Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2019

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 2221 - 2250 of 26982

Full-Text Articles in Entire DC Network

Selective Discrete Particle Swarm Optimization For The Team Orienteering Problem With Time Windows And Partial Scores, Vincent F. Yu, Perwira A. A. N. Redi, Parida Jewpanya, Aldy Gunawan Dec 2019

Selective Discrete Particle Swarm Optimization For The Team Orienteering Problem With Time Windows And Partial Scores, Vincent F. Yu, Perwira A. A. N. Redi, Parida Jewpanya, Aldy Gunawan

Research Collection School Of Computing and Information Systems

This paper introduces the Team Orienteering Problem with Time Windows and Partial Scores (TOPTW-PS),which is an extension of the Team Orienteering Problem with Time Windows (TOPTW). In the context of theTOPTW-PS, each node is associated with a set of scores with respect to a set of attributes. The objective ofTOPTW-PS is to find a set of routes that maximizes the total score collected from a subset of attributes whenvisiting the nodes subject to the time budget and the time window at each visited node. We develop a mathematical model and propose a discrete version of the Particle Swarm Optimization (PSO), …


Study Group Travel Behaviour Patterns From Large-Scale Smart Card Data, Xiancai Tian, Baihua Zheng Dec 2019

Study Group Travel Behaviour Patterns From Large-Scale Smart Card Data, Xiancai Tian, Baihua Zheng

Research Collection School Of Computing and Information Systems

In this paper, we aim at studying the group travel behaviour (GTB) patterns from large-scale auto fare collection (AFC) data. GTB is defined as two or more commuters intentionally and regularly traveling together from an origin to a destination. We propose a method to identify GTB accurately and efficiently and apply our method to the Singapore AFC dataset to reveal the GTB patterns of Singapore commuters. The case study proves that our method is able to identify GTB patterns more accurately and efficiently than the state-of-the-art.


Compositional Verification Of Heap-Manipulating Programs Through Property-Guided Learning, Long H. Pham, Jun Sun, Quang Loc Le Dec 2019

Compositional Verification Of Heap-Manipulating Programs Through Property-Guided Learning, Long H. Pham, Jun Sun, Quang Loc Le

Research Collection School Of Computing and Information Systems

Analyzing and verifying heap-manipulating programs automatically is challenging. A key for fighting the complexity is to develop compositional methods. For instance, many existing verifiers for heap-manipulating programs require user-provided specification for each function in the program in order to decompose the verification problem. The requirement, however, often hinders the users from applying such tools. To overcome the issue, we propose to automatically learn heap-related program invariants in a property-guided way for each function call. The invariants are learned based on the memory graphs observed during test execution and improved through memory graph mutation. We implemented a prototype of our approach …


Optimal Design And Ownership Structures Of Innovative Retail Payment Systems, Zhiling Guo, Dan Ma Dec 2019

Optimal Design And Ownership Structures Of Innovative Retail Payment Systems, Zhiling Guo, Dan Ma

Research Collection School Of Computing and Information Systems

In response to the Fintech trend, an ongoing debate in the banking industry is how to design the new-generation interbank retail payment and settlement system. We propose a two-stage analytical model that takes into account the value-risk tradeoff in the new payment system design, as well as banks’ participation incentives and adoption timing decisions. We find that, as the system base value increases, banks tend to synchronize their investment and adoption decisions. When the system base value is low and banks are heterogeneous, bank association ownership maximizes social welfare. When both the system base value and bank heterogeneity are moderate, …


Smu Teaching Bank: Case Study Of A Multiyear Development Project Utilizing Student Resources, Alan Megargel, Terence P. C. Fan, Venky Shankararaman Dec 2019

Smu Teaching Bank: Case Study Of A Multiyear Development Project Utilizing Student Resources, Alan Megargel, Terence P. C. Fan, Venky Shankararaman

Research Collection School Of Computing and Information Systems

A domain refers to a business sector such as banking, healthcare, insurance, manufacturing etc. For an IS student, it is imperative that the domain knowledge includes a comprehension and understanding of business processes, technology and data related to the chosen domain. For example, when learning the retail banking domain, an IS student must have an understanding of the transactions concerned with retail banking such as fund transfers and loan repayments. The student must also gain a strong foothold in transaction fulfilment processes, the various application services that are used, the data that is transferred, etc. Teaching domain knowledge is very …


