• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.586-595
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• 2010

An analytical study based on physical understandings and aero-thermodynamic theories was conducted to observe the performance characteristics and to derive the essential design parameters of dual ramjet(dual-combustion/dual-mode) propulsion for wide Mach number. The performances and operating limitations of the engines with two types combustors, such as constant pressure- and constant area- combustor, over various flight Mach numbers was investigated. Finally, the transition Mach number from ramjet to scramjet was carried out to optimize performance load balancing of ramjet and scramjet.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.596-604
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• 2010

In order to investigate the operating conditions and major design parameters of a dual ramjet propulsion system, an theoretical analysis of ramjet and scramjet propulsion systems was performed. The performance characteristics of each engine are delivered by thermo-dynamical cycle analysis, considering loss effects in a real engine. The performance sensitivity analysis is conducted by investigating various performance parameters, such as an intake efficiency, combustor inlet Mach number, configuration of the combustor, fuel flow rate, and exhaust nozzle efficiency. Based on these analysis results, the processes of application to dual ramjet cycle engines are specified.

• The Korean Journal of Cytopathology
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• v.11 no.1
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• pp.47-52
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• 2000

Diffuse sclerosing papillary carcinoma(DSPC), a variant of papillary carcinoma of the thyroid, is characterized by diffuse involvement of one or both thyroid lobes, and histologic features such as prominent sclerosis, intense lymphocytic infiltrate, numerous psammoma bodies, and squamous metaplasia together with the characteristic cytoarchitectural pattern of classical papillary carcinoma. We experienced a case of fine needle aspiration cytologic(FNAC) findings of DSPC, which was confirmed by histologic examination of the thyroidectomy specimens. The patient was 26 years old female who presented with diffuse firm enlargement of the thyroid gland with enlargement of many cervical lymph nodes. FNAC smears showed numerous psammoma bodies, many lymphocytes, metaplastic squamous cells, absence of stringy colloid, and epithelial cells showing classical features of papillary carcinoma, such as nuclear grooves, intranuclear unclusions, and ground glass chromatin pattern.

• Journal of Power System Engineering
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• v.20 no.4
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• pp.44-51
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• 2016

An investigation on reliability of reanalysis wind data was conducted using the met mast wind data at four coastal regions, Jeju Island. Shinchang, Handong, Udo and Gangjeong sites were chosen for the met mast sites, and ERA-Interim and MERRA reanalysis data at two points on the sea around Jeju Island were analyzed for creating Wind Statistics of WindPRO software. Reliability of reanalysis wind data was assessed by comparing the statistics from the met mast wind data with those from Wind Statistics of WindPRO software. The relative error was calculated for annual average wind speed, wind power density and annual energy production. In addition, Weibull wind speed distribution and monthly energy production were analyzed in detail. As a result, ERA-Interim reanalysis data was more suitable for wind resource assessment than MERRA reanalysis data.

• Parasites, Hosts and Diseases
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• v.33 no.2
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• pp.85-94
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• 1995

Three types, hitherto commonly known as varieties of Solcoptes scobiei (Linnaeus, 1758) were collected from scabietic patients, pigs and dogs to couirm their taxonomic status. As a result, we consider that the mites of human and pig scabies are different subspecies [S. scobiei scohiei (Linnaeus, 1758) and S. scobiei skis Megnin, 1880, respectively], and that of dog scabies is a different species, S. canis Gerlach, 1857. Infestation rate of human scabies in Korea peaked in 1981-1982 and showed nearly 10% of prevalence rate among outpatients of the dermatology clinic, but decreased dramatically during the past ten years and now lowered below 1% since 1990. On the other hand, dog scabies seems to be increasing recently. Key words: Human scabies, dog scabies, pig scabies, taxonomy, prevalence.

• The Korean Journal of Mycology
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• v.19 no.3
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• pp.167-174
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• 1991

More than 300 specimens of higher fungi were collected from both Mt. Daeduck and Mt. Daesung areas in Kangwon Province during the period from 13 to 19 August, 1990. These fungi were identified and classified into 4 orders, 15 families, 35 genera, 52 species and 1 variety. Dominant species were considered to be Collybia confluens in Tricholomataceae, and Russula emetica in Russulaceae of Agaricales, and Phlogiotis hevelloides in Auriculariales throughout our survey areas. Phlogiotis hevelloides (Fr.) Martin. (장미주걱목이) and Pseudohydnum gelatinosum (Scop. ex Fr.) P. Karst. (혓바늘목이) were newly described in Korea.

