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Optimal Spatial Allocation of Initial Attack Resources for Firefighting in the Republic of Korea Using a Scenario Optimization Model

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Journal of Mountain Science 2014年第2期11卷 323-335页

作者： Yohan LEE Byungdoo LEE Kyung ha kim Korea Rural Economic Institute 117-3 Hoegi-ro Dongdeamun-guSeoul 130-710 South Korea Korea Forest Research Institute Hoegiro 57 Dongdaemun-guSeoul 130-712 South Korea

【Title】 This study explores the optimal spatial allocation of initial attack resources for firefighting in the Republic of Korea. To improve the effectiveness of Korean initial attack resources with a range of policy goals, we create a scenario optimization model that minimizes the expected number of fires not receiving a predefined response. In this study, the predefined response indicates the number of firefighting resources that must arrive at a fire before the fire escapes and becomes a large fire. We use spatially explicit GIS-based information on the ecology, fire behavior, and economic characterizations important in Korea. The data include historical fire events in the Republic of Korea from 1991 to 2007, suppression costs, and spatial information on forest fire extent. Interviews with forest managers inform the range of we address in the decision model. Based on the geographic data, we conduct a sensitivity analysis by varying the parameters systematically. Information on the relative importance of the components of the settings helps us to identify “rules of thumb” for initial attack resource allocations in particular ecological and policy settings.

关键词： Spatial allocation Initial attack Firefighting The Republic of Korea Senario optimization

Histogram equalization using a reduced feature set of background speakers' utterances for speaker recognition

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Frontiers of Information Technology & Electronic Engineering 2017年第5期18卷 738-750页

作者： Myung-jae kim Il-ho YANG Min-seok kim ha-jin YU School of Computer Science University of Seoul

We propose a method for histogram equalization using supplement sets to improve the performance of speaker recognition when the training and test utterances are very short. The supplement sets are derived using outputs of selection or clustering algorithms from the background speakers' utterances. The proposed approach is used as a feature normalization method for building histograms when there are insufficient input utterance *** addition, the proposed method is used as an i-vector normalization method in an i-vector-based probabilistic linear discriminant analysis(PLDA) system, which is the current state-of-the-art for speaker verification. The ranks of sample values for histogram equalization are estimated in ascending order from both the input utterances and the supplement set. New ranks are obtained by computing the sum of different kinds of ranks. Subsequently, the proposed method determines the cumulative distribution function of the test utterance using the newly defined ranks. The proposed method is compared with conventional feature normalization methods, such as cepstral mean normalization(CMN), cepstral mean and variance normalization(MVN), histogram equalization(HEQ), and the European Telecommunications Standards Institute(ETSI) advanced front-end methods. In addition, performance is compared for a case in which the greedy selection algorithm is used with fuzzy C-means and K-means *** YOHO and Electronics and Telecommunications Research Institute(ETRI) databases are used in an evaluation in the feature space. The test sets are simulated by the Opus Vo IP codec. We also use the 2008 National Institute of Standards and Technology(NIST) speaker recognition evaluation(SRE) corpus for the i-vector system. The results of the experimental evaluation demonstrate that the average system performance is improved when the proposed method is used, compared to the conventional feature normalization methods.

关键词： Speaker recognition Histogram equalization i-vector

Predicting Concrete Compressive Strength Using Deep Convolutional Neural Network Based on Image Characteristics

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Computers, Materials & Continua 2020年第10期65卷 1-17页

作者： Sanghyo Lee Yonghan Ahn ha Young kim Division of Architecture and Civil Engineering Kangwon National UniversitySamcheok-si25913Korea School of Architecture and Architectural Engineering Hanyang University ERICAAnsan-si15588Korea Graduate School of Information Yonsei UniversitySeoul03722Korea

In this study,we examined the efficacy of a deep convolutional neural network(DCNN)in recognizing concrete surface images and predicting the compressive strength of concrete.A digital single-lens reflex(DSLR)camera and microscope were simultaneously used to obtain concrete surface images used as the input data for the ***,training,validation,and testing of the DCNNs were performed based on the DSLR camera and microscope image *** of the analysis indicated that the DCNN employing DSLR image data achieved a relatively higher *** accuracy of the DSLR-derived image data was attributed to the relatively wider range of the DSLR camera,which was beneficial for extracting a larger number of ***,the DSLR camera procured more realistic images than the ***,when the compressive strength of concrete was evaluated using the DCNN employing a DSLR camera,time and cost were reduced,whereas the usefulness ***,an indirect comparison of the accuracy of the DCNN with that of existing non-destructive methods for evaluating the strength of concrete proved the reliability of DCNN-derived concrete strength *** addition,it was determined that the DCNN used for concrete strength evaluations in this study can be further expanded to detect and evaluate various deteriorative factors that affect the durability of structures,such as salt damage,carbonation,sulfation,corrosion,and freezing-thawing.

