• 제목/요약/키워드: Attempts

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A Method to Avoid Mutual Interference in a Cooperative Spectrum Sharing System

  • Tran, Truc Thanh;Kong, Hyung Yun
    • Journal of Communications and Networks
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    • 제16권2호
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    • pp.110-120
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    • 2014
  • This article proposes a spectrum sharing method which can avoid the mutual interference in both primary and secondary systems. The two systems make them a priority to use two single-dimension orthogonal signals, the real and imaginary pulse amplitude modulation signals, if the primary system is not in outage with this use. A secondary transmitter is selected to be the primary relay and the active secondary source to perform this. This allows a simultaneous spectrum access without any mutual interference. Otherwise, the primary system attempts to use a full two-dimensional signal, the quadrature amplitude modulation signal. If there is no outage with respect to this use, the secondary spectrum access is not allowed. When both of the previous attempts fail, the secondary system is allowed to freely use the spectrum two whole time slots. The analysis and simulation are provided to analyze the outage performance and they validate the considerable improvement of the proposed method as compared to the conventional one.

Microbe-Mediated Control of Mycotoxigenic Grain Fungi in Stored Rice with Focus on Aflatoxin Biodegradation and Biosynthesis Inhibition

  • Mannaa, Mohamed;Kim, Ki Deok
    • Mycobiology
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    • 제44권2호
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    • pp.67-78
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    • 2016
  • Rice contaminated with fungal species during storage is not only of poor quality and low economic value, but may also have harmful effects on human and animal health. The predominant fungal species isolated from rice grains during storage belong to the genera Aspergillus and Penicillium. Some of these fungal species produce mycotoxins; they are responsible for adverse health effects in humans and animals, particularly Aspergillus flavus, which produces the extremely carcinogenic aflatoxins. Not surprisingly, there have been numerous attempts to devise safety procedure for the control of such harmful fungi and production of mycotoxins, including aflatoxins. This review provides information about fungal and mycotoxin contamination of stored rice grains, and microbe-based (biological) strategies to control grain fungi and mycotoxins. The latter will include information regarding attempts undertaken for mycotoxin (especially aflatoxin) bio-detoxification and microbial interference with the aflatoxin-biosynthetic pathway in the toxin-producing fungi.

X-Ray 및 Neutron 조사에 의한 Toxoplasma gondii의 병원성 및 형태학적 변화에 대하여 (Pathogenic and Morphologic Variation of Toxoplasma gondii by X-Ray and Neutron Flax Irradiation)

  • 한태우
    • 대한수의학회지
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    • 제10권2호
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    • pp.21-51
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    • 1970
  • Series of experiments were conducted to determine lethal does of X-ray and Neutron on Toxoplasma gondii. strain RH and IRI. As well morphological changes of Toxoplasma gondii irradiated or not were compared by use of electron microscope. The pathogenicity test of the irradiated and nonirradiated Toxoplasma gondii was made in mice guinea-pigs, rabbits and pigs: The letahl dose of X-ray and Neutron on RH and IRI strain and the growth rate between two strains after irradiation were shown little differences. Morphological changes were not observed until 18th passage was made. After then, the growth rate was decreased apparently, and atrophied forms were frequently observed in electron microscope. Survival time of animals inoculated with irradiated strain was longer than that of animals giving non-irradiated strain, and Toxoplasma gondii were isolated from all the dead animals. But it is of interest that pigs survived after injection of Toxoplasma gondii remained health and much attempts were failed toisolate Toxplasma gondii remained health and much attempts were slaughtered them. Animals were succumbed after injection of Toxoplasma gondii without any relationship with serum titers. (HA antibody).

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한류문화정책에 대한 시스템사고의 적용 (A Studying Hallyu(Korean Wave) with Systems Thinking)

  • 김헌식
    • 한국시스템다이내믹스연구
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    • 제7권1호
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    • pp.173-212
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    • 2006
  • This paper attempts to provide a more complete acknowledging of Hallyu(Korean Wave), using systems thinking. The central concept is understanding how all the objects of Hallyu(Korean Wave) in a culture system interact with one another. What it attempts to do is understand the feedback loop of Hallyu(Korean Wave) with other country culture, and thus understand the behavior of mass culture agent it make produce. This works is for public management and policy in culture industry and leading culture itself. And alternative policies that alleviate the problem, and implements this solution at Hallyu(Korean Wave) continuance.

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최적 수동 동조질량감쇠기의 특성 (The Properties of Optimal Passive Tuned Mass Dampers)

  • 노필성;강병두;김재웅
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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    • pp.165-172
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    • 1996
  • Recently, the response of a high-rise building to external dynamic force created by wind and earthquake has received much attention. This response is dependent on wind intensity, surrounding environment, building size, shape, mass, stiffness and amount of energy dissipation available in the system. The study has been done on these parameters. Attempts have been made to increase the damping in building system and thereby reduce structural response. These attempts have centered on adding an energy-dissipative system(passive tuned mass damper; passive TMD) to the building system and increasing the overall effective damping. In this paper the optimum condition of passive TMD will be derived with respect to random excitation and the properties of the optimum condition will have been studied.

