• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.315-322
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• 2015

The research carried out on thorium-based fuels indicates that these fuels can be considered as economic alternatives with improved physical properties and proliferation resistance issues. In the current study, neutronic assessment of $UO_2$ in comparison with two $(Th-^{233}U)O_2$, and $(Th-^{235}U)O_2$ thorium-based fuel loads in a heavy water research reactor has been proposed. The obtained computational data showed both thorium-based fuels caused less negative temperature reactivity coefficients for the modeled research reactor in comparison with $UO_2$ fuel loading. By contrast, $^{235}U$-containing thorium-based fuel and $^{235}U$-containing thorium-based fuel loadings in the thermal core did not drastically reduce the effective delayed neutron fractions and delayed neutron fractions compared to $UO_2$ fuel. A provided higher conversion factor and lower transuranic production in the research core fed by the thorium-based fuels make the fuel favorable in achieving higher cycle length and less dangerous and costly nuclear disposals.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.592-603
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• 2015

In this paper, an optical implementation of a novel asymmetrical cryptosystem combined with D-H secret key sharing and triple DES is proposed. The proposed optical cryptosystem is realized by performing free-space interconnected optical logic operations such as AND, OR and XOR which are implemented in Mach-Zehnder type interferometer architecture. The advantage of the proposed optical architecture provides dual outputs simultaneously, and the encryption optical setup can be used as decryption optical setup only by changing the inputs of SLMs. The proposed cryptosystem can provide higher security strength than the conventional electronic algorithm, because the proposed method uses 2-D array data, which can increase the key length surprisingly and uses 3DES algorithm, which protects against “meet in the middle” attacks. Another advantage of the proposed asymmetrical cryptosystem is that it is free to change the user’s two private random numbers in generating the public keys at any time. Numerical simulation and performance analysis verify that the proposed asymmetric cryptosystem is effective and robust against attacks for the asymmetrical cipher system.

• Child Health Nursing Research
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• v.11 no.4
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• pp.381-389
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• 2005

Purpose: This study was done to investigate the effects of a massage program on the growth of premature infants and on the mothers' confidence and satisfaction in the mothering role. Methods: The participants were 29 mothers of premature infants hospitalized in a neonatal intensive care unit at CNU Hospital (14 in the massage program group and 15 in control group). Massage was done for 10-15 minutes, 2-3 times a day for 4 weeks. The data were using the SAS PC+ program. Result: Significant differences were found in the ratios of weight gain (Z=2.24, p=.013), grow in length (Z=2.50, p=.006) and increase in head circumference (Z=1.91, p=.028) between the massage program group and the control group. Confidence in the mothering role was significantly higher for mothers in the massage program group compared to those in the control group (Z=2.69, p=.004), but there was no significant difference in satisfaction with the mothering role between the two groups (Z=.88, p=.191). Conclusion: These results suggest that the massage program enhances growth of premature infants as well as enhancing the mother's confidence in her role as mother. Therefore, the massage program for premature infants can be use as an effective nursing intervention.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.177-180
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• 2002

In this paper, an effective digital watermarking method for copyright protection of binary image data is proposed. First, a binary image is grouped into feature regions which have geometrical features and general one. The watermark for authentication is embedded in general regions in order to preserve geometrical features regions. We have used run-length code and special runs for grouping feature regions and general one. For invisibility of watermark, we have embedded the watermark considering transition sensitivity of each pixel in general regions. The proposed method is applied to some binary image such as character, signature, seal, and fingerprint image to evaluate performance. By the experimental results, the proposed method preserve feature regions of original image and have higher invisibility of watermarks.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.106-111
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• 2007

Increasing genetic variability with mutagenic agents has been broadly employed in plant breeding because it has the potential to alter one or more desirable traits. In this study, a molecular analysis assessed by Amplified Fragment Length Polymorphisms(AFLPs) and a morphological analysis based on seedlings subjected to aluminum stress were compared. Also, an analysis of allelic frequencies was performed to observe unique alleles present in the pool. Genetic distances ranging from 0.448 to 0.953 were observed, suggesting that mutation inducing was effective in generating variability. The genetic distances based on morphological data ranged from 0(genotypes 22 and 23) to 30.38(genotypes 15 and 29). In the analysis of allelic frequency, 13 genotypes presented unique alleles, suggesting that mutation inducing was also targeting unique sites. Mutants with good performance under aluminum stress(9, 15, 18 and 27) did not form the same clusters when morphological and molecular analyses were compared, suggesting that different genomic regions may be responsible for their better performance.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.62-66
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• 1998

