• Title/Summary/Keyword: 2 order system

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A Study on the Development of International Multimodal Transport System in Korea in Terms of Systems Approach (국제복합일관수송체제에 관한 고찰)

  • 신동춘
    • Journal of Korean Society of Transportation
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    • v.5 no.1
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    • pp.85-99
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    • 1987
  • The transport a administration in Korea is meeting demands of developing international multimodal transport system. In the past, as Korea transport policy has been emphasizing on the passenger traffic, the physical distribution sector is far behind international trend. Regarding the urging necessities of reducting costs in transport in order to upgrade the competitive edge of industries, Korea has to develop the most efficient transport system so called international multimodal transport system. The existing transport system is inefficient because each transport mode is separate, so this system is aiming at reducing cost and time and developing freight transport. The scope and scheme of this thesis should be as following. Chapter 2. Systems Approach of International multimodal transport 1. general systems theory 2. definition of International multimodal transport system 3. MTO (multimodal transport operator) Chapter 3. Current Situation and Problems of this System. 1. international law and practice 2.current situation A. Europe B. U.S. C. Japan D. Korea Chapter 4. Policy Goal for Improving this System Chapter 5. conclusion.

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A Study on Improvement of Food Safety Program in School Feeding Setting (학교급식의 위생관리 현황과 개선방안)

  • Bin, Sung-Oh;Kim, Moon-Zoo;Ryu, Jang-Kuen;Roh, Pyong-Ui
    • The Journal of Korean Society for School & Community Health Education
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    • v.2 no.1
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    • pp.19-30
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    • 2001
  • Korea has experiencing outbreaks of food borne illnesses since school feeding programs had been introduced to students. In order to prevent food borne diseases, preventive measures applicable to Korean school system were reviewed. The conclusions are summarized as follows; 1. Raw materials should be purchased through reliable sources in order to ensure the quality of food stuffs in the aspect of food safety and hygiene. 2. The potential causes of food borne illnesses should be carefully identified and control system should be established in order to monitor critical points. 3. Temperature of refrigeration should be monitored and controled continuously in order to safeguard the quality of foods. 4. National and local governments have to provide adequate equipment and utensils to the food establishments of school systems, and public health authorities have to make evaluation of the facilities periodically. The food handlers should be trained in safe food handling and the ways how to prevent food borne illnesses.

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A Basic Study to Predict Solar Insolation using Meteorological Observation Data in Korea (국내 기상 측정결과를 이용한 일사량 예측 방법 기초 연구)

  • Hwangbo, Seong;Kim, Hayang;Kim, Jeongbae
    • Journal of Institute of Convergence Technology
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    • v.4 no.2
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    • pp.27-33
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    • 2014
  • To well design the solar energy system using solar energy, the correlation to calculate solar irradiation is basically needed. So, this study was performed to reveal the relationships between the solar irradiation and four meteorological observation data(dry bulb temperature, relative humidity, sunshine duration, and cloud cover) which are different from previous other researches. And then, we finally proposed the first order non-linear correlation from the measured solar irradiation using four meteorological observation data with MINITAB. To show the deviation of the solar irradiation between measured and calculated, this study compared using the daily total solar irradiance and the maximum peak value. From those results, the calculation error was estimated about maximum 25.4% for the daily total solar irradiance. The error of the solar irradiation between measured and calculated was made from the curve fitting error. So, solar irradiation prediction correlation with higher accuracy can be obtained using 2nd or higher order terms with four meteorological observation data.

PAPR Evaluation and Analysis of Candidate Waveforms Using DFT Spreading for 5G Mobile Communications (DFT Spreading을 사용한 5세대 이동통신 후보 변조기술의 PAPR 평가 및 분석)

  • An, Changyoung;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.12
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    • pp.1091-1099
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    • 2015
  • UFMC(Universal-Filtered Multi-carrier) and FBMC(Filter Bank Multi-carrier) system are receiving attention as candidate waveforms for 5G mobile communication system. But, these systems have high PAPR(Peak to Average Power Ratio) problem because these systems use a number of subcarrier. In this paper, we propose DFT(Discrete Fourier Transform) spreading based DFT-s(spreading)-UFMC system and DFT-s-FBMC system in order to overcome the PAPR drawback. In order to evaluate PAPR performance of the proposed systems, we design and simulate OFDM(Orthogonal Frequency Division Multiplexing), UFMC, FBMC, DFT-s-OFDM, DFT-s-UFMC, DFT-s-FBMC system. As simulation results, each PAPR performance of DFT-s-OFDM system, DFT-s-UFMC system, and DFT-s-FBMC system rise by 2.7 dB, 2.8 dB, and 1.1 dB respectively by DFT spreading technique.

