• Title/Summary/Keyword: Reasonable alternative

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Development of non-destructive method of detecting steel bars corrosion in bridge decks

  • Sadeghi, Javad;Rezvani, Farshad Hashemi
    • Structural Engineering and Mechanics
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    • v.46 no.5
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    • pp.615-627
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    • 2013
  • One of the most common defects in reinforced concrete bridge decks is corrosion of steel reinforcing bars. This invisible defect reduces the deck stiffness and affects the bridge's serviceability. Regular monitoring of the bridge is required to detect and control this type of damage and in turn, minimize repair costs. Because the corrosion is hidden within the deck, this type of damage cannot be easily detected by visual inspection and therefore, an alternative damage detection technique is required. This research develops a non-destructive method for detecting reinforcing bar corrosion. Experimental modal analysis, as a non-destructive testing technique, and finite element (FE) model updating are used in this method. The location and size of corrosion in the reinforcing bars is predicted by creating a finite element model of bridge deck and updating the model characteristics to match the experimental results. The practicality and applicability of the proposed method were evaluated by applying the new technique to a two spans bridge for monitoring steel bar corrosion. It was shown that the proposed method can predict the location and size of reinforcing bars corrosion with reasonable accuracy.

An efficient method for the compressive behavior of FRP-confined concrete cylinders

  • Fan, Xinglang;Wu, Zhimin;Wu, Yufei;Zheng, Jianjun
    • Computers and Concrete
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    • v.12 no.4
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    • pp.499-518
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    • 2013
  • Fiber reinforced polymer (FRP) jackets have been widely used as an effective tool for the strengthening and rehabilitation of concrete structures, especially damaged concrete columns. Therefore, a clear understanding of the compressive behavior of FRP-confined concrete is essential. The objective of this paper is to develop a simple efficient method for predicting the compressive strength, the axial strain at the peak stress, and the stress-strain relationship of FRP-confined concrete. In this method, a compressive strength model is established based on Jefferson's failure surface. With the proposed strength model, the strength of FRP-confined concrete can be estimated more precisely. The axial strain at the peak stress is then evaluated using a damage-based formula. Finally, a modified stress-strain relationship is derived based on Lam and Teng's model. The validity of the proposed compressive strength and strain models and the modified stress-strain relationship is verified with a wide range of experimental results collected from the research literature and obtained from the self-conducted test. It can be concluded that, as a competitive alternative, the proposed method can be used to predict the compressive behavior of FRP-confined concrete with reasonable accuracy.

A Study on the Research of Big Five Personality Factors Affecting Creativity - The Case of K Institute -

  • Lee, Kil-Whoan;Song, Ha-Sik;Park, Jin-Hee
    • International Journal of Contents
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    • v.6 no.3
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    • pp.38-46
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    • 2010
  • In this study, five personality types of employees have any impact on their creativity, a systematic and comprehensive study of literary research and demonstration studies were parallel. Results of the research employee of the extroversion, agreeableness of their creativity (+) showed the impact. In addition, sincerity, openness to experience, personality and creativity of employee creativity (+) for influencing said. Neuroticism to creativity, but nature does not affect any found. This study, five personality types that affect employee creativity of individuals by examining the relationship between personality type and creativity by presenting a model for the study, employees' personality types can have on creativity and offers a realistic alternative to the theory presented you can find the meaning in that. These theoretical and empirical validation of the results of employee productivity oriented organizations, including human resource management in a systematic and reasonable for the type of personality tests are being conducted on the administrative feasibility is expected to be able to provide. Finally, based on the results of these studies, management and administrative implications and future research directions presented.

A Blackboard-Based Scheduling Expert System (흑판모델을 이용한 일정계획 전문가 시스템)

  • Park, Ji-Hyeong;Gang, Mu-Jin;Lee, Gyo-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.1
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    • pp.14-23
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    • 1996
  • Scheduling jobs effectively under consideration of actual loads on machines is one of the most complicated tasks in production control. The complexity of the finite capacity scheduling often makes the conventional methods of industrial engineering fail. As an alternative, Knowledge-based approaches to job-shop scheduling have been evolved recently. This paper presents a blackboard- based scheduling expert system which combines knowledge-based scheduling with interactive scheduling. It is shown to be possible to generate the feasible schedule within a reasonable time. Flexible reaction management is also possible while keeping the changes in the generated schedule to the minimal and adjusting the schedule to tardy operations or working environmental changes. The system is equipped with a rule base with heuristics for handling conflicted event. A case study applying the implemented system is described.

Study on facility classification development of Military Barracks - Focusing on the questionnaire survey and military officials' interview of the army, navy, air force and Marine - (병영 생활관 시설 분류 개선에 관한 연구 - 육·해·공·해병대 설문 조사 및 군 간부 면담 조사를 중심으로 -)

  • Sung, Lee-Yong;Yi, Sang-Ho
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.19-27
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    • 2013
  • The objective of this study was to establish Facility classification for military barracks among military facilities. The military barracks are the place where soldiers spend most of their time. Thus, a new type of space in military barracks is required to improve the quality of life of the soldiers and make the military more advanced for national defense. The research method was to derive problems through a survey of the previous literature and case studies and to select target places in the Army, Navy, Air Force, and Marine based on the derived problems. An improvement scheme was proposed by developing criteria for military barracks spaces through a questionnaire survey. The following results were obtained: Facility classification inside of national defense military facility standard should be reorganized. The alternative plan is demanded for some camp which has no need about setting up the office facility. And the study of reasonable facility area after improvementing facility categorization is required.

