On the Anti-Wishart distribution

We provide the probability distribution function of matrix elements each of which is the inner product of two vectors. The vectors we are considering here are independently distributed but not necessarily Gaussian variables. When the number of components M of each vector is greater than the number of vectors N, one has a $N\times N$ symmetric matrix. When $M\ge N$ and the components of each vector are independent Gaussian variables, the distribution function of the $N(N+1)/2$ matrix elements was obtained by Wishart in 1928. When N > M, what we called the ``Anti-Wishart'' case, the matrix elements are no longer completely independent because the true degrees of freedom becomes smaller than the number of matrix elements. Due to this singular nature, analytical derivation of the probability distribution function is much more involved than the corresponding Wishart case. For a class of general random vectors, we obtain the analytical distribution function in a closed form, which is a product of various factors and delta function constraints, composed of various determinants. The distribution function of the matrix element for the $M\ge N$ case with the same class of random vectors is also obtained as a by-product. Our result is closely related to and should be valuable for the study of random magnet problem and information redundancy problem.Comment: to appear in Physica

EFFECTS OF WHOLE BODY VIBRATION TRAINING ON KNEE EXTENSOR MUSCLE STRENGTH AND RATE OF FORCE DEVELOPMENT

This study compared the effects of 8-week whole-body vibration (WBV) training programs on knee extensor muscle strength and rate of force development. Twenty physically active male subjects were randomly assigned to a whole-body vibration training group (WBV; n =10) or a sham training group (SHAM; n = 10). Maximal voluntary isometric joint moment, rate of force development (RFD) and contractile impulse of the knee extensors were assessed before and after the training period. There were significant differences between WBV and sham groups on improvement percentage of maximum joint moment, RFD and contractile impulse in knee extensor. We concluded that not only knee extensor muscle strength could be enhanced but also muscle contractile abilty could be faster after a 8-week WBV training program

Recrystallized parylene as a mask for silicon chemical etching

This paper presents the first use of recrystallized parylene as masking material for silicon chemical etch. Recrystallized parylene was obtained by melting parylene C at 350°C for 2 hours. The masking ability of recrystallized parylene was tested in HNA (hydrofluoric acid, nitric acid and acetic acid) solution of various ratios, KOH (potassium hydroxide) solution and TMAH (tetramethylammonium hydroxide) at different temperatures and concentrations. It is found that interface between parylene and the substrate can be attacked, which results in undercuts. Otherwise, recrystallized parylene exhibited good adhesion to silicon, complete protection of unexposed silicon and silicon etching rates comparable to literature data

Information System Development Team Collaboration Antecedents

Despite information system development companies have invested substantial resources to support the success of information system development (ISD) projects, the failure rate is still high. Extant studies indicated that the constant changes from socio-technical environments are the main causes of the low success rate. This study argues that team collaboration is a key factor to effectively cope with unexpected disruptions that would have negative effect on overall software product success. This study proposes a research model exploring factors that influence the development of team collaboration. These factors include the team commitment, transactive memory systems (TMS), and collective mind. In addition, the study suggests that the collective mind has an intermediate effect on the team commitment, TMS, and team collaboration. This study takes the information development teams of various companies in Taiwan as its subjects

Q-enhanced fold-and-bond MEMS inductors

This work presents a novel coil fabrication technology to enhance quality factor (Q factor) of microfabricated inductors for implanted medical wireless sensing and data/power transfer applications. Using parylene as a flexible thin-film device substrate, a post-microfabrication substrate folding-and-bonding method is developed to effectively increase the metal thickness of the surface-micromachined inductors, resulting in their lower self-resistance so their higher quality factor. One-fold-and-bond coils are successfully demonstrated as an example to verify the feasibility of the fabrication technology with measurement results in good agreements with device simulation. Depending on target specifications, multiple substrate folding-and-bonding can be extensively implemented to facilitate further improved electrical characteristics of the coils from single fabrication batch. Such Q-enhanced inductors can be broadly utilized with great potentials in flexible integrated wireless devices/systems for intraocular prostheses and other biomedical implants

Noninvasive prediction of Blood Lactate through a machine learning-based approach.

We hypothesized that blood lactate concentration([Lac]blood) is a function of cardiopulmonary variables, exercise intensity and some anthropometric elements during aerobic exercise. This investigation aimed to establish a mathematical model to estimate [Lac]blood noninvasively during constant work rate (CWR) exercise of various intensities. 31 healthy participants were recruited and each underwent 4 cardiopulmonary exercise tests: one incremental and three CWR tests (low: 35% of peak work rate for 15 min, moderate: 60% 10 min and high: 90% 4 min). At the end of each CWR test, venous blood was sampled to determine [Lac]blood. 31 trios of CWR tests were employed to construct the mathematical model, which utilized exponential regression combined with Taylor expansion. Good fitting was achieved when the conditions of low and moderate intensity were put in one model; high-intensity in another. Standard deviation of fitting error in the former condition is 0.52; in the latter is 1.82 mmol/liter. Weighting analysis demonstrated that, besides heart rate, respiratory variables are required in the estimation of [Lac]blood in the model of low/moderate intensity. In conclusion, by measuring noninvasive cardio-respiratory parameters, [Lac]blood during CWR exercise can be determined with good accuracy. This should have application in endurance training and future exercise industry

Synchronous Occurrence of Primary Neoplasms in the Uterus with Squamous Cell Carcinoma of the Cervix and Adenocarcinoma of the Endometrium

SummaryObjectiveSynchronous primary malignant neoplasms of the uterus are uncommon. Patients with synchronous cervical and endometrial cancers are even rarer. We describe a case of cervical squamous cell carcinoma and endometrial endometrioid adenocarcinoma occurring simultaneously in a 47-year-old woman presenting with massive menstrual bleeding. The concept of synchronous primary malignancies of the genital tract is also reviewed in this report.Case ReportA 47-year-old overtly obese female presented with menometrorrhagia of over 6 months' duration. Pelvic examination detected a large cervix but apparently normal externals. Magnetic resonance imaging revealed a mass over the cervical region and endometrial lesions in the uterine cavity. Surgical exploration disclosed a cervical tumor and erosion of the endometrium. The pathologic findings were compatible with synchronous occurrence of primary neoplasms in the uterus with squamous cell carcinoma of the cervix and adenocarcinoma of the endometrium.ConclusionSynchronous genital tract neoplasms are rare but cause more clinical problems than a single neoplasm. It is practical to pay more attention to the differential diagnosis of primary and metastatic tumors. The second primary cancer that occurs in an individual with endometrial cancer may offer an opportunity for early detection. The prognosis for a patient with synchronous gynecologic malignancies does not seem to be worse

BIOMECHANICAL ANALYSIS OF THE EVADING WITH PUSHING TECHNIQUE IN TAI CHI PUSH HANDS

The traditional Chinese martial arts, Tai Chi (TC), include different forms and advanced interactive movements called Push Hands. Very few studies on the biomechanics analysis of TC push hands have been published. To investigate the characteristics of Tai Chi Push Hands, an experienced master was asked to perform the ‘evading with pushing technique’ when he was pushed by another person for three trials. The master’s movements were videotaped and digitized using a motion analysis system combining electromyography and force plate data. The results indicated that the master lowered his COG, shifted his body weight to rear foot, twisted his waist to evade the push, and pushed back with the strength from the lower limbs. It is concluded that the evading with pushing technique is a efficient and effective way to strike back