cssi/SciSciGPT-SciSciNet huggingface dataset:
Identification of MIMO transport systems in tape drives

As tape storage aims at cartridge capacities beyond 100 terabytes, advanced control systems for tape transport are key to achieve a larger volumetric recording density. Reliable and ultra-precise tape transport servomechanisms are required to enable tape-drive operation with thinner tape and to support higher areal data densities by minimizing tape-speed variations, tape deformation, and lateral motion effects during tape operation. In this paper, a new identification method is presented for a multiple-input multiple-output (MIMO) tape-transport system for tape drives as the basis for improved control concepts. The characterization of the tape-transport system is obtained in the frequency domain during closed-loop operation of the tape-transport servomechanism. The output system variables are the primary tape velocity and the tape-tension variation, which are estimated from the information obtained by reading pre-formatted servo information, as well as the tape velocities at the supply and take-up reel provided by Hall sensors. Experimental results are presented to illustrate the proposed identification method.
The validity of diagnoses obtained through the psychological autopsy procedure in adolescent suicide victims: use of family history

A test of validity of the psychiatric diagnoses obtained by the psychological autopsy procedure is described in a consecutive series of 67 adolescent suicide victims. Family history of mental illness in first-degree relatives of subjects was obtained blind to subject diagnosis using the family history method. It was hypothesized that subjects with a given diagnosis, compared with subjects without this diagnosis, would show an increased rate of this disorder among first-degree relatives. This hypothesis was supported insofar as specific associations between subject diagnosis and familial rates of illness were demonstrated for major depression, bipolar illness, conduct and antisocial disorder and substance abuse. These results provide further support for the validity of diagnoses obtained through the psychological autopsy procedure.
ColonyTrak: a web tool and database system for managing experimental animal models

Background Genetically modified animal models are useful for understanding mechanisms of human disease and for development of new therapeutics. Maintaining animal colonies and performing genetic experiments requires careful record keeping. Many commercial or publicly available data management tools exist for animal recordkeeping, however they are rather complicated and may require technical expertise to install and maintain [1,2]. Consequently, biologists often use spreadsheets or database tools that are tied to a single computer, which limits accessibility by multiple users at different locations. Here, we have developed a user-friendly tool called ColonyTrak, designed for the biologist, to enable data management from any remote computer using a web browser.
X-ray studies on top component a and bottom component of alfalfa mosaic virus

Abstract Small-angle X-ray-scattering measurements have been made on dilute solutions of two of the separated components of alfalfa mosaic virus. Top component a has an electronic radius of gyration of 129 A and bottom component 216 A. These results are accurate to about 5%. The extended scattering curve is in best agreement with a prolate, roughly cylindrical, shape for each particle. Top component a has a diameter of about 230 A and a length of 350 A. For bottom component the diameter is 220 A and the length 700 A. These results are not as reliable as the radii of gyration. Rather large hydrations are indicated for both particles.
A note on spin-flip electric dipole transitions

A simplified derivation is given of the spin-flip electric dipole transition matrix element to order (α3), which stresses general principles and the atomic charge operator. Relativistic corrections of order (v/c)2 are necessary. The previous result of Drake for helium-like ions is verified.
Recent Work on U.S. Relations with Costa Rica

Kyle Longley. The Sparrow and the Hawk: Costa Rica and the US during the Rise of Jose Figueres Aviva Chomsky. West Indian Workers and the United Fruit Company in Costa Rica, 1870–1920
Molecular level separation of arsenic (V) from water using cationic surfactant micelles and ultrafiltration membrane

Removal of arsenic (V) from water using surfactant micelles and ultrafiltration membrane was investigated using simulated water and stirred cell ultrafiltration unit. The effects of membrane materials (regenerated cellulose and polyethersulfone), membrane nominal molecular weight cut-off (NMWCO, 5 and 10 kDa), feed water arsenic concentration (from 0 to 221 μg/L), and feed water pH (5.5 and 8) on the efficiency of arsenic (V) removal and the permeate flux were studied with and without the surfactant addition. Polyethersulfone (PES) membranes without the surfactant micelles were found to be ineffective for arsenic removal. Regenerated cellulose (RC) membranes provide better removal than PES membranes due to its negatively charged surface at the experimental conditions. However, the arsenic concentration in permeate water (product water) is not reduced to the new maximum contaminant level (MCL) of 10 μg/L. With the addition of 10 mM cationic surfactant cetylpyridinium chloride (CPC) to the feed water, both PES and RC membranes reduce the arsenic concentration in permeate water well below the MCL. The arsenic removal efficiency and absolute permeate flux were found to depend on the membrane materials, membrane NMWCO, and water pH. Highest arsenic removal, 100%, is achieved for the feed water arsenic concentrations of 22 and 43 μg/L using 5 kDa PES membranes at pH of 5.5 and 10 kDa RC at pH of 8. Regardless of the feed water arsenic concentration, 100% arsenic removal is obtained with 5 kDa PES membranes at pH of 8.
Guided circumferential waves in layered cylinders