• The Korean Journal of Financial Studies
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• v.9 no.1
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• pp.119-144
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• 2003

본 연구에서는 1997년부터 2001년 기간 동안 증권거래소와 KOSDAQ 시장에서 액면분할을 실시한 기업을 대상으로 액면분할의 이사회 공시일을 사건일로 하여 사건일 전후 30일간의 주가, 유동성 지표, 기업수익성 지표 등을 이용하여 액면분할 공시에 따른 시장의 반응을 분석하고, 아울러 액면분할의 신호효과와 유동성 효과를 검증하였다. 본 연구에 이용된 자료는 검증기간 동안 다른 정보의 유입이 없는 순수자료를 이용하여 거래소 상장기업 72개와 KOSDAQ 100개 기업이 최종적으로 표본에 선정되었다. 본 연구에서 액면분할을 실시한 기업들은 두 시장 모두에서 대체로 양의 초과수익률을 나타내었고, 분할비율이 높을수록 양의 초과수익률이 상대적으로 더 강하게 지속되었다. 이런 결과는 미래 기업수익이 호전된다는 신호를 보내기 위하여 액면분할을 실시한다는 신호효과로 인한 것이 아니며, 동시에 고주가의 주식이 액면분할로 투자자금에 제약이 있는 투자자가 투자 가능한 저주가로 전환됨으로써 유동성의 증대를 가져온 결과라고 보기에도 무리가 있다. 액면분할이라는 그 자체가 논리적 근거도 없이 투자자에게 호재로 받아들여져 거래량의 증가를 가져왔다고 판단된다. 이런 현상은 KOSDAQ 시장에서 더욱 확연하게 나타났는데, 1997년부터 2001년까지의 분석기간 중에 KOSDAQ 시장의 무분별한 투기적 열풍이 이런 현상의 원인을 제공한 것이라고 추론된다. 액면분할이 한국시장의 투자자에게 호재로 받아들여진 것에는 액면분할 이후 대체로 주가가 양의 초과수익률을 나타내는 경우가 있었다는 과거의 경험적 사례가 작용한 것으로 아니가 예상된다.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1261-1262
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• 2006

Electro-magnetic launcher(EML)는 전자기력을 이용하여 발사체를 추진시키는 장치이다. EML은 크게 레일건의 형태와 코일건의 형태로 구분되며, 본 논문에서는 코일건의 형태로 설계, 제작하였다. 코일건의 형태인 EML은 솔레노이드에 여자되는 전류에 의해서 발사체에 흡인력이 발생하여 추진, 가속되므로 솔레노이드의 최적형태를 설계하고, 이를 바탕으로 제작하여 EML의 스위칭 시간에 따른 속도를 측정하여, 여자전류의 스위칭 시간에 따른 동작특성을 해석, 실험하여 분석하였다.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2227-2228
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• 2006

Electro-magnetic launcher(EML)는 전자기력을 이용하여 발사체를 추진시키는 장치이다. EML은 크게 레일건의 형태와 코일건의 형태로 구분되며, 본 논문에서는 코일건의 형태로 설계, 제작하였다. 코일건의 형태인 EML은 솔레노이드에 여자되는 전류에 의해서 발사체에 흡인력이 발생하여 추진, 가속되므로 솔레노이드의 최적형태를 설계하고, 이를 바탕으로 제작하여 EML의 스위칭 시간에 따른 속도를 측정하여, 여자전류의 스위칭 시간에 따른 동작특성을 해석, 실험하여 분석하였다.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.82-85
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• 1992

To evaluate the role of hepatobiliary (DISIDA) scan in the diagnosis of biliary obstruction, we studied the clinical characteristics of 9 cases with biliary obstructuon, whose hepatobiliary scans and ultrasonography were not concordant (normal ultrasonography and abnormal hepatobiliary scan). The results were as follows; 1) The main chief complaints (89%) were abdominal pain, especially in RUQ area. The levels of serum bilirubin were elevated in 67% of patients $(normal\sim5.9mg/dl)$ and those of alkaline phosphatase were elevated in 78% of patients $(normal\sim724U/L)$. 2) The final diagnoses were CBD stones (67%), tumor (22%) and 3 cases were associated with C. sinensis. 3) The major obstruction sites were in distal CBD (89%). From the above results we concluded that hepatobiliary scan is a useful diagnostic method of biliary obstruction, especially in distal CBD lesion and early stage, in spite of normal ultrasonography.