• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.9
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• pp.1201-1208
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• 2003

The thickness of flame and preheat zone from burning velocity which was computed by using Premix code of Chemkin program for methane-air mixture. Also the thickness was evaluated from temperature profile which is also obtained from Premix code for the equivalence ratio of 0.5 to 1.6. The computations were carried out for the laminar flame thickness and burning velocity under the unburned gas temperature 0.5bat-30bar and temperature of 300K-700K at ${\Phi}=l.0$. Comparison of the results showed no difference between these two methods. The flame thickness was decreased by increasing the pressure and temperature, but, the affect of pressure is more significant than the effect of temperature on the flame thickness. The thickness of preheat zone was about 66.5% of the flame thickness, and flame thickness and burning velocity were also predicted by using empirical equation.

• The Journal of Korean Society of Virology
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• v.29 no.1
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• pp.23-31
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• 1999

Hantavirus is a genus of the Bunyaviridae family causing two serious diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Puumala virus is a member of hantavirus originally found in Europe, and its natural reservoir is Clethrionomys glareolus. It is also associated with the human disease nephropathia epidemica, a milder form of HFRS. To identify the hantaviruses in bats, bats were collected from Jeong-Sun, Won-Joo, Chung-Ju and Hwa-Cheon area in Korea, and nested RT-PCR was performed with serotype specific primer from M segment. Interestingly, Puumala virus was detected in bats (Rhinolophus ferrum-equinum) only from Won-Joo. The 327 bp nested RT-PCR product, was sequenced. The sequence database search indicates that the sequence is homologous to the published sequence of Puumala viruses. The sequence similarities were ranged from 71% to 97%. The highest sequence similarity was 97% with Puumala virus Vranicam strain, and the lowest was 71% with Puumala virus K27 isolate. Puumala virus Vranicam strain was isolated from a bank vole (Clethrionomys glareolus) in Bosnia-Hercegovina. Puumala virus K27 was isolated from human in Russia. This analysis confirms that bats (Rhinolophus ferrum-equinum) in Korea are natural reservoir of Puumala virus.

• Proceedings of the KSLP Conference
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• 2003.11a
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• pp.170-173
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• 2003

There are more than five systems for transcribing English vowels. Because of this diversity, teachers of English and students are confronted with not a little problems with the English vowel symbols used in the English-Korean dictionaries, English text books, books for Phonetics and Phonology. This study was designed to suggest criterions for the phonemic transcription of English vowels on the basis of phonetic properties of the vowels and a system of English vowel transcription based on the criterions in order to minimize the problems with inter-system differences. A speaker (phonetician) of RP English uttered a series of isolated minimal pairs containing the vowels in question. The suggested vowel symbols are as follows: 1) Simple vowels : /i:/ in beat, /I/ bit, /$\varepsilon$/ bet,/${\ae}$/ bat, /a:/ father, /Dlla/ bod, /$\jmath$:/ bawd, /u/ put, /u:/ boot /$\Lambda$/ but, and /$\partial$/ about /$\Im$:ll$\Im$:r/ bird. 2) Diphthongs : /aI/ in bite, /au/ bout, /$\jmath$I/ boy, /$\Im$ullou/ boat, /er/ bait, /e$\partial$lle$\partial$r/ air, /u$\partial$llu$\partial$r/ poor, /i$\partial$lli$\partial$r/ beer. Where two symbols are shown corresponding to the vowel in a single word, the first is appropriate for most speakers of British English and the second for most speakers of American English.

