• Title/Summary/Keyword: trend algorithm

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Study on Trend Analysis of Indoor Evacuation Path Guidance System for Disaster Situation (재난 상황을 고려한 실내 대피경로 안내기술에 대한 동향 분석 및 비교연구)

  • Yun, Younguk;Kim, Nammoon;Choi, Jae-hyuk;Park, Ji-hye;An, Deock-hyeon;Kim, Youngok
    • Journal of the Society of Disaster Information
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    • v.12 no.2
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    • pp.130-135
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    • 2016
  • In this paper, the trend of evacuation path providing or guidance systems for safety on disaster situation is analyzed. For trend analysis, 31 papers of domestic and international, 29 patents of domestic, and the finished 9 national funded projects, which have been performed for recent 15 years are analysed. As the results of analysis, the previous researches were performed in the view of the guidance systems, but there is no study that can be used for peoples in dangerous situation until now. Also it has technical limitations in using indoor positioning technology for peoples. In this paper, therefore, we propose to use the indoor positioning technology for developing a novel evacuation guidance system for peoples in dangerous situation. It can be utilized to develop a novel evacuation guidance system which is considered indoor disaster situations.

Analysis on the Trend of The Journal of Information Systems Using TLS Mining (TLS 마이닝을 이용한 '정보시스템연구' 동향 분석)

  • Yun, Ji Hye;Oh, Chang Gyu;Lee, Jong Hwa
    • The Journal of Information Systems
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    • v.31 no.1
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    • pp.289-304
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    • 2022
  • Purpose The development of the network and mobile industries has induced companies to invest in information systems, leading a new industrial revolution. The Journal of Information Systems, which developed the information system field into a theoretical and practical study in the 1990s, retains a 30-year history of information systems. This study aims to identify academic values and research trends of JIS by analyzing the trends. Design/methodology/approach This study aims to analyze the trend of JIS by compounding various methods, named as TLS mining analysis. TLS mining analysis consists of a series of analysis including Term Frequency-Inverse Document Frequency (TF-IDF) weight model, Latent Dirichlet Allocation (LDA) topic modeling, and a text mining with Semantic Network Analysis. Firstly, keywords are extracted from the research data using the TF-IDF weight model, and after that, topic modeling is performed using the Latent Dirichlet Allocation (LDA) algorithm to identify issue keywords. Findings The current study used the summery service of the published research paper provided by Korea Citation Index to analyze JIS. 714 papers that were published from 2002 to 2012 were divided into two periods: 2002-2011 and 2012-2021. In the first period (2002-2011), the research trend in the information system field had focused on E-business strategies as most of the companies adopted online business models. In the second period (2012-2021), data-based information technology and new industrial revolution technologies such as artificial intelligence, SNS, and mobile had been the main research issues in the information system field. In addition, keywords for improving the JIS citation index were presented.

AVK based Cryptosystem and Recent Directions Towards Cryptanalysis

  • Prajapat, Shaligram;Sharma, Ashok;Thakur, Ramjeevan Singh
    • Journal of Internet Computing and Services
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    • v.17 no.5
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    • pp.97-110
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    • 2016
  • Cryptanalysis is very important step for auditing and checking strength of any cryptosystem. Some of these cryptosystem ensures confidentiality and security of large information exchange from source to destination using symmetric key cryptography. The cryptanalyst investigates the strengths and identifies weakness key as well as enciphering algorithm. With increase in key size the time and effort required to guess the correct key increases so trend is increase key size from 8, 16, 24, 32, 56, 64, 128 and 256 bits to strengthen the cryptosystem and thus algorithm continues without compromise on the cost of time and computation. Automatic Variable Key (AVK) approach is an alternative to the approach of fixing up key size and adding security level with key variability adds new dimension in the development of secure cryptosystem. Likewise, whenever any new cryptographic method is invented to replace per-existing vulnerable cryptographic method, its deep analysis from all perspectives (Hacker / Cryptanalyst as well as User) is desirable and proper study and evaluation of its performance is must. This work investigates AVK based cryptic techniques, in future to exploit benefits of advances in computational methods like ANN, GA, SI etc. These techniques for cryptanalysis are changing drastically to reduce cryptographic complexity. In this paper a detailed survey and direction of development work has been conducted. The work compares these new methods with state of art approaches and presents future scope and direction from the cryptic mining perspectives.

