• Computers and Concrete
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• v.4 no.3
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• pp.207-220
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• 2007

In this paper, hybrid fibers including high elastic modulus steel fiber and low elastic modulus synthetic macro-fiber (HPP) as two elements were used as reinforcement materials in concrete. The flexural toughness, flexural impact and fracture performance of the composites were investigated systematically. Flexural impact strength was analyzed with statistic analyses method; based on ASTM and JSCE method, an improved flexural toughness evaluating method suitable for concrete with synthetic macro-fiber was proposed herein. The experimental results showed that when the total fiber volume fractions ($V_f^a$) were kept as a constant ($V_f^a=1.5%$), compared with single type of steel or HPP fibers, hybrid fibers can significantly improve the toughness, flexural impact life and fracture properties of concrete. Relative residual strength RSI', impact ductile index ${\lambda}$ and fracture energy $G_F$ of concrete combined with hybrid fibers were respectively 66-80%, 5-12 and 121-137 N/m, which indicated that the synergistic effects (or combined effects) between steel fiber and synthetic macro-fiber were good.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.91-94
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• 1999

A new type of high-T$_c$ superconducting Josephson junctions has been prepared by Ar ion beam etching and electron beam lithography. YBa$_2Cu_3O_{7-x}$ (YBCO) films deposited on (001) SrTiO$_3$ single crystal substrate by pulsed laser deposition were patterned by Ar ion milling with photolithography. The narrow slit with a electroresist mask, about 1000 ${\AA}$ wide, was constructed over a 3 ${\sim}$ 5 ${\mu}$m bridge of a 1200-${\AA}$-thick YBCO film by electron beam lithography. The slit was then etched by the Ar ion beam to form a damaged 600-${\AA}$-thick YBCO. Thus prepared structure forms an S-N-S (YBCO - damaged YBCO - YBCO) type Josephson junctions. Those junctions exhibit RSI-like I-V characteristics at 77 K. The properties of the Josephson junctions such as I$_c$ R$_N$, and J$_c$ were characterized.

• Journal of Welding and Joining
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• v.33 no.1
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• pp.24-29
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• 2015

Residual stresses arising from the materials processing such as welding and joining affect significantly the structural integrity depending on the external loading condition. The quantitative measurement of the residual stresses is of great importance in order to characterize the effects of the residual stresses on the structural safety. In this paper, we introduce a newly devised destructive technique, the contour method (CM), which is applied for the measurements of the residual stress distributions through the thickness of a 80 mm thick steel weld. Residual stresses are evaluated from the contour, which is the normal displacement on a cut surface produced by the relaxation of residual stresses, using a finite element model. The CM provides a two-dimensional map of the residual stresses normal to the cut surface. The CM developed in the present study was validated in comparison with the residual stress distribution determined by a well-established neutron-diffraction residual stress instrument (RSI) instrumented in HANARO neutron research reactor.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.9-21
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• 2020

The aim of this paper is to predict the Borsa Istanbul (BIST) 30 index movements to determine the most accurate buy and sell decisions using the methods of Artificial Neural Networks (ANN) and Genetic Algorithm (GA). We combined these two methods to obtain a hybrid intelligence method, which we apply. In the financial markets, over 100 technical indicators can be used. However, several of them are preferred by analysts. In this study, we employed nine of these technical indicators. They are moving average convergence divergence (MACD), relative strength index (RSI), commodity channel index (CCI), momentum, directional movement index (DMI), stochastic oscillator, on-balance volume (OBV), average directional movement index (ADX), and simple moving averages (3-day moving average, 5-day moving average, 10-day moving average, 14-day moving average, 20-day moving average, 22-day moving average, 50-day moving average, 100-day moving average, 200-day moving average). In this regard, we combined these two techniques and obtained a hybrid intelligence method. By applying this hybrid model to each of these indicators, we forecast the movements of the Borsa Istanbul (BIST) 30 index. The experimental result indicates that our best proposed hybrid model has a successful forecast rate of 75%, which is higher than the single ANN or GA forecasting models.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.530-537
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• 1998