This paper examines the propagation of time harmonic circumferential waves in a two-dimensional (infinitely long) hollow cylinder with an inner shaft. The boundary condition at the interface (between the inner shaft and the outer cylinder) is assumed as free-sliding; that is, the interfacial shear stresses are assumed to be zero, and the normal stress and radial displacements are continuous. The dispersion relationship is obtained from linear elasticity theory, and numerical results for the dispersion curves of the first several modes are presented. In addition, displacement profiles along the radial directions are provided. These results show that, at higher frequencies, the first mode asymptotically tends to a Rayleigh wave on a flat surface, while the second mode also approaches a Rayleigh wave propagating along the free-sliding interface.
Association of p53 and p21 expression with clinical outcome in patients with carcinoma in situ of the urinary bladder.

Abstract Objectives To determine whether p53 and p21 expression in bladder carcinoma in situ (CIS) with or without papillary disease can predict disease recurrence, progression, and survival. Methods Immunohistochemical staining for p53 and p21 was carried out on paraffin-embedded tumor specimens from 47 and 39 patients, respectively, who had CIS with or without Ta or T1 disease, but without muscle-invasive cancer. Immunoreactivity was categorized as either positive (reactivity in 10% or more CIS cells) or negative. Results Expression of p53 and p21 was positive in 28 (60%) of 47 and 12 (31%) of 39 CIS tumors, respectively. p53 expression was not associated with clinical outcome. Positive p21 expression was associated with bladder cancer recurrence ( P = 0.035) and progression ( P = 0.033) when adjusted for the effects of clinical stage and grade. The combined p53/p21 expression status was independently associated with disease recurrence ( P = 0.022), progression ( P = 0.042), and cancer-specific survival ( P = 0.031). Patients with p53+/p21+ expression were at significantly greater risk of disease recurrence, progression, and mortality than those having a p53+/p21− or p53−/p21− phenotype (not significantly different from each other statistically). Conclusions In CIS without muscle-invasive disease, positive p21 expression was independently associated with bladder cancer recurrence and progression. Positive expression for both p53 and p21 puts patients with bladder CIS at the greatest risk of bladder cancer recurrence, progression, and, most importantly, mortality, suggesting a potential rationale for early definitive therapy in these patients. On the other hand, an intact pathway at the level of p21 seems to abrogate the detrimental effects of altered p53 immunoreactivity on the outcome of bladder CIS.
Large System Resource Allocation in Multicell OFDMA Communication Systems: A Variational Analysis Approach

Resource (power and bandwidth) allocation is an important issue in orthogonal frequency division multiple access (OFDMA) systems. For multi-cell systems, the interference across different cells makes the optimization of resource allocation difficult. Large system analysis is applied for multi-cell OFDMA systems with the fairness constraint of equal grade of service (EGOS). An interference function is defined to model the intercell interference. Variational analysis is used to compute the optimal profile of transmit power and bandwidth. The optimal resource allocation is then computed using numerical simulations.
Inhibited electric-quadrupole transitions in odd-neutron spherical nuclei

A number of inhibited electric-quadrupole transitions have been found in odd-$N$ nuclei, and their lifetimes have been measured. The pairing-plus-quadrupole model predicts a correlation between these lifetimes and the shell-model occupation numbers which can be obtained from pickup and stripping reactions. The correlation observed is about that expected from the accuracy of the data on occupation numbers.
The evolution of terrestrial-type planets.

The present internal state of the earth and the age of various events such as core formation and continental formation can be used to place fairly strong constraints on the early history of the earth and, presumably, the other terrestrial planets. The present internal configuration of the earth shows that it is an extremely differentiated body, and the ages of surface rocks indicate that this differentiation took place early in the history of the earth. The gravitational energy associated with the formation of the earth and the thermal energy of core formation are the primary sources of energy for the melting and subsequent gravitational separation of the earth into a core, a crust, a chemically inhomogeneous mantle, and an atmosphere and hydrosphere. The larger the planet the more likely it is to be extensively differentiated and outgassed. The earth probably accreted in 10^5 years or less. This causes the initial temperatures to be high and results in core formation to be essentially simultaneous with accretion. Mars can be accreted without differentiation and with minor outgassing.
Chemical structure/nonlinear optical property relations for fluorenyl ring system derivatives

We present initial work involving chemical-structure/nonlinear-optical (NLO) property relations for a set of fluorene derivatives. This is achievable using our femtosecond white-light continuum pump-probe nonlinear spectrometer which can rapidly characterized a sample's two-photon absorption spectrum.
Estimating and improving the quality of information in a MIS

