Simple Statistical Calculations Research Articles

A Study of ISA Engagement at an Autonomous Management Education and Research Institute, Madhya Pradesh

Employee engagement has remained a major concept in HRD studies, whether it is related to OCBs, task performance, or climate. Different measures have been developed to estimate employee engagement level. One of the recent scales developed is the ISA engagement scale by Soane, et.al.(2012), and it has three facets of employee engagement i.e. intellectual engagement, social engagement and affective engagement. This model was built on the theory of employee engagement by Kahn (1990). The ISA engagement scale has been used in the present research to study the degree of employee engagement at various levels in an autonomous management education institute. Various levels were studied on the basis of job category, age and experience using simple statistical calculation. Among all the three facets of ISA engagement scale, social engagement was found to be low among less experienced and lower age groups in this institute. A slight difference was observed in the average degree of employee engagement on the basis of job tenure. This study contributes to further research done on the third facet i.e. social engagement.

Modeling bidding competitiveness and position performance in multi-attribute construction auctions

Currently, multi-attribute auctions are becoming widespread awarding mechanisms for contracts in construction, and in these auctions, criteria other than price are taken into account for ranking bidder proposals. Therefore, being the lowest-price bidder is no longer a guarantee of being awarded, thus increasing the importance of measuring any bidder’s performance when not only the first position (lowest price) matters.Modeling position performance allows a tender manager to calculate the probability curves related to the more likely positions to be occupied by any bidder who enters a competitive auction irrespective of the actual number of future participating bidders.This paper details a practical methodology based on simple statistical calculations for modeling the performance of a single bidder or a group of bidders, constituting a useful resource for analyzing one’s own success while benchmarking potential bidding competitors.

Statistical significance of MRI in detection of chance type fractures of thoracolumbar vertebrae

BACKGROUND CONTEXT: Chance type fractures, as defined by G Q Chance in 1948, is a flexion-distraction type injury of the spine. There is high suspicion of ligamentous injury on initial X-Rays and CT scan if there is anterior wedging exceeds 40 – 50%, inter-spinous distance widening of more than 20% or vertebral body translation. In case of ligamentous Injury, about half of all patients treated non-operatively will have poor outcomes. Intraoperative finding of ligamentous injury is the gold standard. Although MRI is considered a reliable diagnostic tool for detection of injury to posterior ligamentous complex but limited studies are available that evaluate the correlation statistically. PURPOSE: Quantitatively assess the statistical significance of MRI in detection of suspected Chance type fractures of the thoracolumbar spine. STUDY DESIGN/SETTING: All patients with thoracolumbar vertebral fractures that were operated at HGH, Doha, Qatar from January 2011 to January 2014 were retrospectively assessed. Intraoperative results and reported MRI were used for simple statistical calculations. PATIENT SAMPLE: Non purposive sampling (All eligible patients) OUTCOMEMEASURES: Sensitivity, specificity, positive predictive value, negative predictive value. METHODS: Simple statistical calculations for the Outcome Measures mentioned above were done along with 95% confidence interval calculation. RESULTS: Sensitivity 72.73 % Specificity 100 % PPV 100 % NPV 88.89 % CONCLUSIONS: MRI is not a sensitive indicator for detection of ligamentous injury in Chance type fractures of thoracolumbar vertebra and a positive finding of ligamentous injury on preoperative MRI is highly predictive of injury to the posterior ligamentous complex. CONFLICTS OF INTEREST: None. FUNDING SOURCES: None.

