• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.1112-1114
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• 2017

액체 로켓 엔진은 채택되는 사이클, 하드웨어 구성, 기능 구현상의 짐벌 타입 등에 의해 구성품 배치와 레이아웃의 라우팅이 결정된다. 본 논문에서는 액체로켓엔진에 장착되는 주요 구성품을 기준으로 구동을 담당하는 헬륨(He) 공급 공압라인, 각종 퍼지 공압라인, 주 점화라인 등의 주요 유공압 라인의 개념 라우팅을 수행하였다.

• 한국철도학회논문집
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• 제7권3호
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• pp.232-238
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• 2004

The dynamic characteristics of the current collection process of the high-speed railway are investigated through signals acquired during a test run. The signals are obtained from accelerometers, load cells, and strain gauges attached to various positions of the pantograph, and they are processed in time-and frequency-domains to obtain the dynamic characteristics. The main natural frequency of the pantograph is found to be 8.5Hz. There also are components at low frequencies varying linearly with the train speed. The contact frequency components above 20Hz is attenuated as they pass through the secondary suspension. The main frequency component of the load cell signal is found to be related with the rolling motion of the panhead generated by the stagger in the catenary.

• Journal of Ginseng Research
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• 제19권2호
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• pp.160-164
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• 1995

This study was carried out to compare the root yields, root characters, saponin and ginsenosides contents of 6-year-old p. ginseng and p. quinquefolium. These two ginseng species showed difference in the diameter and ten비h of mainroot. The main root length or p. quinquefolium was shorter than that of p. ginseng, whereas Jakyung-jong and Hwangsook-jong of P. ginseng showed similar root length. Proximate composition were similar between the two species, however, crude fibercontent was significantly higher in main and lateral root of Jakyung-jong and Hwang sook-jong of P ginseng than P quinquefolium. In regard to mineral contents of root, P ginseng contained more Ca and Mn and less Fe and Al than P. quinquefolium. P. quinquefolium contained more of Rbl and Rd of protopanaxadiol saponin, and less or Re, $Rg_1$ and $Rg_2$ of protopanaxatriol saponin than P ginseng. However, no Rf was detected in the p. quinquefolium. Key words Panax ginseng, Panax quinquefolium, ginseng character, ginsenoside.

• Archives of Pharmacal Research
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• 제13권3호
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• pp.269-273
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• 1990

Blood glucose and total lipid levels in rats with streptozotocin-induced diabetes were determined after intraperitoneal administration of methanolic extract of Ixeris dentat whole plants and its main component, cynaroside (=luteolin 7-O--$\beta$-D-glucoside). From the data obtained, it was concluded that intraperitoneal administration of the methanolic extract produced a significant hypoglycemic effect. Total blood lipids were also decreased. Cynaroside in the streptozotocin-diabetic rats failed to exhibit hypoglycemic effect but a significant hypolipemic activity was observed. Thus, it is suggested that this methanolic extract may contain one or more hypoglycemic and hypolipemic principles including the main flavone glucoside, cynaroside, which can significantly reduce the levels triglyceride and total cholesterol in streptozotocin-diabetic rats.

• International Journal of Computer Science & Network Security
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• 제21권9호
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• pp.292-296
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• 2021

The purpose of this article is to explore the modern branding - its nature, history, originality, spirit and value to consumers. In particular, graphic design of the brand is an important component in terms of the modern European culture. The scientific novelty of the work implies the study of the contemporary design, which widely embraces the sphere of cultural and social life and can contribute to the development of progressive phenomena in society, as the design can literally be defined as a rethinking, a search for new meanings. The design itself is a versatile means of communication at the level of feelings and meanings. One of its main goals is the harmonization, and even formation of perception of the world, creation of new images or rethinking the essence of ordinary things. Hence, the research in the field of the design development is topical in the worldwide cultural space..

• 한국항해항만학회지
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• 제30권10호
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• pp.793-800
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• 2006

본 논문에서는, 1995년도, 2000년도, 2004년도, 국내 26개 항만들을 대상으로 2개의 투입변수(접안능력, 하역능력)와 3개의 산출변수(수출화물처리량, 수입화물처리량, 입출항척수)가 있는 경우에 구성될 수 있는 21개의 DEA모형을 제시하고 효율성을 측정하였다. 또한 그러한 효율성 측정결과를 이용하여 주성분분석을 시행하여 핵심투입변수와 산출변수를 추출하였다. 실증분석의 핵심적인 결과를 살펴보면, 핵심투입 변수는 하역능력, 핵심산출변수는 입출항척수로 나타났다. 정책적인 함의는 항만정책당국이 개별항만들의 핵심투입변수와 산출변수가 어떻게 변화해 왔는지를 검토하여 차후 항만투자와 개발 시에 반드시 고려하고 반영해야만 한다.

