• Journal of the Korean Chemical Society
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• v.60 no.4
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• pp.225-234
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• 2016

The activity of 34 sulfonamide derivatives has been estimated by means of multiple linear regression (MLR), artificial neural network (ANN), simulated annealing (SA) and genetic algorithm (GA) techniques. These models were also utilized to select the most efficient subsets of descriptors in a cross-validation procedure for non-linear -log (IC50) prediction. The results obtained using GA-ANN were compared with MLR-MLR, MLR-ANN, SA-ANN and GA-ANN approaches. A high predictive ability was observed for the MLR-MLR, MLR-ANN, SA-ANN and MLR-GA models, with root mean sum square errors (RMSE) of 0.3958, 0.1006, 0.0359, 0.0326 and 0.0282 in gas phase and 0.2871, 0.0475, 0.0268, 0.0376 and 0.0097 in solvent, respectively (N=34). The results obtained using the GA-ANN method indicated that the activity of derivatives of sulfonamides depends on different parameters including DP03, BID, AAC, RDF035v, JGI9, TIE, R7e+, BELM6 descriptors in gas phase and Mor 32u, ESpm03d, RDF070v, ATS8m, MATS2e and R4p, L1u and R3m in solvent. In conclusion, the comparison of the quality of the ANN with different MLR models showed that ANN has a better predictive ability.

• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.4
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• pp.137-147
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• 1998

The neural net application was tried to develop the technique for monitoring the health status of a steel truss bridge which was scaled down to 1/15 of the real bridge for the laboratory experiments. The damage scenarios were chosen as 7 cases. The dynamic behavior, which was changed due to the breakage of the members, of the bridge was investigated by finite element analysis. The bridge consists of single spam, and eight (8) main structural subsystems. The loading vehicle, which weighs as 100 kgf, was operated by the servo-motor controller. The accelerometers were bonded on the surface of 7 cross-beams to measure the dynamic behavior induced by the abnormal structural condition. Artificial neural network technique was used to determine the severity of the damage. At first, the neural net was learnt by the results of finite element analysis, and also, the maximum detection error was 3.65 percents. Another neural net was also learnt, and verified by the experimental results, and in this case, the maximum detection error was 1.05 percents. In future study, neural net is necessary to be learnt and verified by various data from the real bridge.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.398-401
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• 1998

A 56-year-old female with a permanent unipolar pacing(VVI) system underwent elective coronary bypass surgery and mitral valve replacement. Because the unipolar sensing is subject to considerable nonmyocardial electrical noise, the pacing function may be disturbed by the use of electrocautery. Temporary atrial and ventricular bipolar epicardial leads and external generator were used for maintaining A-V sequential pacing during the use of electrocautery. Before aortic cross-clamp was released after cardiac operation, regular cardiac rhythm could spontaneously be resumed with an integrated cardioplegic strategy, avoiding the use of defibrillator

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.9-15
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• 2009

Recently, giant embryonic rice and functional rice food are preferred by more consumers, which are attributed to the fact that the embryo has high concentrations of essential amino acids, fatty acids, and vitamins relative to other parts of rice grains. In this report, the heredity and stability of giant embryo mutations in successive generations were analyzed regarding a giant embryonic line, 'P47', induced by T-DNA insertion and a $F_2$ population from a cross between 'P47' and 'Junam'. The mutant lines with increases of 1.5, 1.7 and 1.8 times on embryo length, width and 100-embryo weight to those of the control showed stable inheritance across three generations. The continuous frequency distributions of embryo size in the $F_2$ population showed that the embryo size is a quantitative trait of polygene controlled. In addition, wide range of transgressive segregations of six traits affecting embryo size confirmed exchange of genetic materials and recombination between genes controlling embryo size. Five giant embryo mutant lines selected from the $F_2$ population will be used for artificial selection and improvement of giant embryonic varieties.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.446-446
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• 2018

The urban rivers have unique hydraulic characteristics between natural rivers and artificial canals. These hydraulic characteristics determine the characteristics of urban rivers with small environmental capacity and fragile ecosystems. With the development and utilization of natural resources, the pollutants that have been produced enter the river through different channels, which seriously damages the urban river ecosystem. Therefore, how to restore contaminated water to a normal state and reproduce a natural, self-regulating ecosystem is one of the most concerned issues in recently. Eco-hydraulics is a cross-disciplinary subject of hydraulics biology and ecology. It is closely related to the protection of rivers, wetlands, and ecological self-repair. In this study, The basic principle of eco-hydraulics is concisely described and its approaches to protection and rehabilitation of river are introduced. The conception of establishing gardenesque eco-pond for urban use is suggested. The strategies including changing the hydrodynamic features of rivers, adjusting the breeds and species and constructing the gardenesque eco-pond for improving the exist ing urban rivers are proposed. It provides scientific information and guidance for the restoration of rivers and wetlands by studying the close relationship between river hydraulic characteristics, currents, and rivers and ecosystems.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2547-2555
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• 2021

