• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.669-675
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• 2011

In this paper, we present the AFP(antenna front plate)s which were designed to reduce the reflection for the sake of the improvement of DF(direction finding) accuracy. The AFP consists of front plate, absorber and radome. The AFPs were optimized respectively by real test and we performed the DF test using our AFPs in laboratory. The DF test shows that the DF accuracy is about 2 times better than the requirement capability. Then, the DF field test was executed using the AFPs, which were installed in helicopter in consideration of the reflection by platform. The result of the DF field test is superior to the requirement capability also, which shows the validity of our design method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5208-5213
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• 2011

In this paper, we proposed a new direction finding(DF) technology using TDOA(time-difference of arrival) and PDOA(phase difference of arriving signal) method. The proposed technology has a good DF accuracy without DF ambiguity. TDOA or PDOA technology is used to the most of intelligence systems in 21 century. The principle of TDOA is to receive a signal with two parallel antennas, measure the time difference of arrival signal, and converse the time difference to the direction of incident signal. Those technology make a DF system small size but the DF accuracy is low into short antenna installation distance. The principle of PDOA is similar to TDOA except measuring the phase difference of arrival signal, These technology get a good DF accuracy in short antenna installation distance but have a DF ambiguity. The proposed DF method is simulated into DF system operation environment with noise, and has a good DF accuracy.

• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.36-41
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• 2011

In the present paper, a direct forcing/fictitious domain (DF/FD) level set method is proposed to simulate the FSI (fluid-solid interaction) in two-phase flow. The main idea is to combine the direct-forcing/fictitious domain (DF/FD) method with the level set method in the Cartesian coordinates. The DF/FD method is a non-Lagrange-multiplier version of a distributed Lagrange multiplier/fictitious domain (DLM/FD) method. This method does not sacrifice the accuracy and robustness by employing a discrete ${\delta}$ (Dirac delta) function to transfer quantities between the Eulerian nodes and Lagrangian points explicitly as the immersed boundary method. The advantages of this approach are the simple concept, easy implementation, and utilization of the original governing equation without modification. Simulations of various water-entry problems have been conducted to validate the capability and accuracy of the present method in solving the FSI in two-phase flow. Consequently, the present results are found to be in good agreement with those of previous studies.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.373-378
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• 2014

The technology of direction finding is very important to make high position fixing accuracy. TDOA(time difference of arrival) direction finding technology is a high accuracy technology and is used in RF system from 1990. The principle of TDOA is to receive an emitter signal with two antennas, measure the time difference of received signal and then convert the time differences to azimuth angle. For high DF(direction finding) accuracy long basis line and high SNR at receiving system are needed. The DF accuracy and position fixing accuracy are simulated with different SNRs and antenna base lines. We obtain the DF accuracy of $0.51^{\circ}$ at $0^{\circ}$ incident azimuth angle in case of 50m base line and 40dB SNR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3104-3109
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• 2009

The technology of direction finding is very important to find the direction of emitters for ELINT(electronic intelligence) system. The principle of TDOA(time difference of arrival) is to receive an emitter signal with two antennas, measure the time difference between two antennas, and converse the time difference to direction difference. This technology can be used in broadband frequency system and make the system very simple because a phase-discriminator and a voltage comparator are not needed. For fine DF accuracy, high time resolution receiver and long basis line antennas are needed. The DF accuracy of noise added signals is simulated with different time

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6A
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• pp.568-576
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• 2010

In this paper, we analyze the outage probability of full duplex relay (FDR) with decode-and-forward (DF) protocol is derived under fading channels. The fading channel for source-relay link is assumed to be Rician fading to consider the infrastructured fixed relay with line of sight (LOS) propagation, and the other fading channels are assumed to be Rayleigh fading. Based on this analytical result, we provide the criterion that FDR shows a lower outage probability than HDR to consider the interference problem and the resource efficiency improvement by full duplex (FD) operation. The accuracy of the analysis is confirmed throughout the simulation results.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.161-168
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• 2000

The purpose of this study was to develop a practical caries activity test using laser fluorescence. The subjects of study were 30 children of $7\sim10$ years old. Fluorescence from initial carious lesion of teeth illuminated by an argon laser(488nm) was observed through barrier alter. For evaluation of accuracy and propriety of this method fer caries activity test, teeth with initial caries lesion on buccal or labial surface of children was examined with visual inspection and laser fluorescence. Visual examination for the dDfFtT and the $Cariescreen^{(R)}$ test were also done. The results from the present study can be summarized as follows: 1. Laser fluorescence test could differentiate initial caries lesions more easily than visiual inspection. 3. There was highest correlation(= 0.73) between laser fluorescent test and $Cariescreen^{(R)}$ test and. And also apparent correlation(= 0.66) exists between laser fluorescent test and caries experience measured by dDfFtT.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1527-1532
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• 2016

