• Title/Summary/Keyword: Fundamental Factors

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Numerical Analysis of Magnetic Flux Density Distribution by an Openable Magnetic Flux Generator for MIAB Welding (MIVB 용접용 개폐형 자속발생기에 의한 자원밀도분포의 수치해석)

  • Ku Jin-Mo;Kim Jae-Woong
    • Journal of Welding and Joining
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    • v.22 no.6
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    • pp.50-56
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    • 2004
  • MlAB(magnetically impelled arc butt) welding is a sort of pressure welding method by melting two pipe sections with high speed rotating arc and upsetting two pipes in the axial direction. The electro-magnetic force, the driving force of the arc rotation, is generated by interaction of arc current and magnetic field induced from the magnetic flux generator in the welding system. In this study, an openable coil system for the generation of magnetic flux and a 3-dimensional numerical model for analyzing the electro-magnetic field were proposed. Through the fundamental numerical analyses, a magnetic concentrator was adopted for smoothing the magnetic flux density distribution in the circumferential direction. And then a series of numerical analysis were performed for investigating the effect of system parameters on the magnetic flux density distribution in the interested welding area.. Numerical quantitative analyses showed that magnetic flux density distribution generated from the proposed coil system is mainly dependent on the exciting current in the coil and the position of coil or concentrator from the pipe outer surface. And the gap between pipe ends and arc current are also considered as important factors on arc rotating behavior.

Systematic Study of Paper Breaks in Papermaking Process Using Fracture Mechanics - (1) Evaluation of Fracture Toughness in Wet State

  • Yung B. Seo;Roh, You-Sun
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2002.05a
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    • pp.76-84
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    • 2002
  • Fracture toughness was considered as one of the good estimates of the paper break tendency of paper web in the press room. Paper break on the paper machine is caused by many factors such as paper machine irregular vibrations, impurities in the fiber furnish, shives, and so on. On the paper machine, the solid content of paper web is changing very rapidly from less than 1% to over 95%. We tried to measure the fracture toughness of paper web at different solid contents for providing the fundamental knowledge of paper break. Stretches of wet web were also measured and compared to the fracture toughness changes. Four different fiber furnishes (SwBKP, HwBKP, ONP, and OCC) were refined to different degrees, and at different solid contents (40%, 60%, 80%, and 95%), their fracture toughnesses were measured. Two fracture toughness measurement methods (essential work of fracture and Tryding's load-widening method) were used, and we found they gave identical results. The stretch curves of the wet webs against the axis of solid contents were very similar to the fracture toughness curves of those.

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Lysophosphatidic Acid-Induced TWIST1 and Slug Expression in Oral Cancer Cell Invasion

  • Cho, Kyung Hwa
    • Journal of dental hygiene science
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    • v.17 no.5
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    • pp.433-438
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    • 2017
  • Relative to its incidence, oral cancer has serious negative social effects. The exact causes of oral cancer have not been clarified, but many studies have implicated smoking and drinking. However, the fundamental mechanism of oral cancer causation has yet to be elucidated. Lysophosphatidic acid (LPA) augments epithelial mesenchymal transition (EMT) and development of various cancer cells. However, a detailed mechanistic explanation for LPA-induced EMT and the effects of EMT-promoting conditions on oral squamous cell carcinoma development remain elusive. In the present study, a quantitative reverse transcription polymerase chain reaction was used to analyze TWIST1, Slug, E-cadherin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcript expression. Immunoblotting was used to analyze TWIST1, Slug, E-cadherin, and GAPDH protein expression. siRNAs were used to silence TWIST1 and Slug transcript expression. A matrigel-coated in vitro invasion insert was used to analyze oral cancer cell invasion. The results of the present study show that the expression levels of TWIST1 and Slug, which are EMT factors, were increased by LPA treatment in YD-10B oral squamous cell carcinoma. Conversely, E-cadherin expression was significantly reduced. In addition, transfection of the cells with TWIST1 and Slug siRNA strongly inhibited LPA-induced oral cancer cell invasion. The present study shows that TWIST1 and Slug mediate LPA-induced oral cancer cell EMT and invasiveness. The present study confirmed the mechanism by which LPA promotes oral cancer cell development, with TWIST1 and Slug providing novel biomarkers and promising therapeutic targets for oral cancer cell development.