Isonymy as an indicator of inbreeding in child populations of Yamal and Gyda tundra

It is known that the term «inbreeding» refers to a descendant of close relatives. As a result of inbreeding in the population the number of homozygotes increases and thus the number of heterozygotes reduces, which degrades the quality of the population (inbreeding-depression), since it increases the frequency of diseases associated with recessive genes in such children. In isolated populations individuals with adverse signs as a result of inbreeding eventually get culled of (Kirkpatrick et al., 2000). Decrease in genetic di-versity as a result of inbreeding, usually leads to that the individual and the population lose their ability to adapt to changing environmental conditions, as many body functions are genetically determined. Simple statistical calculations indicate that all human beings are relatives to some extend. The inbreeding coefficient can be determined by analyzing the family tree based on the number of ancestors to the shared ancestor for both parents. The purpose of this study was to determine the inbreeding coefficient by means of isonymic analysis of the population of 2043 Nenets and Khanty children living in the villages of the Yamal region as well as in tundra assigned to boarding schools located in villages Salemal, Panaevsk, Yar-Sale, Novy Port and Gyda of the Yamal-Nenets autonomous destrict. Inbreeding coefficient was calculated using marital isonymy to estimate the frequency of consanguineous marriages as a measure of inbreeding (Crow and Mange,1965). We calculated the frequency of prospective isonymic marriages for individual Nenets and Khanty surnames for inhabitants of Yar-Sale, Salemal, Panaevsk, Novy Port and Gyda tundra. In Gyda tun-dra for one of the not very common in the region surnames the highest frequency of prospective consanguineous marriages was revealed (0.189). Values of the coefficient of random inbreeding for inhabitants of Yamal and Gyda tundra vary from 0.02 to 0.058 which is much higher than for example in the population of one of the Yakutia regions (0.0007) (Kucher et al., 2010) or in the population of Kirovsk region (0.00321-0.01063) (Kadyshev, 2011). In the population of Gyda tundra we revealed the highest coefficient of random inbreeding (0.058), which is the third world‘s largest value pub-lished to date.

Drug Rehabilitation Center based Survey on Drug Dependence in Dhaka City

Background The study was conducted to know the socio-economic and demographic background of the drug addicts. The study also explored to identify the nature of drug used by the drug addicts and causes of drug addiction. Methods It was a descriptive cross sectional study conducted in a tertiary drug rehabilitation center in Dhaka city, Bangladesh. Purposive sampling strategy was followed and a closed ended questionnaire was utilized for face to face interview with the respondents. The data are analyzed through simple statistical calculation such as frequencies and percentages. Results A total 30 participants agreed to participate in the study. The highest concentration of drug addicts was between the age of 20 and 25 years (43.34%). However, near about half of the respondents (46.67%) took drug at the age of 16-20 years. It is quite alarming that 6.67% respondents took their first drug before the age of 10 and 16.67% took before the age of 15. Most of the addicts were students (40%) and over two thirds of the respondents (63.33%) had no knowledge on harmful impact on drug addictions. The most common type of drug used by the sample addicts were heroine (23.33) followed by Yaba (16.67%) and Phensedyl (16.67%). Familial problem was the main reason (40%) for getting involved with drug addiction followed by frustration of the respondents due to different reasons. Discussion The most important element of the drug demand reduction is the prevention which holds the key to success in the entire fight against drugs. Nationwide concerted action is needed to reduce the illicit demand for drugs. DOI: http://dx.doi.org/10.3329/updcj.v3i1.17982 Update Dent. Coll. j: 2013; 3 (1): 32-36

Kualitas Kegiatan Belajar Mahasiswa Fakultas Ilmu Pendidikan Universitas Negeri Padang

The objective of this research is to describe the quality attitudes of student to learning, including: a) attitudes toward to learning program , b) preparation of students prior to learning activities, c) students attitudes to learning activities in the class, d) students attitudes after learning activities in the class. This study classified as descriptive research, The population of the research is all of student at FIP UNP consist of 2160 people. The sample was specified by using proportional random sampling technique is 162 people. The research data was collected using a questionnaire, and treated with simple statistical calculations, which are: Mean, SD and percentages. The research findings reveal the quality of student attitudes to learning as follows: 1). student attitudes toward to learning program, include; attitudes toward the course, the lecturers, and attitudes towards the learning facilities mostly classified as good, 2). Preparation of students before learning activity, include: studying the material that has been learned, reading materials related to the topics to be discussed in class, mostly of the students attitude showed good and excellent quality. 3) The attitude of students in learning activity, include: attendance, record the material presented lecturer, and participated in the learning process, large of the student have good and very good quality attitude. 4) The students attitude after learning activity, includes; complete lecture notes, completing assignments, looking for support materials, and manage materials and lecture notes, large of the student have good and very good quality.