• Journal of Biomedical Engineering Research
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• v.21 no.2
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• pp.157-163
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• 2000

최근 MR영상을 허혈성 뇌졸중의 초급성기에 뇌조직의 관류 이상을 조기에 진단하려는 연구들이 진행되고 있으나 아직 일반적인 진단용 소프트웨어만 있을 뿐 영상 자료를 후처리하여 뇌조직의 구조 및 기능적인 정보를 제공하는 mapping 영상을 특수 소프트웨어는 실용화되어 있지 않다. 본 논문에서는 Gamma-variate 곡선 정합을 이용한 뇌관류 파라미터 영상 mapping의 알고리즘 구현에 관해 연구하였다. 관류 MR영상의 각 화소마다 측정된 시간에 따른 신호강도의 변화 곡선은 비선형적이어서 뇌관류에 관한 여러 가지 혈역학적 변수들을 보다 정확하게 계산할 수 없었다. 그래서 수렴속도가 빠르고 안정성이 높은 비선형 최적화 알고리즘인 Levenberg-Marquardt 알고리즘(LMA)을 활용하였다. 즉 시간에 따른 신호강도의 변화 곡선을 Gamma-variate 함수를 이용하여 곡선 정합한 후, CBV, MTT, CBF, TTP, BAT, MS의 여러 가지 혈역학적 변수를 LMA에 의해 계산하였다. 그 결과로 관류 MR영상으로부터 얻은 mapping 영상은 초급성 허혈성 뇌졸중에서 관류에 관한 혈역학적 변화를 평가함으로써 나중에 생길 뇌경색의 범위를 예견하는 데에 유용하였다.

• The Korean Journal of Zoology
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• v.20 no.2
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• pp.67-76
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• 1977

The periodic changes of testis and \ulcorner션 epididymidis in Korean hibernating bats, the oriental discoloured bats (Vesportilio superans Thomas) and the Korean greater horseshoe bats (Rhinolophus ferrumequinum korak Kuroda) were studied in order to clarify the possibility of correlation between their histological findings and one of physiological facets, hibernation, and the results obtained were as follows: 1. The spermatogenic function of the oriental discoloured bats obtained in July and August was depressed although the spermatocytes showed a considerable cell proliferation. Few mature sperms were observed in the seminiferous tubules of the bat obtained in August. 2. The spermatogenic function of the Korean greater horeshoe bats obtained in September was not remalkable but a considerable number of sperms were stored in the excretory ducts which were characterized by existence of para-tubular spaces in the ductus epididymidis. 3. The spermatogenic epithelia of the Korean greater horseshoe bats obtained in December showed histologically atrophied figures. However, a vast number of sperm remained in extremely expaned luminae of the ductuc epididymidis which epithelial cells were maintained rectangular in shape. 4. These results suggest that there are periodic changes of the spermatogenic epithelia and the excretory ducts, and that those histological changes are closely related to their wintering.

• Journal of Welding and Joining
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• v.29 no.2
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• pp.88-93
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• 2011

This study produced hypereutectic Al-Si clad layer on 1050 Al alloy by a novel laser cladding method. Pure Si powder was mixed with organic binder to make fluid paste which could be screen-printed on the 1050 Al alloy plate. Pulsed Nd:YAG laser was irradiated on the Si paste layer to melt and alloy with Al substrate. Different laser power of 99 W, 179 W and 261 W, was used to see the difference of the microstructure, composition and hardness of the clad layers. When laser power of 179 W was used, the clad layer had overall Si content of 38wt% and composed of fine primary Si particles and fine eutectic phase. At laser power of 261 W, the clad layer had overall Si content of 24wt% and composed of mainly fine eutectic phase. Vickers hardness of HV176.7 and HV150.3 on the clad layer was obtained at laser power of 179 W and 261 W, respectively.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.20-28
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• 2012

Recently, the scientific study from traditional oriental medicine is being progressed. Moreover, through both oriental medicine and medicine are cooperated with medical examination and treatment, the study in cooperation of merits from oriental medicine as well as from medicine is progressed. In this paper, we will develop automatic needle shot using fuzzy rules and USN techniques, which a user can choose meridian pathways from the menu items built in the cellular phone, so it can perceive patient's body conditions and launch an aneurysm electric pressure of a cycle.

