• Title/Summary/Keyword: First-onset

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Progressive failure of symmetric laminates under in-plane shear : I-positive shear

  • Singh, S.B.;Kumar, Ashwini;Iyengar, N.G.R.
    • Structural Engineering and Mechanics
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    • v.6 no.2
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    • pp.143-159
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    • 1998
  • The objective of this present work is to estimate the failure loads, associated maximum transverse displacements, locations and the modes of failure, including the onset of delamination, of thin, square symmetric laminates under the action in-plane positive (+ve) shear load. Two progressive failure analyses, one using the Hashin criterion and the other using a Tensor polynomial criterion, are used in conjunction with finite element method. First order shear deformation theory along with geometric non-linearity in the von Karman sense have been employed. Variation of failure loads and failure characteristics with five type of lay-ups and three types of boundary conditions has been investigated in detail. It is observed that the maximum difference between failure loads predieted by various criteria depends strongly on the laminate lay-up and the flexural boundary restraint. Laminates with clamped edges are found to be more susceptible to failure due to transverse shear (ensuing from the out of plane bending) and delamination, while those with simply supported edges undergo total collapse at a load slightly higher than the fiber failure load. The investigation on negative (-ve) in-plane shear load is in progress and will be communicated as part-II of the present work.

Mieko Han and her Works on Korean Phonetics (Mieko Han의 한국어 음성학 연구)

  • Ko, Do-Heung
    • Speech Sciences
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    • v.1
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    • pp.213-223
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    • 1997
  • This paper deals with a general review of Mieko S. Han, who made a significant contribution to the studies of Korean phonetics during the 1960' s and early 1970' s. As both a single and joint author, Dr. Han published important papers in both quantity and quality, which have been cited among Korean phoneticians until today. Before Dr. M. Han' s work, professor of USC in the department of East Asian Languages & Cultures, there were only a few phonetics-related publications in Korea, most of which are papers or books based on non-experimental traditional approach. It is known that there was coexistence between traditionalism and structuralism in the field of Korean linguistics. It was, however, fortunate that we had two important phoneticians (M. Han and Chin-W Kim) abroad at that time. Mieko Han' s concern was to investigate experimental characteristics of the system of Korean vowels and consonants using a Spectrograph, which was the single most important tool for analysing phonetic data at that time. Dr. Han conducted her experimental studies on Korean phonetics, mostly funded by the Office of Naval Research, in terms of duration, fundamental frequency, Voice Onset Time (VOT), intensity, and so on. This paper aims to re-appreciate Dr. Han's specific contribution to the study of Korean phonetics since she played an important role as a pioneer of early Korean phonetics. Further, it is highly recommended that Dr. Han's works can be extremely useful for a graduate student, who seriously would like to specialize in Korean phonetics in the first step.

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Phonological processes of consonants from orthographic to pronounced words in the Seoul Corpus

  • Yang, Byunggon
    • Phonetics and Speech Sciences
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    • v.12 no.2
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    • pp.1-7
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    • 2020
  • This paper investigates the phonological processes of consonants in pronounced words in the Seoul Corpus, and compares the frequency distribution of these processes to provide a clearer understanding of conversational Korean to linguists and teachers. To this end, both orthographic and pronounced words were extracted from the transcribed label scripts of the Seoul Corpus. Next, the phonological processes of consonants in the orthographic and pronounced forms were tabulated separately after syllabifying the onsets and codas, and major consonantal processes were examined. First, the results showed that the majority of the orthographic consonants' sounds were pronounced the same way as their pronounced forms. Second, more than three quarters of the onsets were pronounced as the same forms, while approximately half of the codas were pronounced as variants. Third, the majority of different onset and coda symbols were primarily caused by deletions and insertions. Finally, the five phonological process types accounted for only 12.4% of the total possible procedures. Based on these results, this paper concludes that an analysis of phonological processes in spontaneous speech corpora can improve the practical understanding of spoken Korean. Future studies ought to compare the current phonological process data with those of other languages to establish universal patterns in phonological processes.

