• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1330-1333
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• 1993

In this paper, first, the fuzzy Petri net inference mechanism with learning function is proposed by using the extended fuzzy Petri nets. Secondly, a control system with this new inference engine is proposed. This system can do automatically and easily the knowledge acquisition from the operator's empirical data and can also be controller adaptively under the big parameter change.

• Tribology and Lubricants
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• v.30 no.1
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• pp.15-20
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• 2014

A more accurate expression for effective viscosity is obtained using a linear regression of the data from Fukui-Kaneko's model, which are obtained through numerical calculations based on the linearized Boltzmann equation. Veijola and Turowski's expression is adopted as a base function for effective viscosity. The four coefficients in that equation are optimized, and sensitivity analysis is conducted for these coefficients. The results show that the coefficient for the first-order Knudsen number is the most accurate, whereas the coefficient in the exponential of the Knudsen number is the least accurate compared with Fukui-Kaneko's results. The expression for effective viscosity is accurate within 0.02% rms of Fukui-Kaneko's results for the inverse Knudsen numbers from 0.01 to 100 and surface accommodation coefficients ranging from 0.7 to 1.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3727-3732
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• 2013

The interaction between metalloporphyrins and diazine tautomers was investigated using quantum chemistry method. The results showed that the metal atom in the metalloporphyrin was not coplanar with porphin ring, and zinc porphyrin has the most extent of its non-coplanar nature. The most stable complex in nine complexes was iron porphyrin. NBO analysis indicated that the interaction between the lone pair of electrons on the nitrogen atom and the unoccupied lone pair orbital of metal contributes significantly to the stability of the complexes. Through the conceptual DFT parameter and Fukui dual descriptor, the thermodynamic stability and reactivity of complexes were analyzed. The density difference function (DDF) analyzes were performed to explore the rearrangement of electronic density after the coordination interaction. NICS calculation indicated that metalloporphyrin aromaticity was reduced after the coordination interaction, and aromaticity of diazine tautomer was increased along direction vector of the coordination interaction force.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.301-304
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• 2002

Recently, database technologies have been used commonly. But, ordinary technologies aren't suitable to construct a complicated database such as a classical literature database or an archaeological relic's database. Because this kinds of data are semi-structured data that doesn't have regular structures, database schema can't be defined before databases. We have proposed DREAM model for semi-structured databases. In this model, a database consists of five elements and the model has operations similar to operation of set theory. And further we have introduced dynamic schema "shape" showing structure of each element. We have already realized a prototype of DBMS adopting DREAM model (DREAM DBMS) and constructing function of shapes. However, shape is imperfect to describe database structures because it can't explain nested structures of elements. In this paper, we will profuse a "shape graph"that is dynamic schema showing database structures more exactly and extend the DREAM DBMS. Further we will evaluate the performance of constructing function of shapes and shape graphs.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1457-1459
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• 2003

This study reports the surface temperature pattern of the Tokyo Metropolitan area using the ASTER surface temperature product. The product is an image processed by applying temperature-emissivity separation to atmospheric corrected infrared thermal radiance of the land surface, then converted to surface temperature by using Planck's function. Daytime and nighttime observation in a cold season and a warm season were used in this study. As a result, 1) contrast between urban and suburban, 2) extraction of heating area in urban, 3) measurement of cooling effect of green space were achieved.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.78-81
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• 2003

This paper proposes a fuzzy classifier system (FCS) using hyper-cone membership functions (HCMFs) and rule reduction techniques. The FCS can generate excellent rules which have the best number of rules and the best location and shape of membership functions. The HCMF is expressed by a kind of radial basis function, and its fuzzy rule can be flexibly located in input and output spaces. The rule reduction technique adopts a decreasing method by merging the two appropriate rules. We applay the FCS to a tubby rule generation for the inverted pendulum control.

• Progress in Medical Physics
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• v.32 no.2
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• pp.50-58
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• 2021

Purpose: In this study, we investigated the relationship between the noise characteristics and the number of projected images in tomosynthesis using a digital phantom. Methods: The digital phantom consisted of a columnar phantom in the center of the image and a spherical phantom with a diameter of 80 pixels. A virtual scan was performed, and 128 projected images (Tomo_w/o) of the phantoms were obtained. The image noise according to the Poisson distribution was added to the projected images (Tomo_×1). Furthermore, another projected image with additional noise was prepared (Tomo_×1/2). For each dataset, we created datasets with 64 (half) and 32 (quarter) projections by removing the even-numbered images twice from the 128 (fully) projected images. Tomosynthesis images were reconstructed by filtered back projection (FBP). The modulation transfer function (MTF) was estimated using the sphere method, and the noise power spectrum (NPS) was estimated using the two-dimensional Fourier transform method. Results: The MTFs did not change between datasets, and the NPSs improved as the number of projected images increased. The noise characteristics of the Tomo_×1_half images were the same as those of the Tomo_×1/2_full. Conclusions: To achieve a reduction in the patient dose in tomosynthesis acquisition, we recommend reducing the number of projected images rather than reducing the dose per projection.

• ETRI Journal
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• v.42 no.2
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• pp.205-216
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• 2020

An arbiter physical unclonable function (APUF) has exponential challenge-response pairs and is easy to implement on field-programmable gate arrays (FPGAs). However, modeling attacks based on machine learning have become a serious threat to APUFs. Although the modeling-attack resistance of an MA-APUF has been improved considerably by architecture modifications, the response generation method of an MA-APUF results in low uniqueness. In this study, we demonstrate three design problems regarding the low uniqueness that APUF-based strong PUFs may exhibit, and we present several foundational principles to improve the uniqueness of APUF-based strong PUFs. In particular, an improved MA-APUF design is implemented in an FPGA and evaluated using a well-established experimental setup. Two types of evaluation metrics are used for evaluation and comparison. Furthermore, evolution strategies, logistic regression, and K-junta functions are used to evaluate the security of our design. The experiment results reveal that the uniqueness of our improved MA-APUF is 81.29% (compared with that of the MA-APUF, 13.12%), and the prediction rate is approximately 56% (compared with that of the MA-APUF (60%-80%).

• Molecules and Cells
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• v.23 no.3
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• pp.280-286
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• 2007

L-asparaginase (EC 3.5.1.1) catalyzes the hydrolysis of the amide group of L-asparagine, releasing aspartate and $NH_4{^+}$. We isolated a low temperature-inducible cDNA sequence encoding L-asparaginase from soybean leaves. The full-length L-asparaginase cDNA, designated GmASP1, contains an open reading frame of 1,258 bp coding for a protein of 326 amino acids. Genomic DNA blotting and fluorescence in situ hybridization showed that the soybean genome has two copies of GmASP1. GmASP1 mRNA was induced by low temperature, ABA and NaCl, but not by heat shock or drought stress. E. coli cells expressing recombinant GmASP1 had 3-fold increased L-asparaginase activity. A possible function of L-asparaginase in the early response to low temperature stress is discussed.