A Fundamental Study on Slope Stability Due to Filtering Condition of Embankment Material During Rain (성토재료의 필터링 조건이 사면 안정에 미치는 기초연구)

  • Kim, Sang-Hwan;Kim, Hak-Moon;Shin, Jong-Ho;Ko, Dong-Pil
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.419-426
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    • 2008
  • Recently, localized heavy rain due to "EL-LIO" was a kind of reason by risk of slope stability. In this paper, the behaviour of slope when localized heavy rain was studied. In order to perform this study experimental programs were performed. Experimental programs was checked filtering conditions for slope stability due to localized heavy rain. And then, investigated slope stability and fracture mechanism each other types. In the experimental study, performed changing filtering condition by embankment, through five fixing factors such as rainfall intensity, slope shape, geological condition, compaction energy and water content. According to the results of this study, behaviour of facture slope has made a shallow and narrow waterway. This waterway expanded base stone. In order to, suggested a system for slope stability examination.

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A Study on the High School Girl’s Sex Role Identity and Underwear Purchasing Behaviors (여고생의 성역할정체감과 속옷 구매행동)

  • 안양숙;김용숙
    • Journal of Korean Home Economics Education Association
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    • v.11 no.1
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    • pp.1-11
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    • 1999
  • The purpose of this study were to analyze high school girls’sex role identity and underwear purchasing behaviors, and to provide the educational guidelines for high school girls as a underwear comsumer and the fundamental data necessary for the products planning of underwear manufacturing companies. The questionnaire was composed of questions about the types of sex role identity, pursuit factors and purchasing behaviors of underwear. The respondents were girls from 6 high schools in cities in Chonbuk Province. The questionnaires were collected from April 6th to May 12th in 1998. 510 questionnaires were used for data analysis. Frequency, percent, average, standard deviation, F-test, $$\chi$^2$-test, and Duncan’s multiple range test were followed. The results of this study were as follows:1. Among the sex role identity groups, the androgynous group was the largest, and the masculine group was the smallest among high school girls. 2. High school girls sought after practicality most when purchasing underwears, but sought after the brand least. The androgynous group recognized practicality, aesthetics, and sexual attraction most, but the undifferentiated group recognized them least. 3. The high school girls bought underwears objectively when they were worn out, made use of TV, newspaper, and radio advertisements as the information sources, and considered the size, comfort, and style. They recognized the prices of underwears as moderate. They depended on their mother most when purchasing underwears and reflected their dependents opinion on selecting underwears partially. They purchased at the underwear specialty store.

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A Study on Escherichia Coli Disinfection by the Electrochemical Method for Small Sewerage System (소규모 오수처리를 위한 전기화학적 방법에 의한 대장균 소독에 관한 연구)

  • Park, Young-Seek;Jeong, No-Sung;Kim, Dong-Seog
    • Journal of Environmental Science International
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    • v.16 no.4
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    • pp.441-447
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    • 2007
  • This study was carried out to investigate the effect of electrochemical (EC) disinfection of artificial wastewater contaminated by Escherichia coli culture. Circulated batch type electrochemical disinfection system using three plates electrodes was used. Also, the several factors (pH, ORP, DO, temperature, current, conductivity) were measured in order to investigate the fundamental design factor in the EC disinfection system. It was demonstrated that the EC process was highly effective for wastewater disinfection. At the constant voltage, the disinfection efficiency was increased according to time. The disinfection efficiency and current increased as the increase of voltage. The variation of conductivity was a little related to the variation of CFU (colony forming units). The differences in disinfection efficiency according to the ice pack and the variation of electrodes were not occurred. The EC disinfection efficiency and current increased according to the increase of circulating flow rate.

Study on gender-neutral style in modern fashion (현대 패션에 나타난 젠더 뉴트럴 스타일에 관한 연구)

  • Lee, Ji-Eun;Kwak, Tai-Gi
    • Journal of the Korea Fashion and Costume Design Association
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    • v.22 no.3
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    • pp.111-126
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    • 2020
  • The purpose of this study is to understand the gender-neutral phenomenon, to grasp the flow of design, and to seek the future direction of modern fashion design. As for the scope and method of the study, this study was performed based on relevant literature. In terms of visual data, website photos were collected from the collection of S/S in 2016 to F/W in 2020. To assess the properties of the gender-neutral, analysis was implemented on the results after arranging the factors for gender neutrality and the characteristics suggested in the related papers. The fashion-related expert group analyzed the properties of the gender-neutral style from 1,031 pictures, where the gender-neutral style of fashion design collections was applied. As a result of the analysis, the characteristics of the gender-neutral were analyzed and divided into the extended body-positive performance style, the mashup style- respecting the conflicting culture, the street style of coexisting genders, and the fluid style of changing directions. In this study, the attributes were derived as acceptability, playfulness, and sustainability. Accordingly, it is expected that this study will play a fundamental role in the creative fashion design development and unfolding of the fashion industry and fashion designers.

