• Title/Summary/Keyword: Cycle life prediction

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Vibration Characterization of Cross-ply Laminates Beam with Fatigue Damage (피로 손상을 입은 직교 복합재료 적충보의 진동 특성)

  • 문태철;김형윤;황운봉;전시문;김동원;김현진
    • Composites Research
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    • v.14 no.3
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    • pp.1-9
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    • 2001
  • A new non-destructive fatigue prediction model of the composite laminates is developed. The natural frequencies of fatigue-damaged laminates under extensional loading are related to the fatigue life of the laminates by establishing the equivalent flexural stiffness reduction as a function of the elastic properties of sublaminates. The flexural stiffness is derived by relating the 90-ply elastic modulus reduction, and using the laminate plate theory to the degraded elastic modulus and the intact elastic modulus of other laminates. The natural frequency reduction model, in which the dominant fatigue mode can be identified from the sensitivity scale factors of sublaminate elastic properties, provides natural frequency vs. fatigue cycle curves for the composite laminates. Vibration tests were also conducted on $[{90}_2/0_2]_s$ carbon/epoxy laminates to verify the natural frequency reduction model. Correlations between the predictions of the model and experimental results are good.

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Predicting Movie Success based on Machine Learning Using Twitter (트위터를 이용한 기계학습 기반의 영화흥행 예측)

  • Yim, Junyeob;Hwang, Byung-Yeon
    • KIPS Transactions on Software and Data Engineering
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    • v.3 no.7
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    • pp.263-270
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    • 2014
  • This paper suggests a method for predicting a box-office success of the film. Lately, as the growth of the film industry, a variety of studies for the prediction of market demand is being performed. The product life cycle of film is relatively short cultural goods. Therefore, in order to produce stable profits, marketing costs before opening as well as the number of screen after opening need a plan. To fulfill this plan, the demand for the product and the calculation of economic profit scale should be preceded. The cases of existing researches, as a variable for predicting, primarily use the factors of competition of the market or the properties of the film. However, the proportion of the potential audiences who purchase the goods is relatively insufficient. Therefore, in this paper, in order to consider people's perception of a movie, Twitter was utilized as one of the survey samples. The existing variables and the information extracted from Twitter are defined as off-line and on-line element, and applied those two elements in machine learning by combining. Through the experiment, the proposed predictive techniques are validated, and the results of the experiment predicted the chance of successful film with about 95% of accuracy.

Prediction and Prevention of Ovarian Hyperstimulation Syndrome (난소과자극증후군의 예측과 예방)

  • Kim, Hye-Ok;Kang, Inn-Soo
    • Clinical and Experimental Reproductive Medicine
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    • v.37 no.4
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    • pp.293-305
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    • 2010
  • Ovarian hyperstimulation syndrome (OHSS) is a life-threatening iatrogenic complication of ovulation induction. Before ovarian stimulation, identification of patients vulnerable to developing OHSS is necessary. And ovarian stimulation should be started with low doses of gonadotropin or GnRH antagonist protocol. During monitoring of ovarian stimulation with risk of OHSS, coasting, low doses hCG and GnRH agonist for triggering ovulation are considered. If severe OHSS is predicted, cycle cancellation and cryopreservation of all embryos should be considered to reduce late-onset OHSS and morbidity. And metformin and dopamine agonist for reducing OHSS are being proposed as a prophylactic treatment for OHSS.

Collapse Probability of a Low-rise Piloti-type Building Considering Domestic Seismic Hazard (국내 지진재해도를 고려한 저층 필로티 건물의 붕괴 확률)

