• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.51-57
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• 2017

The current study compared the acoustic features of the two phonation types for Korean fricatives (plain: /s/, fortis : /s'/) and the three types for affricates (aspirated : /$ts^h$/, lenis : /ts/, and fortis : /ts'/) in order to determine the phonetic status of the plain fricative /s/. Considering the different manners of articulation between fricatives and affricates, we examined four acoustic parameters (rise time, intensity, fundamental frequency, and Cepstral Peak Prominence (CPP) values) of the 20 Korean native speakers' productions. The results showed that unlike Korean affricates, F0 cannot distinguish two fricatives, and voice quality (CPP values) only distinguishes phonation types of Korean fricatives and affricates by grouping non-fortis sibilants together. Therefore, based on the similarity found in /$ts^h$/ and /ts/ and the idiosyncratic pattern found in /s/, this research concludes that non-fortis fricative /s/ cannot be categorized as belonging to either phonation type.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.4
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• pp.267-270
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• 2018

As a safety measure, dentures are routinely removed before surgery. Aspiration of a denture could be catastrophic, with medicolegal implications. Foreign body aspiration is uncommon in adults; however, aspirations may remain asymptomatic and undiagnosed for long periods of time. We report an adult male who presented with a cough for more than 6 months. On radiography, a foreign body was found migrating within the tracheobronchial tree from one mainstem bronchus to the other, at different time points. The foreign body was later found to be a portion of his denture. The aspiration may have occurred at the time of a surgical procedure.

• Speech Sciences
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• v.9 no.4
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• pp.201-214
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• 2002

In the Japanese language, there is a phonological contrast between not only initial stops, but also non initial in voiced and voiceless sounds. But in the Korean language, voiced sounds do not appear in the initial. Due to this, pronunciation of voiced sounds in the initial will be difficult for Korean. Through this research, I analyzed the minimal pairs by voiced/voiceless sounds of Japanese and Korean, and perception experiment in which Japanese listened to Korean speakers' pronunciations. Japanese pronunciations showed distinct acoustic differences between voiced and voiceless stops, especially in VOT. The duration of vowels after voiced stops was longer than that of voiceless ones. Vowel pitches after voiceless stops were higher. On the other hands, Korean showed three patterns of voiced sounds. There were-VOT values as native speakers, +VOT, and nasal formant tended to occur before prenasalized stops. Koreans pronounced voiceless sounds in strong aspirated, unaspirated, or tense sounds. Finally, Japanese judged sounds with not only -VOT values and prenasalized, but also with +VOT values as voiced. This suggests that we may not consider VOT values as the unique feature of voicing, and that such other phonetic characteristics as the following vowel lengthening should be included here.

• Speech Sciences
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• v.3
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• pp.38-49
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• 1998

Dysarthrias are a sort of neuromotor disorders because of the weakness of neuromotor controls. They are classified in six types on the basis of Mayo clinic research: flaccid, spastic, ataxic, hypokinetic, hypekinetic and mixed types. Five dysarthria types are investigated in this study. MRI, EMG, neuropathological tests are essential diagnostic processing. Visi-Pitch and Spectrgraphy, CSL are used for assessing dysarthria speech. Maximum phonation time, diadochokinetic rate, Voice Onset Time and substitution rate are the speech evaluation parameters. Maximum phonation time and diadochokinetic rates are the lowest in case of spastic and ataxic dysarthrias. Spastic dysarthria shows the substituted glottalized consonants. However, flaccid, ataxic and hypokinetic dysarthrias show the substituted aspirated consonants. VOT is the longest for hypokinetic dysarthria and the shortest for ataxic dysarthria. Jitter shows higher percentage in comparison with control group. Speech evaluation using experimental phonetic instruments help create on international standardization of speech evaluation for speech disorders.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.4
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• pp.13-23
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• 1986