A Study of TRM and ATC Determination for Electricity Market Restructuring (전력산업 구조개편에 대비한 적정 TRM 및 ATC 결정에 관한 연구)

  • 이효상;최진규;신동준;김진오
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.3
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    • pp.129-134
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    • 2004
  • The Available Transfer Capability (ATC) is defined as the measure of the transfer capability remaining in the physical transmission network for further commercial activity above already committed uses. The ATC determination s related with Total Transfer Capability (TTC) and two reliability margins-Transmission Reliability Capability (TRM) and Capacity Benefit Margin(CBM) The TRM is the component of ATC that accounts for uncertainties and safety margins. Also the TRM is the amount of transmission capability necessary to ensure that the interconnected network is secure under a reasonable range of uncertainties in system conditions. The CBM is the translation of generator capacity reserve margin determined by the Load Serving Entities. This paper describes a method for determining the TTC and TRM to calculate the ATC in the Bulk power system (HL II). TTC and TRM are calculated using Power Transfer Distribution Factor (PTDF). PTDF is implemented to find generation quantifies without violating system security and to identify the most limiting facilities in determining the network’s TTC. Reactive power is also considered to more accurate TTC calculation. TRM is calculated by alternative cases. CBM is calculated by LOLE. This paper compares ATC and TRM using suggested PTDF with using CPF. The method is illustrated using the IEEE 24 bus RTS (MRTS) in case study.

A New Perspectives on the Research of Domestic and Overseas Land Category System (국내외 지목체계 운용실태 연구에 관한 새로운 시각)

  • Ryu, Byoung-Chan
    • Journal of Cadastre & Land InformatiX
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    • v.49 no.2
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    • pp.151-167
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    • 2019
  • Korea's current Land Category Classification System(LCCS) can not accurately register of complex and diverse Status of land use in Cadastral Record. Therefore, in order to draw implications for the improvement of LCCS in Korea, Shin SW and four others published a paper titled 'A Study on Land Category System of Domestic and Foreign Country' in 2013. This paper compared the 'land category', 'land use' and 'land cover' of six countries on the same line, and Some non-factual content was described. So, presented a new perspective on this. Looking forward, I hope that reasonable alternative will be presented based on the understanding of LCCS of Germany, Japan and Taiwan. In the future research project, to study the history of LCCS in Germany and Taiwan and suggest to refer to improvement of LCCS of Korea.

The Evaluation on In-Situ Adaptability of Mono-layer Landfill Final Cover System (단층형 매립지 최종복토시스템의 현장 적용성 평가)

  • Yu, Chan;Yun, Sung-Wook
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.5
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    • pp.73-80
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    • 2006
  • The mono-layer cover system is composed of soils only as a filling material and various plants are planted on the surface to control the water balance in the cover system. In this paper, the mono-layer cover system was considered as an alternative landfill final cover system and developed a model that could utilize industrial by-product (especially, coal ash & phosphogypsum) as additive filling materials. The mixture of granite soil, coal ash, and phosphogypsum was placed as a cover material in a box constructed with cement. Laboratory tests were carried out to investigate the environmental effect on the utilization of coal ash & phosphogypsum and to determine the mxing ratio of each materials. In the leaching test, all materials showed lower heavy metal concentration than the threshold values of regulation. The optimum mixing ratio of materials which was applied to field model test was determined to soil (4) : coal ash (1) : phosphogypsum (1) on the volume base. Field model tests were continued from February to July, 2004 in the soil box that was constructed with cement block. It was verified that coal ash and phospogypsum mixed with soil was to be safe environmentally and the water balance of mono-layer cover system was reasonable.

Use of Human Placentas for Practice of Microvascular Surgery (미세수술 술기 습득을 위한 태반의 사용)

  • Kang, Min-Gu;Yoon, Sang-Yup;Chang, Hak
    • Archives of Reconstructive Microsurgery
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    • v.16 no.2
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    • pp.53-56
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    • 2007
  • Purpose: Microsurgical exercise has been performed with rat femoral vessels. But, it needs animal laboratory, anesthesia and its keeping facilities. Materials and Methods: Ten human placentas were studied for suitability in a microvascular exercise. The size and useful length of vessels were measured, and various microvascular anastomoses were performed. Result: The human placenta has many vessels traversing its fetal surface. A variety of sizes are available down to vessels of diameter 1 mm and up to vessels of diameter 6.5 mm (1.0

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Comparison of Sensitivity Analysis Methods for Building Energy Simulations in Early Design Phases: Once-at-a-time (OAT) vs. Variance-based Methods

  • Kim, Sean Hay
    • KIEAE Journal
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    • v.16 no.2
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    • pp.17-22
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    • 2016
  • Purpose: Sensitivity analysis offers a good guideline for designing energy conscious buildings, which is fitted to a specific building configuration. Sensitivity analysis is, however, still too expensive to be a part of regular design process. The One-at-a-time (OAT) is the most common and simplest sensitivity analysis method. This study aims to propose a reasonable ground that the OAT can be an alternative method for the variance-based method in some early design scenarios, while the variance-based method is known adequate for dealing with nonlinear response and the effect of interactions between input variables, which are most cases in building energy simulations. Method: A test model representing the early design phase is built in the DOE2 energy simulations. Then sensitivity ranks between the OAT and the Variance-based methods are compared at three U.S. sites. Result: Parameters in the upper rank by the OAT do not much differ from those by the Main effect index. Considering design practices that designers would chose the most energy saving design option first, this rank similarity between two methods seems to be acceptable in the early design phase.