• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.10
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• pp.938-945
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• 2003

We fabricated Ni-substrate for YBCO coated conductors and evaluated the effects of pressing and annealing temperature and time on texture. Ni substrate was fabricated by powder metallurgy technique and compacts were prepared by applying uniaxial or isostatic pressure. The texture of substrate made by applying cold isostatic pressure (CIP) was stronger than that by uniaxial pressure which we attribute to the fact that the CIP method provided higher density and more uniform density distribution. It was observed that the substrate annealed at 400 C showed both retained texture and recrystallized texture. On the other hand, the texture of substrate significantly improved at annealing temperature above 500 C, forming strong 4-fold symmetry, [111] II ND texture, and FWHM of 9∼10 . It is to be noted that the degree of texture was almost independent of annealing temperature (500∼1000 C) and annealing time(1∼54 min, at 1000 C). EBSD and AFM analysis indicated that 99% of grain boundaries was low angle grain boundary and RMS was approximately 3 nm, respectively. Development of strong cube texture and high fraction of low angle grain boundary of Ni-substrate made by powder metallurgy technique in our study is considered to be suitable for the application of YBCO coated conductors.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.3
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• pp.156-162
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• 2006

The aim of this study is to investigate the full annealing parameter for A3003 Al alloy welded tubes. The A3003 Al alloy tubes with 34 mm in external diameter and 1.3 mm in thickness for OPC drum were manufactured by high frequency induction welding with the V shaped convergence angle $6.7^{\circ}$ and power input 50 kW. The tensile and yield strength decreased with increasing the annealing temperature and time remarkably, but elongation increased remarkably. Vickers hardness in welds and base metal decreased with increasing the annealing temperature and time remarkably. In a certain experimental condition, the welds line in A3003 alloys disappeared at $520^{\circ}C$ for 4hr because of the same mechanical properties and structures between welds and base metal.

• Journal of Magnetics
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• v.10 no.2
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• pp.52-57
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• 2005

In this research, magnetoresistance (MR) ratio (MR), resistivity, and exchange coupling field $(H_{ex})$ behaviors for sputter deposited spin valves with FeMn antiferromagnetic layer have been extensively investigated by rapid thermal annealing (RTA) as well as conventional annealing (CA) method. 10 s of RTA revealed that interdiffusion was not significant up to $325^{\circ}C$ at the interfaces between the layers when the RTA time was short. The MR of FeMn spin valves were reduced when the spin valves were exposed to temperature of $250^{\circ}C$, even for a short time period of 10 s prior to CA. $H_{ex}$ was maintained up to $325^{\circ}C$ of CA when the specimen was subjected to 10 s of RTA at $200^{\circ}C$ prior to CA, which is $25^{\circ}C$ higher than the result obtained from the CA without prior RTA. Therefore, the stability of $H_{ex}$ could be enhanced by a prior RTA before performing CA up to annealing temperature of $325^{\circ}C$. MR and sensitivity of the specimens annealed without magnetic field up to $275^{\circ}C$ were recovered to the values prior to CA, but $H_{ex}$ was not recovered. This means that reduced MR sensitivity and MR during the device fabrication can be recovered by a field RTA.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.580-586
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• 2002

We investigated the effect of ionic component on crystalline morphology development during isothermal annealing in a sodium neutralized sulfonated poly(ethylene terephthalate) ionomer (Ion-PET) by time-resolved small-angle x-ray scattering (TR-SAX S) using synchrotron radiation. At early stage in Ion-PET, SAXS intensity at a low annealing temperature (Ta = 120 $^{\circ}C)$ decreased monotonously with scattering angle for a while. Then SAXS profile showed a peak and the peak position progressively moved to wider angles with isothermal annealing time. Finally, the peak intensity decreased, shifting the peak angle to wider angle. It is revealed that ionic aggregates (multiplets structure) of several nm, calculated by Debye-Bueche plot, are formed at early stage. They seem to accelerate the crystallization rate and make fine crystallites without spherulite formation (supported by optical microscopy observation). From decrease of peak intensity in SAXS,it is suggested that new lamellae are inserted between the preformed lamellae so that the concentration of ionic multiplets in amorphous region decreases to lower the electron density difference between lamellar crystal and amorphous region. In addition, analysis on the annealing at a high temperature (Ta = 210 $^{\circ}C)$ by optical microscopy, light scattering and transmission electron microscopy shows a formation of spherulite, no ionic aggregates, the retarded crystallization rate and a high level of lamellar orientation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.1012-1015
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• 2004

There have been several kinds of attempts to actively control the deflected noise behind the noise barrier. Omoto's work in 1993 would be one of the fundamental studies, where he placed the control sources uniformly parallel to the noise barrier. Following this study, Yang pointed that the average distance between the noise source and control sources is more important than the arrangement of control sources such as a straight line or an arc type distribution. In 2004, Baek tried to show optimal arrangement of control sources while keeping the average distance between the noise source and control sources. He used simulated annealing algorithm which is one of the natural algorithms for the selections of optimal control source positions, but the searching technique was a hybrid of the simulated annealing and the sequential searching to adapt to the vast amount of searching time. This study is about the performance comparison between the pure sequential searching and the hybrid one. The simulation results show very similar performance and a pure simulated annealing searching will be more beneficial for the noise reduction performance but at the cost of computing time.

