Papers by christopher king
Proceedings of the 7th International Conference on Informatics in Control, Automation and Robotics, 2010
A precursor to social interaction is social understanding. Every day, humans observe each other a... more A precursor to social interaction is social understanding. Every day, humans observe each other and on the basis of their observations "read people's minds," correctly inferring the goals and intentions of others. Moreover, this ability is regarded not as remarkable, but as entirely ordinary and effortless. If we hope to build robots that are similarly capable of successfully interacting with people in a social setting, we must endow our robots with an ability to understand humans' intentions. In this paper, we propose a system aimed at developing those abilities in a way that exploits both an understanding of actions and the context within which those actions occur.
Letters in Mathematical Physics, Mar 1, 1997
We study the classical motion of an atom in the vicinity of an infinite straight wire which carri... more We study the classical motion of an atom in the vicinity of an infinite straight wire which carries an oscillating uniform charge. This system has been proposed as a mechanism for trapping cold neutral atoms. The parameters of the problem are the magnitude Q and frequency of oscillation ! of the charge, the mass M and polarizability of the atom, and the angular momentum L of the atom about the wire. For ! 6 = 0 and 2M Q 2 greater than, but close to, L 2 , we prove that the atom's radial motion is periodic (with period 2= !), and that the atom moves in a helical path around the wire. For 2M Q 2 6 L 2 we prove that the atom must either collide with the wire or else escape to infinity in the radial direction.
Contemporary Issues in Behavior Therapy, 1996
Substance abuse is one of the most prevalent health care problems in the United States, accountin... more Substance abuse is one of the most prevalent health care problems in the United States, accounting for a staggering toll on society and the afflicted individual’s physical and emotional well-being (Schilit & Gomberg, 1991). For older adults, in particular, abuse of alcohol and other drugs is a significant and burgeoning problem (Brody, 1982; Parette, Hourcade, & Parette, 1990; Ruben, 1992; Zimberg, 1987). Indeed, epidemiological research conducted over the past several years reveals that alcohol and substance abuse rank third among leading psychiatric problems in Americans 55 years and older, accounting for approximately 10 to 12% of those who receive services from mental health professionals (see Ticehurst, 1990; Zimberg, 1974). Several estimates of problem drinking or alcoholism in older adults have yielded prevalence rates in the general community of between 2 and 10% (cf. Fredriksen, 1992; Gomberg, 1982; Shuckit, 1977), and these most likely are underestimates. Prevalence estimates are even higher in certain settings, such as medical wards and nursing homes (Horton & Fogelman, 1991). Nevertheless, these data suggest that there are between 1 and 3 million older heavy alcohol users in the United States who suffer deleterious medical, emotional, and legal consequences. Further, these sequelae have an untoward impact at the societal level (e.g., high economic losses, increased health care costs, diminished work productivity) as well (Morey & Martin, 1989; Parette et al., 1990). Unfortunately, only 15% of alcoholics in this age group appear to receive some form of mental health treatment (King, Altpeter, & Spada, 1986; National Council on Alcoholism, 1981).
Systems & Control Letters, 2013
Pediatric Emergency Care, 2013
Background: Preliminary evidence suggests that a single prehospital lactate level (pLA) improves ... more Background: Preliminary evidence suggests that a single prehospital lactate level (pLA) improves prediction of morbidity and mortality in adult trauma patients independent of vital signs. However, the value of pLA for pediatric trauma patients is unknown. Our objective was to determine whether pLA is associated with the need for critical care in pediatric trauma patients. Methods: We conducted a cohort study of 217 patients transported by helicopter to a level I pediatric trauma center over 24 months. The primary outcome was the need for predefined critical care measures. Covariates included vital signs and Glasgow Coma Scale (GCS) scores documented by prehospital providers. Results: Forty-one subjects required critical care. Abnormal prehospital vital signs were not associated with need for critical care. Overall, median pLA level for patients who required critical care was 2.1 mmol/L (interquartile range [IQR], 1.6Y2.7 mmol/L) versus 1.7 mmol/L (IQR, 1.2Y2.2 mmol/L) for those who did not (P = 0.01). In addition, there were 85 subjects who had normal vital signs and a normal GCS during transport. Of these, 11 (13%) required critical care. In the subset of patients with normal prehospital vital signs and GCS, median pLA level for patients who required critical care was 2.6 mmol/L (IQR, 1.8Y2.6 mmol/L) versus 1.7 mmol/L (IQR, 1Y2.1 mmol/L) for those who did not (P = 0.01). Conclusions: Prehospital lactate level was higher in pediatric trauma patients who required critical care, including those who had normal prehospital vital signs and GCS. In this cohort, lactate was an early identifier of children with severe traumatic injuries.