Treecaps: Tree-Structured Capsule Networks For Program Source Code Processing, Vinoj Jayasundara, Duy Quoc Nghi Bui, Lingxiao Jiang, David Lo Dec 2019

Treecaps: Tree-Structured Capsule Networks For Program Source Code Processing, Vinoj Jayasundara, Duy Quoc Nghi Bui, Lingxiao Jiang, David Lo

Research Collection School Of Computing and Information Systems

Program comprehension is a fundamental task in software development and maintenance processes. Software developers often need to understand a large amount of existing code before they can develop new features or fix bugs in existing programs. Being able to process programming language code automatically and provide summaries of code functionality accurately can significantly help developers to reduce time spent in code navigation and understanding, and thus increase productivity. Different from natural language articles, source code in programming languages often follows rigid syntactical structures and there can exist dependencies among code elements that are located far away from each other through …


Harmony Search Algorithm For Time-Dependent Vehicle Routing Problem With Time Windows, Yun-Chia Liang, Vanny Minanda, Aldy Gunawan, Angela Hsiang-Ling Chen Dec 2019

Harmony Search Algorithm For Time-Dependent Vehicle Routing Problem With Time Windows, Yun-Chia Liang, Vanny Minanda, Aldy Gunawan, Angela Hsiang-Ling Chen

Research Collection School Of Computing and Information Systems

Vehicle Routing Problem (VRP) is a combinatorial problem where a certain set of nodes must be visited within a certain amount of time as well as the vehicle’s capacity. There are numerous variants of VRP such as VRP with time windows, where each node has opening and closing time, therefore, the visiting time must be during that interval. Another variant takes time-dependent constraint into account. This variant fits real-world scenarios, where at different period of time, the speed on the road varies depending on the traffic congestion. In this study, three objectives – total traveling time, total traveling distance, and …


Digitalization In Practice: The Fifth Discipline Advantage, Siu Loon Hoe Dec 2019

Digitalization In Practice: The Fifth Discipline Advantage, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

Purpose The purpose of this paper is to provide advice to organizations on how to become successful in the digital age. The paper revisits Peter Senge's (1990) notion of the learning organization and discusses the relevance of systems thinking and the other four disciplines, namely, personal mastery, mental models, shared vision and team learning in the context of the current digitalization megatrend. Design/methodology/approach This paper is based on content analysis of essays from international organizations, strategy experts and management scholars, and insights gained from the author's consulting experience. A comparative case study from the health and social sector is also …


Implementing Security-Enhanced Phr System In The Cloud Using Fame, Zuobin Ying, Wenjie Jiang, Ximeng Liu, Shengmin Xu Dec 2019

Implementing Security-Enhanced Phr System In The Cloud Using Fame, Zuobin Ying, Wenjie Jiang, Ximeng Liu, Shengmin Xu

Research Collection School Of Computing and Information Systems

Personal Health Record (PHR) plays an important role in realizing the exchange and interaction of medical information as well as in managing chronic diseases. In the recent decade, plenty of researches have been carried out to resolve the secure sharing issue of PHR in the cloud via access control schemes. Attribute-based Encryption (ABE) is a promising technique, which implements access control by introducing the access policy. When ABE is used to construct access control scheme in the cloud, hiding and updating access policy have always been two research hotspots. However, all of the existing solutions only consider one of these …


Book Reviews Fall 2019 Dec 2019

Book Reviews Fall 2019

New Mexico Historical Review

No abstract provided.


The Books Of Padre Antonio José Martínez, La Dec 2019

The Books Of Padre Antonio José Martínez, La

New Mexico Historical Review

No abstract provided.