Most discussions of MIS's assume that the information in the records is error-free although it is recognized that errors exist. These errors occur because of delays in processing times, lengthy correction times, and, overly or insufficiently stringent data edits. In order to enable the user to implement data edits and correction procedures tailored to the degree of accuracy needed, this paper presents functional relationships between three common measures of data quality. The MIS addressed is one where records in a MIS are updated as changes occur to the record, e.g., a manpower planning MIS where the changes may relate to a serviceman's rank or skills. Since each of the updating transactions may contain an error, the transactions are subjected to various screens before the stored records are changed. Some of the transactions including some that are correct, are rejected; these are reviewed manually and corrected as necessary. In the meantime, the record is out of date and in error. Some of the transactions that were not rejected also lead to errors. The result is that at any given time the MIS record may contain errors.For each of several error control mechanisms, we show how to forecast the level of improvement in the accuracy of the MIS record if these options are implemented.
Mathematical model of prevascular growth of a spherical carcinoma-part II

This paper represents Part II of a study of the prevascular stages of a spherical carcinoma. Recently a mathematical model (Part I) of the prevascular phases of tumor growth was constructed by S.A. Maggelakis and J.A. Adam, [1] in which the effects of non-uniform nutrient consumption and non-uniform inhibitor production on the growth of a spherical carcinoma were investigated. The chemical inhibitor was assumed to be a product of necrosis. In the proposed model, the source of growth inhibitor is assumed to be the metabolic processes of living cells. The evolution of a solid carcinoma is described by an integro-differential equation for the outer tumor radius whose solution depends on the three-dimensional spherically symmetric diffusion equations for the non-uniform nutrient consumption and non-uniform inhibitor production. Successive stages of growth are examined and comparison of the results from the two models is presented.
Oxygen Transport in Aluminum Nitride Substrates

The diffusion of oxygen in commercially available aluminum nitride substrates has been studied by performing interdiffusion-type experiments. The diffusion of oxygen both within AlN grains and along grain boundaries was investigated. By using as-received AlN substrates and an electron microprobe as an analytical tool, it was found that the rate of oxygen diffusion along grain boundaries was strongly influenced by the presence of impurities and/or other phases at these boundaries. The diffusion of oxygen within AlN grains was studied between 1600° and 1900°C in a flowing nitrogen atmosphere by using secondary ion mass spectrometry (SIMS) for determining oxygen concentration profiles. The chemical diffusion coefficient of oxygen in the AlN lattice as a function of temperature is described by the equation The oxygen concentration profiles determined by SIMS also show a contribution from diffusion along grain boundaries. Therefore, it was possible to determine values for the product δD′o (δ= width of grain boundaries, D′o= grain boundary diffusion coefficient of oxygen).
Overlapping-multi-layer deadzone for alleviating over conservativeness in robot adaptive tracking

Abstract We present an overlapping-multi-layer deadzone approach to the adaptive tracking control of robotic manipulators in the presence of an unknown mass matrix and completely unmodeled disturbance torques. Even in the unrealistic case of a known mass matrix, over conservative bounds on the disturbance size lead to an unnecessarily large single-level deadzone and hence an unnecessarily large asymptotic tracking error. Additionally, a single-level deadzone is not assured to prevent the “bursting” phenomenon if the mass matrix is not known. The approach we propose herein is proved to cause convergence of the generalized tracking error to within a user-specified tolerance above the level of the smallest “valid” deadzone size (times a known bound on the square root of the ratio of the largest-possible eigenvalue of the mass matrix to the smallest-possible eigenvalue of the mass matrix), even though this size is not known a priori. The result is that we obtain provable convergence to a tracking error size that is much smaller than we would have with a single-level conservative deadzone. The reason deadzones of sufficient size are needed in the first place is as follows (and this applies even if sigma-modification or e1-modification are used). Even if the mass matrix were unrealistically known, without any deadzone, the following can happen, to the best of our knowledge. We can incur indefinite cycling between (i) and (ii): (i) time periods of Lyapunov function increase, due to a parameter error increase, while the generalized tracking error remains small, (ii) time periods of Lyapunov function decrease due to large reductions in the parameter error while the generalized tracking error simultaneously increases to large peak values before returning back to a small value. With indefinite cycling between (i) and (ii), there is no convergence of the generalized tracking error to small values. This phenomenon has been termed “bursting” by authors such as [P. Ioannou, J. Sun, Robust Adaptive Control, Prentice-Hall, Englewood Cliffs, NJ, 1996.] and is described as “one of the most annoying phenomena in adaptive control.” To the best of our knowledge, this paper, once published, will represent the first presentation of an overlapping-multi-layer deadzone method for adaptive tracking control of robotic manipulators with unknown mass matrix and disturbance torque.
The changing face of adaptive control: The use of multiple models

