• Title/Summary/Keyword: second order adjacent set

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ON SECOND ORDER NECESSARY OPTIMALITY CONDITIONS FOR VECTOR OPTIMIZATION PROBLEMS

  • Lee, Gue-Myung;Kim, Moon-Hee
    • Journal of the Korean Mathematical Society
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    • v.40 no.2
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    • pp.287-305
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    • 2003
  • Second order necessary optimality condition for properly efficient solutions of a twice differentiable vector optimization problem is given. We obtain a nonsmooth version of the second order necessary optimality condition for properly efficient solutions of a nondifferentiable vector optimization problem. Furthermore, we prove a second order necessary optimality condition for weakly efficient solutions of a nondifferentiable vector optimization problem.

Trellis-coded .pi./4 shift QPSK with sliding multiple symbol detection흐름 다중심벌검파를 적용한 트렐리스 부호화된 .pi./4 shift QPSK

  • 전찬우;박이홍;김종일
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.483-494
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    • 1996
  • In this paper, we proposed the receive decoder and Virterbi algorithm with sliding multiple symbol detection using MLSE. the informationis transmitted by the phase difference of the adjacent channel signal at the .pi./4 shift QPSK. In order to apply the .pi./4 shift QPSK to TCM, we use the signal set expansion and the signal set partition by the phase differences. And the Viterbi decoder containing branch mertrice of the squared Euclidean distance of the first, second and Lth order phase difference is introduced in order to extract the information in the differential detection of the Trellis-Coded .pi./4 shift QPSK. The proposed Viterbi decoder and receiver are conceptually same to the sliding multiple symbol detection method using the MLSE. By uisng this method, the study shows that the Trellis-Coded .pi./4 shift QPSK is an attractive scheme for the power and the bandimited systems while also improving the BER performance when the Viterbi decoder is employed to the Lth order phase difference metrics.

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CFD Study for Wave Run-up Characteristics Around a Truncated Cylinder with Damper

  • Zhenhao Song;Bo Woo Nam
    • Journal of Ocean Engineering and Technology
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    • v.37 no.6
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    • pp.225-237
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    • 2023
  • In this study, numerical simulations for a single fixed truncated circular cylinder in regular waves were conducted to investigate the nonlinear wave run-up under various dampers and wave period conditions. The present study used the volume of fluid (VOF) technique to capture the air-water interface. The unsteady Reynolds-averaged Navier-Stokes (URANS) equation with the k- 𝜖 turbulence model was solved using the commercial computational fluid dynamics (CFD) software STAR-CCM+. First, a systematic spatial convergence study was conducted to assess the performance and precision of the present numerical wave tank. The numerical scheme was validated by comparing the numerical results of wave run-up on a bare truncated cylinder with the experimental results, and a good agreement was achieved. Then, a series of parametric studies were carried out to examine the wave run-up time series around the truncated cylinder with single and dual dampers in terms of the first- and second-order harmonic and mean set-up components. Additionally, the local wave field and the flow velocity vectors adjacent to the cylinder were evaluated. It was confirmed that under short wave conditions, the high position of the damper led to a noticeable increase in the wave run-ups with significant changes in the first- and second-order harmonic components.

Multiple Model Adaptive Estimation of the SOC of Li-ion battery for HEV/EV (다중모델추정기법을 이용한 HEV/EV용 리튬이온전지의 잔존충전용량 추정)

  • Jung, Hae-Bong;Kim, Young-Chol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.142-149
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    • 2011
  • This paper presents a new state of charge(SOC) estimation of large capacity of Li-ion battery (LIB) based on the multiple model adaptive estimation(MMAE) method. We first introduce an equivalent circuit model of LIB. The relationship between the terminal voltage and the open circuit voltage(OCV) is nonlinear and may vary depending on the changes of temperature and C-rate. In this paper, such behaviors are described as a set of multiple linear time invariant impedance models. Each model is identified at a temperature and a C-rate. These model set must be obtained a priori for a given LIB. It is shown that most of impedances can be modeled by first-order and second-order transfer functions. For the real time estimation, we transform the continuous time models into difference equations. Subsequently, we construct the model banks in the manner that each bank consists of four adjacent models. When an operating point of cell temperature and current is given, the corresponding model bank is directly determined so that it is included in the interval generated by four operating points of the model bank. The MMAE of SOC at an arbitrary operating point (T $^{\circ}C$, $I_{bat}$[A]) is performed by calculating a linear combination of voltage drops, which are obtained by four models of the selected model bank. The demonstration of the proposed method is shown through simulations using DUALFOIL.

