• Title/Summary/Keyword: Working capacity

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An analysis about the coefficient used to estimate the quay capacity at the container terminal (컨테이너 터미널의 적정 안벽능력 분석에 적용되는 계수들에 대한 분석)

  • 김창곤
    • Journal of Korean Port Research
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    • v.14 no.3
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    • pp.259-267
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    • 2000
  • This study aims to analyse the coefficient used to estimate the quay capacity per year at the container terminal. The capacity of the container terminal is composed of the capacity at the quay side and the other working conditions at the back of the quay side. But when we refer the capacity of the container terminal, generally we used capacity as that of the container terminal. To estimate the quay capacity independently of the working conditions at the back of quay side, we calculate the quay capacity as th product of working hours per year, productivity of container crane and relate other coefficients, such that berth utilization, crane utilization and efficiency. So that coefficients are properly defined to reflect the other working conditions. If we calculate the quay capacity by the product of working hours modified by the berth utilization and crane productivity modified by the crane utilization and efficiency, the meaning of that coefficients must be strictly defined. So there could be no confusion to apply that coefficients to calculate the quay capacity. In this study, we exclusively define the meaning of the berth utilization, crane utilization and efficiency according to the internal-meaning of thats in the function to calculate the quay capacity. And compare each coefficients by decomposing the working hours at the terminal.

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A Study on Level-of-Service Changes of Expressway in Accordance with the Revision of Traffic Capacity at Work-Zone (교통용량 개정에 따른 고속도로 공사구간의 서비스 수준에 대한 연구)

  • Ryu, SungWoo;Park, Kwon-Jea;Han, SeungHwan;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.16 no.3
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    • pp.109-117
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    • 2014
  • PURPOSES : This study analyzes the available working time at work-zone on the Expressway in accordance to the new capacity manual. METHODS : Sensitivity analysis on variables were conducted to calculate the adjusted capacity at work-zone based on previous researches. RESULTS : The main factors which affect available working time at the work-zone were its capacity, number of lanes, terrain and lane width. Other factors have minimal effect on the available working time. Based on the analysis, a calendar of lane closures was suggested. CONCLUSIONS : A series of studies concluded that the capacity at work-zone in the new capacity manual reduced to 76-82% of the existing manual. As such, the available working time decreased. Furthermore, the factors affecting the available working time needs to be considered when making a plan to rehabilitate the distressed pavement.

Methodical Aspects of Experimental Improvement on Working Capacity of Liquid Rocket Engine (액체로켓엔진 시험-개선과정의 방법론)

  • Kim, Cheul-Woong;Bershadskiy, Vitaly A.;Kim, Sang-Heon;Oh, Seung-Hyub
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.1
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    • pp.1-9
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    • 2009
  • As a result of the study on a number of the works, published in Russia, the methodical aspects of experimental improvement on working capacity of LRE (Liquid Rocket Engine) are reviewed. In the article, on the basis of the experience of Russia and USA, the special features of experimental improvement on working capacity of LRE and the methods of its rational implementation formulated. The organizational and technical solutions of experimental improvement on working capacity of LRE for achieving the required level of the reliability and decreasing the material expenditures are presented in the article. These suggested solutions can be used for the development of LRE.

A Study of Children's Comprehension Monitoring Ability: Monitoring Standards Preference and Relationship with Working Memory Capacity (아동의 이해점검 능력에 관한 연구 : 점검기준의 사용과 작업기억 용량과의 관계에서)

  • Song, Young Joo
    • Korean Journal of Child Studies
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    • v.19 no.1
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    • pp.117-129
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    • 1998
  • This study was designed to examine children's comprehension monitoring ability. Specifically the purpose of this study was to investigate (1) children's monitoring standards preference according to monitoring ability, and (2) the relationships between comprehension monitoring and working memory capacity. The subjects were 60 children, 30 each in 2nd and 4th grades. To measure comprehension monitoring ability, 7 stories including erroneous sentences were used. Working memory capacity was measured by the Reading Span Test (Lee, 1995). Results showed that (1) the high and low monitoring children were not different in monitoring standard preference, and (2) comprehension monitoring ability was significantly and positively related to working memory capacity.

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A Psychological Model Applied to Mathematical Problem Solving

  • Alamolhodaei, Hassan;Farsad, Najmeh
    • Research in Mathematical Education
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    • v.13 no.3
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    • pp.181-195
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    • 2009
  • Students' approaches to mathematical problem solving vary greatly with each other. The main objective of the current study was to compare students' performance with different thinking styles (divergent vs. convergent) and working memory capacity upon mathematical problem solving. A sample of 150 high school girls, ages 15 to 16, was studied based on Hudson's test and Digit Span Backwards test as well as a math exam. The results indicated that the effect of thinking styles and working memory on students' performance in problem solving was significant. Moreover, students with divergent thinking style and high working memory capacity showed higher performance than ones with convergent thinking style. The implications of these results on math teaching and problem solving emphasizes that cognitive predictor variable (Convergent/Divergent) and working memory, in particular could be challenging and a rather distinctive factor for students.

