• Journal for History of Mathematics
• /
• v.31 no.2
• /
• pp.55-72
• /
• 2018

Matteo Ricci and Xu Gwangqi translated the first six Books of Euclid's Elements and published it with the title Jihe Yuanben, or Giha Wonbon in Korean in 1607. It was brought into Joseon as a part of Tianxue Chuhan in the late 17th century. Recognizing that Jihe Yuanben deals with universal statements under deductive reasoning, Jo Tae-gu completed his Juseo Gwan-gyeon to associate the traditional mathematics and the deductive inferences in Jihe Yuanben. Since Jo served as a minister of Hojo and head of Gwansang-gam, Jo had a comprehensive understanding of Song-Yuan mathematics, and hence he could successfully achieve his objective, although it is the first treatise of Jihe Yuanben in Joseon. We also show that he extended the results of Jihe Yuanben with his algebraic and geometric reasoning.

• Journal of Environmental Science International
• /
• v.20 no.12
• /
• pp.1607-1615
• /
• 2011

The adsorption performance of cupper and zinc ions($Cu^{2+}$ and $Zn^{2+}$) in aqueous solution was investigated by an adsorption process on reagent grade Na-A zeolite(Z-WK) and Na-A zeolite (Z-C1) prepared from coal fly ash. Z-C1 was synthesized by a fusion method with coal fly ash from a thermal power plant. Batch adsorption experiment with Z-C1 was employed to study the kinetics and equilibrium parameters such as initial metal ions concentration and adsorption time of the solution on the adsorption process. Adsorption rate of metal ions occurred rapidly and adsorption equilibrium reached at less than 120 minutes. The kinetics data of $Cu^{2+}$ and $Zn^{2+}$ ions were well fitted by a pseudo-second-order kinetics model more than a pseudo-first-order kinetics model. The equilibrium data were well fitted by a Langmuir model and this result showed $Cu^{2+}$ and $Zn^{2+}$ adsorption on Z-C1 would be occupied by a monolayer adsorption. The maximum adsorption capacity($q_{max}$) by the Langmuir model was determined as $Cu^{2+}$ 99.8 mg/g and $Zn^{2+}$ 108.3 mg/g, respectively. It appeared that the synthetic zeolite, Z-C1, has potential application as absorbents in metal ion recovery and mining wastewater.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.12
• /
• pp.1607-1612
• /
• 2011

In this study, dynamic analysis of a proportional solenoid valve is performed, and an LQG/LTR controller with an integrator is designed to control the proportional solenoid valve. The dynamic characteristic of a valve is identified using experimental data by employing the frequency-domain modeling technique. The purpose of LQG/LTR control with an integrator is to enhance the system response and to improve the tracking accuracy for a complex input signal. Experimental tests are performed to verify the performance of the controller, and the results prove the high performance of the controller.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1607-1610
• /
• 2009

The carbon-coated Si/Cu powder has been prepared by mechanical ball milling and hydrocarbon gas decomposition methods. The phase of Si/Cu powder was analyzed using X-ray diffraction (XRD), dispersive Raman spectroscopy, electron probe microanalysis (EPMA) and transmission electron microscope (TEM). The carbon-coated Si/Cu powders were used as anode active material for lithium-ion batteries. Their electrochemical properties were investigated by charge/discharge test using commercial LiCo$O_2$ cathode and lithium foil electrode, respectively. The surface phase of Si/Cu powders consisted of carbon phase like the carbon nanotubes (CNTs) with a spacing layer of 0.35 nm. The carbon-coated Si/Cu/graphite composite anode exhibited a higher capacity than commercial graphite anode. However, the cyclic efficiency and the capacity retention of the composite anode were lower compared with graphite anode as cycling proceeds. This effect may be attributed to some mass limitations in LiCo$O_2$ cathode materials during the cycling.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.9
• /
• pp.1607-1613
• /
• 2003

An experimental method to measure Q-parameter in-situ is described. The basic idea comes from the fact that the side necking near a crack tip indicates the loss of stress triaxiality, which can be scaled by Q. From the out-of-plane displacement and the in-plane strain near the surface of side necking, stress field averaged through the thickness is calculated and then Q is determined from the difference between the stress field and the HRR field corresponding to the identical J-integral. To prove the validity, three-dimensional finite element analysis has been performed for a CT configuration with side-groove. Q-value which was calculated directly from the near-tip stress field is compared with that determined by simulating the experimental procedure according to the proposed method, that is, the Q-value determined from the lateral displacement and the in-plane strain. In addition, the effect of location where the displacement and strain are measured is explored.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.6
• /
• pp.1607-1613
• /
• 2008

We investigated the miniaturized free electron laser(FEL) module based on microcolumn. The miniaturized FEL is composed of two parts: electron generation part and radiation emission part. The radiation emission part, called wiggler, consists of a grid plate. While the electrons are passing through the wiggler, electron trajectory shows sinusoidal curve caused by the periodically applied voltage on the grid, and then it give rise to radiation emission. We analyzed the wiggler parameters, grid width, depth, period, applied voltage and the pair wiggler space using 2-D simulation tool.