A Study on the Effects of Droplets Characteristics of Water Mist on the Spray Density on the Floor (미분무 액적특성이 살수밀도에 미치는 영향 연구)

  • Kim, Jong-Hoon;Park, Won-Hee;Kim, Woon-Hyung;Myoung, Sang-Yup
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.120-127
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    • 2021
  • Purpose: In this study, the effect of changes in the variables related to water droplets on the spray density on the floor in the analysis of the water mist fire protection system using FDS was analyzed. Method: When the spray of the water mist nozzle was analyzed in FDS, Particles Per Seconds, Particle Velocity, Size Distribution, and Spray Pattern Shape that can be set in relation to droplets were input to review the analyzed results. Result: In the analysis results, when the number of particles per second was set above a certain value, the spray density of the floor was similar. In the case of Particle Velocity, as the velocity decreases, the spray density of the central portion increases but decreases at a distance of 0.15m or more. From the analysis of the change in the size distribution function, it was found that an increase in the 𝛾 value increases the spray density of the central part, but the value at a remote location decreases. Compared to the result of applying the Gaussian distribution, the median value decreases dramatically when the uniform distribution is applied, but the value at the adjacent position increases. Conclusion: Variables related to the droplet properties of the FDS affect the spray density of the floor. Therefore, in order to increase the reliability of results before performing analyses such as fire suppression or cooling, a sufficient review of input variables is required.

Correction of Rotated Objects in Medical Images Using the Mojette Transform (모젯 변환을 이용한 의료 영상의 회전 물체 보정)

  • Jung, Hyang-Mi;Kim, Ji-Hong
    • Journal of Korea Multimedia Society
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    • v.15 no.11
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    • pp.1341-1348
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    • 2012
  • In this paper, an efficient scheme for correcting rotated objects in medical images using the Mojette transform is presented. The Mojette transform is a kind of discrete Radon transform, where the transform domain is represented by a set of projections. The Mojette transform currently studied in the image compression area is modified for detecting the rotation angle of objects in medical images. First, in order to find accurate rotation angle, the projection value in the Mojette transform is determined by using pixels on the projection line and in addition the linear interpolation of pixels adjacent to the line. Second, at each projection angle, only one projection is implemented for reducing the amount of the calculation in the process of the Mojette transform. Finally, the projection in the Mojette transform is carried out at the predetermined ROI(Region Of Interest) at which the objects are not cropped or added by rotating the image. The simulation results show that the proposed method has good performance for correcting the rotation angle in medical images.

The Status of North Korean Airspace after Reunification (북한 공역의 통일 후 지위)