Abstract Adaptive systems that continuously monitor their own performance and adjust their control strategies to improve it, have been studied for over 50 years. The theory of such systems is now commonly referred to as classical adaptive control. Such control is now well established and is found to be satisfactory when the uncertainty in the system to be controlled (i.e. the plant) is small. During the past 15 years several attempts were made to extend this general methodology to systems with large uncertainties, by using multiple models to identify the plant. Among these, two general methods based on “switching” and “switching and tuning” have emerged as the leading contenders. Recently, a radically different approach was proposed by the authors ( Han & Narendra, 2010b ), in which the multiple models are used to play a significantly larger role in the decision making process, resulting in substantial improvement in performance. In this paper, which is tutorial in nature, the three methods based on multiple models are critically examined. At the same time, alternative methods using fixed and adaptive models are also proposed. In all cases, detailed simulation studies of adaptation in different environments are presented. Theoretical explanations are given, where available, for the wide spectrum of performances observed in the simulation studies.
Evaluation of a frequency-domain algorithm to detect ventricular fibrillation in the surface electrocardiogram

The authors evaluate a frequency-domain algorithm for use by the CREI-GARD computerized arrhythmia system (F.M. Nolle et al. 1986) to detect ventricular fibrillation (VF) in the surface ECG. This was accomplished using: (1) The American Heart Association (AHA) database of 80 ECG tape recordings (channel 1), including 10 recordings with 11 documented VF episodes, and (2) The CREI-GARD database of 35 single-channel recordings of 35 documented VF episodes. The recordings were analyzed using sequential 4.096-s segments. All 46 episodes of VF were correctly identified. The average time between the onset of VF and the first detection was 3 s (range 0 to 9 s). VF episodes occurring in segments in association with ventricular tachycardia (VT) were all correctly identified. There are 19 false VF detections during other episodes of VT out of a total of 684 VT episodes (2.8%). There were five false VF detections during other rhythms. None occurred during artifact. The algorithm is described in detail. >
Patterns and controls of the dynamics of net primary production by understory macroalgal assemblages in giant kelp forests.

Macroalgae are important primary producers in many subtidal habitats, yet little information exists on the temporal and spatial dynamics of net primary production (NPP) by entire subtidal assemblages. This knowledge gap reflects the logistical challenges in measuring NPP of diverse macroalgal assemblages in shallow marine habitats. Here, we couple a simple primary production model with nondestructive estimates of taxon-specific biomass on subtidal reefs off Santa Barbara, California to produce a 4-year time series of net primary production by intact assemblages of understory macroalgae in giant kelp forests off Santa Barbara, California, USA. Daily bottom irradiance varied significantly throughout the year, and algal assemblages were on average exposed to saturating irradiance for only 1.3-4.5 h per day, depending on the time of year. Despite these variable light-limiting conditions, biomass rather than irradiance explained the vast majority of variation observed in daily NPP at all times of the year. Measurements of peak biomass in spring and summer proved to be good predictors of NPP for the entire year, explaining as much as 76% of the observed variation. In contrast, bottom irradiance was a poor predictor of NPP, explaining <10% of the variation in NPP when analyzed seasonally and ~2% when evaluated annually. Our finding that annual NPP by macroalgal assemblages can be predicted from a single, nondestructive measurement of biomass should prove useful for developing time series data that are necessary to evaluate natural and anthropogenic changes in NPP by one of the world's most productive ecosystems.
UTILITY OF SEX, MARITAL STATUS, RACE, AND AGE IN TARGETING POPULATIONS FOR MENTAL HEALTH SERVICES

The relationship between demographic variables and mental health status is reviewed. Utilization of service and severity of symptom are highlighted when possible. Field data based on sex, marital status, race, and age and collected at a southwestern mental health center are presented. By χ2 these variables are contrasted with system entry and diagnosis at entry. Women, white clients, and young adults utilized services with greater frequency and had less severe diagnoses. Results are discussed in terms of national trends and local utilization of the technique.
Pulsed Laser Coating of Hydroxyapatite/Titanium Nanoparticles on Ti-6Al-4V Substrates: Multiphysics Simulation and Experiments

Pulsed laser coating (PLC) of bioceramics/metal nanomaterials on metal substrates was investigated in this research. It is found that due to the nature of the nanosized particles and pulse laser beam, PLC processed hydroxyapatite (HAp) coatings possess strong coating/substrate interfacial bonding strength, and minimum thermal decomposition. Feasibility analysis of PLC is conducted using both simulation and experiments. In the multiphysics simulation, laser interacting with metal nanoparticles and heat conduction is simulated by coupling the electromagnetic (EM) module and heat transfer (HT) module. In experiments, HAp and titanium nanoparticle mixture are coated on Ti-6Al-4V substrate using nanosecond pulsed Nd:YAG laser with wavelength of 1064 nm. Resulting temperature is measured by calibrated infrared (IR) camera and compared with simulation results. Experimental results agree well with simulation which serves as a guidance to find appropriate processing parameters. It is found that resulting temperature increases with increasing of pulse energy linearly and decreasing of pulse duration following the power law. It is recommended that shorter pulses to be used in PLC due to its better sinterability. Microstructure and chemical characterizations confirmed that HAp was physically and chemically maintained due to pulse laser caused rapid heating and cooling processes.
UMI: an interactive supervisory and shared control system for telerobotics