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스케일 공간 필터와 FCM을 이용한 컬러 영상영역화에 관한 연구 (A Study on the Color Image Segmentation Algorithm Based on the Scale-Space Filter and the Fuzzy c-Means Techniques)

  • 임영원;이상욱
    • 대한전자공학회논문지
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    • 제25권12호
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    • pp.1548-1558
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    • 1988
  • In this paper, a segmentation algorithm for color images based on the scale-space filter and the Fuzzy c-means (FCM) techniques is proposed. The methodology uses a coarse-fine concept to reduce the computational burden required for the FCM. The coarse segmentation attempts to segment coarsely using a thresholding technique, while a fine segmentation assigns the unclassified pixels by a coarse segmentation to the closest class using the FCM. Attempts also have been made to compare the performance of the proposed algorithm with other algorithms such as Ohlander's, Rosenfeld's, and Bezdek's. Intensive computer simulations has been done and the results are discussed in the paper. The simulation results indicate that the proposed algorithm produces the most accurate segmentation on the O-K-S color coordinate while requiring a reasonable amount of computational effort.

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컴퓨터 네트워크 가상 실습을 위한 컴포넌트 기반의 시뮬레이터 설계 및 구현 (Design and Implementation of a Component-based Simulator for the Virtual Laboratory of Computer Networks)

  • 임명식;김기형
    • 한국시뮬레이션학회논문지
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    • 제12권1호
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    • pp.1-10
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    • 2003
  • Recently, various network protocols have been developed to keep step with the rapid growth of Internet users. For the education of students in the computer networks classes, there have been many attempts to allow students experiment routers setting, operations and management of networks by themselves, in addition to the classroom lectures based on textbooks. One of the attempts is to install expensive real router experiment sets in laboratories for students, and one another is using router and network simulators for virtual experiments. This paper presents the design and implementation of NetSim, a scalable, component-based simulator environment for the network experimentation. NetSim expands the existing component-based JavaSim simulation tool for the education purpose, and it allows the design and experiment of various networks and protocols. For the evaluation of NetSim, it is shown that the network design and RIP-based router setting process is possible in NetSim.

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Establishing Relationships between Disasters and Global Environmental Problems for Sustainable Communities

  • Sadohara, Satoru
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.19-24
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    • 2008
  • Many types of disasters are related to environmental problems. Today, frequently occurring disasters and global environmental problems have begun to threaten human life and welfare. Consequently, building sustainable communities requires assessing relationships between environmental problems and disasters using a broad, open approach and with a long-term perspective. This paper attempts to identify the need for conceptualizing disasters and environmental problems together by comparing mechanisms of both disasters and environmental problems, and attempts to integrate both of these seemingly different types of phenomena as similar types of risk threatening human existence. Based on this work, a chart is proposed for qualitatively organizing disasters, environmental problems and their mutual influences, as well as providing a framework for potential quantitative analysis. It is hoped this research serves to contribute to effective mitigation to both disasters and environmental problems in today's age of global environmental issues.

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Speech Emotion Recognition Using 2D-CNN with Mel-Frequency Cepstrum Coefficients

  • Eom, Youngsik;Bang, Junseong
    • Journal of information and communication convergence engineering
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    • 제19권3호
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    • pp.148-154
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    • 2021
  • With the advent of context-aware computing, many attempts were made to understand emotions. Among these various attempts, Speech Emotion Recognition (SER) is a method of recognizing the speaker's emotions through speech information. The SER is successful in selecting distinctive 'features' and 'classifying' them in an appropriate way. In this paper, the performances of SER using neural network models (e.g., fully connected network (FCN), convolutional neural network (CNN)) with Mel-Frequency Cepstral Coefficients (MFCC) are examined in terms of the accuracy and distribution of emotion recognition. For Ryerson Audio-Visual Database of Emotional Speech and Song (RAVDESS) dataset, by tuning model parameters, a two-dimensional Convolutional Neural Network (2D-CNN) model with MFCC showed the best performance with an average accuracy of 88.54% for 5 emotions, anger, happiness, calm, fear, and sadness, of men and women. In addition, by examining the distribution of emotion recognition accuracies for neural network models, the 2D-CNN with MFCC can expect an overall accuracy of 75% or more.

Free Energy of Ion Hydration

  • Kim, Hag-Sung;Chung, Jong-Jae
    • Bulletin of the Korean Chemical Society
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    • 제14권2호
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    • pp.220-225
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    • 1993
  • The influence of temperature and pressure on the free energy of the ion hydration has been considered. The ion radii measured by conductometric method and the saturated dielectric constant cited from other works were used to calculate the free energy in the hydration shell. The Born equation was modified in order to fit in our model. In our model, the environment of ion consists of three regions. The innermost one is the hydration shell in which water is immobilized and electrostricted, the middle one is the one which contains less ordered waters than the bulk medium, and the outermost one is the bulk water which is under the influence of the electric field of ion. Our results for the free energy of ion hydration were compared with those of other attempts. Especially, ${\Delta}$G$_{hyd}$ of $Li^+$ ion is considerably too negative in this study at given temperature, comparing with those of other attempts. But ${\Delta}$G$_{hyd}$ of other ions coincides with each other.