The power of an international combustion engine depends on its ability to inhale air whether it is naturally aspirated or turbocharged. The use of fuel injection allows engine efficiency to be increased through a more even distribution of the air/fuel ratio throughout the engine's operation range. The theoretical value for complete combustion in an engine is commonly refered to as stoichiometric, which means that we require 14.7 parts of air to 1 part of gasoline. This stoichiometric ratio can be more closely maintained with electronically controlled fuel injection than it can with carburetion. Because of the greater efficiency of the engine using fuel injection, a horse power increase of at least 10% is produced over its carburetor version. In addition, better fuel economy and less exhaust emissions are also obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.15-22
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• 2002

Lately, our world is faced with very serious problems related to the increased air pollution of the exhaust emissions from automobiles. In particular, the exhaust emissions of diesel engines are recognized as a main cause which strongly influence environment. Lots of researchers have attempted to develop various alternative fuels to reduce these harmful emissions in diesel engine. The purpose of this investigation is to evaluate the possibility of esterfied rice bran oil for diesel fuel substitution in a naturally aspirated D. 1. diesel engine, and also find means to reduce smoke emissions in esterfied rice bran oil combustion. The smoke emission of esterfied rice bran oil is reduced remarkably in comparison with commercial gas oil, that is, it was reduced approximately 58.2% at 2500rpm. But, power, torque and brake specific energy consumption didn't have no large differences. It was concluded that esterfied rice bran oil can utilize effectively as an alternative and renew- able fuel fur diesel engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.62-67
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• 2009

In this study, the potential possibility of biodiesel fuel was investigated as an alternative fuel for a naturally aspirated indirect injection diesel engine. The smoke emission of biodiesel fuel was reduced remarkably in comparison with diesel fuel, that is, it was reduced approximately 36% at 2000rpm, full load condition. And, power, torque and brake specific energy consumption showed no significant differences. However, NOx emission of biodiesel fuel was increased compared with commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) to reduce the NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel(20vol-%) and cooled EGR method$(10{\sim}15%)$.

• The Korean Journal of Cytopathology
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• v.2 no.2
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• pp.148-152
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• 1991

A mediastinal mass was aspirated by fluoroscope-guided fine needle aspiration biopsy in a 47 years old female patient. The first aspiration smears were not diagnostic, because of hemorrhagic background and cell paucity. On the second aspiration, the smears were composed of some clusters of benign epithelial cells in hemorrhagic back-ground. Cells were arranged in mostly solid sheets and tended to form glandular lumina in part. Their nuclei were round and vesicular. Nucleoli were not prominent. These findings were suggestive of benign glandular tissue, which was finally confirmed as mediastinal thyroid gland by open thoracotomy specimen.

• The Korean Journal of Cytopathology
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• v.5 no.2
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• pp.176-179
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• 1994

Orbital meningioma is a rare neoplasm that, even when suspected by CT or echographic examination, requires careful histologic study for precise identification. Fine needle aspiration(FNA) biopsy has become the diagnostic technique of choice in recent years for investigating orbital masses. There have been a few previous reports on FNA biopsy of orbital menigioma. We experienced a case of orbital meningioma in a 11-yr-old boy, diagnosed by FNA biopsy. The cytohistologic features of aspirated material (intranuclear inclusions, psammoma bodies, and cells arranged in whorls) made it easy to diagnose a meningloma.

• The Korean Journal of Cytopathology
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• v.5 no.1
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• pp.65-70
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• 1994

We describe a case of fine needle aspiration cytology of renal angiomyolipoma which was not associated with the clinical complex of tuberous sclerosis and was incidentally found. It was a solitary lesion and the clinical impression before needle aspiration was renal ceil carcinoma. The aspirated specimen showed mature fat cells, clusters of renal tubular epithelial cells and sheets of pleomorphic smooth muscle cells with fibrillary cytoplasm. The nuclei of smooth muscle celis varied in size and shape. Since the treatment of renal angiomyolipoma differs from that of renal ceil carcinoma, the preoperative cytological diagnosis is of great value.