The proportion of dry matter (DM) and mineral elements (Ca, Mg, P, Na, K, Zn) released from eight feeds (2 rice straws, RSI and RS2; 2 grasses, NB21 and guinea; 2 leguminous fodders, glyricidia and erythrina; jak leaves and rice bran) were studied using the nylon bag procedure. Bag incubations up to 10 days were performed in the rumen of cows fed on a ration consisting of 50% wheat straw and 50% hay. Both the type of feed and the incubation time in the rumen significantly influenced (p < 0.01) the proportion of minerals released. In legumes, jak leaves and rice bran about 80% of the potentially degradable DM fraction was solubilized within 24 h in the rumen, and with the grasses, rice straws and jak leaves a considerable proportion of DM was released between 48 and 240 h in the rumen. During the early hours of incubation (up to 24 h) there were distinct differences between and within the feed classes in their ability to release all mineral elements studied. In all test feeds, high proportions of Mg and K were released within 24 h. Some feeds showed a tendency to ad/absorb Ca (grasses, rice straws and rice bran), P (jak leaves, rice straws), Na (glyricidia and rice bran) and Zn (jak leaves) from water and rumen fluid, and this was partly related to the low initial concentration. In terms of absolute quantity of mineral released, legumes (erythrina is superior to glyricidia) are a good source of Ca, Mg, P and Zn, and jak leaves a good source of Ca and Na. Within grasses, guinea contains appreciable quantity of available Mg and P. Rice bran is rich in available Mg, P and Zn.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.2
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• pp.141-147
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• 2009

Background and Objectives: Although laryngopharyngeal reflux disease (LPRD) is a widely recognized disease in the field of otolaryngology, controversies still exist regarding the diagnosis and treatment for it. The purpose of this survey was to find out current trends in diagnosis and management of LPRD among Korean otolaryngologists. Materials and Method: Questionnaires were obtained from 26 Korean otolaryngology specialists by electronic balloting, and 46 members of the Korean Society of Head and Neck Surgery (KSHNS) bye-mail. Survey participants were asked about their preferences in diagnostic policy, duration/dosage of antireflux treatment, and their familiarity to the reflux symptom index (RST) and the reflux finding scores (RFS). Results: The majority of the survey participants (64%) preferred empiric therapy trial with proton pump inhibitors (PPIs) based on patients' symptoms and their laryngeal findings. PPIs alone (27%) or PPIs with prokinetics (32%) were usually prescribed as a first line treatment mostly with once daily schedule in the morning before meal and for less than 4 months of duration (86%). More than 90% of participants were aware of the RSI and RFS, but less than 50% of them were actually using those items in the clinics. Conclusion: Most of Korean otolaryngologists who participated in this survey answered that they prefer starting empirical treatments with proton pump inhibitors mainly based on the patient's symptoms and their laryngeal findings.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.1
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• pp.11-17
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• 2002

This paper compares the difference between the village groves in the Jinan settlement region and the Hamyang settlment region in Honam and the Youngnam mountainous region. The results are as follows: Fifty-one village groves in the Jinan legion were found and 40 village groves were found in the Hamyang region. It was established that the village groves in the Jinan region of Honam province were conserved better than those of Hamyang region of Youngnam province. In the Jinan area, the village groves were principally found in the Jinan-eup and the Hamyang regions, primarily in Seosang-myun and Aneui-myun. So it was determined that the village groves were distributed inequitably in the two regions. In L / W ratio, the Jinan region is 3.6 and Hamyang region is 2.0 Jinan is 1.8 times greater than Hamyang. Therefore, it was concluded that Jinan is stronger than Hamyang in linear function of the village groves. Stone stooge for complementation function was found in 11 village groves in the Jinan region and 6 village groves in Hamyang. So the percentage of the remaining stone storage is 15-20 % of all village groves. Regarding grove makeup, the village gloves in Jinan region is deciduous forest principally. In contrast, the groves of Hamyang are principally coniferous forest. The dominant tree of the Jinan-gun region is Zelkova serrata, but in Hamyang it is Pinus densiflrora. By number, Hamyang region has two times the trees than Jinan region. In density of stand, the Hamyang region is 76.2% higher than Jinan region. In height and diameter of trees, the Jinan region is greater than the Hamyang region. It was identified that RSI of both region is 40%. So in density of trees, both region are sparse. This paper has a limit in ideiltiting the differences between Yolmg-nam ar\ulcorner Hnam village groves because comparative review only examined two regions.