The frequency of reactor coolant leakage is expected to increase over the lifetime of a nuclear power plant owing to degradation mechanisms, such as flow-acceleration corrosion and stress corrosion cracking. When loss of coolant accidents (LOCAs) occur, several parameters change rapidly depending on the size and location of the cracks. In this study, leak flow during LOCAs is predicted using a deep fuzzy neural network (DFNN) model. The DFNN model is based on fuzzy neural network (FNN) modules and has a structure where the FNN modules are sequentially connected. Because the DFNN model is based on the FNN modules, the performance factors are the number of FNN modules and the parameters of the FNN module. These parameters are determined by a least-squares method combined with a genetic algorithm; the number of FNN modules is determined automatically by cross checking a fitness function using the verification dataset output to prevent an overfitting problem. To acquire the data of LOCAs, an optimized power reactor-1000 was simulated using a modular accident analysis program code. The predicted results of the DFNN model are found to be superior to those predicted in previous works. The leak flow prediction results obtained in this study will be useful to check the core integrity in nuclear power plant during LOCAs. This information is also expected to reduce the workload of the operators.

• Journal of Korea Multimedia Society
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• v.22 no.3
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• pp.349-356
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• 2019

When a prescription change occurs in the hospital depending on a patient's improvement status, pharmacists directly classify manually returned pills which are not taken by a patient. There are hundreds of kinds of pills to classify. Because it is manual, mistakes can occur and which can lead to medical accidents. In this study, we have compared YOLO, Faster R-CNN and RetinaNet to classify and detect pills. The data consisted of 10 classes and used 100 images per class. To evaluate the performance of each model, we used cross-validation. As a result, the YOLO Model had sensitivity of 91.05%, FPs/image of 0.0507. The Faster R-CNN's sensitivity was 99.6% and FPs/image was 0.0089. The RetinaNet showed sensitivity of 98.31% and FPs/image of 0.0119. Faster RCNN showed the best performance among these three models tested. Thus, the most appropriate model for classifying pills among the three models is the Faster R-CNN with the most accurate detection and classification results and a low FP/image.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.806-812
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• 2020

Purpose: This is aimed to evaluate the seismic fragility of curved bridge structure with I-shape girder subjected to 12 high frequency ground motions based on Gyeongju earthquake. Method: The linear elastic finite element model of curved bridge with I-Shape cross section was constructed and them linear elastic time history analyses were performed using the 12 artificial ground motions. Result: It was found that displacement response(LS1, LS2) was failed after PGA 0.1g and the stress response also showed failure after PGA 0.2g. Conclusion: The curved bridge with I-shape girder was sensitive to high frequency earthquakes.

• Tribology and Lubricants
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• v.37 no.1
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• pp.1-6
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• 2021

This paper presents the experimental results of hydrophobic surfaces developed using a stereolithography-based additive-manufacturing technique. The additive manufacturing technique can be used to manufacture objects with complex geometries from computer-aided design data. Several additive manufacturing methods, such as selective laser sintering, fused deposition modeling, stereolithography apparatus (SLA), and inkjet-based system, have been developed. The SLA is a form of three-dimensional printing technology used to create prototypes, patterns, and production parts in successive layers through photochemical processes. Light causes chemical monomers and oligomers to cross-link together to form objects composed of polymers. Moreover, this method is economical for fabricating surfaces with high output resolution and quality. Here, we fabricate various surfaces using different shapes using an SLA. The surfaces with micro-patterns are fabricated for 10 cases, including the biomimetic surface. The fabricated surfaces with various micro-patterns are evaluated for hydrophobicity performance based on the static contact angle. The contact angle is measured three times for each case, and the averaged value is used. The results indicate that the arrangements in a staggered structure have a larger contact angle than those in a line when the same micro-pattern is applied. Moreover, the mimetic surfaces exhibit more hydrophobic characteristics than those of artificial micro-patterns.

• Earthquakes and Structures
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• v.24 no.1
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• pp.1-9
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• 2023

A model for calculating structure interacted mechanics is proposed. A structural interaction model and controller design based on tuned mass damping (TMD) was developed to control the induced vibration. A key point is to introduce a new analytical model to evaluate the properties of the TMD that recognizes the motion-dependent nonlinear response observed in the simulations. Aiming at the problem of increased current harmonics and low efficiency of permanent magnet synchronous motors for electric vehicles due to dead time effect, a dead time compensation method based on neural network filter and current polarity detection is proposed. Firstly, the DC components and the higher harmonic components of the motor currents are obtained by virtue of what the neural network filters and the extracted harmonic currents are adjusted to the required compensation voltages by virtue of what the neural network filters. Then, the extracted DC components are used for current polarity dead time compensation control to avert the false compensation when currents approach zero. The neural network filter method extracts the required compensation voltages from the speed component and the current polarity detection compensation method obtains the required compensation voltages by discriminating the current polarity. The combination of the two methods can more precisely compensate the dead time effect of the control system to improve the control performance. Furthermore, based on the relaxed method, the intelligent approach of stability criterion can be regulated appropriately and the artificial TMD was found to be effective in reducing cross-wind vibrations.