An interactive user interface, UMI (User-Macro-Interface), and its complete task execution system have been developed and implemented for use by an operator to describe, simulate, and execute tasks on a multiarm telerobot. The operator interactively sets up the execution environment and specifies input parameters for a variety of available task primitives. Several task primitives can be stored together as a task sequence for later sequence execution. The primitives or sequences can be executed on a graphics simulator or on the JPL Telerobot, which includes two task execution manipulators, one manipulator used for positioning cameras, and two six-degree-of-freedom force reflecting hand controllers used for shared and teleoperation modes of execution. In supervisory control, the operator sets up a task primitive or a sequence of primitives and executes the task autonomously. In teleoperation, the user specifies desired initialization parameters and controls the arms with the hand controllers. In shared control, teleoperated inputs from the operator hand controllers are merged during task execution with inputs from user parameterized autonomous primitives. In all modes of operation, UMI allows the operator to stop execution at any time. The UMI interface is intended as the operator interface at a local command site to prepare and send commands to a remote space telerobot. >
Alternative Approaches for Solving Real-Options Problems: (Comment on Brandão et al. 2005)

Brandao et al. (2005) describe an approach for using traditional decision analysis tools to solve real-option valuation problems. Their approach calls for a mix of discounted cash flow analysis and risk-neutral valuation methods and is implemented using Monte Carlo simulation and binomial decision trees. In this note, I critique their approach and discuss some alternative approaches for solving these kinds of problems. My criticisms and suggestions concern implementation issues as well as more fundamental issues. On implementation, I discuss the use of binomial lattices instead of trees, and alternative methods for estimating volatilities. More fundamentally, I discuss alternative approaches that rely entirely on risk-neutral valuation and model the uncertainties in the problem more directly.
Calculations of chemical shieldings: Theory and applications

This article presents a discussion of the origin of the chemical shieldings, which is followed by a rigorous derivation of quantum mechanical formula for their exact calculation and a discussion of the necessary approximations that make these calculations feasible. Comprehensive information on the resources, software and hardware needed for the calculations is given followed by several examples of actual quantum chemical calculations of chemical shieldings. These examples are used to demonstrate how accurate shielding calculations can be used to help the NMR practitioner to solve practical chemical and structural problems. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 20A: 42–69, 2004.
Profitable Solutions to Climate, Oil, and Proliferation

Protecting the climate is not costly but profitable (even if avoided climate change is worth zero), mainly because saving fuel costs less than buying fuel. The two biggest opportunities, both sufficiently fast, are oil and electricity. The US, for example, can eliminate its oil use by the 2040s at an average cost of $15 per barrel (2000$), half by redoubled efficiency and half by alternative supplies, and can save three-fourths of its electricity more cheaply than operating a thermal power station. Integrative design permits this by making big energy savings cheaper than small ones, turning traditionally assumed diminishing returns into empirically observed expanding returns. Such efficiency choices accelerate climate-safe, inexhaustible, and resilient energy supply—notably the “micropower” now delivering about a sixth of the world’s electricity and 90% of its new electricity. These cheap, fast, market-financeable, globally applicable options offer the most effective, yet most underestimated and overlooked, solutions for climate, proliferation, and poverty.
The influence of thyroxine on the normal development of the pancreas in Rana pipiens larvae

Comparative studies were made of the exocrine pancreas in normal, thyroidectomized, and thyroxine treated Rana pipiens tadpoles during various stages of development. The weight of the pancreas as milligram per cent body weight (mg% B.W.) is greatly reduced during both artificially induced and natural metamorphosis. During natural metamorphosis the reduction in mg% B.W. of the pancreas begins in the early larval stages and continues in a consistently decreasing pattern through the final stages with the maximum reduction (69%) occurring by the mid-larval stages (XVI-XX). In thyroxine treated tadpoles, reduction in mg% B.W. of the pancreas is directly proportional to hormone concentration and the relative weight of the gland is significantly less than that observed in any of the controls of equivalent limb stages even though the absolute weight of the gland has increased over that of the earliest stages (I–V). The pancreas of the thyroidectomized tadpoles showed no significant difference in mg% B. W. when compared to that of a normal control of equivalent limb stage range. Histological investigation of the pancreas revealed no evidence of widespread cellular necrosis of the exocrine elements. Some acinus disorganization, typified by large spaces in the connective tissues and a syncytial nature of the acinar cell cytoplasm, can be seen in the later stages. A discussion of the possible role of thyroid hormone in the normal development of the pancreas is presented. It is concluded that reduction in the mg% B.W. of the pancreas is a naturally occurring phenomenon during metamorphosis resulting from intestinal evacuation and water loss. The water loss may be influenced and regulated indirectly by thyroxine through an effect on cellular and subcellular membrane permeability.
Role of intersystem crossing in the fluorescence quenching of 2-aminopurine 2′-deoxyriboside in solution

