• Title/Summary/Keyword: Large-size

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The Influence of Grain Size on the Fatigue Crack Propagation Behavior in the Low Carbon Steel (SM26C) (저탄소강재(SM25C)의 피로크랙 전파거동에 미치는 결정립 크기의 영향)

  • 김건호
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.1
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    • pp.76-82
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    • 2002
  • In this study, the rotary bending fatigue test was carried out with low carbon steel(SM25C). The specimens were heat-treated in order to change the grain size, and investigated items are fatigue limit, small crack initiation, fatigue crack propagation behavior and possibility of fatigue life prediction according to the different grain size. The summarized result are as follows ; Fatigue limit of the smooth specimen was dependent upon the grain size. The fatigue crack initiation of the small grain size specimen was delayed more than that of the large grain size specimen. And the small cracks of small grain size specimen were distributed in the narrow region of the main crack circumference contrary to the large grain size specimen. The main crack was grown along the grain boundary having co-alliance with small cracks. The experiment material has quantitatively disclosed the possibility of fatigue life prediction because the fatigue crack propagation behavior is dependent upon the grain size.

The Study on Factors Affecting the Expectation Level of Hospital CEOs on Affiliation with Large Size Hospitals (대형병원과의 제휴에 대한 병원경영자의 기대수준에 영향을 미치는 요인분석)

  • Park, Byoung-Seok;Kim, Yang-Kyun
    • Korea Journal of Hospital Management
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    • v.11 no.1
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    • pp.110-126
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    • 2006
  • The purpose of the study is to find the factors influencing small or middle size clinics and hospitals CEOs' expectation level on the affiliation with the large size teaching hospitals. Data for analysis was collected to use self-administrative structured questionnaire on 164 CEOs of small or middle sized clinics and hospitals affiliated with large sized teaching hospital located in Kyung Ki Province. For the study, the researchers develop the constructs for questions on the expectation on the affiliation, the attitude such as confidence, knowledge on the affiliation, previous relationship of the affiliation, and selection guideline of the affiliation with exploratory factor analysis and reliability test. Through the confirmative factor analysis using AMOS 4, the researchers develop constructs based on exact relationship between constructs and questions. CEOs' expectation level on the affiliation is influenced on attitude or confidence, gender, types of clinics and hospitals, distance to the affiliated large hospital, types of recommender, and number of affiliated hospitals. Large sized hospitals that want to affiliation with other clinics and hospitals can promote the affiliation to consider these factors from the results.

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Sinusitis and Adenoid size is related to Snoring in children (코골이를 주소로 내원한 환자의 부비동염과 아데노이드 비후와의 관계)

  • Lee, Hai-Ja
    • The Journal of Pediatrics of Korean Medicine
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    • v.17 no.1
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    • pp.17-27
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    • 2003
  • Background: Snoring in children, is associated Kith adenotonsillar hypertrophy and sinusitis which contribute to upper airway obstruction, so we studied the sinusitis and adenoid size of snoring children with plain radiography Materials and method: Fifty patients having snoring, nasal obstruction in our hospital between November 2001 and November 2002 were studied using plain radiology PNS(water's view) and Neck lateral view(adenoid size with A/N ratio) Results: 1. In oriental medicine, Hu-Bi means laryngopharyngeal edema and obstruction, laryngopharyngeal disease are due to Hwa-Yeoul( fire and hot), sinus disease are due to Fung-Han(wind and cold) and Fung-Yeoul(wind and hot). 2. Age ranged from 2 to 17 year-old ( mean age: 6 years), 5-7 year-old were 18 patients (36%). Age of on set, 25 patients were 1-4 year-old (50%). 3. Of the 50 snoring patients, 37 patients were sinusitis(74%), 20 patients had enlarged adenoid(40%). Of the 20 large adenoid patients, 19 patients were sinusitis(95%). 4. Of the 50 snoring patients, size of tonsil were flowed. Fifteen were severe(3+), 17 patients were moderate(2+) and 15 patients were mild(1+). Of the 20 enlarged adenoid patients, size of tonsil flowed. Five were severe(3+), 11 patients were moderate(2+) and 4 patients were mild(1+). Conclusion : Of the 50 Snoring patients, 37 patients showed sinusitis(74%), 32 patients showed large tonsil(64%), 20 patients showed large adenoid(40%).

