• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.3
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• pp.118-123
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• 1995

We have successfully fabricated a super low noise pseudomorphic HEMT(PHEMT) device with AlGaAs/InGaAs/GaAs sturcture by using improved T-Gate which have increased a large gaet cross-sectional area about two times in comparision with those of conventional T-gate processes. The PHEMSTs with 0.15$\mu$m-long and 140$\mu$m-wide gates have eshibited a super low noise characteristics, the noise figure of 0.45dB with associated gain of 10.87dB at 12GHz. The cut-off rewuqncy of the device is 94gHz with a transconductance of 418mS/mm.

• Bulletin of the Korean Mathematical Society
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• v.43 no.1
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• pp.125-140
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• 2006

Let $g(n,\;l_1,\;l_2,\;d,\;t,\;q)$ be the number of general4-regular graphs on n labelled vertices with $l_1+2l_2$ loops, d double edges, t triple edges and q quartet edges. We use inclusion and exclusion with five types of properties to determine the asymptotic behavior of $g(n,\;l_1,\;l_2,\;d,\;t,\;q)$ and hence that of g(2n), the total number of general 4-regular graphs where $l_1,\;l_2,\;d,\;t\;and\;q\;=\;o(\sqrt{n})$, respectively. We show that almost all general 4-regular graphs are 2-connected. Moreover, we determine the asymptotic numbers of general 4-regular graphs with given connectivities.

• Journal of Software Assessment and Valuation
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• v.15 no.2
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• pp.129-140
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• 2019

In the IoT environment, there is a huge amount of heterogeneous devices with limited capacity. Existing trust evaluation methods are not adequate to accommodate this requirement due to the limited storage space and computational resources. In addition, since IoT devices are mainly human operated devices, the trust evaluation should reflect the social relations among device owners. There is also a need for a mechanism that reflects the tendency of the trustor and environmental factors. In this paper, we propose an adaptable trust evaluation method for SOA-based IoT system to deal with these issues. The proposed model is designed to minimize the confidence bias and to dynamically respond to environmental changes by combining direct evaluation and indirect evaluation. It is expected that it will be possible to secure trust through quantitative evaluation by providing feedback based on social relationships.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.121-133
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• 2011

Effects of roasting on vitamin E content, color, microstructure and moisture of peanuts, and vitamin E content in peanut oils prepared from the roasted peanuts were investigated. Runner-type peanuts were roasted at 140, 150, and $160^{\circ}C$ for 10-20 min. As roasting temperature and time increased, the CIELAB $L^*$ value of peanuts decreased while $a^*$ and $b^*$ values increased, resulting in formation of the golden brown color of roasted peanuts. Moisture ratio (M/Mo) and color $b^*$ value of peanuts roasted at 140 to $160^{\circ}C$ showed a correlation of $b^*=21.61\;(M/Mo)^2-40.62\;(M/Mo)+34.12$ ($R^2=0.9123$). Overall changes in the tocopherol contents of peanuts and peanut oils were significantly affected by roasting temperature and time (p<0.05). Roasting at $140^{\circ}C$ caused a slight increase in the levels of tocopherols of peanuts over roasting time up to 20 min (p<0.05). There was no significant change in the tocopherol levels of peanuts during roasting at $150^{\circ}C$ for 20 min (p>0.05). At $160^{\circ}C$, the levels of tocopherols significantly decreased during the initial 10 min of roasting (p<0.05) while there was no extended loss after 10 min, resulting in about 5, 12, 20, and 10% losses of ${\alpha}$-, ${\beta}$-, ${\gamma}$- and ${\delta}$-T, respectively. After 20 min, total tocopherols decreased by 18%. However, tocopherol contents of pressed peanut oils significantly decreased at all roasting temperatures (p<0.05). After roasting peanuts at $160^{\circ}C$ for 20 min, about 84% of initial ${\alpha}$-T in peanut oils was retained. ${\alpha}$-T was the most stable to roasting while ${\gamma}$-T was the least. Swollen epidermal cells on the inner surface and broken cell walls of parenchyma tissue of peanut cotyledon were observed in peanuts after roasting at $160^{\circ}C$ for 15 min. Severe changes in microstructure of peanut by roasting would contribute to vitamin E stability because of exposure of oil droplets in peanuts to oxygen.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.261-268
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• 2013

