• Journal of applied mathematics & informatics
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• v.32 no.1_2
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• pp.17-26
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• 2014

In this paper, we present an algorithm for computing the number of points on the Jacobian varieties of genus 3 hyperelliptic curves of type $y^2=x^7+ax$ over finite prime fields. The problem of determining the group order of the Jacobian varieties of algebraic curves defined over finite fields is important not only arithmetic geometry but also curve-based cryptosystems in order to find a secure curve. Based on this, we provide the explicit formula of the characteristic polynomial of the Frobenius endomorphism of the Jacobian variety of hyperelliptic curve $y^2=x^7+ax$ over a finite field $\mathbb{F}_p$ with $p{\equiv}1$ modulo 12. Moreover, we also introduce some implementation results by using our algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.663-665
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• 2009

Ubi-Home 환경에서 장치제어를 하기위해 다양한 방법이 제안되었다. 그 중 원격지에서 장치제어를 하기 위해 특정 기기(로봇)를 활용할 수 있다. 하지만 이와 같은 방법에는 로봇과 장치들의 위치인식과 이동경로 설정에 따른 제약사항이 따른다. 또한 이러한 위치인식 및 이동에는 미리 작성된 하나의 맵이 사용되므로 새로운 환경의 변화나 확장에 적용할 수 없다. 따라서 본 논문에서는 로봇과 장비의 위치인식과 이동경로를 위한 학습형 맵 작성 기법을 제안하며, 테스트를 위해 Atmega128v4 MCU와 AX-12+ Motor, AX-S1 Sensor, ZBS-200 Zigbee, CL-1L5/603LM Infrared Ray Sensor로 로봇을 제작하여 실내 환경 모형에서 테스트하였다.

• Journal of applied mathematics & informatics
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• v.38 no.1_2
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• pp.1-12
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• 2020

In this paper, we solve the difference equation $x_{n+1}={\frac{x_nx_{n-2}}{ax_n-bx_{n-2}}}$, n = 0, 1, …, where a and b are positive real numbers and the initial values x_-2, x_-1 and x₀ are real numbers. We also find invariant sets and discuss the global behavior of the solutions of aforementioned equation.

• The Pure and Applied Mathematics
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• v.15 no.2
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• pp.103-110
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• 2008

In this paper, we obtain the general solution and the stability of the cubic functional equation f(2x + y, 2z + w) + f(2x - y, 2z - w) = 2f(x + y, z + w) + 2f(x - y, z - w) + 12f(x, z). The cubic form $f(x,\;y)\;=\;ax^3\;+\;bx^2y\;+\;cxy^2\;+\;dy^3$ is a solution of the above functional equation.

• Journal of Chest Surgery
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• v.27 no.1
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• pp.43-47
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• 1994

Prompt recognition and proper treatment of esophageal perforation or rupture may ax~ert death or minimize complications. We have experienced sixteen patients of esophageal perforation at the department of thoracic and cardiovascular surgery, Hallym Medical college during the period fromJan. 1986 to Sep. 1993. The ratio between male and female patient was 13:3 and their age ranged from 23 years to 67 years old. The major cause of esophageal perforations was spontaneous rupture in 7 cases[45%], surgical trauma in 2 cases[12%], instrumental trauma in 2 cases[12%], and others in 5 cases[31%]. The common site of esophageal perforation was in the lower third portion of the esophagus[10 cases, 62%]. The most consistent symptom of esophageal perforation was chest pain in 11 cases, temperature elevation within a few hours was 9 cases.Contrast roentgenographic studies demonstrated the perforation in all but 2 of the 16 patients. The frequent complications of esophageal perforation were empyema in 7 cases[45 %] and mediastinitis in 2 cases[12%]. fourteen patients had suture closure and drainage with 2 deaths, and 2 patient received only drainage procedures. The mortality rate was 12%[2 cases] and cause of death was sepsis and aortic rupture.

• Journal of Life Science
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• v.21 no.12
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• pp.1698-1704
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• 2011

In this study, we evaluated the protective effects of ethanol extracts from Dendranthema indicum on cell and DNA damages induced by oxidative stress. Antioxidant activities of D. indicum extracts are higher than scavenging activities of DPPH free radical and hydroxyl radical by 92.8% and 73.8%, respectively, and higher than ferrous iron chelating effects by 59.4%. D. indicum extracts showed a protective effect on oxidative cell damage by inhibiting lipid peroxidation by 90.3% in the control group, and inhibiting expression level of p21 protein by 79.6% for the control group. This means D. indicum extracts have a great protective effect against oxidative stress. DNA fragmentation inhibition in D. indicum extracts were 89.6% for the control group, which makes the movement of DNA tail reduced, and phosphorylation of H2AX was 20.2% of the radical experiment group. This means that D. indicum extracts effectively inhibit DNA fragmentation and H2AX phosphorylation. Taken together, we suggest that ethanol extract from D. indicum has a role as a useful chemopreventor against oxidative damage.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.450-461
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• 2022