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Spatial Changes in Work Capacity for Occupations Vulnerable to Heat Stress: Potential Regional Impacts From Global Climate Change

  • Kim, Donghyun;Lee, Junbeom
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.1-9
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    • 2020
  • Background: As the impact of climate change intensifies, exposure to heat stress will grow, leading to a loss of work capacity for vulnerable occupations and affecting individual labor decisions. This study estimates the future work capacity under the Representative Concentration Pathways 8.5 scenario and discusses its regional impacts on the occupational structure in the Republic of Korea. Methods: The data utilized for this study constitute the local wet bulb globe temperature from the Korea Meteorological Administration and information from the Korean Working Condition Survey from the Occupational Safety and Health Research Institute of Korea. Using these data, we classify the occupations vulnerable to heat stress and estimate future changes in work capacity at the local scale, considering the occupational structure. We then identify the spatial cluster of diminishing work capacity using exploratory spatial data analysis. Results: Our findings indicate that 52 occupations are at risk of heat stress, including machine operators and elementary laborers working in the construction, welding, metal, and mining industries. Moreover, spatial clusters with diminished work capacity appear in southwest Korea. Conclusion: Although previous studies investigated the work capacity associated with heat stress in terms of climatic impact, this study quantifies the local impacts due to the global risk of climate change. The results suggest the need for mainstreaming an adaptation policy related to work capacity in regional development strategies.

A Relationship Between Korean EFL Learners' Working Memory Capacity, English Vocabulary Size, and Listening Competence (한국인 영어 학습자의 작업 기억 용량과 영어 어휘 수준 및 듣기 능력 관계 연구)

  • Yi, Koeon;Choi, Sunhee
    • Journal of the Korea Convergence Society
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    • v.12 no.12
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    • pp.365-370
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    • 2021
  • The current study aims to investigate the relationship between working memory capacity, vocabulary size, and listening competence of Korean EFL (English as a Foreign Language) learners. 30 English education majors from a university in Korea were recruited. The backward digit span and the operation span tasks were used to measure the participants' working memory capacity, while the Listening Vocabulary Level Test (LVLT) and the Michigan English Test (MET) were employed to measure their vocabulary size and listening proficiency in English, respectively. The correlational analyses revealed that the bigger one's working memory storage was, the better the person processed incoming input. However, no statistically significant correlation was found between working memory capacity, English vocabulary size, and listening proficiency, possibly due to the small sample size and the homogeneous subjects.

The Effects of Microstructure in Austenitic 316L Stainless Steels on the Strength and Damping Capacity (오스테나이트계 316L 스테인리스강의 강도 및 감쇠능에 미치는 미세조직의 영향)

  • SON DONG-WOOK;LEE JONG-MOON;KIM HYO-JONG;NAM KI-WOO;PARK KYU-SEOP;KANG CHANG-YONG
    • Journal of Ocean Engineering and Technology
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    • v.20 no.1 s.68
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    • pp.1-6
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    • 2006
  • The effects of microstructure on the damping capacity and tensile properties of 316L stainless steel were investigated. Increasing the degree of cold working, the volume fraction of $\varepsilon-martensite$ decreased after rising to maximum value at specific level of cold working, the volume fraction of d-martensite slowly increased and then dramatically increased from the point of decreasing $\varepsilon-martensite$ volume fraction. Increasing the degree of cold working, the behnvior of damping capacity is similar to that of the $\varepsilon-martensite$. After the damping capacity showing the maximum value at about $20\%$ of cold rolling, damping capacity was decreased with the volume fraction of $\varepsilon-martensite$. Tensile strength was proportional to the volume fraction of d-martensite, and elongation steeply decreased in the range low volume fraction of a'-martensite, then slowly decreased in range the above $10\%$ volume fraction of d-martensite. The damping capacity and elongation is strongly controlled by the volume fraction of $\varepsilon$ martensite with liner relationship. However, the effect of the volume fraction of d-martensite and austenite phase on the damping capacity was not observed. Tensile strength was governed by the volume fraction of d-martensite.

Effect of Deformation Induced Martensite on the Damping Capacity of Fe-26Mn-4Co-2Al Alloy (Fe-26Mn-4Co-2Al 합금의 감쇠능에 미치는 가공 유기 마르텐사이트의 영향)

  • Jeong, Kyu-Seong;Kang, Chang-Yong
    • Korean Journal of Materials Research
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    • v.26 no.9
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    • pp.493-497
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    • 2016
  • This study was carried out to investigate the effect of deformation induced martensite on the damping capacity of Fe-26Mn-4Co-2Al damping alloy. ${\alpha}^{\prime}$ and ${\varepsilon}$-martensite were formed by cold working, and; deformation induced martensite was formed with according to the specific direction and the surface relief. With an increasing degree of cold rolling, the volume fraction of ${\alpha}^{\prime}$-martensite increased rapidly, while the volume fraction of ${\varepsilon}$-martensite decreased after rising to a maximum value at a specific level of cold rolling. Damping capacity was increased, and then decreased with an increasing of the degree of cold rolling. Damping capacity was influenced greatly by the volume fraction of ${\varepsilon}$-martensite formed by cold working, but the effect of the volume fraction of ${\alpha}^{\prime}$-martensite have a actually on effect on the damping capacity.

Effects of the Mass of Working Fluid on the Thermal Performance of Heat Pipe with Axial Grooves (그루브형 히트파이프에서 작동유체량이 히트파이프 성능에 미치는 영향)

  • Suh, Jeong-Se;Park, Young-Jun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.1
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    • pp.1-8
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    • 2003
  • An analytical and experimental study of the thermal performance of axial heat pipe with axial groove is conducted to determine the optimal mass of working fluid for the maximum heat transport capacity of heat pipe with axial grooves. Generally, the mass of working fluid has been fully charged by considering only a geometrical shape of axial grooves embedded in a heat pipe. When the heat pipe is operated in a steady state, the meniscus re-cession phenomena of working fluid is occurred in the evaporator region. In this work, the optimal mass of working fluid was obtained from the axial variation of capillary pressure, the radius of curvature and wetting angle of meniscus of liquid-vapor interface. Experimental results were also obtained by varying the mass of working fluid within a heat pipe, and presented for the maximum heat transport capacity corresponding to the operating temperature and the elevation of heat pipe. Finally, the analytical results of the optimal mass of working fluid were compared with those of the experimental mass of working fluid.