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Surface Hardness Measurement of Anodic Oxide Films on AA2024 based an Ink-Impregnation Method

  • Moon, Sungmo;Rha, Jong-joo
    • Journal of the Korean institute of surface engineering
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    • v.53 no.2
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    • pp.80-86
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    • 2020
  • This paper is concerned with type of imperfections present within the anodic oxide films on AA2024 and surface hardness of the anodic film measured after ink-impregnation. The anodic oxide films were formed for 25 min at 40 mA/㎠ and 15±0.5℃ and 300 rpm of magnet stirring rate in 20% sulfuric acid solution. The ink-impregnation allows clear observations of not only the imperfections within the anodic oxide films but also an indentation mark on the oxide film surface made by a pyramidal-diamond penetrator for the hardness measurement. There were observed four different regions in the anodic oxide films on AA2024 and the surface hardness of the anodic oxide films appeared to be crucially dependent on the type of defects, showing 60~100 Hv on the oxide surface region I with large size black defect, 100~140 Hv on the oxide surface region II with large size grey defect, 140~170 Hv on the oxide surface region III with mall size black and/or grey defects and 170~190 Hv on the oxide surface region IV without defects. The pyramidal indentation marks were observed to be distorted in the regions with a large size black and grey defects, while no distortion of the indentation mark was observed in the regions with small size defects and without visible defects.

A Study on Improvement of Size Table Sign for Clothing (의류 치수 조견표 개선에 관한 연구)

  • Shin, Yun-Ha;Lee, Myung-Hee
    • Fashion & Textile Research Journal
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    • v.12 no.1
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    • pp.109-113
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    • 2010
  • Since July 2007, the government has banned the use of the existing non-legal measurement units, and has forced us to use the unified legal measurement. Therefore, the existing clothing size unit also has been changed into centimeter dimensions from inches. However, consumers have been familiar to used to the traditional inches unit. So they have the confusion to directly survey the size table sign for clothing or to contact the employee when purchasing clothing. By the current size table sign the customers can compare the inches unit and centimeters unit, but they are difficult to see it. Therefore, there is necessary to improve the size table sign by the way that can be easy to be found and seen by consumers is given to the clothing corners. In this research, three improved size table signs were developed. And they were evaluated by the consumers in terms of preferences and awareness of them. Eventually, the best size table sign was selected. From this result, if the large-discount mart use the best improved size table sign on behalf of the current one, the problems of existing size table sign will overcome and improve customer satisfaction.

Optimum Tapping Size and Number for Sap Collection of Acer mono (고로쇠나무 수액 채취를 위한 적정 천공 크기와 천공 수)

  • Moon, Hyun-Shik;Kwon, Su-Duk
    • Journal of Ecology and Environment
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    • v.29 no.3
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    • pp.185-189
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    • 2006
  • Optimum tapping size and number for sap collection were investigated to minimize damage on tree growth and secure resources for sap by sap collection of Acer mono. The amounts of sap collected by tapping size of 12 mm, 10 mm and 8 mm was 189 L, 140 L and 193 L, respectively. Fusion rates by tapping size were 100% for 8 mm, 89% for 10 mm and 85% for 12 mm, respectively. Amount of sap by size and number of tapping were much at three, two and three tappings to small, middle and large diameter tree in case of 8 mm tapping, and it was large in quantity at two tappings of 12 mm tapping to large diameter tree, respectively. Trees tapped from one to three tappings of 8 mm size for small diameter tree with treatment of DB ointment (mixture of thiophane ointment and 2% bamboo charcoal powder) were completely filled up within 6 months. Diameter growth by number of tapping of 8 mm size was 0.60 mm for one tapping, 1.12 mm for two tappings and 0.47 mm for three tappings to small, middle and large diameter tree, respectively. In case of 12 mm tapping size, diameter growth was fast in the order of large (0.55 mm), middle (0.30 mm) and small (0.23 mm) diameter tree, respectively.

Care-giver's Needs and Evaluation on the Actual Condition of the Playgrounds in Child Care Facilities (보육시설의 실외놀이 환경실태 및 환경특성에 대한 교사의 평가와 요구)