A Study on the Indoor Thermal Environment of the Large Enclosure Without Cooling Loads from Occupancy in Summer (대공간내 인체발열 미고려시의 하계 온열환경 조사)

  • Jeong, Seong-Jin;Choi, Dong-Ho;Yang, Jeong-Hoon;Seok, Ho-Tae
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.3-8
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    • 2008
  • The purpose of this study is to provide fundamental cooling design data for the large public enclosures as gymnasium. This study executed indoor thermal environment verification of the existing gymnasium by measuring temperature distribution with cooling the space in summer. Cooling loads from human body was not considered. We examined various indoor thermal environment factors of the large enclosed space in this study which include vertical and horizontal temperature distribution, supply and return air flow feature, thermal comfort environment feature, amount of ventilation and etc.

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Capacity Design of Lithium Ion Battery Based on the Characteristics of Materials (${\cdot}$부극 재료의 특성에 따른 리튬이온전지의 용량설계)

  • Moon Seong-In;Doh Chil-Hoon;Yun Seong-Kyu;Yum Duk-Hyung
    • 한국전기화학회:학술대회논문집
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    • 1998.12a
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    • pp.7-27
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    • 1998
  • In order to design capacity of lithium ion battery, some calculations were carried out based on the characteristics of materials by the given battery shape and dimension. The principle of design was built by the interpretation of the correlation of material, electrochemical and battery factors. Parameters of materials are fundamental physical properties of constituent such as cathode. separator, anode, current collectors and electrolyte. Electrochemical factor includes potential pattern as a function of specific capacity, specific discharge capacity(or initial irreversible specific capacity or Ah efficiency) as a function of specific charge capacity and material balancing. Parameters of battery are dimension, construction hardware and performance. Battery capacity was simulated for a lithium cobalt dioxide as cathode and a hard carbon as anode to achieve 1100 mAh for the charge limit voltage of 4.2V, the weight ratio(+/-) of 2.4 and ICR18650. A fabricated test cell (ICR18650) which have weight ratio(+/-) of 2.4 discharged to 1093 mAh for the charge limit voltage of 4.2V. The sequential discharge capacity show good correspondence with designed capacity.

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Development of Health Behavior Assessment Tool of the Korean Elders (한국 노인의 건강행위 사정 도구 개발)

  • 최영희;김순이
    • Journal of Korean Academy of Nursing
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    • v.27 no.3
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    • pp.601-613
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    • 1997
  • This project was conducted using a survey method and through interviewing with four persons aged 60 years and over. An interview with an open-ended questionnaire was also used for elderly persons, families, oriental medicine doctor and nurses. topic-related literature review was also done. In total, 382 statements were derived. For content validity, nursing professionals were involved in this study, From that 48 items are developed. The subjects were 340 elderly persons over 60 years old. Data were collected duicing February and March 1997 and analyzed using the SPSS package The result are as follows. 1. Items with low Cronbach Coefficient alpha which means low correlation with total items were removed. 2. Factor analysis was done in order to confirm construct validity and eight factors were obtained from the results. The first factor, 'positive cognition of the aging process', the second factor, 'relationship network' the third factor, 'maintanence of physical functioning, the fourth factor', 'maintanence of peaceful mind' the fifth factor, 'keeping up with daily tasks' the sixth factor, 'continuous adequate body movement' the seventh factor,'involvement of religion in the elderly person's life and the eight factor', 'appropriate resting'. Cronbach Coefficient alpha for the 33 items was .9127 Based on the result, the following is suggested 1. It is anrticipated that the fundamental health of elderly person could be promoted by assessing healthy behaviors of elderly person with this assessment tool. 2. Further studies could be derived from this research. 3. Validity of this assessment tool should be further tested with and a larger sample of elderly person including in-patient elderly persons as well as nursing home residents.

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