Using response probability and ratio imputation in the estimation under callbacks

Although the response model has been frequently applied to nonresponse weighting adjustment or imputation, the estimation under callbacks has been relatively underdeveloped in the response model. We propose an estimator under callbacks using both the response probability and the ratio imputation and a replication variance estimator of the estimator. We also study the estimation of the response probability. A simulation study illustrates our technique.     

Group variable selection in cardiopulmonary cerebral resuscitation data for veterinary patients

Cardiopulmonary cerebral resuscitation (CPCR) is a procedure to restore spontaneous circulation in patients with cardiopulmonary arrest (CPA). While animals with CPA generally have a lower success rate of CPCR than people do, CPCR studies in veterinary patients have been limited. In this paper, we construct a model for predicting success or failure of CPCR, and identifying and evaluating factors that affect the success of CPCR in veterinary patients. Due to reparametrization using multiple dummy variables or close proximity in nature, many variables in the data form groups, and thus a desirable method should take this grouping feature into account in variable selection. To accomplish these goals, we propose an adaptive group bridge method for a logistic regression model. The performance of the proposed method is evaluated under different simulated setups and compared with several other regression methods. Using the logistic group bridge model, we analyze data from a CPCR study for veterinary patients and discuss their implications on the practice of veterinary medicine.     

Constrained nonparametric maximum likelihood estimation of stochastically ordered survivor functions

This paper considers estimators of survivor functions subject to a stochastic ordering constraint based on right censored data. We present the constrained nonparametric maximum likelihood estimator (C‐NPMLE) of the survivor functions in one‐and two‐sample settings where the survivor distributions could be discrete or continuous and discuss the non‐uniqueness of the estimators. We also present a computationally efficient algorithm to obtain the C‐NPMLE. To address the possibility of non‐uniqueness of the C‐NPMLE of $S_1(t)$ when $S_1(t)\le S_2(t)$ , we consider the maximum C‐NPMLE (MC‐NPMLE) of $S_1(t)$ . In the one‐sample case with arbitrary upper bound survivor function $S_2(t)$ , we present a novel and efficient algorithm for finding the MC‐NPMLE of $S_1(t)$ . Dykstra ( 1982 ) also considered constrained nonparametric maximum likelihood estimation for such problems, however, as we show, Dykstra's method has an error and does not always give the C‐NPMLE. We corrected this error and simulation shows improvement in efficiency compared to Dykstra's estimator. Confidence intervals based on bootstrap methods are proposed and consistency of the estimators is proved. Data from a study on larynx cancer are analysed to illustrate the method. The Canadian Journal of Statistics 40: 22–39; 2012 © 2012 Statistical Society of Canada     

Nonparametric approach to intervention time series modeling

Time series are often affected by interventions such as strikes, earthquakes, or policy changes. In the current paper, we build a practical nonparametric intervention model using the central mean subspace in time series. We estimate the central mean subspace for time series taking into account known interventions by using the Nadaraya–Watson kernel estimator. We use the modified Bayesian information criterion to estimate the unknown lag and dimension. Finally, we demonstrate that this nonparametric approach for intervened time series performs well in simulations and in a real data analysis such as the Monthly average of the oxidant.     

RESOURCE PLANNING FOR MULTIPLE PROJECTS *

This paper is concerned with the estimation of the resource requirements to service multiple projects that use many types of resources. It reports on a systematic procedure to determine the low cost levels of these resources, focusing on the two following characteristics: (1) the comparative cost of standard time to overtime in the utilization of these resources for the economical completion of the projects, and (2) the impact of highly expensive equipment in the determination of the economic levels of the manpower resources that combine with the equipment to form a crew. A numerical example is also presented to illustrate the method. Resource planning is of particular interest in the area of multiproject scheduling, since most of the commonly utilized heuristic solution approaches focus on the allocation of a limited set of available resources. In the corporate strategic planning functions, resource planning is particularly important for capital investment, training and development, and procurement scheduling.     

Intergenerational mobility in the post-1965 immigration era: Estimates by an immigrant generation cohort method

The new second generation of the post-1965 immigration era is observed as children with their parents in 1980 and again as adults 25 years later. Intergenerational mobility is assessed for both men and women in four major racial/ethnic groups, both in regard to children’s status attainment relative to parents and with regard to the rising societal standards proxied by native-born non-Hispanic whites. A profile of intergenerational mobility is prepared using multiple indicators of status attainment: high school and college completion, upper white-collar occupation, poverty, and homeowner ship. The immigrant generation cohort method we introduce accounts for four distinct temporal dimensions of immigrant progress, clarifying inconsistencies in the literature and highlighting differences in mobility between racial/ethnic groups and with respect to different outcome measures. The immigrant generation cohort method consistently finds greater intergenerational mobility than suggested by alternative approaches. Our analysis also shows that the intergenerational progress of women is greater than that of men and provides a more complete record of immigrant mobility overall. Findings for individual racial/ethnic groups accord with some expectations in the literature and contradict others.     

Personality of social robots perceived through the appearance

Past research showed that people are able to perceive the personality of others at zero acquaintances. There are two main ways, verbal and non-verbal methods, which play an important role for one in perceiving personality of others. Extensive research was conducted in relating personality with verbal, paralinguistic and gestures cues. However, there are not much research, to our knowledge, that relates the appearance and perceived personality of robots. The main objective of this research is to relate individual design features with big five perceived personality of the robots. We used the results of rated perceptions across 100 pictorial images of robots and relate the results with the 40 individual design features using General Linear Model (GLM). The initial results of the GLM analysis showed that participants' rating of personality of robot fell along the dimension of perceived friendliness which is a common rotation of extroversion and agreeableness. Some relationships were found between humanlike design features and perceived friendliness of robots. Since participants are more familiar with humans, participants perceived robots with humanlike features friendlier than the others. Some other findings such as color and surface material were found related with participants' perceived friendliness as well. In the future, we will work on the analysis of the main and interaction effects of individual features on user's perceived friendliness.     

Homelessness and Children's Use of Mental Health Services: A Population-Based Study

This study examined whether children who become homeless differ from other low-income children in their mental health service use before and after their first homeless episode, and to what extent homelessness is associated with an increased likelihood of mental health service use. Differences between children with and without new onset of sheltered homelessness in the use of mental health services emerged following homelessness and widened over time. Sheltered homelessness and foster care placement history were associated with increased odds of receiving inpatient and ambulatory mental health services. Findings underscore the importance of collaborations between homeless assistance, foster care, and mental healthcare in efforts to mitigate family homelessness and collateral needs among homeless children.     

INTELLECTUAL PROPERTY PROTECTION AND THE INDUSTRIAL COMPOSITION OF MULTINATIONAL ACTIVITY

In a North‐South model with endogenous foreign direct investment (FDI), we examine the impact of Southern intellectual property rights (IPR) protection on the mode and industrial composition of international technology transfer. A novel feature of the model is that, due to technological reasons, industries differ with respect to their susceptibility to imitation. In equilibrium, licensing occurs in industries where the risk of imitation is low and FDI where it is of intermediate magnitude. Stronger IPRs in the South (1) alter the industrial composition of multinational activity toward licensing at the expense of FDI; (2) reduce local imitation; and (3) increase licensing and, to a lesser extent, FDI. (JEL F10, O34)