• Korean Journal of Materials Research
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• v.19 no.4
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• pp.203-206
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• 2009

$Sn_XSe_{100-X}$ (15|X|30) alloys have been studied to explore their suitability as phase change materials for nonvolatile memory applications. The phase change characteristics of thin films prepared by a Radio Frequency (RF) magnetron co-sputtering system were analyzed by an X-ray diffractometer and 4-point probe measurement. A phase change static tester was also used to determine their crystallization under the pulsed laser irradiation. X-ray diffraction measurements show that the transition in sheet resistance is accompanied by crystallization. The amorphous state showed sheet resistances five orders of magnitude higher than that of the crystalline state in $Sn_XSe_{100-X}$ (x = 15, 20, 25, 30) films. In the optimum composition, the minimum time of $Sn_XSe_{100-X}$ alloys for crystallization was 160, 140, 150, and 30ns at 15mW, respectively. The crystallization temperature and the minimum time for crystallization of thin films were increased by increasing the amount of Sn, which is correlated with the activation energy for crystallization.

• Nuclear Engineering and Technology
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• v.47 no.2
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• pp.165-175
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• 2015

The application of neutron noise analysis (NNA) to the ex-core neutron detector signal for monitoring the vibration characteristics of a reactor core support barrel (CSB) was investigated. Ex-core flux data were generated by using a nonanalog Monte Carlo neutron transport method in a simulated CSB model where the implicit capture and Russian roulette technique were utilized. First and third order beam and shell modes of CSB vibration were modeled based on parallel processing simulation. A NNA module was developed to analyze the ex-core flux data based on its time variation, normalized power spectral density, normalized cross-power spectral density, coherence, and phase differences. The data were then analyzed with a fuzzy logic module to determine the vibration characteristics. The ex-core neutron signal fluctuation was directly proportional to the CSB's vibration observed at 8Hz and15Hzin the beam mode vibration, and at 8Hz in the shell mode vibration. The coherence result between flux pairs was unity at the vibration peak frequencies. A distinct pattern of phase differences was observed for each of the vibration models. The developed fuzzy logic module demonstrated successful recognition of the vibration frequencies, modes, orders, directions, and phase differences within 0.4 ms for the beam and shell mode vibrations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1700-1705
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• 2012

This study is focusing on ripple elimination in the band pass filter. There are generally two design methods in IIR filter design, which are a direct method and an indirect one. The indirect design method that designs the digital IIR LPF using the prototype analog LPF is applied to this study. A Butterworth filter and a Chebyshev filter are the typical prototype analog LPFs. This study shows characteristics of the digital IIR LPFs that are transformed from the prototype analog LPFs. The designed Butterworth and Chebyshev IIR LPFs are also designed as the band pass filters by frequency transformation in order to compare with the proposed cascading Chebyshev BPFs. This study shows frequency characteristics between the transformed IIR BPFs and the proposed cascading Chebyshev BPFs as well. The proposed cascading Chebyshev BPF is designed by cascading the different orders of Chebyshev BPFs. The aspect of the cascading filter is offsetting the ripples to descend them while the pass band ripples of the Chebyshev filter are ascending and vice versa. The designed cascading Chebyshev filter shows the flatness and the sharpness, which represent the advantages of Butterworth filter in the pass band and of Chebyshev filter in the transition band respectively. This result verifies the validity of the designed filter.

• Korean Journal of Materials Research
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• v.8 no.5
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• pp.470-473
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• 1998

$As^+$ was ion-implanted onto $CoSi_{2}$ thin films formed by rapidly thermal-annealed Co/Ti bilayers. Then the specimens were drive-in annealed at 500~100$0^{\circ}C$ to form ultra-shallow $n^+$p junction diodes and to measure their 1- V characteristics. When drive-in annealed at 50$0^{\circ}C$ for 280 sec., 50 nm thick ultra-shallow junctions were formed and di¬odes showed the best 1- V characteristics with low leakage current. In particular. the leakage current was 2 orders lower than that of diodes formed by using Co monolayer. It was attributed to uniform $CoSi_{2}$/Si interfaces.