Kualitas Kegiatan Belajar Mahasiswa Fakultas Ilmu Pendidikan Universitas Negeri Padang

The objective of this research is to describe the quality attitudes of student to learning, including: a) attitudes toward to learning program , b) preparation of students prior to learning activities, c) students attitudes to learning activities in the class, d) students attitudes after learning activities in the class. This study classified as descriptive research, The population of the research is all of student at FIP UNP consist of 2160 people. The sample was specified by using proportional random sampling technique is 162 people. The research data was collected using a questionnaire, and treated with simple statistical calculations, which are: Mean, SD and percentages. The research findings reveal the quality of student attitudes to learning as follows: 1). student attitudes toward to learning program, include; attitudes toward the course, the lecturers, and attitudes towards the learning facilities mostly classified as good, 2). Preparation of students before learning activity, include: studying the material that has been learned, reading materials related to the topics to be discussed in class, mostly of the students attitude showed good and excellent quality. 3) The attitude of students in learning activity, include: attendance, record the material presented lecturer, and participated in the learning process, large of the student have good and very good quality attitude. 4) The students attitude after learning activity, includes; complete lecture notes, completing assignments, looking for support materials, and manage materials and lecture notes, large of the student have good and very good quality.

Anisotropy Distribution of FePt Nanoparticles With Twinned Structures

The existence of the five-fold twinned structures was observed in 3.4 nm FePt nanoparticles, and other n-fold structures were also been found in magnetic nano-grains in recording media. An analytical model, following the spirit of the Stoner-Wohlfarth model, is brought up to study the anisotropy field distribution of FePt or other magnetic nanoparticles with twinned or n-fold structures, based on simple statistical calculations of twin regions' volumes. It is found that the nanoparticle has an effective uniaxial anisotropy, and the average anisotropy field is substantially reduced compared to that of the single crystal. The calculated anisotropy distributions are also compared with the empirical distribution functions used in micromagnetic simulations.

Inverse Temperature Dependent Lifetimes of Transient SN2 Ion-Dipole Complexes

The association and collisional stabilization of the S(N)2 entrance channel complex [Cl(-)...CH3Cl]* is studied in a low-temperature radiofrequency ion trap. The temperature dependence of the ternary rate coefficient is measured and a much stronger inverse temperature dependence than expected from a simple statistical calculation is found. From these data the lifetime of the transient S(N)2 complex has been derived as a function of temperature. It is suggested that the inverse temperature dependent rates of nonsymmetric S(N)2 reactions are related to the observed inverse temperature dependence of the transient ion-dipole complexes.

On the structural convergence of biomolecular simulations by determination of the effective sample size.

Although atomistic simulations of proteins and other biological systems are approaching microsecond timescales, the quality of simulation trajectories has remained difficult to assess. Such assessment is critical not only for establishing the relevance of any individual simulation but also in the extremely active field of developing computational methods. Here we map the trajectory assessment problem onto a simple statistical calculation of the "effective sample size", that is, the number of statistically independent configurations. The mapping is achieved by asking the question, "How much time must elapse between snapshots included in a sample for that sample to exhibit the statistical properties expected for independent and identically distributed configurations?" Our method is more general than autocorrelation methods in that it directly probes the configuration-space distribution without requiring a priori definition of configurational substates and without any fitting parameters. We show that the method is equally and directly applicable to toy models, peptides, and a 72-residue protein model. Variants of our approach can readily be applied to a wide range of physical and chemical systems.