关键词： Deep convolutional neural network(DCNN) non-destructive testing(NDT) concrete compressive strength digital single-lens reflex(DSLR)camera microscope

Analytical Study on Piezoelectric Effects on Exciton Dissociation

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Communications in Computational Physics 2016年第6期20卷 179-187页

作者： SeongMin kim Jaewook ha Hyeok kim Jin-Baek kim The Office of the Theory&Modeling Based Design of Energy harvesting(private lab) Maetan 3-dongYeongtong-guSuwon-siGyeonggi-do 443-373Korea Department of Chemistry Korea Advanced Institute of Science and TechnologyDaejeon 305-701Korea Photo-Electronic Hybrids Research Center Korea Institute of Science and TechnologySeoul 136-791Korea CAE Platform Technology LabSamsung Advanced Institute of Technology

We analytically and numerically compute the Onsager dissociation rate(exciton dissociation)on an interface induced by a piezoelectric potential in an inorganicorganic hybrid p-n junction system(ZnO+(poly(p-phenylene vinylene));PPV).When a positive piezoelectric potential is created at the interface region owing to the deformation of the system,free electrons accumulate at the ***,screening effects are *** is assumed that the electron layer formed at the interface then attracts free holes from the p-type PPV region,which leads to exciton formation,possibly via the Langevin recombination *** increased exciton density can then contribute to the Onsager dissociation rate,which is maximum around the *** paper focuses on the role of piezoelectric effects in promoting exciton formation at the interface and its relation with the exciton dissociation rate.

关键词： Exciton dissociation Onsager rate piezoelectric p-n junction recombination

Probability mass first flush evaluation for combined sewer discharges

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Journal of Environmental Sciences 2010年第6期22卷 915-922页

作者： Inhyeok Park Hongmyeong kim Soo-Kwon Chae Sungryong ha Department of Urban Engineering Chungbuk National University Ecowiz Corporation Cheongju School of Human & Environmental Sciences Eulji University

The Korea government has put in a lot of effort to construct sanitation facilities for controlling non-point source pollution. The first flush phenomenon is a prime example of such pollution. However, to date, several serious problems have arisen in the operation and treatment effectiveness of these facilities due to unsuitable design flow volumes and pollution loads. It is difficult to assess the optimal flow volume and pollution mass when considering both monetary and temporal limitations. The objective of this article was to characterize the discharge of storm runoff pollution from urban catchments in Korea and to estimate the probability of mass first flush （MFFn） using the storm water management model and probability density functions. As a result of the review of gauged storms for the representative using probability density function with rainfall volumes during the last two years, all the gauged storms were found to be valid representative precipitation. Both the observed MFFn and probability MFFn in BE-1 denoted similarly large magnitudes of first flush with roughly 40% of the total pollution mass contained in the first 20% of the runoff. In the case of BE-2, however, there were significant difference between the observed MFFn and probability MFFn.

关键词： first flush combined sewer overflows (CSOs) probability mass first flush storm water management model best management practices

A voltage-controlled chaotic oscillator based on carbon nanotube field-effect transistor for low-power embedded systems

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Chinese Physics B 2014年第5期23卷 617-622页

作者： Van ha Nguyen Wonkyeong Park Namtae kim hanjung Song Department of Nano Systems Engineering Inje University Department of Electronics Engineering Inje University Center for Nano Manufacturing Inje University

This paper presents a compact and low-power-based discrete-time chaotic oscillator based on a carbon nanotube field-effect transistor implemented using Wong and Deng＇s well-known model. The chaotic circuit is composed of a nonlinear circuit that creates an adjustable chaos map, two sample and hold cells for capture and delay functions, and a voltage shifter that works as a buffer and adjusts the output voltage for feedback. The operation of the chaotic circuit is verified with the SPICE software package, which uses a supply voltage of 0.9 V at a frequency of 20 kHz. The time series, frequency spectra, transitions in phase space, sensitivity with the initial condition diagrams, and bifurcation phenomena are presented. The main advantage of this circuit is that its chaotic signal can be generated while dissipating approximately 7.8 μW of power, making it suitable for embedded systems where many chaos-signal generators are required on a single chip.