The Effect of the Turning Rate of the Pod Propeller on the Roll Control System of the Cruise Ship (크루즈선의 횡동요 제어시스템에 미치는 포드 각속도의 영향)

  • Lee, Sung-Kyun;Lee, Jae-Hoon;Rhee, Key-Pyo;Choi, Jin-Woo
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.1
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    • pp.14-25
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    • 2012
  • Recently, the application and installation of the pod propeller to the cruise ship is dramatically increased. It is because pod propulsion system allows a lot of flexibility in design of the internal arrangement of a ship. To reflect this trend, many researches have conducted to use the pod propeller for the roll stabilization of a ship. In the paper, a roll stabilization controller is designed by using fins and pod propellers as the control actuators for cruise ships. Two kinds of control algorithms are adopted for the roll control system; LQR (Linear Quadratic Regulator) algorithm and frequency-weighted LQR algorithm. Through the numerical simulation, the effect of the turning rate of the pod propeller on the roll control system is analyzed. Analysis of the simulation results indicated that the turning rate of the pod propellers is one of the important parameters which give the significant effects on the roll stabilization.

Optimal Mix Proportion of Steel Fiber and Hybrid Fiber Reinforced Concrete Using Harmony Search (화음탐색법을 이용한 강섬유 및 하이브리드 섬유보강 콘크리트의 최적배합 설계)

  • Lee, Chi-Hoon;Lee, Joo-Ha;Yoon, Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.280-283
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    • 2004
  • Today, the guide line of the SFRC mix design and the construction was not embodied, and the convenience of the practical application on the spot is not good. In this research, hence, the program which is optimized to result the mix proportion by the flexural strength and toughness, was developed to apply with ease SFRC on the practical spot. This program would minimize the number of trial mixes and achieve an economical and appropriate mixture. In addition, the theoretical background on which the program is based, will be the basis of the embodied method to mixing SFRC. New algorithm, in this research, was used to develop the mix proportioning program of SFRC. The new algorithm is the Harmony Search which is the heuristic method mimicking the improvisation of music players. And, beside to single fiber reinforced concrete, it was developed the program about the hybrid fiber reinforced concrete that two kinds of steel fibers, which have the different geometry, was reinforced. This will be able to keep the world trend to study, hence, offers the basis of the next generation research.

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A Study on the Emoticon Extraction based on Facial Expression Recognition using Deep Learning Technique (딥 러닝 기술 이용한 얼굴 표정 인식에 따른 이모티콘 추출 연구)

  • Jeong, Bong-Jae;Zhang, Fan
    • Korean Journal of Artificial Intelligence
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    • v.5 no.2
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    • pp.43-53
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    • 2017
  • In this paper, the pattern of extracting the same expression is proposed by using the Android intelligent device to identify the facial expression. The understanding and expression of expression are very important to human computer interaction, and the technology to identify human expressions is very popular. Instead of searching for the emoticons that users often use, you can identify facial expressions with acamera, which is a useful technique that can be used now. This thesis puts forward the technology of the third data is available on the website of the set, use the content to improve the infrastructure of the facial expression recognition accuracy, in order to improve the synthesis of neural network algorithm, making the facial expression recognition model, the user's facial expressions and similar e xpressions, reached 66%.It doesn't need to search for emoticons. If you use the camera to recognize the expression, itwill appear emoticons immediately. So this service is the emoticons used when people send messages to others, and it can feel a lot of convenience. In countless emoticons, there is no need to find emoticons, which is an increasing trend in deep learning. So we need to use more suitable algorithm for expression recognition, and then improve accuracy.

