A Probabilistic Linear Genetic Programming with Stochastic Context-Free Grammar for solving Symbolic Regression problems

Traditional Linear Genetic Programming (LGP) algorithms are based only on the selection mechanism to guide the search. Genetic operators combine or mutate random portions of the individuals, without knowing if the result will lead to a fitter individual. Probabilistic Model Building Genetic Programming (PMB-GP) methods were proposed to overcome this issue through a probability model that captures the structure of the fit individuals and use it to sample new individuals. This work proposes the use of LGP with a Stochastic Context-Free Grammar (SCFG), that has a probability distribution that is updated according to selected individuals. We proposed a method for adapting the grammar into the linear representation of LGP. Tests performed with the proposed probabilistic method, and with two hybrid approaches, on several symbolic regression benchmark problems show that the results are statistically better than the obtained by the traditional LGP.Comment: Genetic and Evolutionary Computation Conference (GECCO) 2017, Berlin, German

A New Approach for Assessing Kinematics of Torso Twist in Baseball Batting: A Preliminary Report

The motions of segments involved in striking and throwing events are generally sequenced in a proximal-to-distal fashion (Putnam 1993). Welch et al. (1995) analyzed baseball batting using a rigid-body-link model with a two-segment torso, and indicated the importance that the lower torso starts rotation in the direction of pitcher before the upper torso, which, in turn, should start before the arm segments. Also, this sequential motion is considered to allow the kinetic link system to generate synergy between the musculature of the torso and upper extremity. Specifically, the upper torso is expected to have an important function to accelerate distal upper extremity and bat. However previous studies employed a two-segment torso model and the influence of the motions of the shoulder-girdles to the torso’s sequential action for twisting was ignored. In the present study, torso’s sequential twisting was analyzed with a three-segment torso model, and the kinematics of torso twist in baseball batting was evaluated

A simple hepatic cyst with elevated serum and cyst fluid CA19-9 levels: a case report

<p>Abstract</p> <p>Introduction</p> <p>Simple hepatic cysts rarely cause symptoms, however, occasionally they become symptomatic due to mass effect, rupture, hemorrhage, and infection. We report a patient with a large hepatic cyst with elevated serum and cyst fluid CA19-9 levels. We studied serum and cyst fluid CA19-9 levels in this patient, before and after the intracystic instillation of minocycline hydrochloride.</p> <p>Case presentation</p> <p>A 76-year-old Japanese woman was diagnosed as having an infected hepatic cyst, by physical examination and enhanced abdominal computed tomography. Serum (170 U/ml; reference: < 37 U/ml) and hepatic cyst fluid (371 U/ml) CA19-9 levels were elevated. After the intracystic instillation of minocycline hydrochloride, necrotic cells in the cyst were drained, and it totally collapsed after 1 week. Cyst fluid CA19-9 levels increased remarkably after the intracystic instillation of minocycline hydrochloride, while serum CA19-9 levels decreased significantly.</p> <p>Conclusion</p> <p>Our study is the first report to reveal the influence of intracystic instillation of minocycline hydrochloride on serum and cyst fluid CA19-9 levels in a patient with a simple hepatic cyst.</p