Strongly Secure Authenticated Key Exchange From Supersingular Isogenies, Xiu Xu, Haiyang Xue, Kunpeng Wang, Ho Man Au, Song Tian Dec 2019

Strongly Secure Authenticated Key Exchange From Supersingular Isogenies, Xiu Xu, Haiyang Xue, Kunpeng Wang, Ho Man Au, Song Tian

Research Collection School Of Computing and Information Systems

This paper aims to address the open problem, namely, to find new techniques to design and prove security of supersingular isogeny-based authenticated key exchange (AKE) protocols against the widest possible adversarial attacks, raised by Galbraith in 2018. Concretely, we present two AKEs based on a double-key PKE in the supersingular isogeny setting secure in the sense of CK+, one of the strongest security models for AKE. Our contributions are summarised as follows. Firstly, we propose a strong OW-CPA secure PKE, 2PKEsidh, based on SI-DDH assumption. By applying modified Fujisaki-Okamoto transformation, we obtain a [OW-CCA, OW-CPA] secure KEM, 2KEMsidh. Secondly, we …


Impact Of Nonlinear Chemical Reaction And Melting Heat Transfer On An Mhd Nanofluid Flow Over A Thin Needle In Porous Media, Muhammad Ramzan, Hina Gul, Seifedine Kadry, Chhayly Lim, Yunyoung Nam, Fares Howari Dec 2019

Impact Of Nonlinear Chemical Reaction And Melting Heat Transfer On An Mhd Nanofluid Flow Over A Thin Needle In Porous Media, Muhammad Ramzan, Hina Gul, Seifedine Kadry, Chhayly Lim, Yunyoung Nam, Fares Howari

All Works

© 2019 by the authors. A novel mathematical model is envisioned discussing the magnetohydrodynamics (MHD) steady incompressible nanofluid flow with uniform free stream velocity over a thin needle in a permeable media. The flow analysis is performed in attendance of melting heat transfer with nonlinear chemical reaction. The novel model is examined at the surface with the slip boundary condition. The compatible transformations are affianced to attain the dimensionless equations system. Illustrations depicting the impact of distinct parameters versus all involved profiles are supported by requisite deliberations. It is perceived that the melting heat parameter has a declining effect on …


New Foundation In The Sciences: Physics Without Sweeping Infinities Under The Rug, Florentin Smarandache, Victor Christianto, Robert Neil Boyd Dec 2019

New Foundation In The Sciences: Physics Without Sweeping Infinities Under The Rug, Florentin Smarandache, Victor Christianto, Robert Neil Boyd

Branch Mathematics and Statistics Faculty and Staff Publications

It is widely known among the Frontiers of physics, that “sweeping under the rug” practice has been quite the norm rather than exception. In other words, the leading paradigms have strong tendency to be hailed as the only game in town. For example, renormalization group theory was hailed as cure in order to solve infinity problem in QED theory. For instance, a quote from Richard Feynman goes as follows: “What the three Nobel Prize winners did, in the words of Feynman, was "to get rid of the infinities in the calculations. The infinities are still there, but now they can …


Automatic Mesh Representation Of Urban Environments, Babatunde Atolagbe Dec 2019

Automatic Mesh Representation Of Urban Environments, Babatunde Atolagbe

Masters Theses and Doctoral Dissertations

A robust watertight mesh generation framework for urban cityscape and waterscape is proposed. The framework, consisting of a set of algorithms implemented in MATLAB, uses geospatial data available from OpenStreetMap and United States Geological Survey repositories, and incorporates Triangle - a popular two-dimensional Delaunay triangulation software - to develop the mesh. For the cityscape component, the facades of the buildings are meshed as structured triangular grids while the roofs and terrains are meshed as unstructured triangular grids using Triangle. For the waterscape component, quadrilateral cells are created based on the requirements of Environmental Fluids Dynamics Code (EFDC) model – a …


Differential Gene Expression In Tendinopathy: Insights Into The Failure Of Wound Healing, Michael Maggio Dec 2019

Differential Gene Expression In Tendinopathy: Insights Into The Failure Of Wound Healing, Michael Maggio

All Theses

Tendon injury can occur from activity-induced overuse, complete laceration or aging-related degeneration and these injuries commonly fail to wound heal without clinical treatment. Moreover, activity-induced overuse accounts for approximately half of all sports injuries and has highest occurrence rates in athletes playing football, baseball and basketball. Current non invasive technique to rest and ice the damaged tissue in combination with either oral NSAIDS or corticosteroid injections has shown little promise with only ~60% of cases regaining functionality of the tendon (Paterno et al., 2013).

