• Title/Summary/Keyword: Solution annealing

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Annealing-temperature Dependent Characteristics of PLZT Thin Films on ITO Coated Glass (ITO 기판에 제작된 PLZT 박막의 소성온도에 따른 특성)

  • Choi, Hyung-Wook;Jang, Nak-Won;Park, Chang-Yub
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.2
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    • pp.128-132
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    • 1998
  • 2/65/35 PLZT stock solution prepared by Sol-Gel processing was spin-coated on ITO coated glass and annealed by RTA(Rapid Thermal Annealing). The crystal structure of films was reported based on the observation of crystallization process and microstructure of the film fabricated at different fabrication condition. Films were crystallized into rhombohedral structure by annealing at $750^{\circ}C$ for 5 min. As the annealing temperature increased, the size of rosette structure of the films was grown up from $2.4{\mu}m$ to $15{\mu}m$, dielectric constant was increased, coercive field was decreased 33.82 kV/cm, remnant polarization was increased to 39.84 ${\mu}C/cm^2$ and Optical transmittance was decreased.

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Realization of flexible polymer solar cell by annealing-free process using 1,8-Diiodooctane as additive

  • Kim, Youn-Su;Ju, Byeong-Kwon;Kim, Kyung-Kon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.383-383
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    • 2011
  • We fabricated thermal annealing-free polymer solar cells (PSC) by processing with additive and applied to flexible substrates. The 1, 8-Diiodooctane of 3 vol% blended with active solution resulted in enhancement of $J_{SC}$ due to increase of light absorption and hole mobility as improving the crystallinity of P3HT. In addition, the $V_{OC}$ of PSCs with additive was improved by inserting $TiO_2$ layer without any treatment. The $TiO_2$ layer prevented the direct contact between active layer and Al electrode and reduced the charge recombination near Active/Al interface. It was confirmed by calculation of J0 and photo-voltage transient measurement. The power conversion efficiencies of annealing-free PSCs using additive for ITO glass and flexible (ITO PEN) substrate were obtained 3.03% and 2.45%, respectively.

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Hybrid Simulated Annealing for Data Clustering (데이터 클러스터링을 위한 혼합 시뮬레이티드 어닐링)

  • Kim, Sung-Soo;Baek, Jun-Young;Kang, Beom-Soo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.2
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    • pp.92-98
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    • 2017
  • Data clustering determines a group of patterns using similarity measure in a dataset and is one of the most important and difficult technique in data mining. Clustering can be formally considered as a particular kind of NP-hard grouping problem. K-means algorithm which is popular and efficient, is sensitive for initialization and has the possibility to be stuck in local optimum because of hill climbing clustering method. This method is also not computationally feasible in practice, especially for large datasets and large number of clusters. Therefore, we need a robust and efficient clustering algorithm to find the global optimum (not local optimum) especially when much data is collected from many IoT (Internet of Things) devices in these days. The objective of this paper is to propose new Hybrid Simulated Annealing (HSA) which is combined simulated annealing with K-means for non-hierarchical clustering of big data. Simulated annealing (SA) is useful for diversified search in large search space and K-means is useful for converged search in predetermined search space. Our proposed method can balance the intensification and diversification to find the global optimal solution in big data clustering. The performance of HSA is validated using Iris, Wine, Glass, and Vowel UCI machine learning repository datasets comparing to previous studies by experiment and analysis. Our proposed KSAK (K-means+SA+K-means) and SAK (SA+K-means) are better than KSA(K-means+SA), SA, and K-means in our simulations. Our method has significantly improved accuracy and efficiency to find the global optimal data clustering solution for complex, real time, and costly data mining process.

Soft Solution Processing : Low-Energy Direct Fabrication of Advanced Inorganic Materials

  • Masahiro Yoshimura;한규승;Wojciech Suchanek
    • Bulletin of the Korean Chemical Society
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    • v.20 no.8
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    • pp.875-878
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    • 1999
  • A new concept ??soft solution processing?? has been introduced to fabricate advanced solid state materials in an economical, environmentally friendly, and energy and material efficient way. The prepared films show the desired and prospective properties despite of low temperature synthesis and no post-synthesis annealing. Successful examples demonstrate that soft solution processing is capable of preparing advanced materials with planned properties through the easy control of reaction conditions in a suitable aqueous solution in a single synthetic step without huge energy consumption and without any sophisticated equipment.

Two-Phase Magnet in the Co/Co2MnSn System

  • Kim, Tae-Wan;Yim, Hye-In;Lee, Hyun-Yong;Lee, Kyoung-Il
    • Journal of Magnetics
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    • v.16 no.1
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    • pp.10-14
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    • 2011
  • This study reports on Co/$Co_2$MnSn two-phase magnets. The Co/$Co_2$MnSn two-phase magnet has Co precipitates in a $Co_2MnSn$ Heusler alloy matrix, in which the two phases are exchange-coupled at the phase boundary. The as-casted Co/$Co_2$MnSn system, which has Co-Mn solid solution precipitates in a $Co_2$MnSn Heusler alloy matrix, showed that the Co solid solution precipitates are crystallographically coherent and there is exchange coupling at the phase boundary. To form pure Co precipitates by removal of Mn solute atoms in Co-Mn solid solution, annealing was carried out 48 hours at $870^{\circ}C$. After annealing, the low $T_c$ and low magnetization phase of the Co-Mn solid solution became a high $T_c$ and high magnetization phase of hexagonal Co.