The maneuverabilities of the training ship M.S. HEUIMANGBONG were studied, based on the data obtained from her Z test. The results obtained were summerized as follows: 1. The maneuvering indices K' and T'of the M.S. HEUIMANGBONG were 0.542, 1.305 at 10$^{\circ}$Z Test and 0.433, 1.351 at 20$^{\circ}$Z test and 0.442, 1.388 at 30$^{\circ}$Z test respectively. The above calculated values K', T' showed that her maneuverabilities were more effective when her rudder was used to small angle than to large angle. 2. As the overshoot angles of the starbord side of the M.S. HEUIMANGBONG were larger than those of port side at 10$^{\circ}$, 20$^{\circ}$and 30$^{\circ}$Z test, her maneuverabilities in port turning were found to be higher than in starbord turning. 3. The running distance of a turn at her 10$^{\circ}$Z test was about 9.9 times her own length and she was considered to have a good maneuverabilities synthetically

• Korean Journal of Remote Sensing
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• v.24 no.1
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• pp.57-64
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• 2008

In the previous study, the Haar wavelet was used as the sole basis function for the 3D discrete wavelet transform because the number of bands is too small to decompose a remotely sensed image in band direction with other basis functions. However, it is possible to use other basis functions for wavelet decomposition in horizontal and vertical directions because wavelet decomposition is independently performed in each direction. This study aims to classify a high spatial resolution image with the six types of basis function including the Haar function and to compare those results. The other wavelets are more helpful to classify high resolution imagery than the Haar wavelet. In overall accuracy, the Coif4 wavelet has the best result. The improvement of classification accuracy is different depending on the type of class and the type of wavelet. Using the basis functions with long length could be effective for improving accuracy in classification, especially for the classes of small area. This study is expected to be used as fundamental information for selecting optimal basis function according to the data properties in the 3D DWT based image classification.

• Journal of Ecology and Environment
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• v.45 no.3
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• pp.152-162
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• 2021

Background: Recent declines in bee populations, along with increasing demand for pollination services in urban, agricultural, and natural environments, have led to strategies to attract wild bees to these areas. One of these strategies is installing artificial nests adjacent to urban gardens and agricultural farms. Bee hotels and nest boxes are among the artificial nests used by gardeners and farmers to attract pollinators. In this paper, we reviewed 50 studies that reported the efficiency of nest boxes and bee hotels in attracting bees. We considered the maximum occupation rate (percentage) as the main index to evaluate the efficiency of artificial nests. Results: The maximum occupation rate of bee hotels was higher in farms (averaged 44.1%) than in forests (averaged 30.3%) and urban (averaged 38.3%) environments. In the case of nest boxes, most studies reported efficiencies of less than 20%, with an occupation rate of 16% and 5.5% on average in forest and urban environments respectively. However, our meta-analysis results showed that there was no significant relationship between the occupation rate of the nests and their installation place. Regression analysis also showed that the structural features of bee hotels (length and diameter) and nest boxes (volume and entrance size) did not affect their efficiency in attracting bees. Conclusion: Our data showed that the strategy of installing artificial nests to attract pollinators is successful only concerning bee hotels, and the use of nest boxes has not been very successful.

• Current Optics and Photonics
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• v.3 no.2
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• pp.105-110
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• 2019

The visible-light communication (VLC) system is a promising candidate to fulfill the present and future demands for a high-speed, cost-effective, and larger-bandwidth communication system. VLC modulates the visible-light signals from solid-state LEDs to transmit data between transmitter and receiver, but the broadcasting and the line-of-sight propagation nature of visible-light signals make VLC a communication system with a limited operating range. We present a novel architecture to increase the operating range of VLC. In our proposed architecture, we guide the visible-light signals through the fiber and amplify the dissipated signals using visible-light fiber amplifiers (VLFAs), which are the most important and the novel devices needed for the proposed architecture of the VLC. Therefore, we design, analyze, and apply a VLFA to VLC, to overcome the inherent drawbacks of VLC. Numerical results show that under given constant conditions, the VLFA can amplify the signal up to 35.0 dB. We have analyzed the effects of fiber length, active ion concentration, pump power, and input signal power on the gain and the noise figure (NF).

• The Journal of the Korean dental association
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• v.57 no.6
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• pp.316-324
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• 2019

The new medical technology assessment system has a basic goal of protecting the public's health rights and promoting the development of the new medical technology with safe and effective medical technology that has been scientifically proven. The purpose of this study is to contribute to the activation of the new medical technology evaluation system by analyzing the application cases of the dental field after the implementation of the new medical technology evaluation system and proposing an efficient approach to approach the new medical technology evaluation system. The number of related literature and medical technology evaluation results are not significant in dental applications, the number of cases and the length of follow-up period of the relevant medical technology adopted as the new medical technology was far higher. As the speed of medical technology development increases, medical technology is expected to develop in the dental field as well. To introduce the medical technology to the clinical site, access to the correct direction of evidence is required to collect and objectify data at the medical site in order to prepare a literary basis for the medical technology.