• Title/Summary/Keyword: reaction network

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Prediction of Solvent Effects on Rate Constant of [2+2] Cycloaddition Reaction of Diethyl Azodicarboxylate with Ethyl Vinyl Ether Using Artificial Neural Networks

  • Habibi-Yangjeh, Aziz;Nooshyar, Mahdi
    • Bulletin of the Korean Chemical Society
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    • v.26 no.1
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    • pp.139-145
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    • 2005
  • Artificial neural networks (ANNs), for a first time, were successfully developed for the modeling and prediction of solvent effects on rate constant of [2+2] cycloaddition reaction of diethyl azodicarboxylate with ethyl vinyl ether in various solvents with diverse chemical structures using quantitative structure-activity relationship. The most positive charge of hydrogen atom (q$^+$), dipole moment ($\mu$), the Hildebrand solubility parameter (${\delta}_H^2$) and total charges in molecule (q$_t$) are inputs and output of ANN is log k$_2$ . For evaluation of the predictive power of the generated ANN, the optimized network with 68 various solvents as training set was used to predict log k$_2$ of the reaction in 16 solvents in the prediction set. The results obtained using ANN was compared with the experimental values as well as with those obtained using multi-parameter linear regression (MLR) model and showed superiority of the ANN model over the regression model. Mean square error (MSE) of 0.0806 for the prediction set by MLR model should be compared with the value of 0.0275 for ANN model. These improvements are due to the fact that the reaction rate constant shows non-linear correlations with the descriptors.

The Adaptive Congestion Control Using Neural Network in ATM network (ATM 망에서 뉴럴 네트워크를 이용한 적응 폭주제어)

  • Lee, Yong-Il;Kim, Yung-Kwon
    • Journal of IKEEE
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    • v.2 no.1 s.2
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    • pp.134-138
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    • 1998
  • Because of the statistical fluctuations and the high 'time-variability' nature of the traffic, managing the resources of the network require highly dynamic techniques with minimal Intervention and reaction times, and adaptive and learning capabilities. The neural networks normalizes the ATM cell arrival rate and queue length and has the adaptive learning algorithm, and experimentally investigated the method to prevent the congestion generated in ATM networks.

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A STUDY OF SIMULATION AND CONTROL OF PAC COSING PROCESS IN WATER PURIFICATION SYSTEM

  • Nahm, Euisuck;Lee, Subum;Woo, Kwangbang;Han, Taehan
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.75-78
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    • 1995
  • In this paper it is concerned to develop control method using jar-test results in order to predict the optimum dosage of coaglant, PAC(PoliAluminum Chloride). Considering the relations with the reactions with the reaction of coagulation and flocculation, the five independent variables ( e, g, turbidity of raw water, water turbidity in flocculators, temperature, pH, and alkalynity) are selected out of parameters and they are put into calculation to develop a neural network model for PAC dosing process in water purification system. This model is utilized to predict optimum dosage of PAC. That is, the optimum dosage of PAC is searched in neural network model for PAC dosing process to minimize the water turbidity in flocculators. This searching is implemented by means of expert heuristics. The efficacy of the proposed contorl schemem and feasibility of acquired neural network model for PAC dosing contorl in water purification system is evaluated by means of computer simulation.

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Comparison of visual colorimetric Analysis and neural network algorithm in urine strip classification (뇨 스트립 분류에서 육안비색법과 신경회로망 알고리즘 비교)

  • Eum, Sang-hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.10
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    • pp.1394-1397
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    • 2020
  • The urine test used as a basic test method of in vitro diagnosis for health care has been used for a long time to be simple and convenient. The urine test method is using a color that appears depending on the change in the ion concentration that reacts over time buried in the standard color test paper(Strips) with a urine sample applied to some reaction reagents. In this paper, it was proposed a neural network algorithm to obtain a suitable and reproducibility and accuracy classifier suitable for the urine analysis system. The experimental results were compared with the visual colorimetric analysis, and the neural network algorithm showed better results.

Human Face Recognition Based on improved CNN Model with Multi-layers

  • Zhang, Ruyang;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • v.24 no.5
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    • pp.701-708
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    • 2021
  • As one of the most widely used technology in the world right now, Face recognition has already received widespread attention by all the researcher and institutes. It has been used in many fields such as safety protection, surveillance system, crime control and even in our ordinary life such as home security and so on. This technology with today's technology has advantages such as high connectivity and real time transformation. But we still need to improve its recognition rate, reaction time and also reduce impact of different environmental status to the whole system. So in this paper we proposed a face recognition system model with improved CNN which combining the characteristics of flat network and residual network, integrated learning, simplify network structure and enhance portability and also improve the recognition accuracy. We also used AR and ORL database to do the experiment and result shows higher recognition rate, efficiency and robustness for different image conditions.