From the literature, this seems to be caused by a combination of poorly perfused tissue along …


Evaluating The Effects Of Sodium, Potassium, Magnesium, And Calcium Concentrations On Dolomite Stoichiometry, Cation Ordering, And Reaction Rate, Hanna F. Cohen Dec 2019

Evaluating The Effects Of Sodium, Potassium, Magnesium, And Calcium Concentrations On Dolomite Stoichiometry, Cation Ordering, And Reaction Rate, Hanna F. Cohen

Masters Theses

Numerous environmental factors affect dolomitization. Shallow peritidal and restricted marine environments, for example, are often associated with more abundant and more stoichiometric dolomite than deeper marine environments. Higher fluid Mg/Ca ratios resulting from gypsum precipitation are often invoked to explain this observation, even when evidence of evaporites is absent. In this study, high-temperature dolomitization experiments show that the concentrations of major cation concentrations (Na, K, Mg, and Ca) impact dolomite stoichiometry and reaction rate. Nearly 200 batch dolomitization experiments were run whereby 100 mg of natural aragonite ooids were dolomitized at 215°C in ionic solutions. Fluid [NaCl] and [KCl] correlate …


Effects Of The Dihydrouracil Lesion On Dna Using 1h/31p 1d And 2d Solution Nmr, Benjamin M. Boyd Dec 2019

Effects Of The Dihydrouracil Lesion On Dna Using 1h/31p 1d And 2d Solution Nmr, Benjamin M. Boyd

Graduate Theses/Dissertations

The effects of the dihydrouracil lesion in DNA were studied using two dimensional NMR spectroscopy. The sequence used was based off of the Drew-Dickerson Dodecamer, with the cytosine in the three position replaced by a dihydrouracil. All of the nonexchangeable proton chemical shifts, with the exception of the H2, H5’, and H5’’, of the lesioned DNA were identified using NOESY spectra and then compared to the chemical shift values of the Drew Dickerson Dodecamer. The largest differences in chemical shifts were observed in the nucleotides neighboring the lesion, both within the strand and on the opposite strand. The imino exchangeable …


Towards The Synthesis Of An Artificial Fluorescent Siderophore, Ashley Burns Dec 2019

Towards The Synthesis Of An Artificial Fluorescent Siderophore, Ashley Burns

Honors Theses

Siderophores are molecules capable of binding ferric ions with high affinity (Ka = 1052). This thesis outlines our attempts to synthesize an artificial siderophore, which incorporates a signaling group to help monitor the uptake of ferric ions. The artificial siderophore is a tripodal molecular receptor synthesized in a five-step procedure with a proposed final sixth step. Rhodamine 6G azide (95.0% yield) was formed from rhodamine 6G and the synthesis of 2-azidoethanamine was modified from the literature. The tripodal arm portion of the sensor was successfully synthesized by protecting the catechol of 2,3-dihydroxybenzaldehyde to form 3-formyl-1,2-phenylene dimethanesulfonate (98.8% yield). The reduction …


Topological Magnetoelectric Effect As Probed By Nanoshell Plasmonic Modes, Railing Chang, Huai Yi Xie, Ya-Chih Wang, Hai-Pang Chiang, P.T. Leung Dec 2019

Topological Magnetoelectric Effect As Probed By Nanoshell Plasmonic Modes, Railing Chang, Huai Yi Xie, Ya-Chih Wang, Hai-Pang Chiang, P.T. Leung

Physics Faculty Publications and Presentations

Axion electrodynamics is applied to study the response of a plasmonic nanoshell with a core made of topological insulator (TI) materials. The electric polarizability of such a system is calculated in the long wavelength limit via the introduction of two scalar potentials satisfying the various appropriate boundary conditions. Our focus is on the topological magneto-electric effect (TME) as manifested in the coupled plasmonic resonances of the nanoshell. It is found that for a TI with broken time-reversal symmetry, such TME will lead to observable red-shifts in the coupled plasmonic modes, with more significant manifestation of such shifts for the bonding …


Comparison And Design Optimization Of A Five-Phase Flux-Switching Pm Machine For In-Wheel Traction Applications, Hao Chen, Xiangdong Liu, Nabeel Demerdash, Ayman M. El-Refaie, Jing Zhao, Jiangbiao He Dec 2019

Comparison And Design Optimization Of A Five-Phase Flux-Switching Pm Machine For In-Wheel Traction Applications, Hao Chen, Xiangdong Liu, Nabeel Demerdash, Ayman M. El-Refaie, Jing Zhao, Jiangbiao He