This study presents a descriptive research on the degree of self-care related to the prevention of radiation exposure after radioactive iodine therapy and on the relations between self-efficacy and social support to propose nursing interventions required for patients after radioactive iodine therapy. The research period lasted from March to May, 2013. The subjects included 108 patients that were receiving radioactive iodine therapy after thyroidectomy at a cancer hospital in Gyeonggi Province. The subjects scored mean 52.10 on self-care out of full 56 and as for the general characteristics of the subjects, there were significant differences in their self-care according to whether they had a child or not(t=-2.312, p=.023) and interest in health(t=5.689, p<.001). There were significant positive correlations between their self-care and their self-efficacy(r=.610, p<.001), family support(r=.646, p<.001), and medical staff support(r=.276, p=.004). Interest in health(t=5.301, p<.001) was predictor on level 1 of hierarchical regression and interest in health(t=2.140, p=.035) and family support(t=3.353, p=.001) turned out to influence the self-care of the subjects, recording total 46.3% explanatory power. The most important predictor was interest in health(${\beta}$=1.309, p=.035) of self-care.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.310-318
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• 2018

Recently, the importance of big data analysis is increasing as a large amount of data is generated by various devices connected to the Internet with the advent of Internet of Things (IoT). Especially, it is necessary to analyze various large-scale IoT streaming sensor data generated in real time and provide various services through new meaningful prediction. This paper proposes a real-time indoor PM10 concentration prediction LSTM model based on streaming data generated from IoT sensor using AWS. We also construct a real-time indoor PM10 concentration prediction service based on the proposed model. Data used in the paper is streaming data collected from the PM10 IoT sensor for 24 hours. This time series data is converted into sequence data consisting of 30 consecutive values from time series data for use as input data of LSTM. The LSTM model is learned through a sliding window process of moving to the immediately adjacent dataset. In order to improve the performance of the model, incremental learning method is applied to the streaming data collected every 24 hours. The linear regression and recurrent neural networks (RNN) models are compared to evaluate the performance of LSTM model. Experimental results show that the proposed LSTM prediction model has 700% improvement over linear regression and 140% improvement over RNN model for its performance level.

• Current Photovoltaic Research
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• v.2 no.3
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• pp.140-145
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• 2014

The globally used PV qualification tests and reports the pass/fail only. Therefore, the reliability of new PV materials and parts can't be compared quantitatively with the reliability of the PV parts and materials in the market. Global PV materials and parts companies test and compare their materials, parts, and modules using the failure-to-test (FTT). However, it takes a long accelerated stress test (AST) until failure. It also needs to test the new and existing materials and parts. Therefore, it requires excessive equipment time and cost. In order to reduce the time and cost, a new reliability enhancement methodology has been developed. It tests the PV materials, parts, and modules in the global market and stores them in the PV reliability database. It reduces the time and cost of the comparison and enhancement of PV reliability. An example of the reliability enhancement of the PV encapsulant, EVA is presented.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.133-140
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• 1990

In monocular vision, bead and eye optokinetic nystagmus (OKN) display directionnal asymmetry, in lower vertebrates such as chickens, T-N stimulation being more efficient in evoking this visuomotor reflex than N-T stimulation. The N-T component of monocular OKN is significantly weaker in chickens. Coil recordings and observation showed that in adult chickens, prolonged monocular visual deprivation by unilateral eyelid suture provoked significant and progressive increase of the N-T component in chickens. This plasticity phenomenon involved the eye and head OKN in chickens. The administration of THIP, a GABA agonist, abolished reversibly the increase of the N-T component in chickens. This fact suggests that the GABAergic system could be involved in determining this plasticity phenomenon observed in adult lower vertebrates.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.140-146
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• 2023

Resource allocation is one of the top challenges in Internet of Things (IoT) networks. This is due to the scarcity of computing, energy and communication resources in IoT devices. As a result, IoT devices that are not using efficient algorithms for resource allocation may cause applications to fail and devices to get shut down. Owing to this challenge, this paper proposes a novel algorithm for managing computing resources in IoT network. The fog computing devices are placed near the network edge and IoT devices send their large tasks to them for computing. The goal of the algorithm is to conserve energy of both IoT nodes and the fog nodes such that all tasks are computed within a deadline. A bi-partite graph-based algorithm is proposed for stable matching of tasks and fog node computing units. The output of the algorithm is a stable mapping between the IoT tasks and fog computing units. Simulation results are conducted to evaluate the performance of the proposed algorithm which proves the improvement in terms of energy efficiency and task delay.

• Journal of radiological science and technology
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• v.38 no.4
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• pp.477-482
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• 2015

Workers in nuclear medicine have performed various tasks such as production, distribution, preparation and injection of radioisotope. This process could cause high radiation exposure to wokers' hand. The purpose of this study was to investigate shielding effect for r-rays of 140 and 511 keV by using Monte-carlo simulation. As a result, it was effective, regardless of lead thickness for radiation shielding in 140 keV r-ray. However, it was effective in shielding material with thickness of more than only 1.1 mm in 511keV r-ray. And also it doesn't effective in less than 1.1 mm due to secondary scatter ray and exposure dose was rather increased. Consequently, energy of radionuclide and thickness of shielding materials should be considered to reduce radiation exposure.