• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1758-1760
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• 2008

Under typical operating conditions, flows in microfluidic devices are laminar and molecular diffusion across the channels is slow, which makes an efficient mixing in microfluidic devices difficult to achieve. The mechanism to achieve effective mixing in laminar flows is that of repetitive stretching and folding. Essential is to generate spatially periodic flows with crossing cross sectional streamlines. A mapping method is employed to analyze mixing in micromixers, enabling us to investigate the progress of mixing both qualitatively and quantitatively. The progress of mixing is characterized by a measure of mixing, called the discrete intensity of segregation. The mapping method is applied to mixing in such micromixers as the staggered herringbone mixer, the barrier embedded micromixer, and the three-dimensional serpentine channel to demonstrate the capability of the numerical scheme to tackle general mixing problems in microfluidic devices.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.1015-1020
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• 1994

This paper presents the Korean digit recognition method under noise environment using the spectral mapping training based on static supervised adaptation algorithm. In the presented recognition method, as a result of spectral mapping from one space of noisy speech spectrum to another space of speech spectrum without noise, spectral distortion of noisy speech is improved, and the recognition rate is higher than that of the conventional method using VQ and DTW without noise processing, and even when SNR level is 0 dB, the recognition rate is 10 times of that using the conventional method. It has been confirmed that the spectral mapping training has an ability to improve the recognition performance for speech in noise environment.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.5
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• pp.10-15
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• 2011

Histogram equalization is an effective method to enhance the contrast of the image. However, it can result in unwanted artifacts such as excessive contrast enhancement and noise amplification. These artifacts can be reduced by modifying an intensity mapping function which is generated by histogram equalization. In this paper, we present a variational approach to the modification of the intensity mapping function. We define a functional whose minimization produces a modified intensity mapping function. Experimental results show that the intensity mapping function obtained by the proposed method can enhance the contrast of the image without visual artifacts.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.30-36
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• 2006

The participants in collaborative environment want to get the right information or documents which are intended to find. In general search systems, documents which contain only the keywords are retrieved. For searching different word-expressions for the same meaning, we perform mapping before searching. Our mapping-based search approach has two parts, ontology-based mapping logic and ontology libraries. The ontology-based mapping consists of three steps such as character matching (CM), definition comparing (DC) and similarity checking (SC). First, the character matching is the mapping of two terminologies that have identical character strings. Second, the definition comparing is the method that compares two terminologies' ontological definitions. Third, the similarity checking pairs two terminologies which were not mapped by two prior steps through evaluating the similarity of the ontological definitions. For the ontology libraries, document ontology library (DOL), keyword ontology library (KOL), and mapping result library (MRL) are defined. With these three libraries and three mapping steps, an ontology-based search engine (OntSE) is built, and a use case scenario is discussed to show the applicability.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.447-449
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• 2012

There are many essential elements in making the realistic 3D games, of which one of the most important is mapping. Mapping can add the details to 3D objects easily, which are impossible or difficult by modeling alone, and can reduce file data capacities to run the game engine. The theory of the mapping is to throw 2D image on 3D object correctly, but they do not match each other at the rate of 1:1 100 percent completely due to the difference of the fundamental property of them. To solve this problem, various kinds of mapping methods are developed and used. This paper will compare and analyze the characteristics, and merits and demerits of these various kinds of mapping methods and will inquire which method is the most efficient one.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.11-18
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• 2007

FFT(Fast Fourier Transform) processor is one of the key components in the implementation of OFDM systems such as WiBro, DAB and UWB systems. Most of the researches on the implementation of FFT processors have focused on reducing the complexities of multipliers, memory and control circuits. In this paper, to reduce the memory size required for IFFT(Inverse Fast Fourier Transform), we propose a new IFFT design method based on a mapping method. By simulations, it is shown that the reposed IFFT design method achieves more than 60% area reduction and much SQNR(Signal-to-Quantization-Noise Ratio) gain compared with previous IFFT circuits.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.42-48
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• 2012

Since the Semantic Web emerged, ontology has been widely used in web environment. Even ontologies belong to the same domain, they may contain same meaning different words, or different meaning same words according to their development background and the type of utilization. In order to share and reuse the ontologies, ontology mapping is required. This paper presents a ontology mapping method that consists of the initial process of multi-level mapping based on lexical information, and the second mapping process using the lexical results and structural similarity. Mapping performance was improved by additionally expanding structural information of blank nodes, which have no lexical information. Through experiments, our method achieved 86.38% in F1-measure.

• Journal of Korean Elementary Science Education
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• v.23 no.3
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• pp.208-218
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• 2004

Many elementary school students have misconception related to dissolution and solution. Moreover, they usually fail to apply the results of the experiments in their science classes to their everyday life, and also have low science achievement. Therefore, they are not interested in science, and sometimes some of them are even afraid of it. The purposes of this study is to investigate the effects of concept mapping activity on science achievement and attitude. In addition, this study also aims at presenting the teaching and learning method of utilizing concept maps in order to have the students form correct concepts. The subjects were classified into two groups one group is composed of thirty-seven students (experimental group) who were participated in concept mapping activity, and the other is composed of thirty-eight students (comparison group) who were participated in the traditional teaching method. The major findings of this study are as follows: First, the concept mapping activity has a positive effect on improving students＇ science achievement. Second, the classes using concept maps have a good influence on forming students＇ science attitude. Third, the concept mapping activity is more effective in improving science achievement of mid and low level students. In conclusion, the loaming by concept mapping activity positively influence students＇ science achievement and attitude. Particularly for the students in mid and high levels, the effect is more remarkable.

• Journal of the Korea Society of Computer and Information
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• v.24 no.8
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• pp.9-17
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• 2019

In this paper, we propose a block mapping technique applicable to NAND flash memory. In order to use the NAND flash memory with the operating system and the file system developed on the basis of the hard disk which is mainly used in the general PC field, it is necessary to use the system software known as the FTL (Flash Translation Layer). FTL overcomes the disadvantage of not being able to overwrite data by using the address mapping table and solves the additional features caused by the physical structure of NAND flash memory. In this paper, we propose a new mapping method based on the block mapping method for efficient use of the NAND flash memory. In the case of the proposed technique, the data modification operation is processed by using a blank page in the existing block without using an additional block for the data modification operation, thereby minimizing the block unit deletion operation in the merging operation. Also, the frequency of occurrence of the sequential write request and random write request Accordingly, by optimally adjusting the ratio of pages for recording data in a block and pages for recording data requested for modification, it is possible to optimize sequential writing and random writing by maximizing the utilization of pages in a block.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.115-123
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• 2023

We introduce a new 'image-mapping' in-situ U-Pb dating method using LA-ICP-MS, proposed by Drost et al. (2018), and show the characteristics and usability of this method through several examples of absolute age results determined by first applying it to samples from the Joseon Supergroup of the Early Paleozoic Era in Korea. Unlike the previous in-situ spot analysis, this in-situ U-Pb dating method for carbonate minerals can determine the absolute age with high reliability by applying the 'image-mapping' method of micro-sized domains based on micro-textural observation, as well as determine the absolute age of multiple geological 'events' that occurred after deposition. This was confirmed in the case of determining the syn-depositional age and the multiple post-depositional ages from carbonate minerals of the Makgol and the Daegi Formations. Therefore, if the 'image-mapping' in-situ U-Pb dating method is applied to determine the absolute age of various types of carbonate minerals that exist in various geological environments throughout the geologic era, it will be possible to secure new geological age information.