• Journal for History of Mathematics
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• v.17 no.1
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• pp.33-42
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• 2004

In this paper, we identify the essential ideas of Fundamental Theorem of Arithmetic(FTA). Then, we compare these ideas with several theorems of Euclid's Elements to investigate whether the essential ideas of FTA are contained in Elements or not. From this, we have the following conclusion: Even though Elements doesn't contain FTA explicitly, it contains all of the essential ideas of FTA. Finally, we assert two reasons why Greeks couldn't mention FTA explicitly. First, they oriented geometrically, and so they understood the concept of 'divide' as 'metric'. So they might have difficulty to find the divisor of the given number and the divisor of the divisor continuously. Second, they have limit to use notation in Mathematics. So they couldn't represent the given composite number as multiplication of all of its prime divisors.

• The Journal of Korean Medical History
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• v.23 no.1
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• pp.67-75
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• 2010

This study was done to research "Ke Sou Lun" of ${\ll}$Yi Guan${\gg}$ of Zhao Xian Ke. The results obtained as follows. 1) He suggested the treatment of chronic cough to strengthen 'Pitu' and 'Shenshui'. 2) He treated chronic cough patient without 'Qingjin' and 'Qinghuo' therapy that use cold herb. 3) We can strengthen 'Yang', after strengthen 'Zhenyin' in case of the chronic cough that contained 'Huo'.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.19-23
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• 2000

The increasing use of plastics in food packaging materials has led to the issue of food-packaging mutual interactions from residues in the plastics. Plastic films are commonly printed by using solvent-based ink to decorate the packaged food for consumer attention. However, the residual solvents can not be completely removed and they can migrate into the contained food which lead to undesirable off-flavors. Partitioning (Kp) of printing ink solvents was studied in two types of plastic films with different chemical structure and polarity. At $25^{\circ}C$, Kp of toluene is higher than that of isopropanol in PP, but isopropanol showed higher Kp value than toluene in EVOH. This showed that polarity had a significant effect on the partitioning of printing ink solvents into the plastic films. Printing solvents had a higher affinity to the polymer with similar polarity than it did to the different one.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.113-119
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• 1998

Recently Electronic Speckle Pattern Interferometry(ESPI) has been studied because it has the advantages to be able to measure the whole-field surface deformations of engineering components and materials in industrial areas with noncontact. The speckle patterns to be formed with interference phenomena of scattering light from rough surfaces illuminated by laser light have phase informations of surface deformations. In this study we used this interference phenomena and the phase shifting method to measure the inplane deformations, together with the use of digital image equipment to process the informations contained in the speckle pattern and to display consequent interferograms on TV monitor. FEA was performed before experiments and we obtained good agreement between the experimental results and FEA.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.549-554
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• 2001

It is possible for concrete using sea sand to contain chloride ion as well as cation such as Na$^{+}$and $K^{+}$ during mixing process. It is known that some cations such as Na$^{+}$and $K^{+}$ remain in pore solution without binding In this study, therefore, we intend to inspect the behavior of cations in cement paste as well as NaCl, CaCl$_2$ and KCI through analysis of pore solution extracted from cement paste with high pressure vessel. As a result, increase of alkali ions by adding sea sand and admixtures to the fresh concrete means use of the cement contained high alkali contents. In this case, alkali ions in pore solution can decrease durability of cement products causing alkali-aggregate reaction or accelerated carbonation. So it needs to be studied.studied.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.139-144
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• 2001

Insulation aging diagnosis system provides early warning regarding electrical equipment defect. Early warning is very important in that it can avoid great losses resulting from unexpected shutdown of the production line. Since relations of insulation aging and partial discharge dynamics are non-linear, it is very difficult to provide early warning in an electrical equipment. In this paper, we propose the design method of insulation aging diagnosis system that use a magnetic wave and acoustic signal to diagnoses an electrical equipment. Proposed system measures the partial discharge on-line from DAS(Data Acquisition System) and acquires 2D patterns from analyzing it. For filtering the noise contained in sensor signals we used ICA algorithms. Using this data, design of the neuro-fuzzy model that diagnoses an electrical equipment is investigated. Validity of the new method is asserted by numerical simulation.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.709-717
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• 2004

Biodiesel has great potential as an alternative fuel for diesel engines that would reduce air pollution. It is a domestically produced, renewable fuel that can be manufactured from fresh or used vegetable oils, or from animal fats. In this study, a biodiesel fuel derived from rice bran oil was tested as an alternative fuel for agricultural diesel engines. The emissions were characterized for both neat and blended biodiesel fuels, and for conventional diesel fuel. Since this biodiesel fuel contained 11 % oxygen, it strongly influenced the combustion process. The use of biodiesel fuel resulted in lower carbon monoxide, carbon dioxide, and smoke emissions, without any increase in nitrous oxide emissions. The study demonstrated that biodiesel fuel could be effectively used as a renewable and environmentally innocuous fuel for agricultural diesel engines.

• Journal of Biosystems Engineering
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• v.28 no.5
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• pp.389-394
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• 2003

The concerns of wood vinegar increase with its various applications to food additive, functional drink, and in the sustainable farming. Chaff vinegar, a by-product of chaff charcoal which is produced by distilling smoke and having similar ingredients and efficacy with wood vinegar, contains harmful tar in the acceptable range and can be mass-produced. A chaff vinegar distiller, commercially mass-productive, was developed using a water cooling system. Initially distilled vinegar by the developed system contained little harmful tar in the acceptable range for the agricultural use and its acidity was about pH 3.2. Treatment of the chaff vinegar in the enhancing emergence test showed greater number of emerged seedlings, and vise-versa. Treatment of diluted in 100-holds showed 44.0% of emerged and 8.6% of not-emerged seedlings.

• Journal of Korean Medical classics
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• v.18 no.3 s.30
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• pp.116-125
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• 2005

1) Objective ${\lceil}Wai-Tai-Mi-Yao{\rfloor}$ had been made by Wang-Dao(王燾) in Tang Dynasty(唐朝). It included fumigation therapy and aroma therapy. Therefore we would like to bring out use sphere and detailed method of Fumigation therapy and Aroma therapy in Tang Dynasty and before period. 2) Conclusions (1) Fumigation therapies of ${\lceil}Wai-Tai-Mi-Yao{\rfloor}$ have contained boil and burn. The effects of fumigation therapy are made by cooperation effect of medicine and heat. (2) Aroma therapies of ${\lceil}Wai-Tai-Mi-Yao{\rfloor}$ have been used to cure infectious, internal, psychologic, dental, pediatric, dermatologic and surgical diseases. Especially these therapies have a good effect on cough. (4) Aroma therapies of ${\lceil}Wai-Tai-Mi-Yao{\rfloor}$ have been used to cure infectious, internal, psychologic, dental, ophthalmic, otolaryngologic, obstetrics, gynecologic, dermatologic and surgical diseases. Expecially this therapy has an good effect on nightmare.

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.171-179
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• 2001

A new passive sampler was developed, improving SPMD (Semipermeable Membrane Devices) that contained triolein in nonporous, low-density polyethylene layflat tubing. Experiments to measure PAHs concentration were carried out at four sites (Dukpo, Sochi, Sohwonggando, Yeonmok) on the southern coast of Korea that were contaminated by oil spills. Passive samplers were deployed at 4 and 8 week intervals at each site. Results showed that bioconcentration levels of PAHs were increased in proportion to exposure duration from all sample sites and accumulation in the passive sampler was much higher than in biota at the Dukpo site. Results of these tests suggest that new passive sampler is a useful tool for measuring bioconcentration organic compounds in aquatic environments.