Strain SPF4211, having hyaluronidase (HAase) inhibition activity, was isolated from P. davidiana (Carriere) Franch fruit (PrDF) sugar extract. The phenotypic and biochemical properties based on 16S rDNA sequencing and an API 50 CHB kit suggested that the organism was B. subtilis. To optimize the HAase inhibition activity of PrDF extract by fermentation of strain SPF4211, a central composite design (CCD) was introduced based on three variables: concentration of PrDF extract (X₁: 1-5%), amount of starter culture (X₂: 1-5%), and fermentation time (X₃: 0-7 days). The experimental data were fitted with quadratic regression equations, and the accuracy of the equations was analyzed by ANOVA. The statistical model predicted the highest HAase inhibition activity of 37.936% under the optimal conditions of X₁ = 1%, X₂ = 2.53%, and X₃ = 7 days. The optimized conditions were validated by observation of an actual HAase inhibition activity of 38.367% from extract of PrDF fermented by SPF4211. These results agree well with the predicted model value.

• Journal of Korean Academy of Nursing
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• v.28 no.3
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• pp.718-728
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• 1998

Breast self-examination is the most effective and easiest way for women to increase the responsible consciousness about their health. The purpose of this study was to test the variables impacted to promote breast self-examination practice. The research design used in this study was a nonequevalent control group of a non-synchronized design. The sample that was assembled consisted of 124 women. A purposive sample consisted of 124 women. Each subject was given to assessed on the following the demographic data related to the breast self-examination, knowledge of self-examination, accuracy, in performing self-examination, self-efficacy about breast cancer and breast self-examination, and the number of subjects who found a mass. The result of this study may be summarized as follows : 1. To examine the theretical model fit to the data, chi square test statistics and goodness of fit index were identified($\chi$$^2$=2.30, df=2, GFI=0.99, AGFI=0.94 RMSR=0.02, NFI=0.99, NNFI=0.99, Critical Number=439). 2. The direct effects of education of breast self-examination were knowledge, self-efficacy, accuracy, number finding a mass. But the Indirect effect of education on breast self-examination was frequency of breast self-examination. 3. Knowlege, as direct paths to the breast self-examination practices, was removed in the theoretical model. The parsimonious best fit model included self-efficacy, accuracy, the number finding mass, frequency of breast self-examination practices. 4. The final model produced a chi-square=5.58(p=0.35) with df=5, and GFI =0.99, AGFI =0.94, RMSR=0.03, NFI=0.99, NNFI=0.99, CN=339 indicating very a good fit. Based on the result of this study, education of breast self-examination is very effective for increasing the competency of the breast self-examination through the knowledge and self-efficacy. Resources to promote self-efficacy may be helpful to increase the frequency of self-examination because self-efficacy is a direct effect on it. These findings suggest the need to develop nursing strategy to promote the self-efficacy of breast self-examination.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.459-474
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• 2000

The purpose of this study is to identify the posture correction program as the development of the posture maintenance performance, and search for the more efficient posture correction program. The data analysis was processed by SPSS. The data was analysed with $x^2$-test, t-test, pearson product moment correlation, and stepwise regression analysis. The finding of this study is as follows: There are the homogeneity between two groups was verified on the know ledges CF=.697, df=2, P>.05), self-efficacy(F=.098, df=2, P>.05) about the posture. The developed posture correction program has proved to enhance the posture maintenance performance(knowledge t=1.60, P<.05 ; posture manintenance t=7.69, P<.01). The type of posture correction program showed some significant differences (t=5.62, P<.01) in the accuracy of movement way among the factors of the posture maintenance performance. The posture maintenance performance affected self-efficacy. Therefore, the major conclusion is as follows: The posture correction program was meaningfully effective on developing the posture maintenance, and with practice created accuracy much more on the posture maintenance movement way. The development of the posture maintenance performance affected the increase of self-efficacy about the posture. The self-efficacy has proved so powerful factor to influence on the posture maintenance performance development. So, the posture correction program should be done systematically and continually, and developing the posture maintenance performance should be done with practice. After the education, it should be reinforced through practice, midterm identification and reeducation and motivated with recognizing the accurate posture measurement. And it should be created the correction program to develop the high self-efficacy about the posture. It needs the strategy to educate the correct posture individually, and to spread to the society for healthy life style.