• Steel and Composite Structures
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• v.50 no.5
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• pp.583-594
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• 2024

In this paper, a Guided Simulated Annealing (GSA) algorithm is presented to optimize 2D and 3D steel frames against Progressive Collapse. Considering the nature of structural optimization problems, a number of restrictions and improvements have been applied to the decision mechanisms of the algorithm without harming the randomness. With these improvements, the algorithm aims to focus relatively on the flawed variables of the analyzed frame. Besides that, it is intended to be more rational by instituting structural constraints on the sections to be selected as variables. In addition to the LRFD restrictions, the alternate path method with nonlinear dynamic procedure is used to assess the risk of progressive collapse, as specified in the US Department of Defense United Facilities Criteria (UFC) Design of Buildings to Resist Progressive Collapse. The entire optimization procedure was carried out on a C# software that supports parallel processing developed by the authors, and the frames were analyzed in SAP2000 using OAPI. Time history analyses of the removal scenarios are distributed to the processor cores in order to reduce computational time. The GSA produced 3% lighter structure weights than the SA (Simulated Annealing) and 4% lighter structure weights than the GA (Genetic Algorithm) for the 2D steel frame. For the 3D model, the GSA obtained 3% lighter results than the SA. Furthermore, it is clear that the UFC and LRFD requirements differ when the acceptance criteria are examined. It has been observed that the moment capacity of the entire frame is critical when designing according to UFC.

• Journal of Life Science
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• v.14 no.1
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• pp.110-114
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• 2004

The optimized RAPD-PCR conditions, that can be utilized as a basic information for analysis of the gelletic characteristics were developed for genetic analysis of four mulberry varieties, named Milsung, Chungil, Suil, and Hansung using a primer, OPY15 (5'-AGTCGCCCTT-3') from Operon company. We tested several different factors for best PCR condition including concentrations of DNA, primer, Mgclu annealing temperature, number of PCR cycle, and prosence/absence of pre-heating time at the begining of PCR reaction in the $25 \mul$volume. The best RAPD profiles were obtained using 50 ng of DNA, 1 $\mu$M of primer, $1 \mum$of $MgCl_2\;,45^{\circ}C$ of annealing temperature and an absence of pre-heating time. An establishment of the stable and reproducible RAPD-PCR conditions are expected to be useful for the subsequent RAPD-related investigation, such as genetic characterization of the mulberry varieties, re-establishment of phylogenetic relationships and development of new varieties.

• ETRI Journal
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• v.32 no.6
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• pp.932-939
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• 2010

In this paper, a fast migration method is proposed. Our method executes local relocation on a model placement where an additional module is added to it for modification with a minimum number of displacements. This method is based on mean-field annealing (MFA), which produces a solution as reliable as a previously used method called simulated annealing. The proposed method requires substantially less time and hardware, and it is less sensitive to the initial and final temperatures. In addition, the solution runtime is mostly independent of the size and complexity of the input model placement. Our proposed MFA algorithm is optimized by enabling module rotation inside an energy function called permissible distances preservation energy. This, in turn, allows more options in moving the engaged modules. Finally, a three-phase cooling process governs the convergence of problem variables called neurons or spins.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.59-60
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• 2003

The undrawn monofilament of poly (trimethylene terephthalate) (PTT) was obtained by melt-spinning. After being annealed at 40 C it was analyzed by the measurements of DSC, DMA, WAXD and ATR FT-IR. Tg of PTT fiber after annealing for more than 96 hours was 20 C higher than that before annealing as determined by the DSC and DMA measurements. The WAXD analysis showed very weak diffraction peaks at 2$\theta$=17$^{\circ}$ and 2$\theta$=24$^{\circ}$ for the annealing time of more than 96 hours. The ATR FT-IR measurements made clear the conformational change of methylene chains of PTT glycol residue from random to gauche-gauche conformation.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.4
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• pp.139-155
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• 2006

The facility location problem of this paper is distinguished from the maximal covering location problem and the flxed-charge facility location problem. We propose the maximal profiting location problem (MPLP) that is the facility location problem maximizing profit with multi-product. We apply to the simulated annealing algorithm, the stochastic evolution algorithm and the accelerated simulated annealing algorithm to solve this problem. Through a scale-down and extension experiment, the MPLP was validated and all the three algorithm enable the near optimal solution to produce. As the computational complexity is increased, it is shown that the simulated annealing algorithm' is able to find the best solution than the other two algorithms in a relatively short computational time.