Optimal Design of Conformal Array Transducers (곡면 배열 트랜스듀서의 최적 설계)

  • Kim, Hoe-Yong;Roh, Yong-Rae
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.1
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    • pp.51-61
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    • 2012
  • In this research, we have analyzed the trend of radiation pattern variation in relation to the change of design variables such as source interval and source number for conformal array transducers arranged in equi-angle, equi-interval, and geodesic dome forms. Through statistical multiple regression analysis of the results, we derived functional forms of the side lobe level and the beamwidth in terms of the design variables. Futhermore, the structure of the array transducer was optimized to achieve the smallest side lobe level while satisfying the requirements on beam width by the GA (genetic algorithm) method. Based on the optimized results, we have determined the equi-interval form as the optimal array geometry among the three conformal array geometries.

File System for Performance Improvement in Multiple Flash Memory Chips (다중 플래시 메모리 기반 파일시스템의 성능개선을 위한 파일시스템)

  • Park, Je-Ho
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.3
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    • pp.17-21
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    • 2008
  • Application of flash memory in mobile and ubiquitous related devices is rapidly being increased due to its low price and high performance. In addition, some notebook computers currently come out into market with a SSD(Solid State Disk) instead of hard-drive based storage system. Regarding this trend, applications need to increase the storage capacity using multiple flash memory chips for larger capacity sooner or later. Flash memory based storage subsystem should resolve the performance bottleneck for writing in perspective of speed and lifetime according to its physical property. In order to make flash memory storage work with tangible performance, reclaiming of invalid regions needs to be controlled in a particular manner to decrease the number of erasures and to distribute the erasures uniformly over the whole memory space as much as possible. In this paper, we study the performance of flash memory recycling algorithms and demonstrate that the proposed algorithm shows acceptable performance for flash memory storage with multiple chips. The proposed cleaning method partitions the memory space into candidate memory regions, to be reclaimed as free, by utilizing threshold values. The proposed algorithm handles the storage system in multi-layered style. The impact of the proposed policies is evaluated through a number of experiments.

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A method for image-based shadow interaction with virtual objects

  • Ha, Hyunwoo;Ko, Kwanghee
    • Journal of Computational Design and Engineering
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    • v.2 no.1
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    • pp.26-37
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    • 2015
  • A lot of researchers have been investigating interactive portable projection systems such as a mini-projector. In addition, in exhibition halls and museums, there is a trend toward using interactive projection systems to make viewing more exciting and impressive. They can also be applied in the field of art, for example, in creating shadow plays. The key idea of the interactive portable projection systems is to recognize the user's gesture in real-time. In this paper, a vision-based shadow gesture recognition method is proposed for interactive projection systems. The gesture recognition method is based on the screen image obtained by a single web camera. The method separates only the shadow area by combining the binary image with an input image using a learning algorithm that isolates the background from the input image. The region of interest is recognized with labeling the shadow of separated regions, and then hand shadows are isolated using the defect, convex hull, and moment of each region. To distinguish hand gestures, Hu's invariant moment method is used. An optical flow algorithm is used for tracking the fingertip. Using this method, a few interactive applications are developed, which are presented in this paper.

An Optimization Method for BAQ(Block Adaptive Quantization) Threshold Table Using Real SAR Raw Data (영상레이다 원시데이터를 이용한 BAQ(Block Adaptive Quantization) 최적화 방법)

  • Lim, Sungjae;Lee, Hyonik;Kim, Seyoung;Nam, Changho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.2
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    • pp.187-196
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    • 2017
  • The size of raw data has dramatically increased due to the recent trend of Synthetic Aperture Radar(SAR) development plans for high resolution and high definition image acquisition. The large raw data has an impact on satellite operability due to the limitations of storage and transmission capacity. To improve the SAR operability, the SAR raw data shall be compressed before transmission to the ground station. The Block Adaptive Quantization (BAQ) algorithm is one of the data compression algorithm and has been used for a long time in the spaceborne SAR system. In this paper, an optimization method of BAQ threshold table is introduced using real SAR raw data to prevent the degradation of signal quality caused by data compression. In this manner, a new variation estimation strategy and a new threshold method for block type decision are introduced.