• 한국시뮬레이션학회논문지
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• 제13권2호
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• pp.1-12
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• 2004

This paper estimated the arrival angle and electric wave delay time using the space method law and the directions of arrival (DOA) estimation algorithm in case of signal correlation. Space method law is the method used to repress cross correlation before applying the weight value to the receiving signal. The values of the diagonal elements in the correlation matrix were averaged to replace as the diagonal elements value. In the area of wireless communication or mobile communication, there are high correlations in case of low delay time difference in multiple waves. This causes the quality of the communication to drop due to interference with the desired signal elements. This paper estimated the arrival angle and electric wave delay time using the space method law and the MUSIC algorithm. With the arrival angle algorithm, the arrival angle cannot be estimated below 5 in case of signal correlations because the angle resolution capacity decreases accordingly. The super resolution capacity was estimated to determine the arrival angle below 5 in this paper. In addition, the proposed algorithm estimated the short delay time difference to be below 20ns.

• ETRI Journal
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• 제40권5호
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• pp.677-686
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• 2018

A novel data hiding technique based on modified histogram shifting that incorporates multi-bit secret data hiding is proposed. The proposed technique divides the image pixel values into embeddable and nonembeddable pixel values. Embeddable pixel values are those that are within a specified limit interval surrounding the peak value of an image. The limit interval is calculated from the number of secret bits to be embedded into each embeddable pixel value. The embedded secret bits can be perfectly extracted from the stego image at the receiver side without any overhead bits. From the simulation, it is found that the proposed technique produces a better quality stego image compared to other data hiding techniques, for the same embedding rate. Since the proposed technique only embeds the secret bits in a limited number of pixel values, the change in the visual quality of the stego image is negligible when compared to other data hiding techniques.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1273-1278
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• 2000

Bridge load rating calculations provide a basis for determining the safe load capacity of bridge. Load rating requires engineering judgement in determining a rating value that is applicable to maintaining the safe use of the bridge and arriving at posting and permit decisions. Load testing is an effective means in calculating the rating value of bridge. In Korea, load carrying capacity of bridge is modified by stress modification factor that is determined from comparisons of measured values and analysis results The stress modification factor may be corrupted by vehicle location error that is defined as the gap of test vehicle location between load testing and analysis. In this study, the effects of vehicle location error to structural response and stress modification factor are investigated, and a new method for evaluating stress modification factor is proposed. The random data analysis shows that the proposed method is less sensitive to vehicle location error than the present method.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1157-1166
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• 2008

Critical surcharge value of silt ground polluted with garbage leachate to the dyes $q_{cr}=3.73c_u$ and ultimate bearing capacity value $q_{ult}=8.60c_u$. Lateral flow pressure at polluted silt ground was about $P_{max}$/3 and depth of maximum lateral flow pressure was found at that of H/3 of soft layer thickness(H). Expression of polluted silt ground of fracture baseline at stability control charge by Matsuo Kawamura is $S_v=3.56\exp\{0.51(Y_m/S_v)\}$.

• 한국산업정보학회논문지
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• 제13권3호
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• pp.23-30
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• 2008

A data hiding method based on least significant bit (LSB) substitution and multi-pixel differencing (MPD) is presented on the proposed method to improve the capacity of the hidden secret data and to provide an imperceptible visual quality. First, a sum of different values for four-pixel sub-block is calculated. The low value of the sum can be located on a smooth block and the high value is located on an edged block. The secret data are hidden into the cover image by LSB method in the smooth block, while MPD method in the edged block. The experimental results show that the proposed method has a higher capacity and maintains a good visual quality.

• 건축역사연구
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• 제32권2호
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• pp.21-35
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• 2023

The purpose of this study is to develop a method for establishing an educational system for World Heritage interpretation applicable to World Heritage sites and to design an education program for World Heritage interpretation by applying the developed education system in this study. This study first identified the definition of interpretation and the relationship between interpretation and education through previous research and analyzed the role and significance of heritage interpretation due to the paradigm transition in the capacity building of World Heritage sites. Next, the educational status of World Heritage interpretation was analyzed through educational institutions, educational subjects, and curriculum examples. Finally, this study argues that a method for establishing a World Heritage interpretation education system should be presented according to the composition of the curriculum, and the interpretation curriculum planning by interpreters should be proposed focusing on the Outstanding Universal Value (OUV) of World Heritage sites.

• 한국식품저장유통학회지
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• 제30권5호
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• pp.758-769
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• 2023

The main aim of this study was to determine python fat's several physicochemical properties, including dimensions, color, structure, acid value (AV), saponification value (SV), density, and recovery efficiency. The optimum yield obtained was approximately 80.40% at 180℃ for 60 min with an AV of 0.3366 and SV of 179.56 mg KOH/g. Fatty acids, comprising oleic acid (72.462%), palmitic acid (26.243%), linolenic acid (0.835%), and myristic acid (0.459%), were identified using gas chromatography-mass spectrometry (GC-MS). The python fat had a very weak antioxidant capacity and almost no antibacterial ability with gram-positive (Staphylococcus aureus - ATCC 25923 and Bacillus cereus - ATCC 10876) and gram-negative (Escherichia coli - ATCC 25922 and Salmonella enterica - ATCC 35664) bacteria (used the paper disc diffusion method for antibiotic susceptibility testing). Moreover, python fat is considered to be very resistant to high temperatures.

• Journal of information and communication convergence engineering
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• 제3권2호
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• pp.67-71
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• 2005

Interference occurs by signals received from directions that were different from the signals of the users in a mobile communication system. Various studies have been undertaken, including diversity, equalizer, etc., in order to reduce interference. In this study, the weighted value of the array antenna was obtained to improve signal-to-noise ratio. The weighted value was obtained as an eigen value and an eigen vector by using the correlation coefficient of the signal. The weighted value obtained was then applied to the CDMA system to increase system performance and capacity. Both QPSK and OQPSK modulation systems were applied to analyze performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.581-586
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• 2002

Addition of steel fiber to shotcrete is to improve the brittleness of concrete. Quality of steel fiber reinforced shotcrete can be evaluated by quantitive analysis of toughness characteristics after cracking. The toughness characteristics can be expressed by absolute value of energy absorption capacity, non-dimensional toughness index related to the energy absorption capacity, and equivalent flexural strength at arbitrary deflection. In this study, merits and demerits of flexural toughness by RTA round panel of Australia and other specifications have been analyzed.

• Smart Structures and Systems
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• 제4권2호
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• pp.123-135
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• 2008

Damping capacity of SMA damping devices is simulated numerically under distinct geometry and loading conditions. Two-dimensional numerical simulations are performed on the basis of a phenomenological model of dynamics of martensite-austenite phase boundaries. Results of the simulations predict the time delay and the value of the stress transferred to other parts of a construction by a damper device.