Electrical and Computer Engineering Faculty Research and Publications

A comparative study of five-phase outer-rotor flux-switching permanent magnet (FSPM) machines with different topologies for in-wheel traction applications is presented in this paper. Those topologies include double-layer winding, single-layer winding, C-core, and E-core configurations. The electromagnetic performance in the low-speed region, the flux-weakening capability in the high-speed region, and the fault-tolerance capability are all investigated in detail. The results indicate that the E-core FSPM machine has performance advantages. Furthermore, two kinds of E-core FSPM machines with different stator and rotor pole combinations are optimized, respectively. In order to reduce the computational burden during the large-scale optimization process, a mathematical technique …


Study Of Amorphous Boron Carbide And Hydrogenated Boron Carbide Materials Using Molecular Dynamics And Hybrid Reverse Monte Carlo, Rajan Khadka Dec 2019

Study Of Amorphous Boron Carbide And Hydrogenated Boron Carbide Materials Using Molecular Dynamics And Hybrid Reverse Monte Carlo, Rajan Khadka

Graduate Theses/Dissertations

We present a computational study of amorphous boron carbide (a-BxC) models using Molecular Dynamics (MD) studied with Stillinger-Weber (SW) and ReaxFF potential. The atomic structure factor (S(Q)), radial distribution function (RDF) and bond lengths comparison with other experimental and ab initio models shows that a random arrangement of icosahedra (B12, B11C) interconnected by chains (CCC, CBC) are present in a-BxC. Afterward, Hybrid Reverse Monte Carlo (HRMC) technique is used to recreate a-BxC structures. The existing SW potential parameters of Boron are optimized for the α-rhombohedral (Icosahedral B12 …


Seasonal Time Series Models With Application To Weather And Lake Level Data, Mengqing Qin Dec 2019

Seasonal Time Series Models With Application To Weather And Lake Level Data, Mengqing Qin

Graduate Theses/Dissertations

This work studies seasonal time series models with application to lake level and weather data. The thesis includes related time series concepts, integrated autoregressive moving average models (abbreviated as ARIMA), parameter estimation, model diagnostics, and forecasting. The studied time series models are applied to the data of daily lake level in Beaver Lake (1988-2017) and the data of daily maximum temperature in New York Central Park (1870-2017). Due to seasonality of the data, three different approaches are proposed to the modeling: regression method, functional ARIMA method and multiplicative seasonal ARIMA method. The forecasted values of the year 2018 are compared …


Monongahela River, Wv Channel Catfish Population Assessment, Kristen Lee Chestnut-Faull Dec 2019

Monongahela River, Wv Channel Catfish Population Assessment, Kristen Lee Chestnut-Faull

Graduate Theses/Dissertations

Channel Catfish Ictalurus punctatus populations have been evaluated using many sampling gears in rivers. However, a consensus has not been reached on which gear or gears produce the most reliable population demographics. Specifically, this study compares population demographics of Channel Catfish throughout the Monongahela River, WV using multiple gear types. Fish were sampled seasonally during 2018 using baited hoop nets, low- frequency electrofishing, and trotlines. Firstly, too few fish were collected using electrofishing and were excluded from all analyses. In terms of relative abundance, fish sampled with hoop nets had higher catch rates (mean SCPUE = 5.8, SE = 0.4) …


Quantifying The Effectiveness Of Cedar Revetment In Mitigating Bank Erosion In Riceford Creek, Minnesota, Talia A. Klein Dec 2019

Quantifying The Effectiveness Of Cedar Revetment In Mitigating Bank Erosion In Riceford Creek, Minnesota, Talia A. Klein

Graduate Theses/Dissertations

Southeastern Minnesota has incised streams that are susceptible to bank erosion. Previously, efforts have been made to identify sections of Riceford Creek that have high erosion susceptibility using the Bank Erosion Hazard Index (BEHI). Locally harvested cedars were then used as a revetment strategy to mitigate erosion of the stream banks prioritized by the BEHI analysis. This study aims to 1) determine if cedar revetment effectively mitigates bank erosion in Riceford Creek and 2) determine if the BEHI method is an effective way of quantifying erosion hazard in Riceford Creek. This study focuses on two sections in Riceford Creek where …


