• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.2
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• pp.167-177
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• 1996

The cutoff frequencies of a double ridged rectangular waveguide are calculated by applying the modal analysis to its cross-section. And the characteristic impedance of its $TE_{10}$ mode is evaluated in a frequency range of 6 to 18 GHz. When both ends of a linearly tapered rectangular wa- veguide consists of single and double ridged rectangular cross-sections, the equivalent nonuniform transmission line of its $TE_{10}$ mode is solved numerically. It is shown that the input impedance at its single ridged terminal becomes nearly constant in the wide bandwidth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.45-51
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• 2004

In this paper, the relationship between the mechanical properties of alumina abrasives and grinding performance was investigated. Micro vickers hardness and fracture strength of all abrasives used in this study were measured. The grinding experiments were earned out with alumina grinding wheels made by various kinds of alumina abrasives including 32A, WA, ART, ALOMAX, and RA. The performance of such grinding wheel for grinding SKD11 was evaluated by specific grinding energy, grinding-ratio, and surface roughness. The grinding wheels composed by the harder abrasives and the lower fracture strength abrasives showed better grinding performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.903-906
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• 1997

For the net shape manufacturing, grinding is a important process that influences directly the accuracy and the integrity of products. We studied and researched the grinding force, surface roughness, and grinding wheel durability, according to the change of a feed speed of the table and a depth of the cut step by step with experiment that it is used to WA wheel. Workpiece materials were used STDII. The purpose of this study proposes the basic data for design of the machine tool and for controlling the machining parameters to obtain optimum performance of plunge grinding system during operation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.565-568
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• 2003

In this paper we deal with behavior of the magnetic abrasive using Ba-Ferrite on polishing characteristics in a new internal finishing of STS304 pipe applying magnetic abrasive polishing. The magnetic abrasive using Ba-Ferrite grain WA was used to resin bond fabricated at low temperature. And Ba-Ferrite of magnetic abrasive powder was crused into 200 mesh. The previous research made an experiment in the static and the dynamic state on the movement of magnetic abrasive grain. In this paper. We investigated into the changes of the movement of magnetic abrasive grain. In reference to this result. we have made the experiment which is set under the condition of the magnetic flux density. polishing velocity according to the form of magnetic brush.

• Ocean Science Journal
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• v.41 no.1
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• pp.53-57
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• 2006

A specimen of Aetobatus flagellum was collected at Uljin in June 2005 for the first time in Korea. This specimen is characterized by the cephalic fin, the long snout, the dorsal fin between pelvic fins, spiracles on the dorsal side of the disc, the deeply notched nasal curtain and the one row of the teeth in the lower and the upper jaws. And unlike Aetobatus narinari, it does not have any spots on the its dorsal side of the disc. We report this specimen as the first record from Korea and name it 'Bak-jui-ga-o-ri' in Korean.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.640-645
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• 1996

5-Alkyl-2(3H)-benzofuranones(3a-e) were prepared from Friedel-Crafts reaction of 4-alkylphenols with methyl 2-chloro-2-(methylthio)acetae(1) followed by the treatment of zinc du st-acetic acid. The reaction of disubstituted phenols with 1 in the presence of stannic chloride afforded 3-methyltWa-2(3H)-benzofuranone derivatives(11a-c), which were readily converted into 2(3H)-benzofuranone derivatives(12a-c) by desulfurization with zinc dust-acetic acid.

• Journal of the Korean Statistical Society
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• v.22 no.1
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• pp.113-124
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• 1993

In this paper we show that the results of Ahn and Cho (1992) can be applied to a more general class of seasonal models, especially models with autocorrelated errors. Employing the idea of the "two-step estimation" method, we provide test statistics which are easy to compute and have the same asymptotic properties as those in Ahn and Cho (1992) for seasonal unit roots. A numerical example is presented to illustrate the methods and concepts. The power of the test statistics for finite samples is examined through a Monte Carlo sampling experiment.xperiment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.565-569
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• 2003

One-year-long groundwater-level data have been collected from 18 wells in Cheon-an area. The result of barometric efficiency, autocorrelation, cross-correlation and statistical distribution evaluated from the measurement data shows that groundwater-level measurements from observation wells are the principal source of information about aquifer characteristics. Data from WA-2 has high barometric efficiency as well as steady decreasing auto-correlation coefficient, which means nonleaky confined aquifer, Most aquifers in this study show the unconfined properties so that barometric efficiencies are mostly low and the coefficients of cross-correlation between groundwater-level and precipitation are commonly high. This study showed that the long-term groundwater-level monitoring data without artificial stress such as pumping would give accurate information about aquifer characteristics.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.388-390
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• 2004

본 연구는 자돈 설사의 원인이 되는 대장균, 살모넬라 등 그람음성균을 억제할 수 있는 유산균의 이용을 위해 선발된 균주의 과산화수소 대사를 구명하기 위해 수행하였다. 대장균 억제유산균중 superoxide dismutase 활성이 우수한 균주가 관찰되었으며, 과산화수소 이외에 그람음성균 억제에 유효한 bacteriocin-like compounds의 존재 유무, 대사과정에서 과산화수소 생성과 관련된 다른 효소 활성, superoxide dismutase 유전자 클로닝에 관한 연구가 진행중이다.

• CELLMED
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• v.7 no.4
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• pp.19.1-19.5
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• 2017

Fasad i.e. venesection is an old classical method of treatment in the Unani system of medicine. Fasad is Arabic word which means "to open". In the process, complete evacuation which drains out blood and dominating humours mixed with blood from veins. Fasad is carried out when the kamiyat (quantity) of the blood is excess in the body and patient is either exposed to the risk of developing a disease or has actually developed one. In classical literature of Unani system of medicine, physicians wrote a lot about this procedure. The details of venesection is mentioned in the given paper on the basis of classical literature including history, indications, types, amount of blood to be venesected, time, person, procedure, complications and special focus has been made on the number of vessels to be venesected and their benefits with respected to disease and condition.