SAFETY STUDIES ON HYDROGEN PRODUCTION SYSTEM WITH A HIGH TEMPERATURE GAS-COOLED REACTOR

  • TAKEDA TETSUAKI
    • Nuclear Engineering and Technology
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    • v.37 no.6
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    • pp.537-556
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    • 2005
  • A primary-pipe rupture accident is one of the design-basis accidents of a High-Temperature Gas-cooled Reactor (HTGR). When the primary-pipe rupture accident occurs, air is expected to enter the reactor core from the breach and oxidize in-core graphite structures. This paper describes an experiment and analysis of the air ingress phenomena and the method fur the prevention of air ingress into the reactor during the primary-pipe rupture accident. The numerical results are in good agreement with the experimental ones regarding the density of the gas mixture, the concentration of each gas species produced by the graphite oxidation reaction and the onset time of the natural circulation of air. A hydrogen production system connected to the High-Temperature Engineering Test Reactor (HTTR) Is being designed to be able to produce hydrogen by themo-chemical iodine-Sulfur process, using a nuclear heat of 10 MW supplied by the HTTR. The HTTR hydrogen production system is first connected to a nuclear reactor in the world; hence a permeation test of hydrogen isotopes through heat exchanger is carried out to obtain detailed data for safety review and development of analytical codes. This paper also describes an overview of the hydrogen permeation test and permeability of hydrogen and deuterium of Hastelloy XR.

Electric Discharge Analysis Using Nonlinarly-Coupled Equation of Electromagnetic Field and Charge Transport (방전현상 해석을 위한 전자장 및 전하이동 방정식의 비선형 결합 알고리즘)

  • Lee, Se-Yeon;Park, Il-Han;Lee, Se-Hee
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1494-1495
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    • 2006
  • A complete finite element analysis method for discharge onset process, which is governed and coupled by charge transport equation and electric field equation, was presented. The charge transport equation of first order was transformed into a second-order one by utilizing the artificial diffusion scheme. The two second-order equations were analyzed by the finite element formulation which is well-developed for second-order ones. The Fowler-Nordheim injection boundary condition was adopted for charge transport equation. After verifying the numerical results by comparing to the analytic solutions using parallel plane electrodes with one carrier system, we extended the result to blade-plane electrodes in 2D xy geometry with three carriers system. Radius of the sharp tip was taken to be 50 ${\mu}m$. When this sharp geometry was solved by utilizing the space discretizing methods, the very sharp tip was found to cause a singularity in electric field and space charge distribution around the tip. To avoid these numerical difficulties in the FEM, finer meshes, a higher order shape function, and artificial diffusion scheme were employed.

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Pulsed Radiofrequency Lesioning of the Suprascapular Nerve for Referred Shoulder Pain due to Metastatic Liver Cancer - A case report - (전이성 간암으로 인한 어깨통증 환자에서 박동성 고주파술 경험 - 증례보고 -)

  • Kim, Hyung Tae;Jang, In Su;Han, Sang Ji;Lee, Jun Hak;Kwon, Young Eun
    • The Korean Journal of Pain
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    • v.20 no.2
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    • pp.230-234
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    • 2007
  • A diagnosis of shoulder pain is varied and difficult to make. The initial onset of liver cancer is difficult to detect and patients typically do not complain of symptoms as most tumors are asymptomatic. If the symptoms of the patients develop, the first symptom is usually pain that extends from the abdomen to the back and shoulder. A suprascapular nerve block is used in the treatment of the referred shoulder pain due to a metastatic hepatoma, but the effectiveness of the treatment has been limited because of its short duration. Recently, the advent of pulsed radiofrequency (PRF) lesioning has proved a successful treatment for chronic refractory pain involving the peripheral nerves. We experienced a case of a 66-year-old male patient complaining of referred right shoulder pain due to metastatic liver cancer, which was relieved after PRF lesioning of the suprascapular nerve.

Controversies in Usefulness of EEG for Clinical Decision in Epilepsy: Pros. (간질 치료에서 뇌파의 임상적 유용성에 관한 논란: 긍정적 관점에서)

  • Shon, Young-Min;Kim, Yeong In
    • Annals of Clinical Neurophysiology
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    • v.9 no.2
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    • pp.63-68
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    • 2007
  • The EEG plays an important diagnostic role in epilepsy and provides supporting evidence of a seizure disorder as well as assisting with classification of seizures and epilepsy syndromes. There are a variety of electroclinical syndromes that are really defined by the EEG such as Lennox-Gastaut syndrome, benign rolandic epilepsy, childhood absence epilepsy, juvenile myoclonic epilepsy and also for localization purposes, it is vitally important especially for temporal lobe epilepsy. The sensitivity of first routine EEG in diagnosis of epilepsy has been known about 20-50%, but this proportion rises to 80-90% if sleep EEG and repetitive recording should be added. Convincing evidences suggest that the EEG may also provide useful prognostic information regarding seizure recurrence after a single unprovoked attack and following antiepileptic drug (AED) withdrawal. Moreover, patterns in the EEG make it possible to disclose an ictal feature of nonconvulsive status epilepticus, separate epileptic from other non-epileptic episodes and clarify the clues predictive of the cause of the encephalopathy (i.e., triphasic waves in metabolic encephalopathy). Therefore, regardless of its low sensitivity and other pitfalls, EEG should be considered not only in the situation of new onset episode such as a newly developed, unprovoked seizure or a condition manifesting decreased mentality from obscure origin, but also as a barometer of the long-term outcome following AED withdrawal.