Optics Express, 2010
We present a novel method to accurately measure 3D polishing influence functions by using a swing... more We present a novel method to accurately measure 3D polishing influence functions by using a swing arm profilometer (SAP) and a laser tracker. The laser tracker is used to align the SAP and measure the parameters of the SAP setup before measuring the influence function. The instruments and the measurement method are described, together with measurement uncertainty analysis. An influence function deliberately produced with asymmetric form in order to create a challenging test is measured, and compared with that of a commercial 3D profilometer. The SAP result is 48.2µm in PV, 7.271mm 3 in volume. The 3D profilometer result is 48.4µm in PV, 7.289mm 3 in volume. The forms of the two results show excellent correlation. This gives confidence of the viability of the SAP method for larger influence functions out of range of the commercial instrument.
Linear Algebra and its Applications, 2009
The original version of this paper appeared in Linear Algebra and its Applications, volume 430, p... more The original version of this paper appeared in Linear Algebra and its Applications, volume 430, pp.34-40, 2009. Here we correct a slight gap in the statement and proof of Lemma 3.1 in that paper. We revisit the theorem of Barker, Berman and Plemmons on the existence of a diagonal quadratic Lyapunov function for a stable linear time-invariant (LTI) dynamical system [1]. We use recently derived results to provide an alternative proof of this result and to derive extensions.
Letters in Mathematical Physics, 1992
We compute the scattering operator for a simplified model of an atom interacting a with a quantiz... more We compute the scattering operator for a simplified model of an atom interacting a with a quantized field. The field is restricted to the vacuum and one-particle sectors, and the atom has only two states. We also solve the inverse scattering problem for the same model. The methods used rely on the particular form of the interaction, which is chosen to mimic the interaction between radiation and matter.
The Journal of Urology, 2014
INTRODUCTION AND OBJECTIVES: The impact of percutaneous nephrostolithotomy (PCNL) on renal functi... more INTRODUCTION AND OBJECTIVES: The impact of percutaneous nephrostolithotomy (PCNL) on renal function has long been a concern especially in the setting of multi-tract access. Previous studies have demonstrated minimal renal injury with PCNL when using serum creatinine and GFR as markers. Tc99m-MAG3 nuclear renography is a superior marker of renal function and may better elucidate injury. We hypothesize that multi-tract PCNL could negatively affect renal function as compared to single-access PCNL. METHODS: We performed a retrospective review of 307 consecutive patients undergoing PCNL from 2011-2012 at Wake Forest Baptist Health. A comparison of single and multi-access ( 2) PCNL was undertaken using Tc99m-MAG3 nuclear renogram parameters in addition to serum creatinine values. Other variables assessed include age, sex, and BMI. Data collected was within a year of PCNL treatment. Statistical analysis was performed with Statsplus . RESULTS: A total of 110 patients (74 single access, 36 multiple access) were identified for which pre and post-PCNL renograms were available. There was no significant differences in age, gender, BMI, serum creatinine, or MAG3 renogram derived T/2 between these cohorts. We noted a significant decrease in Tc99m-MAG3 split function in the operated kidney for patients with multiple access versus single access PCNL (-2.28%, p 0.05, respectively). Successive decrease in renal function was suggested with increasing number of percutaneous accesses into the kidney although this was not statistically significant (likely due to the low number of cases with more than 2 accesses [F(2,107)1⁄41.487, p1⁄40.23]). CONCLUSIONS: We present one of the largest series of renal function assessment with Tc99m-MAG3 nuclear renography in patients undergoing single versus multi-access percutaneous nephrostolithotomy. Multi-tract PCNL appears to be associated with a significant decline in renal function as assessed by Tc99m-MAG3 nuclear renography. This suggests that numerous accesses may exacerbate perioperative renal injury. Further review of patient and peri-operative parameters is needed to both further elucidate and to confirm this relationship.
The Journal of Urology, 2013
ABSTRACT Background / Purpose: Post-therapy bladder neck contractures can be a challenge to treat... more ABSTRACT Background / Purpose: Post-therapy bladder neck contractures can be a challenge to treat. Some reports of transurethral injection of scars with various agents have shown promise. We compare use of intralesional injection with mitomycin C and tacrolimus combined with TUIBN in a 10-patient cohort. Main conclusion: At a median of 7.5 months follow up, it seems that intralesional injection combined with transurethral incision can provide potency.