Measuring the Agreement Between two Methods to Assess Gestational Age: P060

Introduction: In clinical practice, a new method for gestational age assessment often can only be evaluated by comparing it with other established techniques (“gold standard”). Objective: To describe, through graphical techniques and simple statistical calculations, a way of evaluating the agreement between two methods for the clinical assessment of gestational age, and thereby to determine if they are exchangeable. Material and methods: This is an observational cohort study. Between 2000 and 2001, 137 women with pregnancies of less than 16 gestational weeks were prospectively enrolled at Maternidad Sardá of Buenos Aires. The last normal menstrual period (LNMP) and ultrasound scan (US) measurements were used to the estimate of the gestational age. Mean difference (d: FUM – US), standard deviation (sd), 95% confidence interval and average value between both methods were calculated for each case and plotted (“95% limits of agreement” [d + 2 sd]). Results: Mean gestational age at first ultrasound scan was 19.6 + 4.9 (95% CI 18.7 – 20.4) weeks. Concordance between both methods increased by 71.5% (63 - 78) at +/- 10 days to 82.5% (95% CI 75 - 87) at +/- 2 weeks. The mean difference was 0.35 + 1.89 (95% CI 0.03 – 0.67) weeks and the 95% limits of agreement showed that, regardless of the gestational age, the differences reached 7.5 weeks. Conclusions: The estimate of gestational age by the last normal menstrual period was higher than that by ultrasound scan in 25% of the cases and lower in 20%, suggesting that in the clinical practice these methods are not exchangeable.

Nuclear collisions induced by single-cycle laser pulses: Molecular approach to fusion

We study the possibility for energetic nuclear collisions in a gas of molecules driven by ultra-intense and ultra-short laser pulses. The idea is to use the fact that nuclei in a molecule can be pre-aligned in front of each other and can be driven into each other by a very strong (field intensities approaching 1023 W/cm2) and ultra-short (few-femtosecond, single-cycle) laser pulse, since the nuclei of different masses will acquire different velocities when driven by the same electric field. The nuclei may collide with high kinetic energy needed to overcome the Coulomb barrier, and these collisions may lead to fusion. We have performed classical simulation of nuclear motion and a simple statistical ensemble calculation. Our results show that nuclear collisions may occur on a sub-attosecond time scale, during which the nuclei will experience large acceleration and emit zeptosecond bursts of light.

Proportions, odds, and risk.

Perhaps the most common and familiar way that the results of medical research and epidemiologic investigations are summarized is in a table of counts. Numbers of subjects with and without the outcome of interest are listed for each treatment or risk factor group. By using the study sample data thus tabulated, investigators quantify the association between treatment or risk factor and outcome. Three simple statistical calculations are used for this purpose: difference in proportions, relative risk, and odds ratio. The appropriate use of these statistics to estimate the association between treatment or risk factor and outcome in the relevant population depends on the design of the research. Herein, the enumeration of proportions, odds ratios, and risks and the relationships between them are demonstrated, along with guidelines for use and interpretation of these statistics appropriate to the type of study that gives rise to the data.

The effect of rotations around all 11 single bonds in the unit cell of nylon-11 on the free energy of a disordered chain

First the reason for the 2–3 orders of magnitude difference in the Young modulus of a polymer chain in an ordered (crystalline) phase and in a macroscopic disordered sample is explained. This explanation points out: (1) that in a macroscopic sample the different chains are randomly oriented in respect to each other and (2) because of the polydispersity in the chain lengths, shorter chains will not be kept in the same position as in the crystalline phase. Consecutively, for nylon-11 a simple statistical mechanical calculation was performed for the total energy per unit cell, for the entropy term and for the free energy per unit cell in the case of free rotations around all the 11 single bonds of the unit cell. The results show a dominant role of the configurational entropy in accordance with C.F. von Weizsäcker's general considerations back in 1958.