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Common functional Problems during Pregnancy and Association with Nutritional Status and Weight of Newborns (임신기의 입덧 및 변비 증상과 임신부의 영양상태 및 신생아 체중과의 관계)

  • 최봉순;이인숙;신정자;박명희;정효지
    • Korean Journal of Community Nutrition
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    • v.8 no.2
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    • pp.138-148
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    • 2003
  • Morning sickness during pregnancy is a very common functional problem with different kinds of symptom, but little data are available concerning the nutrition intervention program fur pregnant women in local area. A total of 152 pregnant women who had experienced morning sickness were surveyed to investigate the relationships between morning sickness, nutrient intakes and pregnancy outcome. The results showed that prevalent symptoms were nausea (68.4%), heartburn (59.2%), morning sickness (48.7%), vomiting (42.1%), and constipation (44.7%). The onset of the symptom occurred during the first 3 months (9.3 $\pm$ 2.3 weeks) ; 21.1% of the subjects was experienced two symptom at the same time. This significantly correlated with vomiting (p < 0.01), nausea (p < 0.001), morning sickness (p < 0.001), and heartburn (p < 0.01) with pregnancy weight. There were also correlations between the four symptoms and nutrient intakes. Mean birth weight of 21 newborns was 3.06 $\pm$ 0.42 kg, and the one and five minutes of Apgar scores were 7.74 $\pm$ 0.99 and 8.84 $\pm$ 0.69, respectively. There were negative correlations between vomiting and pregnancy outcomes (p < 0.05). Our data support that morning sickness, especially vomiting during pregnancy is associated with Apgar score and body weight of newborn. (Korean J Community Nutrition 8(2) : 138~148, 2003)

Cutout shape and size effects on response of quasi-isotropic composite laminate under uni-axial compression

  • Singh, S.B.;Kumar, Dinesh
    • Structural Engineering and Mechanics
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    • v.35 no.3
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    • pp.335-348
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    • 2010
  • Cutouts are often provided in structural and aircraft components for ventilation, for access, inspection, electric lines and fuel lines or sometimes to lighten the structure. This paper addresses the effects of cutout shape (i.e., circular, square, diamond, elliptical-vertical and elliptical-horizontal) and size on buckling and postbuckling response of quasi-isotropic (i.e., $(+45/-45/0/90)_{2s}$) composite laminate under uni-axial compression. The finite element method is used to carry out the investigation. The formulation is based on first order shear deformation theory and von Karman's assumptions are used to incorporate geometric nonlinearity. The 3-D Tsai-Hill criterion is used to predict the failure of a lamina while the onset of delamination is predicted by the interlaminar failure criterion. It is observed that for the smaller size cutout area there is no significant effect of cutout shape on load-deflection response of the laminate. It is also concluded that the cutout size has substantial influence on the buckling and postbuckling response of the laminate with elliptical-horizontal cutout, while this effect is observed to be the least in case of laminate with elliptical-vertical cutout.

A Case of Green Tobacco Sickness (GTS) in Elderly Patient (담뱃잎농부병으로 진단된 고령 환자 1례)

  • Jeong, Dong Kil;Kim, Doh-Eui
    • Journal of The Korean Society of Clinical Toxicology
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    • v.17 no.2
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    • pp.132-134
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    • 2019
  • Green tobacco sickness is an illness caused by dermal exposure to nicotine. The common symptoms of the disease include dizziness, headache, nausea, vomiting, severe general weakness, fluctuations of blood pressure or heartbeat, abdominal cramping, chills, increased sweating, salivation, and difficulty breathing. A 79-year-old female arrived at the emergency room for an evaluation of sudden onset dizziness. Magnetic resonance imaging and angiography of the brain did not show any relevant abnormal findings. Four days later, with supportive care, she said that she had harvested green tobacco for six hours on the day of admission and the tobacco harvest was the first time in her life. She sweated excessively during the hot and humid weather and the tobacco leaves were wet from rain the night before. The serum cotinine tested at five days of admission was 16ng/ml. She was diagnosed with acute nicotine poisoning by her clinical symptoms and the half-life of cotinine in the blood.