• 천문학회지
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• 제38권2호
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• pp.237-240
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• 2005

We present images of L1551 IRS5 at angular resolutions as high as ${\~}$30 mas, corresponding to a spatial resolution of ${\~}$5 AU, made at 7 mm with the VLA. Previously known to be a binary protostellar system, we show that L1551 IRS5 is likely a triple protostellar system. The primary and secondary components have a projected separation of ${\~}$46 AU, whereas the tertiary component has a projected separation of ${\~}$11 AU from the primary component. The circumstellar dust disks of the primary and secondary components have dimensions of ${\~}$15 AU, whereas that of the tertiary component has a dimension of ${\~}$10 AU. Their major axes are closely, but not perfectly, aligned with each other, as well as the major axis of the surrounding flattened, rotating, and contracting molecular condensation (pseudodisk). Furthermore, the orbital motion of the primary and secondary components is in the same direction as the rotational motion of this pseudodisk. We suggest that all three protostellar components formed as a result of the fragmentation of the central region of the molecular pseudo disk. The primary and secondary components, but apparently not the tertiary component, each exhibits a bipolar ionized jet that is centered on and which emergers perpendicular to its associated dust disk. Neither jets are resolved along their base, implying that they are driven within a radial distance of ${\~}$2.5 AU from their central protostars. Finally, we show evidence for what may be dusty matter streams feeding the two main protostellar components.

• 응용통계연구
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• 제19권2호
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• pp.319-330
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• 2006

현실세계에서 관찰되는 시그널(signal)은 다양한 주파수(frequency)들의 시그널로 혼합되어 있는 경우가 많다. 예를 들어 태양 흑점 자료의 경우 약 11년 주기와 85년 주기로 변동한다는 사실은 널리 알려져 있다. 또한 경제 시계열 자료의 경우는 통상적으로 계절요인(seasonal component), 순환요인(cyclic component) 그리고 장기적인 추세요인(long-term trend)으로 분해하여 분석한다. 이러한 시계열 자료를 구성요소별로 분해하는 것은 오래된 주제중 하나이다. 전통적인 시계열자료 분석기법으로 스펙트럴 분석기법 등이 널리 사용되고 있으나 시계열 자료들이 비정상(nonstationary)일 경우에는 적용하기 어렵다. Huang et. al(1998)은 경험적 모드분해법(empirical mode decomposition)이라고 하는 자료적응적인(data-adaptive) 방법을 제안하였는데, 비정상성(nonstationarity)에 대한 강건성(robustness)으로 여러 분야에 널리 응용되고 있다. 그러나 Huang et. at(1998)은 잡음(error)에 의해 오염된 자료에 대한 구체적인 처리방법은 제시하지 못하고 있다. 본 논문을 통하여 효율적인 잡음제거 방법을 제안하고자 한다.

• 자원리싸이클링
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• 제10권5호
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• pp.36-43
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• 2001

The chlorine component in fly ash from municipal solid waste incineration ash was removed by water washing for the purpose of recycling fly ash as a raw material of ordinary portland cement. The samples were a different kind of 리y ashes using $Ca(OH)_2$and NaOH as media of wet scrubber for flue gas cleaning. The content of soluble salts of fly ash using $Ca(OH)_2$and NaOH was 32.8%, 50.1% and the content of chlorine component, 22.9% and 26.0% respectively, which was KCl, NaCl, CaC1OH mainly. When each fly ash was washed using water under conditions of a agitation speed of 300 rpm, a liquid to solid ratio of 10, most soluble salts in fly ash were dissolved within 30 minutes and the content of chlorine component in ash was diminished to the content of 4.4%, 2.O% at $20^{\circ}C$ and 1.7%, 0.8% at $50^{\circ}C$ respectively. And the main compound of residual chlorine component in ash after water washing was friedel`s salt ($3CaO.A1_2$$O_3$.$CaCl_2$.$10H2$O). From analysis results of water quality for wastewater by water washing, the components exceeding discharged wastewater standard were only Pb and Cd. But As pH was controlled to 10 with addition of $CO_2$(g) or $Na_2$$_CO3$in water, the concentration of heavy metals such as Pb and Cd was also under discharged wastewater standard.

• 한국분말재료학회지
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• 제27권2호
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• pp.139-145
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• 2020

The powder manufacturing process using the gas atomizer process is easy for mass production, has a fine powder particle size, and has excellent mechanical properties compared to the existing casting process, so it can be applied to various industries such as automobiles, electronic devices, aviation, and 3D printers. In this study, a modified A4032-xSn (x = 0, 1, 3, 5, and 10 wt.%) alloy with low melting point properties is investigated. After maintaining an argon (Ar) gas atmosphere, the main crucible is tilted; containing molten metal at 1,000℃ by melting the master alloy at a high frequency, and Ar gas is sprayed at 10 bar gas pressure after the molten metal inflow to the tundish crucible, which is maintained at 800℃. The manufactured powder is measured using a particle size analyzer, and FESEM is used to observe the shape and surface of the alloy powder. DSC is performed to investigate the change in shape, according to the melting point and temperature change. The microstructure of added tin (Sn) was observed by heat treatment at 575℃ for 10 min. As the content of Sn increased, the volume fraction increased to 1.1, 3.1, 6.4, and 10.9%.