Journal of the American Chemical Society, 1989
A gold-gold bond forms when [Au(p(CH2),PPh,)], (Aw-Au = 2.977 (1) A) is oxidized to [Au(~-(CH,),P... more A gold-gold bond forms when [Au(p(CH2),PPh,)], (Aw-Au = 2.977 (1) A) is oxidized to [Au(~-(CH,),PPh,)I,XY (X u = CI,, CH3Br, CF3CH21, (NO,),, etc.) (Au-Au = 2.55-2.7 Metal-metal bond formation may occur during the initial step of the oxidative addition3 or subsequent to metal-ligand bond formation. To further explore possible metal-metal bond formation related to this initial step, we have crystallized and structurally studied the adduct of SO2 with [Au(~-(CH,),PP~,)]~. SO, coordinates axially as a Lewis acid by removing electron (I) Basil,
Journal of Neurotrauma, 2010
Therapeutic hypothermia remains a promising treatment for patients with severe traumatic brain in... more Therapeutic hypothermia remains a promising treatment for patients with severe traumatic brain injury (TBI). Multiple animal studies have suggested that hypothermia is neuroprotective after TBI, but clinical trials have been inconclusive. Systemic hypothermia, the method used in almost all major clinical trials, is limited by the time to target temperature, the depth of hypothermia, and complications, problems that may be solved by selective brain cooling. We evaluated the effects on brain temperature of a cooling device called the ChillerPad,™ which is applied to the dura in a non-human primate TBI model using controlled cortical impact (CCI). The cortical surface was rapidly cooled to approximately 15°C and maintained at that level for 24 h, followed by rewarming over about 10 h. Brain temperatures fell to 34-35°C at a depth of 15 mm at the cortical gray/white matter interface, and to 28-32°C at 10 mm deep. Intracranial pressure was mildly elevated (8-12 mm Hg) after cooling and rewarming, likely due to TBI. Other physiological variables were unchanged. Cooling was rapidly diminished at points distant from the cooling pad. The ChillerPad may be useful for highly localized cooling of the brain in circumstances in which a craniotomy is clinically indicated. However, because of the delay required by the craniotomy, other methods that are more readily available for inducing hypothermia may be used as a bridge between the time of injury to placement of the ChillerPad.
Inorganica Chimica Acta, 1991
ABSTRACT
IEEE Transactions on Intelligent Transportation Systems, 2014
This paper introduces and illustrates some novel stochastic policies that assign parking spaces t... more This paper introduces and illustrates some novel stochastic policies that assign parking spaces to cars looking for an available parking space. We analyse in detail both the main features of a single park, i.e., how a car could conveniently decide whether to try its luck at that parking lot or try elsewhere, and also the case when more parking lots are available, and how to choose the best one. We discuss the practical requirements of the proposed strategies in terms of infrastructure technology and vehicles' equipment and the mathematical properties of the proposed algorithms in terms of robustness against delays, stability and reliability. Preliminary results obtained from simulations are also provided to illustrate the feasibility and the potential of our stochastic assignment policies. • We assume that this car-park is instrumented so that its occupancy can be estimated. • We assume that this information can be broadcasted to potential customers on a continuous basis. • We assume that cars arrive and depart to/from the carpark according to two Poisson processes. The Poisson arrival processes throughout the paper. The use of Poisson processes to model bursty traffic is well established.
Communications in Mathematical Physics, 2010
Hastings [12] recently provided a proof of the existence of channels which violate the additivity... more Hastings [12] recently provided a proof of the existence of channels which violate the additivity conjecture for minimal output entropy. In this paper we present an expanded version of Hastings' proof. In addition to a careful elucidation of the details of the proof, we also present bounds for the minimal dimensions needed to obtain a counterexample.
Communications in Mathematical Physics, 2003
This paper derives an inequality relating the p-norm of a positive 2×2 block matrix to the p-norm... more This paper derives an inequality relating the p-norm of a positive 2×2 block matrix to the p-norm of the 2× 2 matrix obtained by replacing each block by its p-norm. The inequality had been known for integer values of p, so the main contribution here is the extension to all values p ≥ 1. In a special case the result reproduces Hanner's inequality. A weaker inequality which applies also to non-positive matrices is presented. As an application in quantum information theory, the inequality is used to obtain some results concerning maximal p-norms of product channels.
Bioorganic & Medicinal Chemistry Letters, 2011
Biphenylacetic acid (5) was identified through a library screen as an inhibitor of the prostaglan... more Biphenylacetic acid (5) was identified through a library screen as an inhibitor of the prostaglandin D 2 receptor DP2 (CRTH2). Optimization for potency and pharmacokinetic properties led to a series of selective CRTH2 antagonists. Compounds demonstrated potency in a human DP2 binding assay and a human whole blood eosinophil shape change assay, as well as good oral bioavailability in rat and dog, and efficacy in a mouse model of allergic rhinitis following oral dosing.
Bioorganic & Medicinal Chemistry Letters, 2010
AM643 (compound 6, 3-{3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-py... more AM643 (compound 6, 3-{3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid) was identified as a potential candidate for formulation as a topical agent for the treatment of skin disorders involving leukotriene production. Dermal application of 6 using a prototypical vehicle in a murine ear arachidonic acid model showed significant reduction in the concentrations of leukotrienes in mouse skin with concomitant reduction in ear swelling.
Journal of Aging and Identity, 2002
Narratives of Japan's maturation as a postindustrial society raise critical interest in narr... more Narratives of Japan's maturation as a postindustrial society raise critical interest in narratives of personal and collective maturation within the most rapidly aging population in the world. Japanese popular culture is a rich source of representations of tensions between institutional projects of modernization and significant cultural and social changes that these projects have unintentionally engendered. The animated movie Rojin-Z represents
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Papers by christopher king