  • Choi, Mock-Wha;Byun, Hea-Ryun
    • Journal of the Korean housing association
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    • v.19 no.6
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    • pp.105-114
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    • 2008
  • The purpose of this study is to classify playground types according to the physical characteristics of playgrounds in child care facilities, to analyze the needs of care-givers and to evaluate the adequacy of playgrounds according to playground types. The specific areas discussed in this study were the evaluation of the adequacy in the physical characteristics of playgrounds for children's outdoor play activities by the care-givers, who assist in the outdoor play activities of children and manage safety in the playground, and a report on playground requirements of them. Data was collected from field survey carried out to investigate the physical characteristics of playgrounds of 21 child care facilities. This survey incorporated a structured-questionnaire for the purpose of evaluating the adequacy of the physical characteristics of playgrounds (location and size of the playground, play equipments, the composition of play areas, ground covers, and location of sidewalk in the playground) by the 181 care-givers from the facilities and investigating the needs of them. The major results showed the following. 1) In field survey, it was observed that while the location and the size of the playgrounds varied widely, ground cover, play equipments, and the composition of play area turned out to be identical, regardless of the location and the size of the playgrounds. 2) The playgrounds were classified into five types according to the number of children and the size of the playground. The five types include A-type as a large-scale facility/smallsize playground, B-type as a small-scale facility/large-size playground, C-type as a small-scale facility/small-size playground, D-type as a middle-scale facility/large-size playground, and E-type as a large-scale facility/large-size playground. 3) The adequacy of the physical characteristics of playground in the D-type was evaluated to be higher than that of the other types. The adequacy of the C-type playground was evaluated to be lower than that of the other types in terms of size and the composition of play areas within the playground. 4) The care-givers of the D-type and the E-type playground expressed a desire to install various play equipments, while the care-givers of the C-type playground did not wish to install play equipment. 5) Various outdoor play areas were needed in the D-type playground.

A Study on the Characteristics of the Number of Family Members Affecting Housing Size Choice (주택규모 선택에 영향을 미치는 가구원수별 특성에 관한 연구)

  • Lee, Joo-Hyung;Lim, Jong-Hyun;Kang, Nam-Hoon
    • Journal of the Korean housing association
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    • v.21 no.2
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    • pp.123-132
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    • 2010
  • The housing market requires customized housing to be supplied according to the various characteristics of households. Multinominal Logistic Regression was used to analyze the effects of variables of household characteristics according to the number of family members on the choice of housing size in the scope of the whole country's housing market. Analysis showed that the number of family members has its own characteristics. When a household has a smaller number of family members, there are more variables affecting choice of housing size. Living and housing expenses variables served as significant variables that affect all household types. Results showed that households with more living and housing expenses are more likely to choose a large sized house and where households have a greater number of family members, there is more influence on that choice. The age of the householder was only found to be a meaningful variable in 1-2 person households and 3-4 person households, particularly in the choice of a small or large sized house. This shows that the age of the householder does not play an important role in choosing medium sized houses for households of under 4 people, but affects the choice of small and large sized houses. The academic ability of household members also served as a significant variable. While 1-2 person households with high academic ability tend to select a large sized house, 3-4 person households with high academic ability tend to select a small sized house. It is observed that members of both 1-2 person households and 3-4 person households tend to select their house between a large sized house and a small sized house in order to own their own houses. The result of this research suggests that there are various and detailed variables on the choice of housing size. Especially, a notable result is that household characteristics more significantly affect the housing size choice of 1-2 person households, while the trend of an aging society will more significantly affect a 3-4 person households' choice of a large sized house. Therefore, a study on the choice of housing size according to characteristics of elderly households and 1-2 person households should be continually analyzed.

Analysis of Heat Treatment Process for Large Forgings Considering Phase Transformation (대형 단조품 담금질 과정의 조직 및 응력분포 해석)

  • 이정호;이부윤;전제영;이명렬;조종래
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.964-968
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    • 1996
  • The demands of size and quality of large steel shaft forgings for ship building, power plant, steel plant, etc. are rapidly increasing, and some of these productions are manufactured from ingot weighing more than 300 tons. For use as rotating components. shafts require toughness, strength and homogeneity, and therefore are produced through a variety of heat treatments. According to the increase of ingot size, micro- and macrosegregation and also mass effect of the product increase. Thus, special care should be paid to the heat treatment of such large shaft forgings. In this paper, the heat treatment of large shaft forgings such as rotor and back-up roll is calculated using the commercial finite element code SYSWELD. Calculated distributions of temperature and phase are compared with experimental data. The continuous cooling transformation diagram, thermal and mechanical properites of each phase are used. The phase proportion, hardness and residual stress during water quenching are discussed.

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A Case Study on Construction Cost Reduction of Large-size Building Foundation using Bi-directional High Pressure Pile Load Test(BDHPLT) (양방향 고유압 말뚝재하시험을 이용한 대형건축물 기초의 공사비 절감에 관한 사례 연구)

  • Kim, Nam-Il;Kim, Sang-Il;Choi, Yong-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.518-525
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    • 2009
  • The bi-directional high pressure pile load test(BDH PLT) which is a kind of pile load tests was conducted to find out a reasonable design procedure of large-diameter drilled shafts of large-size building structures. The behaviors of bearing capacity and settlement of the large-diameter drilled shafts were analyzed and the results obtained from BDH PLT were also compared with those obtained from the equations suggested in the specification. In case of the reasonable design procedure adopted, the construction cost could be saved at least 15 ~ 28%. It could be concluded that BDH PLT should be needed for the foundation construction cost reduction of the high-rise building structures.

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