  • Kwon, Chang-Young
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.1
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    • pp.287-325
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    • 2017
  • Considering the development of aerospace, military science and technology since the 20th century, the sky is very important for the nation's existence and prosperity. The proverb "Whosoever commands the space commands the world itself!" emphasizes the need for the command of the air. This essay is the first study on the status of airspace after reunification. First, the territorial airspace is over the territory and territorial sea, and its horizontal extent is determined by the territorial boundary lines. Acceptance of the present order is most reasonable, rather than attempting to reconfigure through historical truths about border issues, and it could be supported by neighboring countries in the reunification period. For peace in Northeast Asia, the reunified Korea needs to respect the existing border agreement between North Korea and China or Russia. However, the North Korean straight baselines established in the East Sea and the Yellow Sea should be discarded because they are not available under United Nations Convention on the Law of the Sea. It is desirable for the reunified Korea to redefine the straight baselines that comply with international law and determine the territorial waters up to and including the 12-nautical mile outside it. Second, the Flight Information Region (hereinafter "FIR") is a region defined by the International Civil Aviation Organization (hereinafter "ICAO") in order to provide information necessary for the safe and efficient flight of aircraft and the search and rescue of aircraft. At present, Korea is divided into Incheon FIR which is under the jurisdiction of South Korea and Pyongyang FIR which is under the jurisdiction of North Korea. If North Korea can not temporarily exercise control of Pyongyang FIR due to a sudden change of circumstances, it is desirable for South Korea to exercise control of Pyongyang FIR, and if it is unavoidable, ICAO should temporarily exercise it. In reunified Korea, it is desirable to abolish Pyongyang FIR and integrate it into Incheon FIR with the approval of ICAO, considering systematic management and control of FIR, establishment of route, and efficiency of management. Third, the Air Defense Identification Zone (hereinafter "ADIZ") is a zone that requires easy identification, positioning, and control of aircraft for national security purposes, and is set up unilaterally by the country concerned. The US unilaterally established the Korea Air Defense Identification Area (KADIZ) by the Declaration of Commitment on March 22, 1951. The Ministry of Defense proclaimed a new KADIZ which extended to the area including IEODO on December 13, 2013. At present, North Korea's military warning zone is set only at maritime boundaries such as the East Sea and the Yellow Sea. But in view of its lack of function as ADIZ in relations with China and Russia, the reunified Korea has no obligation to succeed it. Since the depth of the Korean peninsula is short, it is necessary to set ADIZ boundary on the outskirts of the territorial airspace to achieve the original purpose of ADIZ. Therefore, KADIZ of the reunified Korea should be newly established by the boundary line that coincides with the Incheon FIR of the reunified Korea. However, if there is no buffer zone overlapping with or adjacent to the ADIZs of neighboring countries, military tensions may rise. Therefore, through bilateral negotiations for peace in Northeast Asia, a buffer zone is established between adjacent ADIZs.

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Analysis of Plants Social Network for Vegetation Conservation on Cheongwansan Provincial Park in Jeollanam-do (천관산도립공원 식생보전을 위한 식물사회네트워크 분석)

  • Ji-Woo Kang;Sang-Cheol Lee;Hyun-Mi Kang
    • Korean Journal of Environment and Ecology
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    • v.37 no.5
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    • pp.392-402
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    • 2023
  • This study was conducted to understand the characteristics of the plant society in Cheongwansan Provincial Park, which lacks research on plants, and to establish basic data necessary for sustainable vegetation management and provincial park research. This study set up 126 quadrats were installed in Cheongwansan Provincial Park to investigate the species that emerged, and interspecies association analysis was conducted focusing on species excluding rare species. The results were written in a sociogram using the Gephi 0.10 program, modular analysis was conducted to distribute groups between adjacent nodes, and network centrality and structure analysis were conducted. As a result of the analysis, the Smilax china showed the highest frequency of appearance in the survey area. Next, it was found to be high in the order of Quercus serrata, Eurya japonica, Styrax japonicus, and Sasa borealis. Interspecies association analysis was conducted on 69 species excluding rare species, and plant social networks were visualized based on benign binding. The Plant Social Network consists of 69 nodes and 396 connecting lines, and one species formed interspecies bonds with an average of about 17.9 species, connecting each other in 2.3 steps. 69 species were divided into three groups through modular analysis, and the first group consisted mainly of evergreen broad-leaved and trees that appeared in warm-temperate region, and the second group consisted mainly of deciduous broad-leaved. The three groups were mainly divided into trees that grow well in sunny and dry sunlight.

Development of 3D Impulse Calculation Technique for Falling Down of Trees (수목 도복의 3D 충격량 산출 기법 개발)

  • Kim, Chae-Won;Kim, Choong-Sik
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.1-11
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    • 2023
  • This study intended to develop a technique for quantitatively and 3-dimensionally predicting the potential failure zone and impulse that may occur when trees are fall down. The main outcomes of this study are as follows. First, this study established the potential failure zone and impulse calculation formula in order to quantitatively calculate the risks generated when trees are fallen down. When estimating the potential failure zone, the calculation was performed by magnifying the height of trees by 1.5 times, reflecting the likelihood of trees falling down and slipping. With regard to the slope of a tree, the range of 360° centered on the root collar was set in the case of trees that grow upright and the range of 180° from the inclined direction was set in the case of trees that grow inclined. The angular momentum was calculated by reflecting the rotational motion from the root collar when the trees fell down, and the impulse was calculated by converting it into the linear momentum. Second, the program to calculate a potential failure zone and impulse was developed using Rhino3D and Grasshopper. This study created the 3-dimensional models of the shapes for topography, buildings, and trees using the Rhino3D, thereby connecting them to Grasshopper to construct the spatial information. The algorithm was programmed using the calculation formula in the stage of risk calculation. This calculation considered the information on the trees' growth such as the height, inclination, and weight of trees and the surrounding environment including adjacent trees, damage targets, and analysis ranges. In the stage of risk inquiry, the calculation results were visualized into a three-dimensional model by summarizing them. For instance, the risk degrees were classified into various colors to efficiently determine the dangerous trees and dangerous areas.

