• Title/Summary/Keyword: condition

Search Result 66,426, Processing Time 0.07 seconds

Segregated finite element method by introducing a improved open boundary condition (개선된 개방경계조건을 도입한 분리유한요소법)

  • Oh, Seung-Hun;Min, Tae-Gee;Yoo, Jung-Yul
    • Proceedings of the KSME Conference
    • /
    • 2000.04b
    • /
    • pp.698-703
    • /
    • 2000
  • In a computational fluid dynamics, the imposition of open boundary condition has an important part of the accuracy but it is not easy to find the optimal boundary rendition. This difficult is introduced by making artificial boundary in unbounded domairs. Such open boundary requires us to ensure the continuity of all primitive variables because the nature is in continuum. Here we introduce a revised well-conditioned open boundary condition particularly in FEM and apply it to various problems-entrainment, body force, short domains.

  • PDF

The Effects of Slab Size on Pavement Life Cycle Cost

  • Parsons, Timothy A.;Hall, Jim W.Jr
    • International Journal of Highway Engineering
    • /
    • v.8 no.2 s.28
    • /
    • pp.49-54
    • /
    • 2006
  • The purpose of this study was to determine the effect of expansion joint spacing (slab size) on the life cycle costs of owning Portland Cement Concrete (PCC) airfield pavements. Previous research has shown that slab size has a statistically significant impact on pavement performance. A probabilistic life cycle cost analysis was performed to determine if the effect of slab size on pavement performance would affect the total cost of ownership of PCC pavements. Data from 48 Pavement Condition Index (PCI) inspections of military and civilian airfields were used to develop probability-of-distress-by-condition curves, which were then used to develop probabilistic cost-of-repair-by-condition curves. A present worth life cycle cost analysis was then performed for various slab sizes, using construction costs, rehabilitation costs, and maintenance costs. Maintenance costs were determined by assuming a condition deterioration rate appropriate for each slab size and applying the cost-by-condition curves. The probabilistic cost-of-repair-by-condition curves indicated that smaller slabs are more expensive to repair on a unit cost basis. Life cycle cost analysis showed that larger slabs have a higher total cost of ownership than smaller slabs due to a faster rate of deterioration.

  • PDF

Reducing Exhaust Hydrocarbon at Gasoline Engine with Catalytic Converter using Synchronized Secondary Air Injection (촉매가 장착된 가솔린엔진에서 동기화된 2차공기분사에 의한 배기 탄화수소 저감)

  • 심현성;민경덕;정석호
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.9 no.2
    • /
    • pp.67-74
    • /
    • 2001
  • A synchronized secondaty air injection method has been developed to hydrocarbon emission by injecting secondary air intermittently into exhaust port. The method has been tested in a single cylinder spark-ignition engine operating at cold-steady / cold-start conditions. Effects of air injection timing, intake pressure and engine air-fuel ratio have been investigated at cold-steady condition. Also, hydrocarbon emission and exhaust gas temperature with catalytic conberter are compared with a continuous SAI method and base condition at cold-start condition. Resules show that hydrocarbon reduction rate and exhaust gas temperature are sensitive to the timing of synchronized SAI. At cold-steady condition, HC emission is minimum at engine air-fuel ratio of 10. At cold-start condition, the accumulated hydrocarbon emission during the first 120 s decreases about 56% and 22% with the synchronized and continuous SAI, respectively, compared to that of base condition.

  • PDF

The Study on the Influence of Working Condition and Job Satisfaction to the Change of Occupation of Cosmetologist (Hair & Skin Care) (미용사(헤어, 피부)의 근무여건과 직무만족이 이직에 미치는 영향에 관한 연구)

  • Kim, Miok;An, Hyeonkyeong
    • Journal of Fashion Business
    • /
    • v.17 no.5
    • /
    • pp.138-150
    • /
    • 2013
  • This paper is purposed to study on the Influence of Working Condition and Job Satisfaction on the change of occupation of Cosmetologist(Hair & Skin Care) to reduce cosmetologist change of occupation. The research methods are surveying with 250 persons & doing statistics analysis such as frequency, factor, regression analysis, using SPSS V.14. The results are as belows; 1. working conditions are reduced by two factors (1) welfare working condition, (2) basic working condition, and job satisfactions are reduced by one factor job satisfaction. 2. There is a relationship demographic characteristics, such as years, income/month, number of colleague in working area, working time/day, day off/month, with change of occupation. 3. There is a relationship working condition with change of occupation. 4. There is a relationship job satisfaction with change of occupation.

An Analysis of the Effect of Weather Condition with Work Sections in Building Construction (건축공사 공종별 기후요소 영향도 분석)

  • Kim Baek-Joong;Seo Jang-Woo;Kang Kyung-In
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2006.05a
    • /
    • pp.141-144
    • /
    • 2006
  • The building construction is an essential field to consider weather condition because construction works are performed in a site. From this reason, this study evaluated the effect of weather condition with work sections in building construction by Analytic Hierarchy Proces (AHP) method. The results of this study as follows : (1) The effect of weather condition with work sections is affected by rainfall in summer season, and by a low temperature in winter season (2) The effect of weather condition with work sections is 0.235 for mold work, 0.210 for concrete work, 0.181 for steel-frame work.

