All-Pac-12 talent Mikayla Pivec's career in Corvallis has been memorable to say the least. While it's difficult to choose just three, her top moments include a career-high 19 rebounds against Washington, a buzzer-beating layup against ASU, and breaking Ruth Hamblin's Oregon State rebounding record this year against Stanford.

Oregon State basketball player Destiny Slocum has opted to enter the transfer portal for her final season of eligibility. Slocum, a 5-foot-7 guard, averaged a team-best 14.9 points and had 4.7 assists a game this past season with the Beavers, who finished the season ranked No. 14 with a 23-9 record. In a statement released by the university on Thursday, Slocum thanked everyone who supported her in the decision.

AUSTIN, Texas (AP) -- Texas dismissed women's basketball coach Karen Aston on Friday, ending an eight-year stint that included four straight trips to the NCAA Tournament Sweet 16 from 2015-2018.

Over four years in Eugene, Ruthy Hebard has made a name for herself with reliability and dynamic play. She's had many memorable moments in a Duck uniform. But her career day against Washington State (34 points), her moment reaching 2,000 career points and her NCAA record for consecutive made FGs (2018) tops the list. Against the Trojans, she set the record (30) and later extended it to 33.

Kobe Bryant was already immortal. Bryant and fellow NBA greats Tim Duncan and Kevin Garnett headlined a nine-person group announced Saturday as this year’s class of enshrinees into the Naismith Memorial Basketball Hall of Fame. Two-time NBA champion coach Rudy Tomjanovich finally got his call, as did longtime Baylor women’s coach Kim Mulkey, 1,000-game winner Barbara Stevens of Bentley and three-time Final Four coach Eddie Sutton.

Hear how former Oregon State guard and current member of the WNBA's LA Sparks Sydney Wiese is recovering from a COVID-19 diagnosis, seeing friends and family show support and love during a trying time.

Sabrina Ionescu wins the Wooden Award for the second year in a row, becoming the fifth in the trophy's history to win in back-to-back seasons. With the honor, she completes a complete sweep of the national postseason player of the year awards. As a senior, Ionescu matched her own single-season mark with eight triple-doubles in 2019-20, and she was incredibly efficient from the field with a career-best 51.8 field goal percentage.

Pac-12 Networks' Mike Yam interviews former Oregon State guard Sydney Wiese to hear how she's recovering from contracting COVID-19. Wiese recounts her recent travel and how she's been lifted up by steadfast support from friends, family and fellow WNBA players. See more from Wiese during "Pac-12 Playlist" on Monday, April 6 at 7 p.m. PT/ 8 p.m. MT on Pac-12 Network.

COLUMBIA, S.C. (AP) -- South Carolina freshman Aliyah Boston has won the Lisa Leslie Award given to the top center in women’s college basketball.

Pac-12 Networks' Ashley Adamson speaks with Oregon stars Sabrina Ionescu, Ruthy Hebard and Satou Sabally to hear how special their recent Naismith Starting 5 honor was, as the Ducks comprise three of the nation's top five players. Ionescu (point guard), Sabally (small forward) and Hebard (power forward) led the Ducks to a 31-2 record in the 2019-20 season before it was cut short.

Pac-12 Networks' Ashley Adamson catches up with Oregon's "Big 3" of Sabrina Ionescu, Ruthy Hebard and Satou Sabally to hear how they're adjusting to the new world without sports while still preparing for the WNBA Draft on April 17. They also share how they're staying hungry for basketball during the hiatus.

After sweeping every national player of the year award, Sabrina Ionescu is off to the WNBA level where her skills will make an instant impact — not just to her new team but the league as a whole. She averaged 17.5 points, 8.6 rebounds and 9.1 assists for the Ducks in 2019-20, rewriting her own NCAA career triple-double record and becoming the first in college basketball history with at least 2,000 points, 1,000 rebounds and 1,000 assists.

Athletic forward Satou Sabally is preparing to take the leap to the WNBA level following three productive seasons at Oregon. As a junior, she averaged 16.2 points and 6.9 rebounds per game while helping the Ducks sweep the Pac-12 regular season and tournament titles. At 6-foot-4, she also drained 45 3-pointers for Oregon in 2019-20 while notching a career-best average of 2.3 assists per game.

