Estimating mixtures of normal distributions via empirical characteristic function

This paper uses the empirical characteristic function (ECF) procedure to estimate the parameters of mixtures of normal distributions. Since the characteristic function is uniformly bounded, the procedure gives estimates that are numerically stable. It is shown that, using Monte Carlo simulation, the finite sample properties of th ECF estimator are very good, even in the case where the popular maximum likelihood estimator fails to exist. An empirical application is illustrated using the monthl excess return of the Nyse value-weighted index.     

Design and analysis considerations for comparing dynamic treatment regimens with binary outcomes from sequential multiple assignment randomized trials

In behavioral, educational and medical practice, interventions are often personalized over time using strategies that are based on individual behaviors and characteristics and changes in symptoms, severity, or adherence that are a result of one's treatment. Such strategies that more closely mimic real practice, are known as dynamic treatment regimens (DTRs). A sequential multiple assignment randomized trial (SMART) is a multi-stage trial design that can be used to construct effective DTRs. This article reviews a simple to use ‘weighted and replicated’ estimation technique for comparing DTRs embedded in a SMART design using logistic regression for a binary, end-of-study outcome variable. Based on a Wald test that compares two embedded DTRs of interest from the ‘weighted and replicated’ regression model, a sample size calculation is presented with a corresponding user-friendly applet to aid in the process of designing a SMART. The analytic models and sample size calculations are presented for three of the more commonly used two-stage SMART designs. Simulations for the sample size calculation show the empirical power reaches expected levels. A data analysis example with corresponding code is presented in the appendix using data from a SMART developing an effective DTR in autism.     

On the mean L1-error in the heteroscedastic deconvolution problem with compactly supported noises

We study the heteroscedastic deconvolution problem when random noises have compactly supported densities. In this context, the Fourier transforms of the densities can vanish on the real line. We propose a truncated type of estimator for target density and derive the convergence rate of the mean L¹-error uniformly over a class of target densities. A lower bound for the mean L¹-error is also established. Some simulations will be given to illustrate the performance of the proposed estimator.     

Social Relays of China’s Power Projection? Overseas Chinese Collective Actions for Security in France

Once known as a silent and even a model minority, hardworking and keeping a low profile, the Chinese community in Paris, one of the largest Chinese diasporic population in Europe, has organized several massive demonstrations since 2010 to demand police protection amid mounting security concerns. Based on qualitative methods combining ethnographic research, media analysis, observation of the collective actions, and interviews of key actors involved, this article analyses the evolution of these mobilizations and their aftermath, on a span of eight years from June 2010 to July 2018, aiming to comprehend the role of China’s influence diplomacy in regard to the actions of overseas Chinese for security. There hasn’t been any study on the role that overseas Chinese might play in China’s foreign policy towards Europe.     

Institutions matter: The case of Vietnam

The paper investigates institutional reforms in Vietnam and their impact on the economic performance of firms. Using the provincial competitiveness index 2006 (PCI06) and firm-level data in Vietnam in 2005, the results show that provincial competitiveness is economically and statistically significant in explaining cross-province differences in firm performance. We find that a 1% point improvement in government practice could increase the daily value-added of an average firm by an amount equivalent to nearly three times per capita GDP per day. The results show that an improvement in providing market information, more secure land tenure and labor training assistance has a positive effect on firm performance. By contrast, weaknesses in the judiciary system and administrative reforms impede growth of non-state firms. The findings indicate that governance is an important obstacle to the development of the non-state sector in Vietnam.     

On multivariate variable-kernel density estimates for time series

Let X₁ be a strictly stationary multiple time series with values in R^d and with a common density f. Let X₁,.,.,X_n, be n consecutive observations of X₁. Let k = k_n, be a sequence of positive integers, and let H_ni be the distance from X_i to its kth nearest neighbour among X_j, j i. The multivariate variable-kernel estimate f_n, of f is defined by where K is a given density. The complete convergence of f_n, to f on compact sets is established for time series satisfying a dependence condition (referred to as the strong mixing condition in the locally transitive sense) weaker than the strong mixing condition. Appropriate choices of k are explicitly given. The results apply to autoregressive processes and bilinear time-series models.     

Stress,Task, and Relationship Orientations of Vietnamese Working Adults: Do Age,Gender, and Government Work Experience Make a Difference?

Adult people are always structured diversely based on their gender, age, and work experience in the government versus private enterprises. To investigate the task, relationship and stress orientations of Vietnamese adults, this research examined 294 Vietnamese people living in three main cities in Vietnam including Hanoi (the capital) in the north, Vinh in the middle and Ho Chi Minh in the south. It found that they have different mean scores on task and relationship orientations. Gender, age and government work experience seem to be essential factors in leadership orientation and overload stress perception. Additionally, older people appear to be more task-oriented than their younger counterparts. In summary, the Vietnamese respondents confirmed a moderate stress perception regardless of age, gender and government work experience.

     

批判视角下解构现代社会的“媒介崇拜”

在现代性视野下,现代人已无法自拔于对媒介的盲目崇拜。借助于批判理论和视角揭示现代"媒介崇拜"的实质,层层剥离出话语崇拜、符号崇拜、收视崇拜和具体表现为消费崇拜、偶像崇拜、镜头崇拜的信息崇拜等主要崇拜形式和类型,并引发对媒介"他者"和受众"自我"的反思。     

Structural Validation and Multiple Group Assessment of the Short Internalized Homonegativity Scale in Homosexual and Bisexual Men in 38 European Countries: Results From the European MSM Internet Survey

Internalized homonegativity (IH) is the internalization of negative attitudes and assumptions about homosexual people by homosexual people themselves. To measure IH, Smolenski, Diamond, Ross, and Rosser (2010) and Ross, Rosser, and Smolenski (2010) revised the Reactions to Homosexuality Scale (RHS) to develop the Short Internalized Homonegativity Scale (SIHS) with eight items. Using the European Men Who Have Sex With Men Internet Survey (EMIS) data, with an analytic sample of 130,718 gay and bisexual men in 38 European countries, we confirmed the validity of the SIHS scale in both training and validation data, in strata of Ross, Berg, et al.’s (2013) three “homosexual discrimination” country clusters, of age, and of education level. However, the performance was less adequate in comparison of gay versus bisexually identified individuals. The latent SIHS structure contains only minor variations across these three strata. The seven-item scale performed as well as the eight-item scale. The SIHS is a promising candidate for standard IH measures, which is invariant across cultural, age, and educational strata.