Student Discourse And Problem Solving In A High School Mathematics Classroom, Natalie J. Chism Dec 2019

Student Discourse And Problem Solving In A High School Mathematics Classroom, Natalie J. Chism

Graduate Theses/Dissertations

The purpose of this study was to explore the problem-solving process and discourse in three high school Algebra 2 classes and analyze how discourse might be used to facilitate the problem-solving process. High school Algebra 2 students in this study were asked to engage in discourse with their peers in order to reach conclusions in open-ended problem-solving tasks. The teacher acted as the facilitator and encouraged students to act as the mathematical authorities. On two different days, students were given two different real-life problem-solving tasks and asked to reach possible conclusions to those tasks. Three research questions guided the study: …


Electronic Word-Of-Mouth (Ewom): Examining The Relationship Between Factors Influencing Ewom Activities And Passengers’ Purchasing Involvement In The Context Of Aviation, Ratchada Ruenruoy Dec 2019

Electronic Word-Of-Mouth (Ewom): Examining The Relationship Between Factors Influencing Ewom Activities And Passengers’ Purchasing Involvement In The Context Of Aviation, Ratchada Ruenruoy

Theses and Dissertations

The purpose of the study was manifold: (a) to examine the relationship a set of targeted factors has on electronic Word-of-Mouth (eWOM) activities in the context of aviation, (b) to examine the extent to which these factors affect airline passengers’ purchasing involvement, and (c) to determine the extent to which eWOM activities mediate the relationship between the targeted factors and purchasing involvement. Research factors included (a) purchasing perceptions, which consisted of satisfaction, loyalty, perceived value, and service quality; (b) social environment, which consisted of age, gender, and cultural differences relative to Hofstede’s (1980) cultural dimensions; and (c) experiences, which consisted …


Effect Of Multiple Operant Training Across Similar And Different Response Topographies, Ashley Anna Felde Dec 2019

Effect Of Multiple Operant Training Across Similar And Different Response Topographies, Ashley Anna Felde

Theses and Dissertations

This study compared skill acquisition rates during multiple operants training across similar responses and different responses in children with Autism Spectrum Disorder (ASD). Secondary measures included functional independence of verbal operants and children’s teaching condition preference. Discrete-trial instruction was used during both teaching conditions. An adapted alternating treatment design embedded in a nonconcurrent multiple baseline across participants was used to examine rates of skill acquisition. Results showed that two of the three participants acquired skills in fewer sessions during the multiple operants training across similar responses when compared to multiple operant training across different responses. Two of the three participants …


Investigating The Effects Of Altitude And Flap Setting On The Specific Excess Power Of A Pa-28-161 Piper Warrior, Tjimon Meric Louisy Dec 2019

Investigating The Effects Of Altitude And Flap Setting On The Specific Excess Power Of A Pa-28-161 Piper Warrior, Tjimon Meric Louisy

Theses and Dissertations

The high number of General Aviation (GA) accidents attributed to Loss of Control suggests that GA pilots are lacking low speed awareness and are unable to appropriately recognize when the aircraft is in a low energy state. There is, therefore, an urgent need for the development of an energy management system which is applicable to GA aircraft that can alert the pilot in situations of low energy conditions and recommends to the pilot the appropriate corrective action to restore conditions to a safe energy state. This will require the development of an algorithm that governs this energy management system that …


Development Of A Novel System For The Analysis Of The Cardiovascular And Autonomic Nervous Systems, Seyedmohsen Dehghanojamahalleh Dec 2019

Development Of A Novel System For The Analysis Of The Cardiovascular And Autonomic Nervous Systems, Seyedmohsen Dehghanojamahalleh

Theses and Dissertations

Chapter 1 - An introduction to autonomic nervous system (ANS) and cardiovascular system (CVS): The performance of the ANS can be evaluated by quantizing the changes made by the autonomic nervous system. The most common parameters that are being used in autonomic nervous system assessment tests are blood pressure, heart rate, pressure pulse wave velocity, heart rate variability, and pulse waveform. In this dissertation, we designed and developed a system that assesses the activity of these two systems. Therefore, we represented four methods to 1- evaluate the dependence of neuro- and cardiovascular systems on sex, 2- non-invasively estimate the blood …