Ruthy Hebard, who ranks 2nd in Oregon history in points (2,368) and 3rd in rebounds (1,299), prepares to play in the WNBA following four years in Eugene. Hebard is the Oregon and Pac-12 all-time leader in career field-goal percentage (65.1) and averaged 17.3 points per game and a career-high 9.6 rebounds per game as a senior.

Arizona's Aari McDonald and Pac-12 Networks' Ashley Adamson discuss the guard's decision to return for her senior season in Tucson and how she now has the opportunity to be the face of the league. McDonald, the Pac-12 Defensive Player of the Year, was one of the nation's top scorers in 2019-20, averaging 20.6 points per game.

Oregon State guard Mikayla Pivec is the epitome of a versatile player. Her 1,030 career rebounds were the most in school history, and she finished just one assist shy of becoming the first in OSU history to tally 1,500 points, 1,000 rebounds and 500 assists. She'll head to the WNBA looking to showcase her talents at the next level following the 2020 WNBA Draft.

UCLA guard Japreece Dean is primed to shine at the next level as she heads to the WNBA Draft in April. The do-it-all point-woman was an All-Pac-12 honoree last season, and one of only seven D-1 hoopers with at least 13 points and 5.5 assists per game.

Learn how Oregon stars Sabrina Ionescu and Ruthy Hebard developed a lasting bond as college freshmen and carried that through storied four-year careers for the Ducks. Watch "Our Stories Unfinished Business: Sabrina Ionescu and Ruthy Hebard" debuting Wednesday, April 15 at 7 p.m. PT/ 8 p.m. MT on Pac-12 Network.

Ruthy Hebard and Sabrina Ionescu have had a remarkable four years together in Eugene, rewriting the history books and pushing the Ducks into the national spotlight. Catch the debut of "Our Stories Unfinished Business: Sabrina Ionescu and Ruthy Hebard" at Wednesday, April 15 at 7 p.m. PT/ 8 p.m. MT on Pac-12 Network.

With the spotlight on her growing ever brighter, Sabrina Ionescu is aware she's becoming her own brand. One of the most decorated players in women's college basketball, Ionescu is about to go pro with the WNBA draft coming up Friday. Ionescu said Oregon has prepared her to understand how much impact she can have in the community and on women's basketball.

The Tennessee Lady Vols have added forward-center Keyen Green as a graduate transfer from Liberty. Coach Kellie Harper announced Wednesday that Green has signed a scholarship for the upcoming season. The 6-foot-1 Green spent the past four seasons at Liberty and graduated in May 2019.

LEXINGTON, Ky. (AP) -- Sophomore guards Jazmine Massengill and Robyn Benton transferred to Kentucky from Southeastern Conference rivals Wednesday.

Maori Davenport, who drew national attention over an eligibility dispute during her senior year of high school, is transferring to Georgia after playing sparingly in her lone season at Rutgers. Lady Bulldogs coach Joni Taylor announced Davenport's decision Wednesday. The 6-foot-4 center from Troy, Alabama will have to sit out a season under NCAA transfer rules before she is eligible to join Georgia in 2021-22.

Pac-12 Networks' Ashley Adamson speaks with former Arizona State women's basketball player Michelle Tom, who is now a doctor treating COVID-19 patients in Winslow, Arizona.

Pac-12 Networks' Ashley Adamson speaks with former Arizona State women's basketball player Michelle Tom, who is now a doctor treating COVID-19 patients Winslow Indian Health Care Center and Little Colorado Medical Center in Eastern Arizona.

Baylor has signed a transfer point guard for the third year in a row, and this one can play multiple seasons with the Lady Bears. Jaden Owens is transferring from UCLA after signing a national letter of intent with Baylor, which had graduate transfers at point guard each of the past two seasons. The Texas native just completed her freshman season with the Bruins and has three seasons of eligibility remaining.

Just two years removed from the euphoria of winning her second national championship, Muffet McGraw knew it was time. The Hall of Fame coach retired Wednesday with a resume that includes two national championships in 33 seasons at the school, a surprising decision to many of the countless players and coaches she has influenced on and off the court as a mentor and advocate for women. ''I am proud of what we have accomplished and I can turn the page to the next chapter in my life with no regrets, knowing that I gave it my best every day,'' said McGraw, a four-time winner of the AP women's basketball Coach of the Year.

