• Title/Summary/Keyword: internal capacity

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Internal force monitoring design of long span bridges based on ultimate bearing capacity ratios of structural components

  • Hu, Ke;Xie, Zheng;Wang, Zuo-Cai;Ren, Wei-Xin;Chen, Lei-Ke
    • Structural Monitoring and Maintenance
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    • v.5 no.1
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    • pp.93-110
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    • 2018
  • In order to provide a novel strategy for long-span bridge health monitoring system design, this paper proposes a novel ultimate bearing capacity ratios based bridge internal force monitoring design method. The bridge ultimate bearing capacity analysis theories are briefly described. Then, based on the ultimate bearing capacity of the structural component, the component ultimate bearing capacity ratio, the uniformity of ultimate bearing capacity ratio, and the reference of component ultimate bearing capacity ratio are defined. Based on the defined indices, the high bearing components can then be found, and the internal force monitoring system can be designed. Finally, the proposed method is applied to the bridge health monitoring system design of the second highway bridge of Wuhu Yangtze river. Through the ultimate bearing capacity analysis of the bridge in eight load conditions, the high bearing components are found based on the proposed method. The bridge internal force monitoring system is then preliminary designed. The results show that the proposed method can provide quantitative criteria for sensors layout. The monitoring components based on the proposed method are consistent with the actual failure process of the bridge, and can reduce the monitoring of low bearing components. For the second highway bridge of Wuhu Yangtze river, only 59 components are designed to be monitored their internal forces. Therefore, the bridge internal force monitoring system based on the ultimate bearing capacity ratio can decrease the number of monitored components and the cost of the whole monitoring system.

Nonlinear Dynamic Capacity of Reinforced Concrete Special Moment Frame Buildings (철근 콘크리트 특수 모멘트 골조 건물의 비탄성 동적 성능값)

  • Kim, Tae-Wan;Kim, Tae-Jin
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.209-216
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    • 2006
  • For evaluation of building performance, a nonlinear dynamic capacity of the building is a key parameter. In this study, an reinforced concrete special moment resisting frame building was chosen to study the process of determining the nonlinear dynamic capacity. The building, which was designed by IBC 2003 representing new codes, was composed of special moment resisting frames in the perimeter and internal frames inside the building. The capacity, which is inter-story drift capacity, consists of two categories, local and global collapses. Global collapse capacity was determined by incremental dynamic analysis. Local collapse capacity was determined by the same method except for utilizing damage index. In audition to this, it was also investigated that the effect of including internal frames designed by gravity load in the analysis. Results showed that the damage index is a useful tool for determining local collapse. Furthermore, including the internal frames with special frames in the analysis is very important in determining the capacity of a building so both must be considered at the same time.

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Influence of Internal and External Capacity on Adults' Food Waste Disposal Capacity (내적역량과 외적역량이 성인의 식품 쓰레기 처분에 대한 실천역량에 미치는 영향)

  • Kim, Ji Eun;Choi, Kyoung Sook
    • Korean Journal of Community Nutrition
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    • v.26 no.6
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    • pp.455-466
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    • 2021
  • Objectives: The purpose of this study was to investigate the effects of internal and external capacity on the practical capacity for food waste disposal in adults. Methods: The study subjects were 410 adults who answered a structured questionnaire. The survey was conducted in January 2021. Data were analyzed through descriprive analysis, t-test, ANOVA, and multiple regression analysis using the SPSS Win 24.0. Results: First, in the analysis of internal capacity, attitude (3.95 out of 5 points) scored higher than knowledge (3.59 points). Attitudes showed significant differences according to gender (P < 0.001), age (P < 0.001), and income (P < 0.001). Knowledge showed significant differences according to gender (P < 0.01) and age (P < 0.05). Second, in the analysis of capacity, market constraints (3.73 points) scored the highest, followed by institutional conditions (3.48 points) and reference group (3.36 points). Market constraints differed according to gender (P < 0.001), and institutional conditions differed according to income (P < 0.001). There was a significant difference in the reference group according to the level of education (P < 0.05) and income (P < 0.05). Third, the practical capacity scores appeared in the order of separating discharge behavior, using behavior, purchasing behavior, and leadership behavior. Separating discharge behavior showed significant differences according to gender (P < 0.001), education level (P < 0.05), and income (P < 0.01). Using behavior showed a difference according to gender (P < 0.01), and purchasing behavior showed a significant difference according to income (P < 0.05). Leadership behavior showed no difference according to demographic factors. Fourth, internal capacity and external capacity showed a significant positive relationship with practical capacity. Factors affecting purchasing behavior were knowledge, attitude, institutional conditions, and reference group, and their explanatory power was 53%. Factors influencing using behavior were knowledge, attitude, institutional conditions, and reference group, and had an explanatory power of 37%. Leadership behavior was influenced by institutional conditions and the reference group, with an explanatory power of 31%. Conclusions: Internal capacity, external capacity, and practical capacity show differences according to demographic factors. Factors influencing the practical capacity of adults were knowledge, attitude, institutional conditions, and reference group.