• Korean Journal of Head & Neck Oncology
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• v.33 no.2
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• pp.23-27
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• 2017

Background and Objectives: Gastric acid reflux is known to be the most important cause of contact granuloma. Therefore, anti-gastric acid reflux medication has been used as the first line treatment although there are other treatment methods such as surgery or steroid injections. Actually, the role of surgery in the treatment of contact granuloma has not been established clearly. The purpose of this study was to evaluate the effectiveness of surgical treatment for contact granuloma. Materials and Methods: We retrospectively reviewed the medical records of 14 patients who were diagnosed with contact granuloma and treated with surgery from 2011 to July 2016 at Hanyang University hospital. Results: Of 14 patients, 9 (64.3%) were male and 5 (27.4%) were female. The mean age was 53.8 (${\pm}6.1$) years. The main symptoms were voice change followed by globus, dyspnea, and asymptomatic. Mean Reflux Finding Score (RFS) before surgery was 13.5 and mead Reflux Symptom Index (RSI) was 10.4. The causes of surgery were inadequate response to proton pump inhibitor (PPI) in 4 cases, airway obstruction with large granuloma in 8 cases, and differential diagnosis in 2 cases. Of 14 patients, recurrence occurred in 8 (53.3%) patients after surgery. In 8 recurrent cases, 5 patients showed complete remission and 3 patients showed partial remission with PPI medication. Conclusion: The role of surgery in the treatment of contact granuloma might be limited due to high recurrence rate.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.23 no.2
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• pp.124-128
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• 2012

Background and Objectives : There are many diagnostic modalities to evaluate laryngopharyngeal reflux. However, ideal diagnostic methods have not been established yet. The purpose of this study is to evaluate the effectiveness of Water-Siphon test as a diagnostic test of laryngopharyngeal reflux. Subjects and Methods : From November 2006 to September 2007, we performed esophagography with Water-Siphon test and questionnaire, physical examination for 227 patients with laryngopharyngeal reflux symptoms. The results of Water-Siphon test were classified according to the degree of reflux, the number of reflux, the retention time and analyzed about the relationship with the reflux symptom index (RSI), reflux finding score (RFS). Results : The degree of reflux was related with pseudosulcus, thick endolaryngeal mucus. The number of reflux was related with thick endolaryngeal mucus. A positive predictive value of Water-Siphon test was 82.7% and sensitivity was 91.5%. Conclusion : Water-Siphon test is a reliable diagnostic test for laryngopharyngeal reflux.

• Journal of the Ergonomics Society of Korea
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• v.23 no.2
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• pp.105-120
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• 2004

With the new technology and the popularization of mobile phone. the functions and designs of mobile phone have been varied rapidly. However. based on the user's level of familiarity on mobile phone function and knowledge of information technology. the using behaviors of mobile phone. especially between the young users who are well acquainted with the latest function and technology and the over middle-aged users who are relatively not. would be quite different. A survey was conducted to investigate the various using behaviors of mobile phone in different age groups. The total number of six hundred and sixty-seven people from age seventeen to sixty participated in this study. The participants were divided into young group (age between 17 to 29) and the over middle-aged group (age between 40 to 60) to compare the difference group considered design. price. and function of the mobile phone as three important factors. on the other hand. the over middle-aged group considered quality of communication. price and ease of use as three important factors. All the respondents of the young group know how to use the text messaging function. however for the over middle-aged group. 40% of the respondents knows how to use the text messaging function. The over middle-aged group seemed mainly use the mobile phone for voice communication. however the young group had a tendency to communicate each other with short text message rather than through voice conversation. Twenty percentage of young group responded that they had an experience of pain or discomfort at the thumb. the thenar eminence area. or carpus area during pushing the mobile phone keypad. The excessive frequent use of keypad may cause the risk of repetitive strain injury (RSI). The results of this study could provide important information to understand the way of using mobile phone in different age groups. and also could be used to design and market the mobile phone.