  • Kim, Dae-Hwan;Kim, Taewan;Chu, Yurim
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.7_spc
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    • pp.485-494
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    • 2016
  • The risk-based assessment, also called time-based assessment of structure is usually performed to provide seismic risk evaluation of a target structure for its entire life-cycle, e.g. 50 years. The prediction of collapse probability is the estimator in the risk-based assessment. While the risk-based assessment is the key in the performance-based earthquake engineering, its application is very limited because this evaluation method is very expensive in terms of simulation and computational efforts. So the evaluation database for many archetype structures usually serve as representative of the specific system. However, there is no such an assessment performed for building stocks in Korea. Consequently, the performance objective of current building code, KBC is not clear at least in a quantitative way. This shortcoming gives an unresolved issue to insurance industry, socio-economic impact, seismic safety policy in national and local governments. In this study, we evaluate the comprehensive seismic performance of an low-rise residential buildings with discontinuous structural walls, so called piloti-type structure which is commonly found in low-rise domestic building stocks. The collapse probability is obtained using the risk integral of a conditioned collapse capacity function and regression of current hazard curve. Based on this approach it is expected to provide a robust tool to seismic safety policy as well as seismic risk analysis such as Probable Maximum Loss (PML) commonly used in the insurance industry.

Development of the Maintenance System for Gate Bridge (배수갑문 노후도 감시시스템 구축연구)

  • Kim, Kwan-Ho;Cho, Young-Kweon;Kim, Myeong-Won
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1025-1028
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    • 2008
  • Using of maintenance system for gate bridge algorism, We made out algorism and engine for prediction of life cycle by neutralization, freezing-thawing and damage from sea wind. To objective of this system, user can use easily with maintenance system for gate bridge. Also, to improve of maintenance efficiency, web-program made out by superannuated evaluation and analysis of field exposure data. To develope web-program, we framing structure design of database, which is adapted to method of maintenance, repair, and reinforcing

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An Improved Calibration Method for the COCOMO II Post-Architecture Model

  • Yoon, Myoung-Young
    • Journal of Korea Society of Industrial Information Systems
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    • v.5 no.2
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    • pp.47-55
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    • 2000
  • To date many software engineering cost models have been developed to predict cost, schedule, and effort of the software under development. The COCOMO Ⅱ is well- suited for the new software development life cycle such as non-sequential and rapid- development processes. The traditional regression approach based on the least square criterion is the most commonly used technique for empirical calibration in the COCOMO Ⅱ model. It has a few assumptions frequently violated by software engineering data sets. The source data is also generally imprecise in reporting size effort, and cost-driver ratings, particularly across different organizations. And that the outlier for the source data is a peculiarity and indicates a data point. To cope with difficulties, in this paper, we propose a new regression method for calibrating COCOMO Ⅱ post-architecture model based on the minimum relative error(MRE) criterion. The characteristic of the proposed method is insensitive to the extreme values of the data in the empirical calibration. As the experimental results, It is evident that our proposed calibration method MRE was shown to be superior to the traditional regression approach for model calibration, as illustrated by the values obtained for standard deviation(^σ), and prediction at level LPRED(L) measures.

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Development of a Rule-based BIM Tool Supporting Free-form Building Integrated Photovoltaic Design (비정형 건물일체형 태양광 발전 시스템 규칙기반 BIM설계 지원 도구 개발)

  • Hong, Sung-Moon;Kim, Dae-Sung;Kim, Min-Cheol;Kim, Ju-Hyung
    • Journal of KIBIM
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    • v.5 no.4
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    • pp.53-62
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    • 2015
  • Korea has been at the forefront of green growth initiatives. In 2008, the government declared the new vision toward 'low-carbon society and green growth'. The government subsidies and Feed-in Tariff (FIT) increased domestic usage of solar power by supplying photovoltaic housing and photovoltaic generation systems. Since 2000, solar power industry has been the world's fastest growing source with the annual growth rate of 52.5%. Especially, BIPV(Building Integrated Photovoltaic) systems are capturing a growing portion of the renewable energy market due to several reasons. BIPV consists of photovoltaic cells and modules integrated into the building envelope such as a roof or facades. By avoiding the cost of conventional materials, the incremental cost of photovoltaics is reduced and its life-cycle cost is improved. When it comes to atypical building, numerous problems occur because PV modules are flat, stationary, and have its orientation determined by building surface. However, previous studies mainly focused on improving installations of solar PV technologies on ground and rooftop photovoltaic array and developing prediction model to estimate the amount of produced electricity. Consequently, this paper discusses the problem during a planning and design stage of BIPV systems and suggests the method to select optimal design of the systems by applying the national strategy and economic policies. Furthermore, the paper aims to develop BIM tool based on the engineering knowledge from experts in order for non-specialists to design photovoltaic generation systems easily.

