• JSTS:Journal of Semiconductor Technology and Science
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• 제7권4호
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• pp.215-220
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• 2007

Leakage current of CMOS circuits has become a major factor in VLSI design these days. Although many circuit-level techniques have been developed, most of them require significant amount of designers' effort and are not aligned well with traditional VLSI design process. In this paper, we focus on technology mapping, which is one of the steps of logic synthesis when gates are selected from a particular library to implement a circuit. We take a radical approach to push the limit of technology mapping in its capability of suppressing leakage current: we use a probabilistic leakage (together with delay) as a cost function that drives the mapping; we consider pin reordering as one of options in the mapping; we increase the library size by employing gates with larger gate length; we employ a new flipflop that is specifically designed for low-leakage through selective increase of gate length. When all techniques are applied to several benchmark circuits, leakage saving of 46% on average is achieved with 45-nm predictive model, compared to the conventional technology mapping.

• 반도체디스플레이기술학회지
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• 제20권2호
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• pp.137-140
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• 2021

High dynamic range (HDR) technology has been drawing attention in the field of imaging and consumer entertainment. As tools for capturing and creating HDR contents, encoding, and transmission evolve to support HDR formats, various display capabilities are being developed and increased. Hence, there is need for remapping native HDR imagery for display on lower quality legacy standard dynamic range (SDR) displays. This operation is referred to as tone mapping. In this paper, we present a sectional tone mapping method by Lenzen, and expand upon a tone mapping approach to improve temporal stability while maintaining picture quality. Compared to the existing block-based sectional tone mapping, our method uses the edge awareness-based tone mapping. We estimate the performance of the objective metric on temporal flickering. The experimental result shows that the algorithm maintains a smoother relationship between the output luminance values, and this reveals success in reducing halos and improving temporal stability with adopted edge aware filtering.

• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.78-84
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• 2022

In this paper, to improve further the bit-error rate (BER) performance of the stronger channel user in non-uniform source non-orthogonal multiple access (NOMA) with symmetric superposition coding (SSC), we propose a smart bit-to-symbol (BTS) mapping of SSC. First, the analytical expression for the total allocated power of the proposed BTS mapping scheme is derived, and then we show that the BER of the proposed BTS mapping scheme improves further, compared to that of the existing BTS mapping scheme. Moreover, based on the simulations, the signal-to-noise (SNR) gain of the proposed BTS mapping scheme over the existing BTS mapping scheme is calculated. In result, the proposed BTS mapping could be a candidate scheme for non-uniform source SSC NOMA with the SNR gain.

• 한국초등과학교육학회지:초등과학교육
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• 제29권3호
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• pp.341-349
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• 2010

In this study, the effects of concept mapping with feedbacks providing explanatory comments on students' achievement, science learning anxiety, and science learning motivation were investigated in the undergraduate general chemistry course. The aptitude-treatment interactions between students' level of mastery goal orientation and the concept mapping with explanation feedback treatment were also examined. Sixty-seven freshmen from an university of education were assigned to a control group and a treatment group. The tests of mastery goal orientation, science anxiety, and science learning motivation were administered as pretests. For the treatment group, feedback providing students with explanatory comments through whole class discussion was presented after each concept mapping. Whereas the control group students were presented with opportunities solving excercise problems followed by explanation feedback. The intervention was lasted for 10 weeks (30 class periods). After the instructions, a researcher-made achievement test, the science learning anxiety test, and the science learning motivation test were administered. The results indicated that no statistically significant difference was found in students' achievement. In the science learning anxiety, however, the scores of the treatment group was significantly lower than those of the control group. The scores of the treatment group also tended to be higher, though not significant, than those of the control group in the science learning motivation. However, no significant aptitude-treatment interactions were found in all dependent variables.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권3호
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• pp.153-164
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• 2011

Equivalence relations and mappings for crisp sets are very well known. This paper attempts an investigation of equivalence relations and mappings for fuzzy sets. We list some concepts and results related to fuzzy relations. We give some examples corresponding to the concept of fuzzy equality and fuzzy mapping introduced by Demirci [1]. In addition, we introduce the notion of preimage and quotient of fuzzy equivalence relations. Finally, we investigate relations between a fuzzy equivalence relation and a fuzzy mapping.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권7호
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• pp.2957-2980
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• 2020

Ensemble clustering commonly integrates multiple basic partitions to obtain a more accurate clustering result than a single partition. Specifically, it exists an inevitable problem that the incomplete transformation from the original space to the integrated space. In this paper, a novel ensemble clustering algorithm using a newly reconstructed mapping coefficient (ECRMC) is proposed. In the algorithm, a newly reconstructed mapping coefficient between objects and micro-clusters is designed based on the principle of increasing information entropy to enhance effective information. This can reduce the information loss in the transformation from micro-clusters to the original space. Then the correlation of the micro-clusters is creatively calculated by the Spearman coefficient. Therefore, the revised co-association graph between objects can be built more accurately because the supplementary information can well ensure the completeness of the whole conversion process. Experiment results demonstrate that the ECRMC clustering algorithm has high performance, effectiveness, and feasibility.

• International Journal of CAD/CAM
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• 제9권1호
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• pp.103-109
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• 2010

Recently, various conformal geometric methods have been presented for non-rigid surface matching and registration. This work proposes to improve the robustness of conformal geometric methods to the boundaries by incorporating the symmetric information of the input surface. We presented two symmetric conformal mapping methods, which are based on solving Riemann-Cauchy equation and curvature flow respectively. Experimental results on geometric data acquired from real life demonstrate that the symmetric conformal mapping is insensitive to the boundary occlusions. The method outperforms all the others in terms of robustness. The method has the potential to be generalized to high genus surfaces using hyperbolic curvature flow.

• Kyungpook Mathematical Journal
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• 제46권3호
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• pp.399-408
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• 2006

The action of mapping class groups of a handlebody on the first homology group is investigated. A homological analogy of mapping class groups of a handlebody is defined and its system of generators is given.

• 한국초등과학교육학회지:초등과학교육
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• 제28권3호
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• pp.292-303
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• 2009

In this study, we investigated the characteristics of the analogies, the mapping understanding, and the mapping errors on saturated solution of scientifically-gifted and general elementary students. Fifth graders (n=60) at four scientifically-gifted education institutes in Seoul and/or Gyeonggi province and fifth graders (n=91) at three elementary schools in Seoul were selected and assigned to the scientifically-gifted group and the general group respectively. After the students of each group performed the experiment and were taught about the target concept in the first class, they administered the test on the self-generating analogies on the target concept in the second class. The results revealed that the students in the scientifically-gifted group made more analogies, especially verbal/pictorial, structural/functional, enriched, and higher systematic ones, and had deeper understanding of the analogy than those in the general group. The numbers of the shared attributes included in the student-generated analogies and the scores of the mapping understanding of the students in the scientifically-gifted group were significantly higher than those in the general group. The students in the scientifically-gifted group had fewer mapping errors than those in the general group. However, not a few students in the scientifically-gifted group had at least one mapping error. Educational implications of these findings are discussed.

• 대한수학회보
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• 제39권1호
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• pp.43-51
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• 2002

The aim of this paper is to prove a convergence theorem of a generalized Ishikawa iteration sequence for two multi-valued strongly pseudo-contractive mappings by using an approximation method in real uniformly smooth Banach spaces. We generalize and extend the results of Chang and Chang, Cho, Lee, Jung, and Kang.