Multiuser detection in a dynamic environment — Part II: Joint user identification and parameter estimation

The problem of jointly estimating the number, the identities, and the data of active users in a time-varying multiuser environment was examined in a companion paper (IEEE Trans. Information Theory, vol. 53, no. 9, September 2007), at whose core was the use of the theory of finite random sets on countable spaces. Here we extend that theory to encompass the more general problem of estimating unknown continuous parameters of the active-user signals. This problem is solved here by applying the theory of random finite sets constructed on hybrid spaces. We doso deriving Bayesian recursions that describe the evolution withtime of a posteriori densities of the unknown parameters and data.Unlike in the above cited paper, wherein one could evaluate theexact multiuser set posterior density, here the continuous-parameter Bayesian recursions do not admit closed-form expressions. To circumvent this difficulty, we develop numerical approximationsfor the receivers that are based on Sequential Monte Carlo (SMC)methods (“particle filtering”). Simulation results, referring to acode-divisin multiple-access (CDMA) system, are presented toillustrate the theory.

Concrete Pavement Joint Sawing, Cleaning, and Sealing, November 2004

Proper storage practices are critical to protect materials from intermingling, contamination, or degradation, and to maintain consistent aggregate gradation throughout a project. Concrete Paving Workforce Reference no.3

What is the value of joint processing of pilots and data in block-fading channels?

The spectral efficiency achievable with joint processing of pilot and data symbol observations is compared with that achievable through the conventional (separate) approach of first estimating the channel on the basis of the pilot symbols alone, and subsequently detecting the datasymbols. Studied on the basis of a mutual information lower bound, joint processing is found to provide a non-negligible advantage relative to separate processing, particularly for fast fading. It is shown that, regardless of the fading rate, only a very small number of pilot symbols (at most one per transmit antenna and per channel coherence interval) shouldbe transmitted if joint processing is allowed.

Iowa Water Pollution Control Works and Drinking Water Facilities Financing Programs, (Joint Programs of the Iowa Finance Authority and The Iowa Department of Natural Resources), Independent Auditor's Reports, Financial Statements and Supplemental Information, June 30, 2004

State Audit Reports

When mothers work and fathers care. Joint household fertility decisions in Denmark and Spain

We analyze second birth decisions within the theoretical framework of joint household decision making, comparing two countires that represent the international extremes in terms of women's career behaviour, Denmark and Spain. Using all 8 ECHP panels we apply discrete time estimations of the likelihood of a second birth and show that in Spain, fertility behaviour continues to conform to the classic "Becker model" while in Denmark we identify a radically new behavioral pattern according to which career-women's fertility is conditional of their partners' contribution to care for the children.

Joint determinants of education enrolment and first birth timing in France and West Germany

We examined the reciprocal influence between educational decisions and the timing of first births, using the Family and Fertility Surveys of France and West Germany. Since these two processes are potentially endogenous, we modelled them jointly, using event history models. We hypothesise that the reciprocal impact of educational and fertility careers, as well as the impact of the common determinants of both processes, are gender specific and context specific.The results show a significant endogeneity for women and men in both countries. This endogeneity is stronger for women than for men, while no substantial differences are found between the two countries. Removing this shared and unobserved heterogeneity, the results show a stronger reciprocal impact between the processes for women than for men. A similar impact of being enrolled in education on first birth in both countries is found, while the effect of the birth (and especially of the pregnancy) of the first child on terminating one’s education appeared to be more marked in West Gernany than in France.

The Point system of selection of immigrants in Quebec

The present paper is aimed at identifying what are the effects of the Point System of Selection of immigrants in Quebec. I defend that the distribution of points results in a different composition of immigrant stocks in terms of origin mix and not in terms of labour skills. To do so, I carry out a longitudinal descriptive analysis on the national composition of immigrants in Quebec and two other significant provinces (Ontario and British Columbia), as well as an analysis of the distribution of points in Quebec and in the rest of Canada.

FRAX® International Task Force of the 2010 Joint International Society for Clinical Densitometry & International Osteoporosis Foundation Position Development Conference.

