• Journal of the Chungcheong Mathematical Society
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• v.30 no.1
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• pp.103-116
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• 2017

In this paper, we show that the solutions to perturbed differential system $$y^{\prime}=f(t,y)+{{\displaystyle\smashmargin{2}{\int\nolimits_{t_0}}^{t}}g(s,y(s),T_1y(s))ds+h(t,y(t),T_2y(t))$$ have asymptotic property by imposing conditions on the perturbed part ${\int_{t_0}^{t}}g(s,y(s),T_1y(s))ds,h(t,y(t),T_2y(t))$, and on the fundamental matrix of the unperturbed system y' = f(t, y).

• Communications of the Korean Mathematical Society
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• v.27 no.1
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• pp.77-95
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• 2012

For a bounded linear operator T we prove the following assertions: (a) If T is algebraically (p, k)-quasihyponormal, then T is a-isoloid, polaroid, reguloid and a-polaroid. (b) If $T^*$ is algebraically (p, k)-quasihyponormal, then a-Weyl's theorem holds for f(T) for every $f{\in}Hol({\sigma}T))$, where $Hol({\sigma}(T))$ is the space of all functions that analytic in an open neighborhoods of ${\sigma}(T)$ of T. (c) If $T^*$ is algebraically (p, k)-quasihyponormal, then generalized a-Weyl's theorem holds for f(T) for every $f{\in}Hol({\sigma}T))$. (d) If T is a (p, k)-quasihyponormal operator, then the spectral mapping theorem holds for semi-B-essential approximate point spectrum $\sigma_{SBF_+^-}(T)$, and for left Drazin spectrum ${\sigma}_{lD}(T)$ for every $f{\in}Hol({\sigma}T))$.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.57-63
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• 2018

IoT devices are used in many areas to perform various roles and functions in a cloud environment. However, a method of access control that can stably control the IoT device has not been proposed yet. In this paper, we propose a hierarchical multi-level property access control scheme that can perform stable access of IoT devices used in a cluster environment. In order to facilitate the access of the IoT device, the proposed method not only provides the ID key (security token) unique to the IoT device by providing the IoT Hub, but also allows the IoT Hub to authenticate the X.509 certificate and the private key, So that the private key of the IoT device can not be seen outside the IoT device. As a result of the performance evaluation, the proposed method improved the authentication accuracy by 10.5% on average and the processing time by 14.3%. The overhead of IoT Hub according to the number of IoT attributes was 9.1% lower than the conventional method.

• Journal of Digital Contents Society
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• v.11 no.3
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• pp.283-290
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• 2010

The effectiveness of 3.0T phase array coil images was tested by comparing signal-to-noise ratios for the same coil images relative to 1.5T endorectal coil images. Signal intensities were measured in the three regions of prostate, central and peripheral (right and left) after 40 patients with prostate cancer were imaged during the period between Jan. 2008 and Oct. 2009 with T2 W, T1 W, and DW images obtained respectively using endorectal coil on a 1.5T MR scanner and phase array coil on a 3.0T MR scanner. For quantitative analysis, comparisons of average SNRs for the same ROIs were made between groups scanned with a 1.5T and a 3.0T MR scanner. The signal-to-noise ratios were shown to increase more sharply when using a phase array coil at a 3.0T MR scanner compared to using an endorectal coil at a 1.5T MR scanner.

• International Journal of Oral Biology
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• v.37 no.2
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• pp.57-62
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• 2012

The nasal cavity encounters various irritants during inhalation such as dust and pathogens. To detect and remove these irritants, it has been postulated that the nasal mucosa epithelium has a specialized sensing system. The oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) that can detect harmful substances to prevent ingestion. Recently, solitary chemosensory cells expressing T2R subtypes have been found in the respiratory epithelium of rodents. In addition, T2Rs have been identified in the human airway epithelia. However, it is not clear which T2Rs are expressed in the human nasal mucosa epithelium and whether they mediate the removal of foreign materials through increased cilia movement. In our current study, we show that human T2R receptors indeed function also in the nasal mucosa epithelium. Our RT-PCR data indicate that the T2R subtypes (T2R3, T2R4, T2R5, T2R10, T2R13, T2R14, T2R39, T2R43, T2R44, T2R 45, T2R46, T2R47, T2R48, T2R49, and T2R50) are expressed in human nasal mucosa. Furthermore, we have found that T2R receptor activators such as bitter chemicals augments the ciliary beating frequency. Our results thus demonstrate that T2Rs are likely to function in the cleanup of inhaled dust and pathogens by increasing ciliary movement. This would suggest that T2Rs are feasible molecular targets for the development of novel treatment strategies for nasal infection and inflammation.

• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.273-283
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• 2011

The objective of this study was to determine the feeding effect of a diet containing Cordyceps with fly pupa on the changes in blood lipid profile from broiler chickens, fatty acids and thiobarbituric acid reactive substances (TBARS) in chicken meat. A total of 360 chicks (Ross strain 308) were divided on hatch day into four treated groups with respect to a 35-day feeding regimen: T1 (control group), T2 (2.0% Cordyceps with fly pupa), T3 (3.5% Corceps with fly pupa) and T3 (5.0% Cordyceps with fly pupa). Blood triacylglyceride and total cholesterol level was significantly decreased by 5.32-10.63% and 9.23-12.62%, respectively, in groups T2, T3 and T4 when compared to T1 (p<0.05). Water holding capacity was significantly highest in T2 (p<0.05), while there were no significant differences among groups T2, T3 and T. In chicken meat, the ratio of saturated fatty acid to unsaturated fatty acid was high in the T3 and T4 groups, the ratio of n-6 to n-3 fatty acid was low in the T2, T3 and T4 groups and oleic acid (18:1n-9) was high in the T2, T3 and T4 groups, when compared to T1 (p<0.05). TBARS tended to increase according to the storage time (in days), and was significantly lower in the chicken thigh muscles with skin in groups T2, T3 and T4 as compared to T1 (p<0.05). These results suggest that a diet containing 2.0-3.5% of Cordyceps with fly pupa may decrease blood lipid and improve both the shelf-life and quality of broiler chicken meat.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.27 no.1
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• pp.97-102
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• 2023

IoT is being used in a lot of industry domain such as smart home, smart ocean, smart energy, and smart farm, as well as legacy information services. For a server, an IoT device using the same protocol is a trusted object. Therefore, a malicious attacker can use an unauthorized IoT device to access IoT-based information services and access unauthorized important information, and then modify or extract it to the outside. In this study, to improve these problems, we propose an IoT device authentication system used in IoT-based information service. The IoT device authentication system proposed in this study applies identifier-based authentication such as MAC address. If the IoT device authentication function proposed in this study is used, only the authenticated IoT device can access the server. Since this study applies a method of terminating the session of an unauthorized IoT device, additional research on the access deny method, which is a more secure authentication method, is needed.

• Journal of applied mathematics & informatics
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• v.42 no.3
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• pp.635-646
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• 2024

In this research work, we introduce and investigate four innovative types of soft spaces, pushing the boundaries of traditional spatial concepts. These new types of soft spaces are named as soft T_b space, soft T^#_b space, soft T^##_b space and soft_αT^#_b space. Through rigorous analysis and experimentation, we uncover and propose distinct characteristics that define and differentiate these spaces. In this research work, we have established that every soft $T_{\frac{1}{2}}$ space is a soft _αT^#_b space, every soft T_b space is a soft _αT^#_b space, every soft T^#_b space is a soft _αT^#_b space, every soft T_b space is a soft T^#_b space, every soft T^#_b space is a soft T^##_b space, every soft $T_{\frac{1}{2}}$ space is a soft ^#T_b space and every soft T_b space is a soft #T_b space.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.1
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• pp.52-60
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• 1995

This experiment was carried out to determine the effect of nitrogen application level of cattle sluny(T1:150, T3:250, T53.50 kglha) and chemical fertilizer(T2:150, T4:250, T6:350 kg/ha) on the growth characteristics, dry matter yield and chemical soil property of Sorghum-Sudangrass hybrid [Sorghum bicolor L. Moench]. The results obtained are summarized as follows: Mean stem diameter was significantly increased by increasing nitrogen application level of cattle slurry and chemical fertilizer. Especially, T6 treatment was the highest as 11.1 mm, while T1 treatment w a the lowest as 0.3 mrn. According to the same level of nitrogen application, cattle slurry treaunent(T1, T3 and T5) were showed a lower mean stem hardness than chemical fertilizer treatment(T2, T4 and T6). Especially, T3 treatment was the softest at 0.7 kg/$cm^2$. The dead stubble and tiller number were increased by increasing nitrogen level of cattle slurry and chemical fertilizer(P

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7656-7666
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• 2015

The purpose of this study was to explore the determinants of subjective happiness among Korean adolescents and to supply basic data for enhancing to subjective happiness among Korean adolescents. This study used the 2014 Korean Youth Health Risk Behavior On-lin Survey data. It conducted a secondary data analysis of 72,060 cases. It conducted frequency analysis, t-test, ANOVA and multiple regression analysis by SPSS 18.0. Although various independent variables influenced on emotional support(t=44.335, p<,001), gender(t=27.730, p<.001), grade(t=25.347, p<.001), economic status(t=-25.345, p<.001), living arrangement(t=-6.158, p<.001), school record(t=-7.512, p<.001), father's educational status(t=-2.378, p<.001), subjective health status(t=46.062, p<.001), depression(t=-23.837, p<.001), sleep(t=19.871, p<.001), level of stress(t=-78.685, p<.001), alcohol(t=-13.481, p<.001) and drug use(t=-2.671, p<.01), smoking(t=-11.988, p<.001), breakfast(t=4.443, p<.001), activity(t=4.757, p<.001) were key factors of subjective happiness among Korean adolescents. The findings of this study were as follow: male middle students, who had emotional support, higher economic status, school record and father's educational level, living with family showed higher levels of subjective happiness. It also having good subjective health status, not depressed, more sufficient sleep, lower stress, no experience of drinking, smoking and drugs, more physical activity and having breakfast showed higher levels of subjective happiness.