Performance Characteristics of Refrigerant R170(Ethane) Refrigeration System Using Liquid-gas Heat Exchanger (액-가스 열교환기를 이용한 R170(에탄)용 냉동시스템의 성능 특성)

  • Ku, Hak-Keun
    • Journal of Power System Engineering
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    • v.20 no.5
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    • pp.78-85
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    • 2016
  • This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system using R170. These liquid-gas heat exchangers(internal or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. Exception for the effect of inner diameter, the RCI of R170 with respect to refrigerant mass flowrate, the length and effectiveness of internal heat exchanger is about 2.1~3.3% higher than that of R13 at the same experimental conditions. With a thorough grasp of these effect, it is necessary to design the R170 compression refrigeration cycle using internal heat exchanger.

A Study on the Performance of Recycled Cells for application to Residential BESS (주택용 BESS에 적용하기 위한 재활용 셀의 성능에 관한 연구)

  • Phil-Jung Kim;Seong-Soo Yang
    • Journal of IKEEE
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    • v.28 no.1
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    • pp.14-19
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    • 2024
  • To determine the performance of recycled cells for application to residential BESS, cells used over the past 5 years were selected. The basic specifications of the cell used in the test are nominal voltage of 3.7[V], nominal capacity of 2,200[mAh], charging voltage of 4.05[V], continuous discharge current of 1[C](2,200[mA]), continuous charging current of 0.5[C](1,100[mA]). For new cells, the internal resistance was 21.3±1[mΩ], but for recycled cells, the average internal resistance was 25.38[mΩ], an increase of about 19.1[%]. The charge·discharge capacity was approximately 18.9~19.3[%] lower than that of a new cell. Because internal resistance and charge·discharge capacity are closely related to cell aging, cells to be applied to BESS need to use products with an initial internal resistance of 1.5 times or less and a charge·discharge capacity performance of 70[%] or more.

Performance Analysis of R-1270(Propylene) Refrigeration System Using Internal Heat Exchanger (내부 열교환기를 이용한 R-1270용 냉동시스템의 성능 분석)

  • Ku, Hak-Keun
    • Journal of Power System Engineering
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    • v.18 no.4
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    • pp.36-42
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    • 2014
  • This paper considers the influence of internal heat exchangers on the efficiency of a refrigerating system using R-1270. These internal heat exchangers(liquid-gas or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as the mass flowrate of R-1270, inner diameter tube and length of internal heat exchanger, to optimal dimensions of the heat exchanger is also analyzed. The main results were summarized as follows : the mass flowrate of R-1270, inner diameter tube and length of internal heat exchanger, and effectiveness have the influences on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. With a thorough grasp of it is possible to design the R-1270 compression refrigeration cycle using internal heat exchanger.

Factors Affecting the Internal Audit Effectiveness of Steel Enterprises in Vietnam

  • DINH, The Hung;PHAM, Duc Cuong;NGUYEN, Tuan Thi
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.271-283
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    • 2021
  • This article provides empirical evidence on factors of internal audit (IA) characteristics affecting the internal audit effectiveness in steel enterprises in Vietnam. The study uses data from survey obtained from 114 responses representing owners, managers, and internal auditors from 38 steel enterprises in Vietnam for period from 2018 to 2019. Data collected is firstly checked with Cronbach's Alpha, then the EFA test, and the model linear regression is used to test the relationship between internal audit characteristics and internal audit effectiveness. Results reveal that internal audit effectiveness in steel enterprises in Vietnam is influenced by various internal factors, including the size of internal audit, the scope of internal audit, the capacity of internal auditors, the independence of internal auditor, and the operational bases and methods of internal audit. Based on the research results, the paper makes six recommendations: strengthening operational basis of IA; increasing the independence of IA; increasing the size and capacity of IA staff; expanding and not underestimate the scope of IA; and reforming the internal governance structure. These proposed recommendations could be applied, not only for steel companies in Vietnam, but also for other companies in Vietnam or other companies in jurisdictions that have similar conditions.

