Prediction-observer Scheme for Linear Systems with Input-output Time-delay

Varinia Fragoso-Rubio,Martín Velasco-Villa,Miguel A. Hernández-Pérez,Basilio del Muro-Cuéllar,Juan Francisco Márquez-Rubio 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8

This work deals with the prediction and control problems associated with a class of linear systems with time-delay at the input-output path. A general prediction observer scheme that estimates the future value of the delayed system from the output is proposed. Later, a full-information predictor-observer is introduced and the convergence of the estimated future values is formally proven for a time-delay τ of any size by increasing the dimension of the proposed predictor-observer. The estimated future state is used to design a feedback law that compensates the delay effects on the original system. The performance of the prediction-observation control strategy is shown by means of numerical simulations. Thus, it is illustrated that the performance of the proposed full-information predictor-observer is improved with respect to the sequential sub-predictors previously presented in the literature.

Centre-to-limb properties of small, photospheric quiet-Sun jets

Rubio da Costa, F.,Solanki, S. K.,Danilovic, S.,Hizberger, J.,Martí,nez-Pillet, V. Springer-Verlag 2015 Astronomy and astrophysics Vol.574 No.-

Performance-based Analysis of Code-base Designed Structures in the Philippines

Rubio. Christabel Jane P,Tabong. Kristoffer Dave A.,Lucio. Mark Elson C.,Jeong. Sangman 한국방재학회 2017 한국방재학회논문집 Vol.17 No.3

본 연구에서는 비선형등가정적해석법(nonlinear static pushover analysis)을 사용하여 지진 발생시 예측 가능한 성능 요건을 충족시키는 코드 기반 설계 구조의 기능을 조사하였다. 이는 SAP2000을 사용하여 Makati Science High School (MSHS)건물의 골조 구조를 개발함으로써 수행되었다. 이후, Applied Technology Council (ATC)에서 제공된 콘크리트 건물의 내진평가 및 보강에 대한 코드인 ATC-40 조항에 따라 비선형등가정적해석법이 수행되었다. 이 분석을 통해 pushover curve를 얻었으며, 이 그래프는 모든 분석단계에서 구조물의 변위에 따른 소성힌지의 위치 및 상태를 나타낸 것이다. 필리핀의 대부분 학교건물은 일반적으로 대피소로 사용되기 때문에 Immediate Occupancy(IO)성능기준을 만족하기 위해 ATC-40에서 제공된 허용 기준과 pushover curve를 비교하였다. 비교결과 분석을 통해, MSHS 건물은 지진발생시 비상대피소로의 기능을 수행할 수 있는 것으로 평가되었다. 본 연구는 코드기반으로 설계된 건물의 변수와 IO 성능기준의 관계를 이해하는데 기여할 수 있다. 또한, 비선형등가정 적해석절차를 이용하여 지진발생시 MSHS 건물에 미치는 손상 결과를 예측할 수 있다. The ability of code-base designed structures to meet predictable performance requirement in an event of an earthquake was investigated in this study using nonlinear static pushover analysis. This was performed by developing the structural framework of Manila Science High School (MSHS) building using SAP2000. Subsequently, a nonlinear static pushover analysis according to the provisions of ATC-40, a code provided by the Applied Technology Council (ATC) on Seismic Evaluation and Retrofit of Concrete Buildings was performed. The analysis generated a pushover curve, a graph that displays the total drift of the structure versus base shear and the possible location and condition of the plastic hinges at every step of the analysis. Results were compared with the acceptable criteria provided by ATC-40 for Immediate Occupancy (IO) performance level since most school buildings in the Philippines are commonly used as evacuation centers. By analyzing the results, it was found out that the MSHS building will behave at Immediate Occupancy after an earthquake event. This study can contribute in verifying if the parameters used in code-base designed structures satisfy the requirements for IO performance level. Also, this study can estimate the possible post-earthquake damage effects on the MSHS building by using the nonlinear static analysis procedure.

Spatial and temporal dynamics of in vitro photodynamic cell killing: extracellular hydrogen peroxide mediates neighbouring cell death

Rubio, Noemi,Fleury, Sean P.,Redmond, Robert W. Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.4

Photodynamic killing of a cell population is generally considered to result from direct effects that occur in each cell. In some scenarios this may be an over-simplification and the potential for cell-cell signaling processes to contribute to the response of a population to photodynamic stress is addressed in this paper. Photodynamic killing of EMT6 cells in culture was studied in time and space using computerized time-lapse microscopy. The rate of cell killing was dependent on the fluence with both rapid and slower processes evident, the proportion of the former increasing with fluence. The spatial distribution of cell death was non-random and for the slow cell killing process was found to occur preferentially in the vicinity of dead or dying cells, suggesting a local signaling process. An inhibitory effect of extracellular catalase indicated the involvement of hydrogen peroxide in the spread of cell death and NADPH oxidase was determined as the principal source of hydrogen peroxide. This cell signaling pathway was observed for membrane-bound and mitochondrial photosensitizers but not for a nuclear photosensitizer. These secondary cell signalling pathways extend the oxidative damage to cells in space and time.

마닐라 광역시 물공급 이슈(Issues) 진단

Rubio, Christabel Jane,김이형,정상만 한국습지학회 2008 한국습지학회지 Vol.10 No.3

The Philippine government enacted the National Water Crisis Act in 1995, as a response to the burgeoning situation of water supply systems in the country. This act led to the privatization of Metropolitan Waterworks and Sewerage System (MWSS), sector having jurisdiction and control over all waterworks and sewerage systems in a service area including Metro Manila. Nowadays, the region's supply of water is still facing a lot of difficulties, both in quality and quantity. The unabated migration of people to the metro which increases its population, tapping from the aged pipelines, lack of water facilities and infrastructure, excessive groundwater withdrawal, environmental degradation, and surface and groundwater pollution are some of the issues that Metro Manila have to deal with. These situations lead to two primary water supply issues suffered by Metro Manila: water shortage and flooding. The purpose of this paper was to present water supply in Metro Manila with respect to the problems in its distribution, environmental implications and quality. In this paper, several technical reports, published literature, and news articles were consulted and became the major basis for identifying gaps and suggesting remedial measures.