Feasibility of Deep Learning Algorithms for Binary Classification Problems (이진 분류문제에서의 딥러닝 알고리즘의 활용 가능성 평가)

  • Kim, Kitae;Lee, Bomi;Kim, Jong Woo
    • Journal of Intelligence and Information Systems
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    • v.23 no.1
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    • pp.95-108
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    • 2017
  • Recently, AlphaGo which is Bakuk (Go) artificial intelligence program by Google DeepMind, had a huge victory against Lee Sedol. Many people thought that machines would not be able to win a man in Go games because the number of paths to make a one move is more than the number of atoms in the universe unlike chess, but the result was the opposite to what people predicted. After the match, artificial intelligence technology was focused as a core technology of the fourth industrial revolution and attracted attentions from various application domains. Especially, deep learning technique have been attracted as a core artificial intelligence technology used in the AlphaGo algorithm. The deep learning technique is already being applied to many problems. Especially, it shows good performance in image recognition field. In addition, it shows good performance in high dimensional data area such as voice, image and natural language, which was difficult to get good performance using existing machine learning techniques. However, in contrast, it is difficult to find deep leaning researches on traditional business data and structured data analysis. In this study, we tried to find out whether the deep learning techniques have been studied so far can be used not only for the recognition of high dimensional data but also for the binary classification problem of traditional business data analysis such as customer churn analysis, marketing response prediction, and default prediction. And we compare the performance of the deep learning techniques with that of traditional artificial neural network models. The experimental data in the paper is the telemarketing response data of a bank in Portugal. It has input variables such as age, occupation, loan status, and the number of previous telemarketing and has a binary target variable that records whether the customer intends to open an account or not. In this study, to evaluate the possibility of utilization of deep learning algorithms and techniques in binary classification problem, we compared the performance of various models using CNN, LSTM algorithm and dropout, which are widely used algorithms and techniques in deep learning, with that of MLP models which is a traditional artificial neural network model. However, since all the network design alternatives can not be tested due to the nature of the artificial neural network, the experiment was conducted based on restricted settings on the number of hidden layers, the number of neurons in the hidden layer, the number of output data (filters), and the application conditions of the dropout technique. The F1 Score was used to evaluate the performance of models to show how well the models work to classify the interesting class instead of the overall accuracy. The detail methods for applying each deep learning technique in the experiment is as follows. The CNN algorithm is a method that reads adjacent values from a specific value and recognizes the features, but it does not matter how close the distance of each business data field is because each field is usually independent. In this experiment, we set the filter size of the CNN algorithm as the number of fields to learn the whole characteristics of the data at once, and added a hidden layer to make decision based on the additional features. For the model having two LSTM layers, the input direction of the second layer is put in reversed position with first layer in order to reduce the influence from the position of each field. In the case of the dropout technique, we set the neurons to disappear with a probability of 0.5 for each hidden layer. The experimental results show that the predicted model with the highest F1 score was the CNN model using the dropout technique, and the next best model was the MLP model with two hidden layers using the dropout technique. In this study, we were able to get some findings as the experiment had proceeded. First, models using dropout techniques have a slightly more conservative prediction than those without dropout techniques, and it generally shows better performance in classification. Second, CNN models show better classification performance than MLP models. This is interesting because it has shown good performance in binary classification problems which it rarely have been applied to, as well as in the fields where it's effectiveness has been proven. Third, the LSTM algorithm seems to be unsuitable for binary classification problems because the training time is too long compared to the performance improvement. From these results, we can confirm that some of the deep learning algorithms can be applied to solve business binary classification problems.