Mapping Between Models for Pathway Dynamics and Structural Representations of Biological Pathways

  • Yavas, Gokhan;Ozsoyoglu, Z. Meral
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.415-420
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    • 2005
  • Mathematical modeling and simulation of biochemical reaction networks gained a lot of attention recently since it can provide valuable insights into the interrelationships and interactions of genes, proteins and metabolites in a reaction network. A number of attempts have been made for modeling and storing biochemical reaction networks without their dynamical properties but unfortunately storing and efficiently querying of the dynamic (mathematical) models are not yet studied extensively. In this paper, we present a novel nested relational data schema to store a pathway with its dynamic properties. We then show how to make the mapping between this dynamic pathway schema with the corresponding static pathway representation.

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Theoretical Mechanism Studies on the Enantioselectivity of aza-MBH-type Reaction of Nitroalkene to N-tosylimine Catalyzed by Thiourea-tertiary Amine

  • Lu, Nan;Wang, Huatian;Wang, Yangping
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3591-3596
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    • 2013
  • The enantioselective aza-Morita Baylis Hillman reaction of nitroalkene and N-tosylimine catalyzed by thiourea-tertiary amine has been investigated using density functional theory. Enantioselectivity is dominated by the cooperative effect of non-covalent and weak covalent interactions imposed by different units of catalyst. As Lewis base, the tertiary amine unit activates nitroalkene via weak covalent bond. The weak covalent interaction orients the reaction in a major path with smaller variations of this bond. The aromatic ring unit activates N-tosylimine via ${\pi}-{\pi}$ stacking. The non-covalent interaction selects the major path with smaller changes of the efficient packing areas. Thiourea unit donates more compact H-bonded network for species of the major path. The calculated ee value in xylene solution phase (97.6%) is much higher than that in N,N-Dimethylformamide (27.2%). Our conclusion is also supported by NBO analysis.

A Visualization of Movie Reviews based on a Semantic Network Analysis (의미연결망 분석을 활용한 영화 리뷰 시각화)

  • Kim, Seulgi;Kim, Jang Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.1
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    • pp.1-6
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    • 2019
  • This study visualized users reaction about movies based on keywords with high frequency. For this work, we collected data of movie reviews on . A total of six movies were selected, and we conducted the work of data gathering and preprocessing. Semantic network analysis was used to understand the relationship among keywords. Also, NetDraw, packaged with UCINET, was used for data visualization. In this study, we identified the differences in characteristics of review contents regarding each movie. The implication of this study is that we visualized movie reviews made by sentence as keywords and explored whether it is possible to construct the interface to check users' reaction at a glance. We suggest that further studies use more diverse movie reviews, and the number of reviews for each movie is used in similar quantities for research.

An Attention-based Temporal Network for Parkinson's Disease Severity Rating using Gait Signals

  • Huimin Wu;Yongcan Liu;Haozhe Yang;Zhongxiang Xie;Xianchao Chen;Mingzhi Wen;Aite Zhao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.10
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    • pp.2627-2642
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    • 2023
  • Parkinson's disease (PD) is a typical, chronic neurodegenerative disease involving the concentration of dopamine, which can disrupt motor activity and cause different degrees of gait disturbance relevant to PD severity in patients. As current clinical PD diagnosis is a complex, time-consuming, and challenging task that relays on physicians' subjective evaluation of visual observations, gait disturbance has been extensively explored to make automatic detection of PD diagnosis and severity rating and provides auxiliary information for physicians' decisions using gait data from various acquisition devices. Among them, wearable sensors have the advantage of flexibility since they do not limit the wearers' activity sphere in this application scenario. In this paper, an attention-based temporal network (ATN) is designed for the time series structure of gait data (vertical ground reaction force signals) from foot sensor systems, to learn the discriminative differences related to PD severity levels hidden in sequential data. The structure of the proposed method is illuminated by Transformer Network for its success in excavating temporal information, containing three modules: a preprocessing module to map intra-moment features, a feature extractor computing complicated gait characteristic of the whole signal sequence in the temporal dimension, and a classifier for the final decision-making about PD severity assessment. The experiment is conducted on the public dataset PDgait of VGRF signals to verify the proposed model's validity and show promising classification performance compared with several existing methods.

A Flexible Network Access Scheme for M2M Communications in Heterogeneous Wireless Networks

  • Tian, Hui;Xie, Wei;Xu, Youyun;Xu, Kui;Han, Peng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.10
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    • pp.3789-3809
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    • 2015
  • In this paper, we deal with the problem of M2M gateways' network selection for different types of M2M traffic in heterogeneous wireless networks. Based on the difference in traffic's quality of service (QoS) requirements, the M2M traffic produced by various applications is mainly classified as two categories: flexible traffic and rigid traffic. Then, game theory is adopted to solve the problem of network-channel selection with the coexistence of flexible and rigid traffic, named as flexible network access (FNA). We prove the formulated discrete game is a potential game. The existence and feasibility of the Nash equilibrium (NE) of the proposed game are also analyzed. Then, an iterative algorithm based on optimal reaction criterion and a distributed algorithm with limited feedback based on learning automata are presented to obtain the NE of the proposed game. In simulations, the proposed iterative algorithm can achieve a near optimal sum utility of whole network with low complexity compared to the exhaustive search. In addition, the simulation results show that our proposed algorithms outperform existing methods in terms of sum utility and load balance.