Osteoporosis is a serious worldwide epidemic. FRAX® is a web-based tool developed by the Sheffield WHO Collaborating Center team, that integrates clinical risk factors and femoral neck BMD and calculates the 10 year fracture probability in order to help health care professionals identify patients who need treatment. However, only 31 countries have a FRAX® calculator. In the absence of a FRAX® model for a particular country, it has been suggested to use a surrogate country for which the epidemiology of osteoporosis most closely approximates the index country. More specific recommendations for clinicians in these countries are not available. In North America, concerns have also been raised regarding the assumptions used to construct the US ethnic specific FRAX® calculators with respect to the correction factors applied to derive fracture probabilities in Blacks, Asians and Hispanics in comparison to Whites. In addition, questions were raised about calculating fracture risk in other ethnic groups e.g., Native Americans and First Canadians. The International Society for Clinical Densitometry (ISCD) in conjunction with the International Osteoporosis Foundation (IOF) assembled an international panel of experts that ultimately developed joint Official Positions of the ISCD and IOF advising clinicians regarding FRAX® usage. As part of the process, the charge of the FRAX® International Task Force was to review and synthesize data regarding geographic and race/ethnic variability in hip fractures, non-hip osteoporotic fractures, and make recommendations about the use of FRAX® in ethnic groups and countries without a FRAX® calculator. This synthesis was presented to the expert panel and constitutes the data on which the subsequent Official Positions are predicated. A summary of the International Task Force composition and charge is presented here.

Evaluation of Transverse Joint Forming Methods for PCC Pavement, January 2006

The members of the Iowa Concrete Paving Association, the National Concrete Pavement Technology Center Research Committee, and the Iowa Highway Research Board commissioned a study to examine alternative ways of developing transverse joints in portland cement concrete pavements. The present study investigated six separate variations of vertical metal strips placed above and below the dowels in conventional baskets. In addition, the study investigated existing patented assemblies and a new assembly developed in Spain and used in Australia. The metal assemblies were placed in a new pavement and allowed to stay in place for 30 days before the Iowa Department of Transportation staff terminated the test by directing the contractor to saw and seal the joints. This report describes the design, construction, testing, and conclusions of the project.

The value of serum procalcitonin level for differentiation of infectious from noninfectious causes of fever after orthopaedic surgery.

BACKGROUND: Early diagnosis of postoperative orthopaedic infections is important in order to rapidly initiate adequate antimicrobial therapy. There are currently no reliable diagnostic markers to differentiate infectious from noninfectious causes of postoperative fever. We investigated the value of the serum procalcitonin level in febrile patients after orthopaedic surgery. METHODS: We prospectively evaluated 103 consecutive patients with new onset of fever within ten days after orthopaedic surgery. Fever episodes were classified by two independent investigators who were blinded to procalcitonin results as infectious or noninfectious origin. White blood-cell count, C-reactive protein level, and procalcitonin level were assessed on days 0, 1, and 3 of the postoperative fever. RESULTS: Infection was diagnosed in forty-five (44%) of 103 patients and involved the respiratory tract (eighteen patients), urinary tract (eighteen), joints (four), surgical site (two), bloodstream (two), and soft tissues (one). Unlike C-reactive protein levels and white blood-cell counts, procalcitonin values were significantly higher in patients with infection compared with patients without infection on the day of fever onset (p = 0.04), day 1 (p = 0.07), and day 3 (p = 0.003). Receiver-operating characteristics demonstrated that procalcitonin had the highest diagnostic accuracy, with a value of 0.62, 0.62, and 0.71 on days 0, 1, and 3, respectively. In a multivariate logistic regression analysis, procalcitonin was a significant predictor for postoperative infection on days 0, 1, and 3 of fever with an odds ratio of 2.3 (95% confidence interval, 1.1 to 4.4), 2.3 (95% confidence interval, 1.1 to 5.2), and 3.3 (95% confidence interval, 1.2 to 9.0), respectively. CONCLUSIONS: Serum procalcitonin is a helpful diagnostic marker supporting clinical and microbiological findings for more reliable differentiation of infectious from noninfectious causes of fever after orthopaedic surgery.