2-Aminopurine is a fluorescent probe widely used to study local dynamics as well as charge and energy transfer reactions in DNA/RNA. Despite its broad utilization, the nonradiative relaxation pathways responsible for the variation in its fluorescence quantum yield and fluorescence lifetime in different solvents are still under scrutiny. In this work we use steady-state absorption and emission spectroscopy and broad-band transient absorption covering the time scale from femtoseconds to microseconds to investigate the excited-state dynamics of 2-aminopurine 2′-deoxyriboside (2APdr) in acetonitrile, ethanol, and aqueous buffer solution at pH 7. It is shown that up to ∼40% of the initial excited-state population decays by intersystem crossing to the triplet state depending on the solvent used, thus competing effectively with fluorescence emission. Furthermore, the rate of formation and yield of the triplet state depend sensitively on the hydrogen-donor ability and polarity of the solvent.
Geometric hitting sets and their variants

This thesis explores a few geometric optimization problems that arise in robotics and sensor networks. In particular we present efficient algorithms for the hitting-set problem and the budgeted hitting-set problem. Given a set of objects and a collection of subsets of the objects, called ranges, the hitting-set problem asks for a minimum number of objects that intersect all the subsets in the collection. In geometric settings, objects are typically a set of points and ranges are defined by a set of geometric regions (e.g., disks or polygons), i.e., the subset of points lying in each region forms a range. The first result of this thesis is an efficient algorithm for an instance of the hitting-set problem in which both the set of points and the set of ranges are implicitly defined. Namely, we are given a convex polygonal robot and a set of convex polygonal obstacles, and we wish to find a small number of congruent copies of the robot that intersect all the obstacles. Next, motivated by the application of sensor placement in sensor networks, we study the so-called “art-gallery” problem. Given a polygonal environment, we wish to place the minimum number of guards so that the every point in the environment is visible from at least one guard. This problem can be formulated as a hitting-set problem. We present a sampling based algorithm for this problem and study various extensions of this problem. Next, we study the geometric hitting-set problem in a dynamic setting, where the objects and/or the ranges change with time and the goal is to maintain a hitting set. We present algorithms which maintain a small size hitting set with sub-linear update time. Finally, we consider the budgeted hitting-set problem, in which we are asked to choose a bounded number of objects that intersect as many ranges as possible. Motivated by applications in network vulnerability analysis we study this problem in a probabilistic setting.
Doppler Sonography in Pregnancies Complicated with Pregestational Diabetes Mellitus

Antepartum fetal surveillance constitutes an essential component of the standards of care in managing pregnancies complicated with pregestational diabetes mellitus. Fetal hyperglycemia is associated with increased oxidative metabolism, hypoxemia, and increased brain and renal perfusion without any significant changes in fetoplacental perfusion. Moreover, the relationship between abnormal umbilical arterial Doppler indices and the quality of glycemic control remains unproven; however, observational studies suggest significant diagnostic efficacy of the umbilical arterial Doppler method in diabetic pregnancies complicated with FGR or hypertension. Although there are no randomized trials specifically addressing this issue, existing evidence suggests that Doppler velocimetry of the umbilical artery may be beneficial for antepartum fetal surveillance in diabetic pregnancies in the presence of these complications. Such utilization should be integrated with the existing standards of practice.
Cystic and Fibrocystic Disease of the Long Bones

University of Minnesota Masters thesis. June 1918. Major: Surgery. 1 computer file (PDF); 25 pages.
Tensor MUSIC in multidimensional sparse arrays

Tensor-based MUSIC algorithms have been successfully applied to parameter estimation in array processing. In this paper, we apply these for sparse arrays, such as nested arrays and coprime arrays, which are known to boost the degrees of freedom to O(N2) given O(N) sensors. We consider two tensor decomposition methods: CANDECOMP/PARAFAC (CP) and high-order singular value decomposition (HOSVD) to derive novel tensor MUSIC spectra for sparse arrays. It will be demonstrated that the tensor MUSIC spectrum via HOSVD suffers from cross-term issues while the tensor MUSIC spectrum via CP identifies sources unambiguously, even in high- dimensional tensors.1
Nonparametric Inference in Factorial Designs with Censored Data

A method is proposed for testing the hypotheses of no main effects and no interaction in factorial designs with several observations per cell. The method uses the fact that these hypotheses can be expressed in terms of a vector of contrasts. It is based on the observation that nonparametric estimation of these contrasts is no more difficult than estimation of the location difference in the two-sample problem. To implement the method with censored data, a new extension of the Hodges-Lehmann estimator is proposed. The estimator is simple to compute and its variance is easily evaluated. A simulation study examines the performance of the proposed estimation and testing method in the context of a two-by-two design, and a real data set from a three-way layout with heavy censoring is analyzed.
Synthesis of Existing BIM Maturity Toolsets to Evaluate Building Owners