Purpose: DNA damage and repair responses are induced by metabolic diseases and environmental stress. The balance of DNA repair response and the antioxidant system play a role in modulating the entire body's health. This study uses a high-fat and high-calorie (HFC) drink to examine the new roles of a plant-based multivitamin/mineral supplement with phytonutrients (PMP) for regulating the antioxidant system and cellular DNA repair signaling in the body resulting from metabolic stress. Methods: In a double-blind, randomized, parallel-arm, and placebo-controlled trial, healthy adults received a capsule containing either a PMP supplement (n = 12) or a placebo control (n = 12) for 8 weeks. Fasting blood samples were collected at 0, 1, and 3 hours after consuming a HFC drink (900 kcal). The blood samples were analyzed for the following oxidative stress makers: areas under the curve reactive oxygen species (ROS) levels, plasma malondialdehyde (MDA), erythrocytes MDA, urinary MDA, oxidized low-density lipoprotein, and the glutathione:oxidized glutathione ratio at the time points. We further examined the related protein levels of DNA repair signaling (pCHK1 (Serine 345), p-P53 (Serine 15), and 𝛄H2AX expression) in the plasma of subjects to evaluate the time-dependent effects of a HFC drink. Results: In a previous study, we showed that PMP supplementation for eight weeks reduces the ROS and endogenous DNA damage in human blood plasma. Results of the current study further show that PMP supplementation is significantly correlated with antioxidant defense. Compared to the placebo samples, the blood plasma obtained after PMP supplementation showed enhanced DNA damage response genes such as pCHK1(Serine 345) (a transducer of DNA response) and 𝛄H2AX (a hallmark of DNA damage) during the 8 weeks trial on metabolic challenges. Conclusion: Our results indicate that PMP supplementation for 8 weeks enhances the antioxidant system against oxidative stress and prevents DNA damage signaling in humans.

• Animal Systematics, Evolution and Diversity
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• v.5 no.1
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• pp.33-58
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• 1989

The identified Ceratinomorpha consist of 41 species, 21 genera and 12 families. Among them, two species, Clathria mosulpia and Haliclona ulreungia, were new species and the following species were new to Korea: Ophlitaspongia pennata california De Laubenfels, 1936, Desmacella rosea Fristedt, 1887, Clathria dayi Levi, 1963, Clathria parva Levi, 1963, Ax-ociella cylindrica Hallman, 1920, Axocielita calla (De Laubenfels, 1934), Myxilla sigmatifera ( (Levi, 1963), Haliclona perlucida (Griessinger, 1971), Petrosia nigricans Lindgren, 1897, G Gel/ius arcoferus Vosmaer, 1885, Reniera ventillabrum Fristedt, 1887, Reniera pigmentifera D Dendy, 1905, and Coelosphaera physa (Schmidt, 1875)

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1078-1079
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• 2006

The paper presents the possibilities of obtaining new composite materials based on sintered porous ceramics with particles and fibre of $Al_2O_3$ infiltrated by aluminum alloy. The EN AC - AlSi12 alloy features the matrix material, whereas the RF50AX-301 preform, of Saffil Automotive, was used as the reinforcement. Examinations of ceramics preforms permeability were made. Metallographic examination of composite materials made on light microscope and in scanning electron microscope show that aluminum alloys fill micropores in the matrix. New composite materials show twice higher value of hardness in comparison with matrix. Results indicate that it is possible to infiltrate porous ceramic with liquid aluminum alloy to obtain new composite materials were advantageous properties of each component are connected.

• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1326-1333
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• 1998

The study of coupled relaxation for methyl spin system in 2,6-dichlorotoluene was performed on the basis of the magnetization mode formalism. Using five initial perturbing pulse sequences, eight experimntal data sets were obtained, which were fitted with theoretical expressions with nine spectral density parameters. The same experiment was carried out at both 50.3 MHz and 125.6 MHz in carbon frequency. The measured spectral densities at both fields are similar in the exception of that related with carbon random field term. Furthermore, from the dipolar spectral density, the physical values may be extracted depending on the model of molecular reorientation. For example, it was assumed that the molecular framework undergoes asymmetric diffusive rotational process and methyl group reorients by either diffusive rotation about its symmetry axis or jump among internal rotational potential minima.