Niele Ivey is coming home.

DETROIT (AP) -- Detroit Mercy hired AnnMarie Gilbert as women’s basketball coach.

See some of Sabrina Ionescu's remarkable accomplishments at Oregon set to the Star Wars opening crawl.

During Wednesday's "Pac-12 Perspective" podcast, Natalie Chou shared why she is using her platform to speak out against racism she sees in her community related to the novel coronavirus.

Pac-12 Networks' Mike Yam has a conversation with UCLA's Natalie Chou during Wednesday's "Pac-12 Perspective" podcast. Chou reflects on her role models, passion for basketball and how her mom has made a big impact on her hoops career.

The Pac-12 Student-Athlete Advisory Committee voted to award the Oregon State women’s basketball team with the Pac-12 Sportsmanship Award for the 2019-20 season, honoring their character and sportsmanship before a rivalry game against Oregon in Jan. 2020 -- the day Kobe Bryant, his daughter, Gigi, and seven others passed away in a helicopter crash in Southern California. In the above video, Aleah Goodman and Madison Washington share how the teams came together as one in a circle of prayer before the game.

On the day Kobe Bryant suddenly passed away, the Beavers embraced their rivals at midcourt in a moment of strength to support the Ducks, many of whom had personal connections to Bryant and his daughter, Gigi. For this, Oregon State is the 2020 recipient of the Pac-12 Sportsmanship Award.

During Friday's "Pac-12 Perspective," Stanford head coach Tara VanDerveer spoke about Haley Jones' positionless game and how the Cardinal used the dynamic freshman in 2019-20. Download and listen wherever you get your podcasts.

Pac-12 student-athletes give shout-outs to their moms ahead of Mother's Day on May 10th, 2020 including UCLA's Michaela Onyenwere, Oregon's Sabrina Ionescu and Satou Sabally, Arizona's Aari McDonald, Cate Reese, and Lacie Hull, Stanford's Kiana Williams, USC's Endyia Rogers, and Aliyah Jeune, and Utah's Brynna Maxwell.

Eunji Lim.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 2053--2097.

Abstract:
We study the asymptotic behavior of the least squares estimators when the model is possibly misspecified. We consider the setting where we wish to estimate an unknown function $f_{*}:(0,1)^{d} ightarrow mathbb{R}$ from observations $(X,Y),(X_{1},Y_{1}),cdots ,(X_{n},Y_{n})$; our estimator $hat{g}_{n}$ is the minimizer of $sum _{i=1}^{n}(Y_{i}-g(X_{i}))^{2}/n$ over $gin mathcal{G}$ for some set of functions $mathcal{G}$. We provide sufficient conditions on the metric entropy of $mathcal{G}$, under which $hat{g}_{n}$ converges to $g_{*}$ as $n ightarrow infty $, where $g_{*}$ is the minimizer of $|g-f_{*}| riangleq mathbb{E}(g(X)-f_{*}(X))^{2}$ over $gin mathcal{G}$. As corollaries of our theorem, we establish $|hat{g}_{n}-g_{*}| ightarrow 0$ as $n ightarrow infty $ when $mathcal{G}$ is the set of monotone functions or the set of convex functions. We also make a connection between the convergence rate of $|hat{g}_{n}-g_{*}|$ and the metric entropy of $mathcal{G}$. As special cases of our finding, we compute the convergence rate of $|hat{g}_{n}-g_{*}|^{2}$ when $mathcal{G}$ is the set of bounded monotone functions or the set of bounded convex functions.

Laurent Gardes.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 661--701.

Abstract:
The first part of the paper is dedicated to the construction of a $gamma$ - nonparametric confidence interval for a conditional quantile with a level depending on the sample size. When this level tends to 0 or 1 as the sample size increases, the conditional quantile is said to be extreme and is located in the tail of the conditional distribution. The proposed confidence interval is constructed by approximating the distribution of the order statistics selected with a nearest neighbor approach by a Beta distribution. We show that its coverage probability converges to the preselected probability $gamma $ and its accuracy is illustrated on a simulation study. When the dimension of the covariate increases, the coverage probability of the confidence interval can be very different from $gamma $. This is a well known consequence of the data sparsity especially in the tail of the distribution. In a second part, a dimension reduction procedure is proposed in order to select more appropriate nearest neighbors in the right tail of the distribution and in turn to obtain a better coverage probability for extreme conditional quantiles. This procedure is based on the Tail Conditional Independence assumption introduced in (Gardes, Extremes , pp. 57–95, 18(3) , 2018).