Performance Analysis of R744 (Carbon Dioxide) Transcritical Refrigeration System Using Internal Heat Exchanger (내부 열교환기를 이용한 R744용 초임계 냉동사이클의 성능 분석)

  • Son, Chang-Hyo;Oh, Hoo-Kyu
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.4
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    • pp.459-465
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    • 2009
  • This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system. These internal heat exchangers(liquid-suction or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as gas cooler pressure and evaporation temperatures, superheat in the evaporator and temperature of gas cooler outlet, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R744, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative capacity index) of this system. With a thorough grasp of these effect, it is necessary to design the R744 compression refrigeration cycle using internal heat exchanger.

Selection of Reference Equations for Lung Volumes and Diffusing Capacity in Korea (우리나라 성인 폐용적 및 폐확산능 정상예측식의 선정)

  • Song, Eun Hee;Oh, Yeon Mok;Hong, Sang Bum;Shim, Tae Sun;Lim, Chae Man;Lee, Sang Do;Koh, Youn Suck;Kim, Woo Sung;Kim, Dong Soon;Kim, Won Dong;Kim, Tae Hyung
    • Tuberculosis and Respiratory Diseases
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    • v.61 no.3
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    • pp.218-226
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    • 2006
  • Background: The lung volume and diffusing capacity are influenced by ethnicity. However, there are no equations for predicting the normal lung volume in the adult Korean population, and there is only one equation for diffusing capacity. The aim of this study is to select the most suitable reference equation for the Korean population. Method: 30 men and 33 women at Hanyang University Guri Hospital, and 27 men and 34 women at Asan Medical Center in healthy nonsmoking adults were enrolled in this study. The subject's age, gender, height, weight, lung volume by plethysmography, and diffusing capacity by a single breathing method were obtained. The most suitable equation with the lowest sum of residuals between the observed and predicted values for lung volume and diffusing capacity was selected. Result: At Hanyang University Guri Hospital, the equations with the lowest sum of residuals in the total lung capacity were ECSC's equation in males (sum of residual: 0.04 L) and Crapo/Morris's equation (-1.04) in women. At the Asan Medical Center, the equations with the lowest sum of residuals in the total lung capacity were Goldman/Becklake's equation in males (sum of residual: -2.35) and the ECSC's equation -4.49) in women. The equations with the lowest sum of residuals in the Diffusing capacity were Roca's equation in males (sum of residual: -13.66 ml/min/mmHg) and Park's in women (25.08) in Hanyang University Guri hospital and Park's equation in all cases in the Asan Medical Center (male: -1.65, female: -6.46). Conclusions: Until a reference equstion can be made for healthy Koreans by sampling, ECSC's equation can be used for estimating the lung volume and Park's can be used for estimating the diffusing capacity.

Development and Tracking Control of a Multi-Link Climbing Robot with High Payload Capacity and Various Transition Abilities (높은 유효하중 능력과 다양한 벽면전환 능력을 가진 다관절 등반로봇의 개발 및 추종제어)

  • Oh, Jongkyun;Lee, Giuk;Kim, Jongwon;Seo, TaeWon
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.10
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    • pp.915-920
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    • 2013
  • Payload capacity and transition ability are essential for climbing robots to apply the robots to various applications such as inspection and exploration. This paper presents a new climbing robotic platform with multi-link structure of track-wheel modules to enhance payload capacity and transition ability, and its tracking controller design and experimental results. The compliances between track-wheel modules achieve stable internal and external transitions while the large adhesion area of the track-wheel module enhances the payload capacity of the robot. Kinematic model-based tracking controller is designed and implemented for autonomous internal transition, and the gains of the controller are optimized by experimental design. Experiments on the automatic internal transitions are performed and the results guarantee autonomous internal transition with little tracking error.