An Investigation of the Adequacy of Urban Evacuation Centers Using Index-based Flood Risk Assessment

RUBIO CHRISTABEL JANE,유인상,김하룡,김상단,정상만 한국방재학회 2019 한국방재학회논문집 Vol.19 No.2

With frequent intense flood events in recent years, reliable flood risk assessment has become a critical component of flood mitigation. This research aims to assess the adequacy of pre-determined evacuation centers using a multi-criteria flood risk map that considers urban-specific indicators such as physical, social, economic, and environmental criteria. The analytical hierarchy process (AHP) was used as the multi-criteria decision technique for calculating the weight of each criterion. These criteria weights were used to spatially map the flood risk index using an overlay function in a geographic information system (GIS), with the flood risk index divided into seven categories ranging from very low risk to very high risk. Then, 202 pre-determined evacuation centers from the Disaster Response Operations Monitoring and Information Center (DROMIC) were plotted on the developed flood risk map. Very high risk areas were found mostly in the City of Manila. This could be attributed to its very high exposure index values. The highest number of evacuation centers were found at Valenzuela where flood risk ranges from moderately low risk to moderate high risk. Only two evacuation centers were declared within Quezon City where flood risk ranges from very low risk to moderately high risk. Remarkably, there were no declared evacuation centers in Pasig and Pateros. The approach in this study is merely one of several flood risk assessment applications. Results from this study can assist the government agencies responsible in assessing the sufficiency and reliability of pre-determined evacuation centers.

Effect of laser shock peening and cold expansion on fatigue performance of open hole samples

Rubio-Gonzalez, Carlos,Gomez-Rosas, G.,Ruiz, R.,Nait, M.,Amrouche, A. Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5

Mechanical fastening is still one of the main methods used for joining components. Different techniques have been applied to reduce the effect of stress concentration of notches like fastener holes. In this work we evaluate the feasibility of combining laser shock peening (LSP) and cold expansion to improve fatigue crack initiation and propagation of open hole specimens made of 6061-T6 aluminum alloy. LSP is a new and competitive technique for strengthening metals, and like cold expansion, induces a compressive residual stress field that improves fatigue, wear and corrosion resistance. For LSP treatment, a Q-switched Nd:YAG laser with infrared radiation was used. Residual stress distribution as a function of depth was determined by the contour method. Compact tension specimens with a hole at the notch tip were subjected to LSP process and cold expansion and then tested under cyclic loading with R=0.1 generating fatigue cracks on the hole surface. Fatigue crack initiation and growth is analyzed and associated with the residual stress distribution generated by both treatments. It is observed that both methods are complementary; cold expansion increases fatigue crack initiation life, while LSP reduces fatigue crack growth rate.

Pilot Early Warning System of the University of Santo Tomas

Rubio.Christabel Jane P,Poblete.Shikara,Jose.Malcolm L.,Ban. Jeevan Kumar 한국방재학회 2016 Journal of Disaster Management Vol.1 No.3

During typhoon season, the University of the Santo Tomas (UST) and its outlying areas are the most susceptible to floods in Manila. In line with this, a model was developed in order to generate a more realistic flood simulation. Storm Water Management Model (SWMM) was utilized for the hydrologic modeling of surface run-off. A flood forecasting and early warning system was developed for UST which is located at España Boulevard, Sampaloc, Manila to aid the Thomasian community in times of rainfall events. This study aimed to determine the flood volume within and surrounding the university, to generate inundation reports for 5yr, 15yr, 25yr and 50yr return periods, and to plan a framework for the sensor and broadcasting device integrating the resulting critical amount of rainfall. The data processing was divided into two sequence: accumulate hydrologic data and plot study area input. Accumulation of hydrologic data includes gathering of rainfall data and drainage properties while plot of study area is the actual modelling of the study area in SWMM. Lead time and critical amount of rainfall needed were obtained after a successful simulation of the model. The resulting initial flood occurrence and flood volumes were applied in the proposal of a flood warning system for the University of Santo Tomas. After the simulation and data analysis, the lead time and critical amount of rainfall attained in this study using SWMM, presented advantageous outcomes to predict flooding in the UST. Moreover, the resulted values were suitable for integration on a web-based flood warning system.

Onset of Kuppers-Lortz-like dynamics in finite rotating thermal convection

Rubio, A.,Lopez, J.M.,Marques, F. CAMBRIDGE UNIVERSITY PRESS 2010 Journal of fluid mechanics Vol.644 No.-

필리핀의 수자원 평가

Rubio, Christabel Jane,이주헌,정상만 한국습지학회 2008 한국습지학회지 Vol.10 No.3

This paper sought to provide information regarding the water resources in the Philippines, focusing on the issues of water quality, status of water use and water scarcity, and other threats to water availability. Although the country has sufficient amount of water resources, it was found out that water availability is still threatened by some major water resources problems: increasing water demand due to drastic growth in population, water resources pollution, droughts and flooding and weak institutional framework to address these problems. Water quality problems include increasing groundwater and surface water pollution. Moreover, drought and flooding have also increased damages in recent years due to deteriorating watersheds and high economic and population growth. In relation to these, the government enacted national laws to define and deal with water control and quality management. The objective of this research was to present and evaluate current conditions and issues on Philippine water resources.