• Annual Conference of KIPS
• /
• 2012.11a
• /
• pp.1607-1610
• /
• 2012

국제 무역의 활성화와, 운송수단의 기술적 발전은 국가 간 교역을 증대시키게 되었다. 특히 해상 무역 물동량의 증가는 국제항을 다양한 재화 및 여객 소통의 중심으로 만들었고, 경제적 관문으로써의 중요성이 높아지고 있으며 점차 국가 주요 기반 시설로 자리 잡고 있다. 즉, 원활한 교역을 위한 물류 효율화 달성과 안전한 항만 운영을 위한 보안 제도 강화의 필요성이 증대됨에 따라, 이를 효과적으로 관리 유지할 필요가 있게 되었다. 이에 본 논문은 자동화 고부가가치 서비스가 가능한 정보 중심의 u-Port(Ubiquitous Port)를 국가 전략적 차원에서 육성한 대한민국 사례를 기반으로 효율적인 항만물류를 위한 기반 시스템으로 활용될 수 있도록 해운물류표준화 기구인 IMO(International Maritime Organization)에 선진 사례로 소개하고 활용할 수 있는 방안을 제시하고자 한다. u-Port는 수출입 화물 관리가 용이하며 항만 보안을 강화하는 등 항만 업무 효율화를 제공할 수 있다는 장점으로 향후 개발도상국 또는 후진국의 항만 업무 생산성 및 투명성을 높일 수 있는 기반을 지원할 수 있을 것이다.

• Journal of Korean Clinical Health Science
• /
• v.11 no.1
• /
• pp.1607-1615
• /
• 2023

purpose: In addition to evaluating the quality of sleep of college students, the effect on non-face-to-face online learning satisfaction is identified and used as basic data for improving the quality of remote lectures. Methods: From June 1 to June 24, 2022, a self-entry survey was conducted on students enrolled in the dental hygiene department of D University in Daegu. To evaluate the non-face-to-face online learning satisfaction and sleep quality of the study subjects using the lBM SPSS Statistics 21 program, ANOVA analysis was conducted on the difference between individual stress levels and non-face-to-face online learning satisfaction. The correlation between sleep quality, stress, and non-face-to-face online learning satisfaction was analyzed using Pearson's correlation coefficient. Results: The lower the quality of sleep, the higher the stress, resulting in statistically significant results (p<0.001). The higher the quality of sleep, the higher the learning satisfaction, resulting in statistically significant results (p<0.001). There was a statistically significant positive correlation between learning satisfaction and stress (r=0.591, p<0.01). Conciussions: Through the above results, in order to improve the satisfaction of non-face-to-face online learning, it is necessary to manage the individual's learning environment and health to relieve stress. Instructors also need to communicate with learners and apply teaching methods considering learners' academic abilities.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.47 no.3
• /
• pp.205-212
• /
• 2021

The skin fibroblasts of different origins showed different expression levels of MMP-1 in response to TNF-α treatment or UV irradiation. We hypothesized that this is caused by polymorphism in the MMP-1 promoter region. To elucidate it, first of all, we analyzed and classified the genotype of the -1607 site of the MMP-1 promoter in 23 commercially available primary fibroblasts, and then we examined the expression of MMP-1 by TNF-α or UVB stimulation for each classified genotype. As a result of the analysis, fibroblasts with 6 1G/1G genotypes, 10 1G/2G genotypes, and 7 2G/2G genotypes were identified. Hs68 and Detroit 551 cell lines were confirmed to have 1G/2G genotypes. In the 1G/1G genotype, MMP-1 was expressed twice as high as that of the control group by TNF-α treatment, and was hardly expressed by UV light. In the case of the 1G/2G genotype, MMP-1 was expressed 2.45 fold higher by TNF-α treatment, and 1.4 fold by UV light than the control. In the case of the 2G/2G genotype, MMP-1 was expressed 1.35 fold by TNF-α treatment, and was highly expressed by 2.5 fold by ultraviolet rays compared to control. It can be estimated that MMP-1 expression is better induced in the 1G genotype by TNF-α and in the 2G genotype by UV light. In addition, it can be presumed that MMP-1 expression is increased by creating a site where the Ets transcription factor can bind by another G inserted at the -1607 position. These studies have not been conducted at all in fibroblasts in relation to skin aging, so it is an area that needs to be further studied in the future. In conclusion, since the skin is an organ that is affected by both intrinsic aging and photoaging at the same time, when analyzing the expression of MMP-1 as a target for improving skin aging, it is necessary to select cells with a genotype suitable for the experimental conditions of the study.

• (The)Study of the Eastern Classic
• /
• no.37
• /
• pp.411-439
• /
• 2009

Fu-Shan(傅山, 1607~1684) was a progressive actualist between the late Ming(明) dynasty and the early Qing(淸) dynasty. He regards the intellectuals at that time as scarecrows leaned on the empty and exaggerative moral philosophy which the neo-confucian of Song(宋) dynasty established. He thinks that the neo-confucian discussion cause harmful side effects, disregarding the utility side and the variety of the actual world. His thought becomes known all in political thought and literature. He asserts that the neo-confucian ideas provides the logical frame which regulates the actual world and creates a kind of absolute moral ideology. Therefore he insists that the Saint in the true sense of the word consequently is the social reformer and revolutionist who exposes the irrational elements of society. He insists that literature also must be able to express vividness of the actual world. He thinks that genuine literature must have creative contents and find one's own free wild way. He asserts that old literary style from the mimicry is the act which goes against human natural. He thinks that the writing must be able to express the actual world.