As designers and contractors become more advanced users, facility owners have also begun to make significant strides toward adopting Building Information Modeling (BIM) within their organizations. In fact, many larger owner organizations are now contractually requiring BIM on their construction projects. However, operationalizing the technology during the Operations and Maintenance (O&M) phase is a consistent hurdle that many owners have been unable to overcome thus far. The improvement of building owners’ BIM competency is critical to reaping the full benefits of BIM over the building life cycle. Therefore, this research aims to identify what key characteristics building owner organizations must possess to become mature BIM users. An in depth analysis of the existing BIM maturity assessment tools was conducted to make comparisons between the different variables measured. Suggestions are made for adding variables that have not yet been considered in the evaluation of building owner BIM competency and which may also be important.
WIND TUNNEL TEST AND RESPONSE ANALYSIS OF HIGH-VOLTAGE TRANSMISSION TOWER SUBJECTED TO COMBINED LOADS OF WIND AND RAIN

This paper introduces the derivation of rain load, the design of aeroelastic model of high-voltage transmission tower and wind tunnel test. Based on the existing production, an improved rain load formula is derived from a different idea and that the facade and rear of tower are considered to be impinged by droplets, and then programming is conducted to obtain the time history curves of wind-rain loads. According to the similarity criterion, the aeroelastic model for wind tunnel test is established, and the frequency of the aeroelastic model is measured and compared with the expected frequency which proves that the aeroelastic model is accurate. According to the rain load pressure calculation formula, the scale ratios of wind-rain loads for wind tunnel test are derived; the validation of theoretical calculation is performed through the wind tunnel test and the result proves that the theoretical calculation is feasible and effective.
Difficult patients: their construction in group therapy.

Written from the perspective of intersubjective theory, this article addresses how the leader and group members co-construct the difficult patient. Too often, therapists and patients have tended to attribute difficulties in therapy groups to "the difficult patient" without appreciating how they themselves contribute to the construction, the needs this construction serves, and the potential value of such patients to the group. Mistakes in group leadership, vicissitudes of intersubjectivity, disturbing intrapsychic defenses, and whole-group dynamics interact to produce the difficult patient. Also discussed is the group member who is difficult but who no longer meets the criteria for patienthood. By exploring the factors involved in the co-construction of the difficult patient, the authors hope to guide clinicians in the deconstruction of such impediments, thus allowing the difficult patient to become "just another group patient."
Adapting evidence-based behavioral weight loss programs for emerging adults: A pilot randomized controlled trial:

Emerging adults are at high risk of obesity but behavioral weight loss programs do not meet their needs. Emerging adults (N = 52, age = 22.3 ± 2 years, body mass index = 34.2 ± 5.5 kg/m2, 46.2% non...
Perihepatic, Pulmonary, and Renal Abscesses Due to Spilled Gallstones.

Abstract Background Spilled gallstones are common during laparoscopic cholecystectomy; however, they rarely lead to postoperative complications. Perihepatic abscesses develop in Case Report We present a 57-year-old man with history of cholecystectomy 2 years prior who presented with cough and flank pain and was discovered to have a perihepatic abscess invading his lung and kidney secondary to a spilled gallstone. Why Should Emergency Physicians Be Aware of This? Although most perihepatic abscesses can be treated with percutaneous drainage and antibiotics, abscesses secondary to spilled gallstones usually require open or laparoscopic surgery to drain the abscess and retrieve the gallstone. Prompt identification of spilled gallstones in patients with intra-abdominal and intrathoracic abscesses can thereby guide disposition and decrease morbidity and mortality.
Experimentally benchmarked fiber propagation model for 50Gbps PAM-4 MMF links employing multimode VCSELs

MMF propagation of multimode VCSEL signals with preferential coupling of VCSEL modes into fiber modes and colored noise is modeled and benchmarked using 50Gbps PAM-4 and 25Gbps PAM-2 experimental results at 850nm and 940nm.
Impact of Need-Based Financial Aid on Student Persistence at Public Institutions: An Application of the Regression-Discontinuity Design

We take advantage of a unique program design to estimate the effect of financial aid on first-to-second year persistence. In Tennessee, need-based financial aid is given to eligible students on a first-come, first-served basis, based on when the student files the Free Application for Federal Student Aid. Using a regression-discontinuity design, we compare the persistence among eligible students who received need-based aid in the first and second years of college with eligible students who failed to to apply before the undisclosed cutoff date in the second year. Students at the University of Tennessee who retained their financial aid were 9.5 percentage points more likely to persist than students who lost their financial aid.
Autonomy, Authority, and Observability: Properties of Advanced Automation and their Impact on Human-Machine Coordination

Abstract In a variety of domains, problems with human-machine coordination are a matter of considerable concern. These problems are the result of a mismatch between human information processing strategies and the communication skills of automated systems. Results of recent empirical research on pilot interaction with advanced cockpit automation on the Airbus A-320 illustrate how problems with man-machine coordination are changing in nature in response to the ongoing evolution of modern systems from passive tools to active yet ‘silent’ agents. The highly autonomous and powerful nature of modern technology in combination with low system observability fails to support operators’ expectation-driven approach to monitoring.
Spatial spillover and the socio-ecological determinants of diabetes-related mortality across US counties