Simple Probabilistic and Statistical Risk Calculations in an Aquifer

An objective methodology is proposed for assessing potential ground water yield on the basis of the randomness inherent in hydrogeological parameters as a result of uncertainty. Randomness is used here in the statistical sense to describe the ground water phenomenon on a regional basis. A systematic approach to selecting aquifer parameters is presented that leads to reliable ground water storage and subsurface flow estimates by incorporating a certain risk level. In addition, the averages of the specific ground water capacity and subsurface flow rate are calculated through a perturbation approach. This study demonstrates that cross-correlations between basic hydrogeologic variables might underestimate or overestimate model parameter values. Furthermore, the results of aquifer storage and subsurface flow estimates are obtained in the form of probability distribution functions. It is proved that the surface flow rates are presented by a log-normal distribution. Contrary to conventional point estimate, a simple and objective methodology is proposed in order to obtain the most probable interval estimates. Accordingly, projections of likely future ground water storage and flow rates can be readily calculated.

Near-barrier fusion reactions induced by α on197Au,193Ir,191Ir,185Re,181Ta,121Sb and69Ga nuclei

Fusion-evaporation cross-sections for the α-induced reactions upon197Au,193Ir,191Ir,185Re,181Ta,121Sb and69Ga nuclei at bombarding energies near the Coulomb barrier have been measured by off-line observation of the γ-rays emitted in the radioactive decay of the residual nuclei using stacked foil technique. The total fusion cross-section for the systems have been compared with simple statistical model calculations using the code ALICE/91 as well as with the coupled channel calculations that include the β2 and ν4 slatic deformations and dynamic couplings of the vibrational/rotational states of the target and the projet tile using the code CCDEF.

Dissociation dynamics of HNCO and DNCO after laser photoexcitation in the vacuum ultraviolet

Using the laser photolysis–laser-induced fluorescence “pump–probe” technique, the gas-phase dissociation dynamics of HNCO(X̃ 1A)+hν→H+NCO and DNCO(X̃ 1A)+hν→D+NCO after photoexcitation at the Lyman-α wavelength were studied under collision-free conditions at room temperature. In the vacuum ultraviolet photodissociation experiments narrow band tunable Lyman-α laser radiation (λ≈121.4–121.6 nm) was used both to photodissociate the parent molecules and to detect the produced nascent H and D atom products via (2p 2P←1s 2S) laser induced fluorescence. The following quantum yields ΦH–D for H–D atom formation were determined by a photolytic calibration method: ΦH=(0.62±0.15) and ΦD=(0.51±0.17). For HNCO and DNCO the measured H–D atom Doppler line shapes can be well described by a single Gaussian function, which corresponds to a statistical Maxwell–Boltzmann-like distribution of the translational energy. From the measured H and D atom Doppler profiles the average H and D atom kinetic energy was determined to be ET(H)=(137±10) kJ/mol and ET(D)=(115±4) kJ/mol, respectively. The average kinetic energies were found to be in reasonable agreement with results from simple statistical calculations in which it is assumed that H–D atoms are produced in combination with NCO in the ground electronic state (X̃ 2Π). A dissociation mechanism is suggested in which H–D atom formation proceeds via a statistical unimolecular decay of a hot H–DNCO intermediate formed by a radiationless transition of the optically excited bound H–DNCO state to a lower-lying dissociative state.

‘‘Dynamical’’ versus ‘‘statistical’’ rotational distributions in hyperthermal NO–Pt(111) scattering