Ruofei Zhao, Yuanzhi Li, Yuekai Sun.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 632--660.

Abstract:
We study the convergence behavior of the Expectation Maximization (EM) algorithm on Gaussian mixture models with an arbitrary number of mixture components and mixing weights. We show that as long as the means of the components are separated by at least $Omega (sqrt{min {M,d}})$, where $M$ is the number of components and $d$ is the dimension, the EM algorithm converges locally to the global optimum of the log-likelihood. Further, we show that the convergence rate is linear and characterize the size of the basin of attraction to the global optimum.

Maddalena Cavicchioli.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 605--631.

Abstract:
The paper treats the modeling of stationary multivariate stochastic processes via a frequency domain model expressed in terms of cepstrum theory. The proposed model nests the vector exponential model of [20] as a special case, and extends the generalised cepstral model of [36] to the multivariate setting, answering a question raised by the last authors in their paper. Contemporarily, we extend the notion of generalised autocovariance function of [35] to vector time series. Then we derive explicit matrix formulas connecting generalised cepstral and autocovariance matrices of the process, and prove the consistency and asymptotic properties of the Whittle likelihood estimators of model parameters. Asymptotic theory for the special case of the vector exponential model is a significant addition to the paper of [20]. We also provide a mathematical machinery, based on matrix differentiation, and computational methods to derive our results, which differ significantly from those employed in the univariate case. The utility of the proposed model is illustrated through Monte Carlo simulation from a bivariate process characterized by a high dynamic range, and an empirical application on time varying minimum variance hedge ratios through the second moments of future and spot prices in the corn commodity market.

Emanuel Ben-David, Bala Rajaratnam.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 580--604.

Abstract:
The Wishart distribution defined on the open cone of positive-definite matrices plays a central role in multivariate analysis and multivariate distribution theory. Its domain of parameters is often referred to as the Gindikin set. In recent years, varieties of useful extensions of the Wishart distribution have been proposed in the literature for the purposes of studying Markov random fields and graphical models. In particular, generalizations of the Wishart distribution, referred to as Type I and Type II (graphical) Wishart distributions introduced by Letac and Massam in Annals of Statistics (2007) play important roles in both frequentist and Bayesian inference for Gaussian graphical models. These distributions have been especially useful in high-dimensional settings due to the flexibility offered by their multiple-shape parameters. Concerning Type I and Type II Wishart distributions, a conjecture of Letac and Massam concerns the domain of multiple-shape parameters of these distributions. The conjecture also has implications for the existence of Bayes estimators corresponding to these high dimensional priors. The conjecture, which was first posed in the Annals of Statistics, has now been an open problem for about 10 years. In this paper, we give a necessary condition for the Letac and Massam conjecture to hold. More precisely, we prove that if the Letac and Massam conjecture holds on a decomposable graph, then no two separators of the graph can be nested within each other. For this, we analyze Type I and Type II Wishart distributions on appropriate Markov equivalent perfect DAG models and succeed in deriving the aforementioned necessary condition. This condition in particular identifies a class of counterexamples to the conjecture.

Gregor Pasemann, Wilhelm Stannat.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 547--579.

Abstract:
A parameter estimation problem for a class of semilinear stochastic evolution equations is considered. Conditions for consistency and asymptotic normality are given in terms of growth and continuity properties of the nonlinear part. Emphasis is put on the case of stochastic reaction-diffusion systems. Robustness results for statistical inference under model uncertainty are provided.

François Bachoc, Baptiste Broto, Fabrice Gamboa, Jean-Michel Loubes.

Source: Electronic Journal of Statistics, Volume 14, Number 1, 503--546.

Abstract:
In the framework of the supervised learning of a real function defined on an abstract space $mathcal{X}$, Gaussian processes are widely used. The Euclidean case for $mathcal{X}$ is well known and has been widely studied. In this paper, we explore the less classical case where $mathcal{X}$ is the non commutative finite group of permutations (namely the so-called symmetric group $S_{N}$). We provide an application to Gaussian process based optimization of Latin Hypercube Designs. We also extend our results to the case of partial rankings.