A Study on the Probabilistic Vulnerability Assessment of COTS O/S based I&C System (상용 OS기반 제어시스템 확률론적 취약점 평가 방안 연구)

  • Euom, Ieck-Chae
    • Journal of Convergence for Information Technology
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    • v.9 no.8
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    • pp.35-44
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    • 2019
  • The purpose of this study is to find out quantitative vulnerability assessment about COTS(Commercial Off The Shelf) O/S based I&C System. This paper analyzed vulnerability's lifecycle and it's impact. this paper is to develop a quantitative assessment of overall cyber security risks and vulnerabilities I&C System by studying the vulnerability analysis and prediction method. The probabilistic vulnerability assessment method proposed in this study suggests a modeling method that enables setting priority of patches, threshold setting of vulnerable size, and attack path in a commercial OS-based measurement control system that is difficult to patch an immediate vulnerability.

Inventory Estimation of 36Cl and 41Ca in Concrete of Kori Unit 1 (고리 1호기의 콘크리트 내 36Cl 및 41Ca의 방사화재고량 평가)

  • Jang, Mee;Lim, Jong Myoung;Kim, Hyun Chul;Kim, Chang-Jong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.1
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    • pp.121-126
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    • 2019
  • The radionuclide inventory prediction of a nuclear power plant can help establish decommissioning plan by providing information of radiation environment. Accumulated radionuclides in reactors and related facilities after reactor shutdown can be divided into neutron activated materials and contaminated materials. Among the neutron activated radionuclides, $^{36}Cl$ and $^{41}Ca$ are important from the viewpoint of disposal because of its long half-life and physiochemical characteristics. In this research, we calculated the radionuclides of $^{36}Cl$ and $^{41}Ca$ in bioshielding concrete by estimating the neutron flux and cross section using the MCNPX. And we evaluated the inventories of $^{36}Cl$ and $^{41}Ca$ using the activation calculation code ORIGEN2.

A Study on Yin Yang, Wuxing, Mutual Collision, and Zangfu Combination of the Ten Heavenly Stems (십간(十干)의 음양(陰陽), 오행(五行), 상충(相沖), 장부배합(臟腑配合)에 관(關)한 연구)

  • Yoo, Young-Joon;Yun, Chang-Yeol
    • Journal of Korean Medical classics
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    • v.32 no.2
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    • pp.17-31
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    • 2019
  • Objectives : Understanding the Ten Stems and Twelve Branches is necessary to grasp the laws of change in Heaven and Earth. Methods : Based on relevant contents in East Asian classics, the Yin Yang, Sibling Wuxing, Husband-Wife Wuxing combinations as well as Mutual Collision and Zangfu combination were examined. Results & Conclusion : Yin Yang combination of the Ten Stems are divided according to odd/evenness. The Sibling Wuxing combination is categorized according to one life cycle of vegetation, resulting in Jia Yi Wood, Bing Ding Fire, Wu Ji Earth, Geng Xin Metal, Ren Gui Water. The Husband-Wife Wuxing combination of the Ten Stems are Jia Ji Earth, Yi Geng Metal, Bing Xin Water, Ding Ren Wood, Wu Gui Fire, which corresponds to the principles of the Duihuazuoyong Theory. Within the Husband-Wife Wuxing combination lies three principles which are Yin Yang combination, Mutual Restraining combination, and the Yang Stem restraining the Yin Stem. The Mutual Collision of the Ten Stems are Jia and Geng, Yi and Xin, Ren and Bing, Gui and Ding against each other. In matching Zangfu to the Ten Stems, Jia matches with Gallbladder, Yi matches with Liver; Bing matches with Small Intestine, Ding matches with Heart; Wu matches with Stomach, Ji matches with Spleen; Geng matches with Large Intestine, Xin matches with Lung; Ren matches with Bladder, Gui matches with Kidney. : When the adjacent vectors are extracted, the count-based word embedding method derives the main herbs that are frequently used in conjunction with each other. On the other hand, in the prediction-based word embedding method, the synonyms of the herbs were derived.