensation process is performed. This method not only improves contrast by adopting different constraints on each pixel value, but also preserves more visual details. In order to prevent over enhancement, histogram modification technique is applied. Furthermore, it can control the rate of image contrast using control parameters. Subjective and objective evaluations show that proposed algorithm is better than existing algorithms.