Rotational distributions from NO–Pt(111) scattering have been reported [Wiskerke et al., J. Chem. Phys. 102, 3835 (1995)]. At lower incoming energies (<1 eV) clear rotational rainbows are seen, but the distributions for higher energies approach Boltzmann distributions with apparent temperatures far exceeding the surface temperature. We compare here the NO–Pt(111) scattering distributions to the predictions of a simple statistical model. The model assumes randomization of the available energy, subject to (partial) conservation of parallel linear momentum and angular momentum about the surface normal. Some characteristics of the rotational and angular distributions which arise from such a statistical energy repartitioning are discussed and compared to experimental results. It is seen that a combination of peaked angular distributions and Boltzmann-type rotational distributions independent of the scattering angle are reproduced by a simple statistical calculation with partial conservation of parallel linear momentum. For the NO–Pt(111) system, it is shown that a complete description of the high-energy scattering requires specifically dynamical assumptions. The transition from ‘‘dynamics’’ to ‘‘statistics’’ most likely arises from a combination of increased averaging, resulting from a competition between scattering via different regions of the potential energy surface, and a weakening of the rainbow features, perhaps due to the onset of chattering collisions.

Noise studies for detection limits for some electrothermal atomic absorption determinations and calculation of the optimal detection limit from one atomization

A simple statistical calculation, confirmed experimentally, shows that in Zeeman-effect electrothermal atomic absorption spectrometry the value of the integrated absorbance [graphic omitted] measured during a time t in the absence of neutral atoms can be broken down into two terms according to [graphic omitted] In this relationship mi is a constant, different for each atomization indicated by the index i, and x is a random value whose standard deviation can be calculated from the standard deviation and the number of measurements of the instantaneous absorbance. The calculation of mi allows one to decrease the error due to the integration of the blank signal and, therefore, to decrease the detection limit. If a non-negligible variation of the mi value is induced in the atomization step, calculation of mi after this step is more advisable. For the tested apparatus, the proposed post-atomization correction improves the accuracy of measurements and reduces the instrumental detection limit (IUPAC). An improvement by a factor of 5 is obtained, for example, for the detection limit of aluminium with an integration time of 3 s. Moreover, it has been shown for manganese and aluminium that the value of the detection limit obtained after correction is very similar to that calculated from a single atomization using the following equation resulting from statistical approximations: [graphic omitted] where s is the standard deviation of the instantaneous blank absorbances, Ts the sampling rate, tint the integration time, m the mass of metal injected and QA the corresponding measured integrated absorbance. The use of this equation, which is based on the measurement of the real experimental noise from one atomization, can offer an important saving of time.

Site structure sensitivity of diene hydrogenation and isomerization reactions on MOS 2/ γ-Al 2O 3 catalysts

The hydrogenation and isomerization of two diene molecules, cis-1,3-pentadiene and 2-methyl1,3-butadiene (isoprene), have been performed at 50°C on a 13.8 wt% MoO 3/ γ-Al 2O 3 sulfided hydrotreating catalyst. The alumina support was not active for hydrogenation and its activity for isomerization was found poisoned by the presence of the MoS 2 phase. The observed diene hydrogenation and isomerization activities are therefore attributed to the sulfide phase. Both the activity and the product distribution have been found strongly dependent on the sulfur content of the ( 1 010) edge plane of the MoS 2 slabs. In that edge plane all the Mo ions are similar. Therefore the active sites responsible for the various catalytic functions must be distinguished on the basis of the environment of the Mo ions. More precisely hydrogenation has been found sensitive to Mo ions tricoordinatively unsaturated (cus) and isomerization to 2-cus and 4-cus Mo ions. However, as each vacancy or sulfur ion is shared by two Mo ions in the ( 1 010) edge plane, a full description of the sites leads us to consider an “elementary ensemble” of two Mo ions and their six associated sulfur ions and/or vacancies. The active sites responsible for the different catalytic functions observed correspond primarily to different configurations of sulfur ions and vacancies in the “elementary ensemble” or, in other words, to different site structures. It is shown that due to its strongly preferred 3–4 hydrogenation, the reaction scheme of isoprene hydrogenation is simple enough to correspond to a catalytic function for each product. It is then shown that different site structures could be assigned to each of these functions and that simple statistical calculations can satisfactorily explain the experimental product distribution. The selectivity and activity of the catalyst for the diene hydrogenation and isomerization reactions studied are therefore dependent on the structure of the sites present in the ( 1 010) edge plane of the MoS 2 slabs.