• Wind and Structures
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• v.38 no.3
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• pp.215-229
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• 2024

Guyed mast structures exhibit characteristics such as high flexibility, low mass, small damping ratio, and large aspect ratio, leading to a complex wind-induced vibration response mechanism. This study analyzed the time- and frequency-domain characteristics of the wind-induced response of a guyed mast structure using measured acceleration response data obtained from the Shenzhen Meteorological Gradient Tower (SZMGT). Firstly, 734 sets of 1-hour acceleration samples measured from 0:00 October 1, 2021, to 0:00 November 1, 2021, were selected to study the vibration shapes of the mast and the characteristics of the generalized extreme value (GEV) distribution. Secondly, six sets of typical samples with different vibration intensities were further selected to explore the Gaussian property and modal parameter characteristics of the mast. Finally, the modal parameters of the SZMGT are identified and the identification results are verified by finite element analysis. The findings revealed that the guyed mast vibration shape exhibits remarkable diversity, which increases nonlinearly along the height in most cases and reaches a maximum at the top of the tower. Moreover, the GEV distribution characteristics of the 734 sets of samples are closer to the Weibull distribution. The probability distribution of the structural wind vibration response under strong wind is in good agreement with the Gaussian distribution. The structural response of the mast under wind loading exhibits multiple modes. As the structural response escalates, the first three orders of modal energy in the tower display a gradual increase in proportion.

• Journal of the Daesoon Academy of Sciences
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• v.23
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• pp.1-36
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• 2014

The purpose of this study is to research the religious-ethical meaning of the scripture (Jeongyung, 典經) of Daesoonjinrihoe, one of religious orders in Korea. It is 'the reorganizing in the order of heaven and earth' (ROHE, 天地公事)that the believers of Daesoonjinrihoe regard as the essence and basis of their religious belief in Jeongyung, and so I focus on it in this paper. And I have applied the method of religious ethics that recognize the relation religion and morality for understanding religious-ethical meaning of moral principles and norms. In the process of this study I have selected a lot of moral principles, norms and activities in ROHE, and sorted them with their social context of ROHE. In this research I have found some characteristics of ethical norms in the ROHE according to three divisions of ethical category such as personal, social and natural ethics. The understanding of mind is an important point of personal ethic in the ROHE. The mind is understood as the subject and object of personal ethical attitude and volition. So one could have ethical attitude by oneself with mind as subject, and reflect and correct on his ethical faults with the mind as ethical object. The distinctiveness of social ethic in the ROHE is special concerns to the weak at that time such as sick person, illegitimate children, shamans, farmhands and etc. This is a logical consequence of the ethical altruism of the ethic of mutual beneficence(相生) and the dignity of human(人尊) in ROHE. And the ethics of mutual beneficence is applied to natural ethic of ROHE. Since natural world including all sort of plants and animals is intimately related to the human worlds, so it is a desirable attitude for to accommodate to the changes of nature. Even if these characteristics of ethics in ROHE are justified by the religious beliefs, the norms from them are available in our religious pluralistic societies, since they have common ethical values of other religious ethics. It is my concluding remark that religious orders or denominations have to offer a lot of moral norms suitable to religious pluralistic situation. Because it is needed for our society to conquer various sort and kind conflicts among religions, and to act harmoniously together for public peace.