• Speech Sciences
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• v.10 no.4
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• pp.73-79
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• 2003

There are more than five systems for transcribing English vowels. Because of this diversity, teachers of English and students are confronted with not a little problems with the English vowel symbols used in the English-Korean dictionaries, English text books, books for Phonetics and Phonology. This study was designed to suggest criterions for the phonemic transcription of English vowels on the basis of phonetic properties of the vowels and a system of English vowel transcription based on the criterions in order to minimize the problems with inter-system differences. A speaker (phonetician) of RP English uttered a series of isolated minimal pairs containing the vowels in question. The suggested vowel symbols are as follows: (1) Simple vowels: /i:/ in beat, /I/ bit, /$\varepsilon$/ bet, /${\ae}$ bat, /a:/ father, /Dlla/ bod, /c:/ bawd, /$\upsilon$ put, /u:/ boot /$\Lambda$/ but, and /e/ about /$\varepsilon:ll3:r$/ bird. (2) Diphthongs: /aI/ in bite, /a$\upsilon$/ bout, /cI/ boy, /3$\upsilon$llo$\upsilon$/ boat, /eI/ bait, /eelleer/ air, /uelluer/ poor, /iellier/ beer. Where two symbols are shown corresponding to the vowel in a single word, the first is appropriate for most speakers of British English and the second for most speakers of American English.

• KSBB Journal
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• v.28 no.1
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• pp.36-41
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• 2013

Carotenoids are fat-soluble red-orange colored pigments found in plants and seafood-derived products, including algae, seaweeds, and fish muscle. In this study, we have demonstrated the molecular mechanism underlying the antioxidants and anti-inflammatory properties of ascidian tunic carotenoids using mouse macrophage cell line (RAW 264.7). Cell viability was not affected by treatment of carotenoids < 10 ${\mu}g/mL$. This treatment also showed negative inhibition on lipopolysaccharide (LPS)-stimulated nitric oxide (NO) and cyclooxygenase-2 (COX-2). The DPPH radical scavenging activity of carotenoids was 47.2% at 100 mg/mL. It also has a potential reducing power (1.025) comparable with ascorbic acid (1.584). The ascidian tunic carotenoids would make a candidate for the commercially interesting biologically active cosmetic pigments.

• The Korean Journal of Zoology
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• v.36 no.1
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• pp.36-50
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• 1993

한국산 관박쥐(Rhinolophusfewmequinum Jroma의 웅성생식 pattern을 알아보기 위하여 정소의 형태변화와 세정관 정상피의 1년주기를 조사하여 다음과 같은 결론을 얻었다. 정자형성은 5월에 시작되어 10월말에 완료되었다. 7월초부터 10월중순까지는 정자변태과정이며, 정자형성과정의 활성도가 가장 높은 달은 8월 중순경이었다. 또한 교미가 끝난 11월경부터 세정관내에는 미성숙한 정자세포가 Sertoli cell의 식작용과정의 일환으로 포식되어졌고, 91년 12월부터 92년 1월, 2월, 3월, 그리고 동면각성기인 4월의 실험군에서도 역시 점진적으로 식작용 과정을 관찰할 수 있었다. 교미가 끝난 후의 세정관 내에는 새로운 정자를 만들기 위한 준비단계로서 미성숙된 정자들이 Sertoli cell의 식작용에 의해 정화(cleaning)되므로 이 기간을 정화기간(cleaning time)이라 볼 수 있다. 따라서 정소내 세정관의 1년 주기를 볼 때 정화기간은 동면 개시기인 11월부터 익년 4월까지 약 6개월에 걸쳐 이루어 진다. 이상의 결과로 볼때, 정자형성은 동면각성 직후부터 시작하여 10월경에 완료되며 교미개시기에는 정지되고, 동면기 동안 정자형성이 일어나지 않는 점으로 보아 한국산 관박쥐는 'Pipistnfluspottem'에 속한다고 할 수 있다.