Tool Path Optimization for NC Turret Operation Using Simulated Annealing (풀림모사 기법을 이용한 NC 터릿 작업에서의 공구경로 최적화)

  • 조경호;이건우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1183-1192
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    • 1993
  • Since the punching time is strongly related to the productivity in sheet metal stamping, there have been a lot of efforts to obtain the optimal tool path. However, most of the conventional efforts have the basic limitations to provide the global optimal solution because of the inherent difficulties of the NP hard combinatorial optimization problem. The existing methods search the optimal tool path with limiting tool changes to the minimal number, which proves not to be a global optimal solution. In this work, the turret rotation time is also considered in addition to the bed translation time of the NCT machine, and the total punching time is minimized by the simulated annealing algorithm. Some manufacturing constraints in punching sequences such as punching priority constraint and punching accuracy constraint are incorporated automatically in optimization, while several user-interactions to edit the final tool path are usually required in commercial systems.

Optimal sensor placement for mode shapes using improved simulated annealing

  • Tong, K.H.;Bakhary, Norhisham;Kueh, A.B.H.;Yassin, A.Y. Mohd
    • Smart Structures and Systems
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    • v.13 no.3
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    • pp.389-406
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    • 2014
  • Optimal sensor placement techniques play a significant role in enhancing the quality of modal data during the vibration based health monitoring of civil structures, where many degrees of freedom are available despite a limited number of sensors. The literature has shown a shift in the trends for solving such problems, from expansion or elimination approach to the employment of heuristic algorithms. Although these heuristic algorithms are capable of providing a global optimal solution, their greatest drawback is the requirement of high computational effort. Because a highly efficient optimisation method is crucial for better accuracy and wider use, this paper presents an improved simulated annealing (SA) algorithm to solve the sensor placement problem. The algorithm is developed based on the sensor locations' coordinate system to allow for the searching in additional dimensions and to increase SA's random search performance while minimising the computation efforts. The proposed method is tested on a numerical slab model that consists of two hundred sensor location candidates using three types of objective functions; the determinant of the Fisher information matrix (FIM), modal assurance criterion (MAC), and mean square error (MSE) of mode shapes. Detailed study on the effects of the sensor numbers and cooling factors on the performance of the algorithm are also investigated. The results indicate that the proposed method outperforms conventional SA and Genetic Algorithm (GA) in the search for optimal sensor placement.

Evaluation of Electrical Properties of IZO Thin-Film with UV Post-Annealing Treatment Time (IZO 박막 트랜지스터의 UV를 이용한 후열처리 조사 시간에 따른 전기적 특성 평가)

  • Lee, Jae-Yun;Kim, Han-Sang;Kim, Sung-Jin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.2
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    • pp.93-98
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    • 2020
  • We investigated the effect of a post-annealing process using ultraviolet (UV) light on the electrical properties of solution-processed InZnO (IZO) thin-film transistors (TFTs). UV light was irradiated on IZO TFTs for different time periods of 0s, 30s, and 90s. We measured transfer and retention stability curves to evaluate the performance of the fabricated TFTs. In addition, we measured height, amplitude, and phase AFM images to analyze changes in the surface and morphology of the devices. AFM measurements were performed by setting the drive amplitude of the cantilever tip to 47.9 mV in tapping mode, then dividing the device surface into 500 nm × 500 nm. In the case of IZO TFT irradiated with UV for 30s, the electron mobility and Ion/Ioff ratio were improved, the threshold voltage was reduced by approximately 2 V, and the subthreshold swing also decreased form 1.34 V/dec to 1.11 V/dec.

Effects of Continuous Annealing Parameters on Microstructures in a Cold-Rolled High Strength Steel (고장력 냉연강판에서 미세조직에 대한 연속어닐링조건의 영향)

  • Jeong, Woo Chang
    • Journal of the Korean Society for Heat Treatment
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    • v.17 no.5
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    • pp.283-292
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    • 2004
  • The effects of the annealing parameters on microstructures were examined in a cold-rolled high strength steel containing 0.1% C, 0.5% Si, 1.5% Mn, and 0.04% Nb. It was impossible to avoid martensite in the microstructure even though the continuous annealing parameters were controlled. This indicates that the alloying elements such as silicon and manganese contributing to manganese equivalent($Mn_{eq}$) should be reduced to produce the ferrite-pearlite microstructure for the solid solution and precipitation hardened steel. It was found that a decrease in the rapid cooling temperature to $520^{\circ}C$ was effective to change the microstructure from ferrite-martensite to ferrite-pearlite-martensite. Typical dual-phase properties exhibiting a low yield ratio and a continuous yielding behavior were obtained when the rapid cooling temperature was in the range of $680^{\circ}C$ to $600^{\circ}C$. The critical volume fraction of martensite for the typical properties of dual-phase steel was about 11 percent.

SIMULATED ANNEALING FOR LINEAR SCHEDULING PROJECTS WITH MULTIPLE RESOURCE CONSTRAINTS

  • C.I. Yen
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.530-539
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    • 2007
  • Many construction projects such as highways, pipelines, tunnels, and high-rise buildings typically contain repetitive activities. Research has shown that the Critical Path Method (CPM) is not efficient in scheduling linear construction projects that involve repetitive tasks. Linear Scheduling Method (LSM) is one of the techniques that have been developed since 1960s to handle projects with repetitive characteristics. Although LSM has been regarded as a technique that provides significant advantages over CPM in linear construction projects, it has been mainly viewed as a graphical complement to the CPM. Studies of scheduling linear construction projects with resource consideration are rare, especially with multiple resource constraints. The objective of this proposed research is to explore a resource assignment mechanism, which assigns multiple critical resources to all activities to minimize the project duration while satisfying the activities precedence relationship and resource limitations. Resources assigned to an activity are allowed to vary within a range at different stations, which is a combinatorial optimization problem in nature. A heuristic multiple resource allocation algorithm is explored to obtain a feasible initial solution. The Simulated Annealing search algorithm is then utilized to improve the initial solution for obtaining near-optimum solutions. A housing example is studied to demonstrate the resource assignment mechanism.

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