• Journal of the Korean association of regional geographers
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• v.9 no.2
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• pp.135-152
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• 2003

The purpose of this study is to suggest the model of supporting decision making and the method of evaluating criteria and alternatives by value judgement and to apply the model and method suggested to the case of the University Student's housing choice. The criteria and alternatives are evaluated in terms of intuitive judgement and the Analytic Hierarchy Process(AHP). The university students of the Daegu Metropolitan area consider the socioeconomic and environmental factors more important than the characteristics of housing to evaluate their future housing types. In terms of the student's intuitive judgement, socio-educational environment, accessibility, economy, natural environment, and the characteristics of housing are considered in order as an important criteria of evaluating housing. The orders of the important criteria done by an intuitive judgement and the AHP are different. In terms of the AHP, apartment, detached dwelling, and row house are preferred in order as the student's future housing types. The orders of preferred housing types are, however, dynamically changed based on specific criteria. In sum, the model of decision making and the method of evaluating criteria and alternatives by value judgement will be applied to the real problems defined by uncertainty and high risk.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.624-633
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• 2023

Purpose: It Vas intended to identify problems and derive improvement plans by grasping the current status of safety management of public institutions among construction Vork orders. Method: By comparing the disaster status of public institutions compared to the total construction Vork, the analysis Vas conducted based on the results of the evaluation of the level of safety activities of public institutions Vith a high disaster rate and the results of actual consulting. Result: As a result of comparing and analyzing the current status of safety management of public institutions, the current status and problems of safety management in public institutions Vith a high accident rate Vere similarly discovered. Safety management organizations, document management systems, safety management systems, and risk assessment activities are operated Vithout reflecting the size and characteristics of the organization, so improvement in the relevant field is needed. Conclusion: Safety-related professionals and organizations should be formed according to the size of construction orders, and responsibility and authority should be clearly assigned. Since risk assessment is conducted formally to prepare a safety and health ledger, it is necessary to derive risk factors to prevent safety accidents for the actual construction. It is expected that the level of safety activities can be improved if it is improved by reflecting the size and characteristics of public institutions.

• The Journal of the Petrological Society of Korea
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• v.24 no.4
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• pp.347-364
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• 2015

The purpose of the work was carried out to contribute the factors related to geologic realm in the disaster stability evaluation items of the national wood culture heritages. Among the total heritages, the study targets mainly include 304 cases interpreted as a rock type in the geologic map of the bedrocks with GIS interpretation. The cases show the geologic ages, geologic provinces and rock types as the following distribution characteristics. In geologic ages, they are decreasing in the orders of Jurassic, Cretaceous, Quaternary, Precambrian, Age-unknown Cambro-Ordovician Carboniferous and Tertiary. Among the ages, the former fours occupy 285 cases (93.8%) of the targets, which show most of the wood culture heritages. In geologic provinces classified into 15, they are decreasing in the orders of Daebo intrusives, alluvium, Gyeongsang supergroup, Bulgugsa intrusives, Yeongnam massif, and Gyeonggi massif which occupy of predominant distribution 271 cases (89.1%) of them. In rock types of 52, those of 6, which are Jgr, Qa, Kp, Krt+Kav+Kav1+Kav2, Kbgr and GC2, occupy total 182 cases (59.9%) showing distinctly dominant trends from the rest of 46.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.237-242
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• 1999

In this paper, we analyze transmission characteristics of ultrashort laser pulses using the property of high-order pulses which are systematically obtained following their orders. The high-order pulses are easily derived from a modified PRS system model. But we make clear they are very useful to cover wider area and more accurate transmission characteristics of ultrashort pulses than Gaussian or Sech pulse approximations used conventionally. This may be based on the fact that the spectra and bandwidths of the high-order pulses are beautifully related to their orders. first modifying the generalized PRS system model, we propose a new model for deriving any type of high-order pulse. And we offer a novel analysis method of ultrashort pulse transmission which has any shape and FWHM, using the proposed model. In addition, by fixing the pulse range $\tau$=1(ps) and varying the order of the pulse from n:1 to n=100, we obtain spectra of ultrashort pulses with 1(ps)-150(fs) FWHM's, which are widely used in fiber communications. As a one-step further, we derive PSD's of their pulse trains when they are applied to Unipolar signaling scheme. These PSD's are decided in the range of possible pulse intervals. All of these results are not only coincided with some conventional experimental works but also will be applied to any pioneering ultrashort pulse in the future.