Abstract The spatial structure of diabetes-related mortality in US counties is evident from previous studies. However, it is not clear if spatial variation in diabetes-related mortality is associated with spatial variation in socioecological factors. We analyze the spatial spillover effect of changes in socioeconomic gradients (education, employment, household income), retail food environments, and access to health care, on diabetes-related mortality rates across the United States. Seven-year aggregates of multiple cause mortality data from the CDC WONDER compressed mortality database were merged with several sources of county-level data to examine mortality clusters, factors associated with the clusters, and spatial spillover effects in 3109 continuous US counties. The results suggest that high diabetes-related mortality cluster counties are located throughout the Southern Plains, Southeastern, and Appalachian regions. Lower socioeconomic status, a high density of fast food restaurants, a lack of access to grocery stores, a high proportion of Blacks, and low physical activity characterize high diabetes-related mortality rates clusters. The impacts from improvements in socioeconomic gradients and the retail food environment in neighboring counties spill over, and reduce the diabetes-related mortality rate in a particular county. This result implies that improvements in socioeconomic status and access to healthy food would significantly reduce diabetes-related mortality rates in contiguous US counties.
La política de inmigración en España: reflexiones sobre la emergencia del discurso de la diferencia cultural

En este articulo se analiza como, desde los espacios institucionalizados de poder, se conciben y problematizan la inmigracion, el asentamiento y la integracion de la poblacion extranjera no-comunitaria en Espana. En particular, se examina como se construyen los argumentos de diferenciacion y amenaza, haciendo especial hincapie en la categorizacion de "los otros culturales". Usando el caso espanol, analizamos como, desde el marco europeo, la politica de inmigracion utiliza un "discurso dominante y privilegiado" que organiza y clasifica los significados acerca de la inmigracion, los inmigrantes y los problemas que estos provocan. Concluimos reflexionando sobre el poder que en estos procesos de diferenciacion ejercen estos discursos y las politicas publicas al crear, reproducir y proyectar una serie de demarcaciones simbolicas que obstaculizan, en gran medida, la integracion de los "otros-extranjeros" entre "nosotros-los espanoles". Abstract This article analyzes how the immigration, settlement, and integration of Spain's nonCommunity foreign population is conceptualized and questioned in the institutionalized spaces of power. It specifically examines the construction of arguments of differentiation and threat, with special emphasis on the categorization of "the cultural other." Using the Spanish case, we analyze how immigration policy within the European framework utilizes a dominant and privileged discourse that organizes and classifies the meanings of migration, immigrants, and the issues they raise. We conclude by reflecting on the power these discourses and policies exert through these differentiation processes as they create, reproduce, and project a series of symbolic demarcations that largely impede the integration of the "foreign-others" and "us-the Spaniards."
Direct measurements of gas/particle partitioning and mass accommodation coefficients in environmental chambers

Secondary organic aerosols (SOA) are a major contributor to fine particulate mass and wield substantial influences on the Earth’s climate and human health. Despite extensive research in recent years, many of the fundamental processes of SOA formation and evolution remain poorly understood. Most atmospheric aerosol models use gas/particle equilibrium partitioning theory as a default treatment of gas-aerosol transfer, despite questions about potentially large kinetic effects. We have conducted fundamental SOA formation experiments in a Teflon environmental chamber using a novel method. A simple chemical system produces a very fast burst of low-volatility gas-phase products, which are competitively taken up by liquid organic seed particles and Teflon chamber walls. Clear changes in the species time evolution with differing amounts of seed allow us to quantify the particle uptake processes. We reproduce gas- and aerosol-phase observations using a kinetic box model, from which we quantify the aerosol mass acco...
Modeling Oil Shale Pyrolysis: High-Temperature Unimolecular Decomposition Pathways for Thiophene

The thermal decomposition mechanism of thiophene has been investigated both experimentally and theoretically. Thermal decomposition experiments were done using a 1 mm × 3 cm pulsed silicon carbide microtubular reactor, C4H4S + Δ → Products. Unlike previous studies these experiments were able to identify the initial thiophene decomposition products. Thiophene was entrained in either Ar, Ne, or He carrier gas, passed through a heated (300–1700 K) SiC microtubular reactor (roughly ≤100 μs residence time), and exited into a vacuum chamber. The resultant molecular beam was probed by photoionization mass spectroscopy and IR spectroscopy. The pyrolysis mechanisms of thiophene were also investigated with the CBS-QB3 method using UB3LYP/6-311++G(2d,p) optimized geometries. In particular, these electronic structure methods were used to explore pathways for the formation of elemental sulfur as well as for the formation of H2S and 1,3-butadiyne. Thiophene was found to undergo unimolecular decomposition by five pathwa...