  • PDF

EXPERIMENTAL RESEARCH ON SHIP MANEUVERABILITY ACCORDING TO LOADING CONDITION

  • Nguyen, Thanh Nhat Nam;Im, Nam-Kyun;Tran, Van Luong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2011.06a
    • /
    • pp.7-9
    • /
    • 2011
  • In December 2002, International Maritime Organization (IMO) has adopted the Resolution MSA.137(76) Standards for the Ship Maneuverability. For applying the standards, we have to estimate and evaluate the Maneuverability of a ship at the design stage in difference of trim and displacement as accurate as possible. In this paper, the effect of loading condition on the ship Maneuverability was investigated through 3 methods : numerical simulation, free running model ship and real ship data.. Firstly, We carried out numerical simulation, free running model ship experiments and real ship experiments at ballast condition, half loaded condition and full loaded condition with difference of trim.. Secondly, by comparing these results of 3 methods, we draw out the trend of ship Maneuverability due to the change of trim and displacement of a ship.

  • PDF

The Method on Safety and Maintenance Based Domestic Infrastructure Facilities for Survey of Actual Condition (안전 및 유지관리기반 국내 인프라 실태조사 수행 방안)

  • Lee, Jeong-Seok
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2015.05a
    • /
    • pp.230-231
    • /
    • 2015
  • Recently, although researching and developing of safety and maintenance on domestic infrastructure facilities in KOREA are important, there has been very little research regarding on a comprehensive and integrated survey of actual condition. Therefore this study asserts the necessity of the survey process of actual condition by period planning(short-term, middle-term, long-term). The purpose of this study is to investigate current situation and to suggest the whole process method, and to establish survey process of actual condition on domestic infrastructure facilities.

  • PDF

Experimental Examination of Nonslip Technique of Floors (바닥의 미끄럼 방지기술에 관한 실험적 검토)

  • Shin, Yoon-Ho;Baek, Koen-Hyuk;Choi, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2009.05b
    • /
    • pp.235-238
    • /
    • 2009
  • The study of our investigating and analyzing through experiments the performance on nonslip techniques, which has been nationally applied and represented, showed the following results. 1) In wearing shoes condition, regardless the shape of the surface and surface condition of the object, it satisfied the performance standard in cleaned and dried condition and the pulverulent body mixed liquid dispersed moisture condition. However, for the case of the non-slip agent treatment, not likely as the non-slip tape treatment case, the effect was not approved as it shows almost the same CSR as none treatment. 2) In bare foot condition, it satisfied the performance standard in most of the objects except for the Ceramic tile (A), Ceramic tile (B), pure and soapy water dispersed condition.

  • PDF

Growth Simulation of Ilpumbyeo under Korean Environment Using ORYZA2000: I. Estimation of Genetic Coefficients

  • Lee Chung-Kuen;Shin Jae-Hoon;Shin Jin-Chul;Kim Duk-Su;Choi Kyung-Jin
    • Proceedings of the Korean Society of Crop Science Conference
    • /
    • 2004.04a
    • /
    • pp.100-101
    • /
    • 2004
  • [ $\bigcirc$ ] In the growth simulation using genetic coefficients calculated with fooled data under various condition, WAGT was not higher and LAI, WLVG, WSO were higher, but WST was similar before grain-filling stage after the became lower because of higher translocation of carbohydrates than in the growth simulation using genetic coefficients calculated with data under high nitrogen applicated condition. $\bigcirc$ Genetic coefficients should be calculated with data showing potential in ORYZA2000, but under 180 kg and 240 kg N condition in 2003, plants were infected by panicle blast and also yield was not higher than under 120 kg N condition showing not potential condition and therefore not appropriate for genetic coefficients estimation compared with pooled data from various condition.

  • PDF

Study of the Film Thickness in the Elastohydrodynamic Lubrication of Circular Contact under the Dynamic Loading Condition with Multigrid Multilevel Method (동하중조건에서의 다중격자 다중차원법을 이용한 점접촉 탄성유체윤활 유막두께연구)

  • 장시열
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2001.06a
    • /
    • pp.218-223
    • /
    • 2001
  • Many research of elastohydrodynamic lubrication (EHL) has been performed under the condition of steady state loding. However, mechanical elements undergo severe high loads that are fluctuating in general. Conventional numerical method for the circular contact of EHL study has a difficulty in converging the film pressure and thickness especially in high load of steady state. In this work, multigrid multilevel method expels the convergence problem under the condition of high load and very stable convergence is obtained under the dynamic loading condition over 1.0GPa. Several results of dynamic loading condition are shown and compared with those of steady state condition.

  • PDF