A Pattern Recognition System Using 2D Wavelets and Second-Order Neural Networks (2D wavelet과 이차신경망을 이용한 패턴인식 시스템)

  • Lee, Bong-Kyu
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.10
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    • pp.473-478
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    • 2001
  • Image processings using the two-dimensional wavelet transform (2DWT) have been a very active research area in recent years because the 2DWT possess many good properties. However, the discrete 2DWT can not be used for pattern recognition directly because it does not have the translation property. In this paper, we show why conventional discrete two-dimensional wavelet transforms cannot be used for pattern recognitions directly. Then, we propose a new method that makes it possible to use discrete 2DWT to pattern recognition without modification of standard pyramidal algorithms. The main idea of our method is to postprocess the wavelet transformed images using the second-order neural network. To justify the validity of the method, evaluations with test images were performed. The effectiveness of the method can be shown by the evaluation results.

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The Effect of Polarizability on Reactivity of 4-Nitrophenyl Benzoate and Its Sulfur Containing Analogues with Anionic Nucleophiles in Ethanol

  • Kwon, Dong-Sook;Park, Jee-Young;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.15 no.10
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    • pp.860-864
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    • 1994
  • 2nd-order rate constants have been measured spectrophotometrically for the reactions of 4-nitrophenyl benzoate (1), S-4-nitrophenyl thiobenzoate (2) and 4-nitrophenyl thionbenzoate (3) with alkoxides, aryloxides and thioaryloxides in absolute ethanol at 25.0 ${\pm}0.1$${\circ}C$. The substitution of O by polarizable S in the leaving group has little affected the reactivity of 2 toward the charge localized species (eg. $EtO^-$ and $CF_3CH_2O^-$), while the effect of the similar replacement in the carbonyl group has led to a decrease in reactivity by a factor of 10. However, the reactivity of these esters toward charge delocalized aryloxides has been found to be in the order $1<3{\le}2$. The effect of replaced sulfur atom on reactivity becomes more significant for the reaction with polarizable thioaryloxides, i.e. the reactivity increases in the order $1<2{\ll}3$. The difference in reactivity for the present system is attributed to a polarizability effect.

Application of Bioisosterism in Development of Novel Cardiotonics Based on (2'-Aminoethyl)carbostyril and (2'-Aminoethyl)-1-hydroxy-2-pyridone Systems

  • Yoon, Sung-Hwa
    • Journal of Pharmaceutical Investigation
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    • v.22 no.3
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    • pp.49-63
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    • 1992
  • Two different types of chemical manipulations of dobutamine were investigated in order to develop novel, improved cardiotonic drugs. Three new analogues of carbostyril, in which the m-hydroxy group of dobutamine was isosterically modified with an amide type carbostyril system, were synthesized from, ${\rho}-methoxyphenethylamine$ via multi-steps. Two analogues of (2'-aminoethyl)-1-hydroxy-2-pyridone system which has isosteric structural similarity with dopamine without having the COMT vulnerable m-hydroxy group were synthesized via 12 synthetic steps. Their biological stabilities in various media and inotropic activities were evaluated.

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Mechanical Milling of Lithium with Metal Oxide and its Reactivity with Gases

  • Yokoi, Tomomichi;Yamasue, Eiji;Okumura, Hideyuki;Ishihara, Keiichi N.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.959-960
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    • 2006
  • Li reacts with $N_2$ at room temperature. In order to activate Li, the mechanical milling of Li with stable metal oxide, namely, $Al_2O_3$ and MgO, using a high energy vibrating ball mill was performed. In the case of Li-MgO system, it reacts with $N_2$, but hardly reacts with $O_2$. The reaction with $N_2$ generally produces $Li_3N$, while for some vigorous reactions the $Mg_3N_2$ is produced as the major phases. In the case of $Li-Al_2O_3$ system, reactivities with both $N_2$ and $O_2$ are high. The difference is explained in terms of the reaction mechanism and the Li state.

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Development of high-precision 2-axis translation system comprised of microstage and global stage (Microstage와 global stage를 결합한 초정밀 2축 이동장치 개발)

  • 김종윤;엄태봉
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.311-314
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    • 1997
  • According to the development of industrial equipment such as semiconductor manufacturing machines, optical device, and precision machine tool, a high-precision translation system with wide range has been required. This paper describes a high-precision 2-axis translation system, which consists of microstage and global stage. In order to achieve the highresolution in the long range, some engineering techniques are used. Three linear guides with flexible coupling are adopted to reduce the motor vibration in the global stage. A simple elastic hinge structure activated by five PZT is applied to reduce the angular dev~atlon. As the result of combination of microstage and global stage associated with some engineering techniques, the 2-axis translation system can measure the 200 X 200 mrn range with the nanometer accuracy.

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