关键词： chaos generator carbon nanotube field-effect transistor bifurcation random noise generator

Thresholdless coherence in a superradiant laser

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Light(Science & Applications) 2024年第11期13卷 2549-2555页

作者： Seung-Hoon Oh Jinuk kim Junseo ha Gibeom Son Kyungwon An Department of Physics and Astronomy&Institute of Applied Physics Seoul National UniversitySeoulKorea Korea Research Institute of Standards and Science DaejeonKorea

Lasing threshold in the conventional lasers is the minimum input power required to initiate laser *** has been widely accepted that the conventional laser threshold occurring around a unity intracavity photon number can be eliminated in the input-output curve by making the so-calledβparameter approach *** recent experiments,however,have revealed that even in this case the photon statistics still undergo a transition from coherent to thermal statistics when the intracavity mean photon number is decreased below *** the coherent output is only available above the diminished threshold,the long-sought promise of thresholdless lasers to produce always coherent light has become ***,we present an always-coherent thresholdless laser based on superradiance by two-level atoms in a quantum superposition state with the same phase traversing a high-Q *** lasing was observed without the conventional lasing threshold around the unity photon number and the photon statistics remained near coherent even below *** coherence was improved by reducing the coupling constant as well as the excited-state amplitude in the superposition *** results pave a way toward always-coherent thresholdless lasers with more practical media such as quantum dots,nitrogen-vacancy centers and doped ions in crystals.

关键词： laser coherent lasing

A Novel Secure Scan Design Based on Delayed Physical Unclonable Function

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Computers, Materials & Continua 2023年第3期74卷 6605-6622页

作者： Weizheng Wang Xingxing Gong Xiangqi Wang gwang-jun kim Fayez Alqahtani Amr Tolba School of Computer and Communication Engineering Changsha University of Science and TechnologyChangsha410114China College of Information Science and Engineering Hunan Women’s UniversityChangsha410138China College of Mathematics and Computational Science Hunan First Normal UniversityChangsha410138China Department of Computer Engineering Chonnam National UniversityGwangju61186Korea Software Engineering Department College of Computer and Information SciencesKing Saud UniversityRiyadh12372Saudi Arabia Computer Science Department Community CollegeKing Saud UniversityRiyadh11437Saudi Arabia

The advanced integrated circuits have been widely used in various situations including the Internet of Things,wireless communication,*** its manufacturing process exists unreliability,so cryptographic chips must be rigorously *** to scan testing provides high test coverage,it is applied to the testing of cryptographic integrated ***,while providing good controllability and observability,it also provides attackers with a backdoor to steal *** the text,a novel protection scheme is put forward to resist scan-based attacks,in which we first use the responses generated by a strong physical unclonable function circuit to solidify fuseantifuse structures in a non-linear shift register(NLSR),then determine the scan input code according to the configuration of the fuse-antifuse structures and the styles of connection between the NLSR cells and the scan *** the key is right,the chip can be tested normally;otherwise,the data in the scan chain cannot be propagated normally,it is also impossible for illegal users to derive the desired scan *** proposed technique not only enhances the security of cryptographic chips,but also incurs acceptable overhead.

关键词： Cryptographic chips scan testing scan-based attacks hardware security PUF

Internet of Things Based Solutions for Transport Network Vulnerability Assessment in Intelligent Transportation Systems

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Computers, Materials & Continua 2020年第12期65卷 2511-2527页

作者： Weiwei Liu Yang Tang Fei Yang Chennan Zhang Dun Cao gwang-jun kim Business School University of Shanghai for Science and TechnologyShanghai200093China Zhejiang University Urban and Rural Planning&Design Institute Hangzhou310023China School of Computer&Communication Engineering Changsha University of Science&TechnologyChangsha410004China Department of Computer Engineering Chonnam National UniversityGwangju61186Korea

Intelligent Transportation System(ITS)is essential for effective identification of vulnerable units in the transport network and its stable ***,it is necessary to establish an urban transport network vulnerability assessment model with solutions based on Internet of Things(IoT).Previous research on vulnerability has no congestion effect on the peak time of urban road *** cascading failure of links or nodes is presented by IoT monitoring system,which can collect data from a wireless sensor network in the transport *** IoT monitoring system collects wireless data via Vehicle-to-Infrastructure(V2I)channels to simulate key segments and their failure ***,the topological structure vulnerability index and the traffic function vulnerability index of road network are extracted from the vulnerability *** two indices are standardized by calculating the relative change rate,and the comprehensive index of the consequence after road network unit is in a failure ***,by calculating the failure probability of road network unit and comprehensive index of road network unit in failure state,the comprehensive vulnerability of road network can be evaluated by a risk calculation *** short,the IoT-based solutions to the new vulnerability assessment can help road network planning and traffic management departments to achieve the ITS goals.

关键词： Internet of Things Intelligent Transport Systems vulnerability assessment transport network