Logarithm Of Number Research Articles

14 - Give It A Shot: Participation in Just-in-Time Immunization Workshop Followed by Peer Influenza Vaccination is Associated with Improved Resident Confidence in Immunization Skills

The Accreditation Council for Graduate Medical Education (ACGME) Pediatric Residency Program Requirements state that residents must demonstrate competence in immunization administration. Despite a required simulation immunization workshop, graduate survey results indicate that our residents do not feel prepared to perform this procedure. Residents identify a lack of opportunities to vaccinate in a non-simulation supervised environment as a contributor to their lack of confidence. The Center for Disease Control recommends, and hospital policy requires, that all residents receive the influenza vaccine unless contraindicated. This can be logistically challenging due to schedule restrictions. A just-in-time (JIT) immunization workshop followed by peer influenza vaccination could provide an opportunity for residents to receive their vaccination at work and gain experience vaccinating in a supervised environment. To assess the impact of a JIT immunization workshop preceding peer influenza vaccination on resident confidence in their immunization skills. We developed a voluntary session including a review of immunization administration and JIT simulated practice followed by supervised peer vaccination. All residents were surveyed one month post session rating their confidence administering immunizations on a 5-point Likert scale. Mann Whitney U test was used to compare residents who participated to those who did not. One third of residents participated in the session (N = 30). On one month follow up, residents who participated were more likely to report feeling confident in their immunization skills than those who did not (P = .02). A JIT immunization workshop followed by peer influenza vaccination provides an opportunity for residents to receive their required immunization at work and is associated with improved resident confidence in their procedural skills. Next steps include assessing if session implementation is associated with changes in ACGME graduate survey results and number of immunizations residents log.

Abstract 1714: A multifactorial model of T-cell expansion and durable clinical benefit in response to a PD-L1 inhibitor

Abstract There is an urgent need to improve prediction of patient response to checkpoint inhibitor immunotherapy. Checkpoint inhibitors have achieved unprecedented successes in treating late-stage cancers, but response rates vary across patients, and known biomarkers for response such as high mutation load are not predictive for every patient. Predicting response to checkpoint inhibitors is a critical priority for avoiding adverse responses, identifying additional patients who may benefit, and accelerating the development of new treatments. A key challenge for predicting response is modeling features of the immune system and cancer simultaneously. Recently, clinicians have begun to collect a wealth of molecular tumor and immune system data before and during immunotherapy, but researchers have yet to model how molecular and clinical features interact to affect response. To address this challenge, we developed multifactorial models for response to checkpoint inhibitors. Our approach is based off of the elastic net–a machine learning method for regression that automatically selects informative features from the data–and models clinical, tumor, and immune system features simultaneously. We applied our model to data from Snyder et al. (PLoS Medicine, 2017), who measured mutations and gene expression in the tumor and T-cell receptor (TCR) sequences in the tumor and blood in 29 urothelial cancers treated with anti-PD-L1. Rather than model the clinical response of each patient directly, we modeled the response of each patient's immune system and used the predicted immune responses to stratify patients based on expected clinical benefit. By modeling the immune response, we have the advantage of predicting fine-grained, molecular measurements that are predictive of clinical response. Our models predict immune response with high accuracy, and that predicted immune response is associated with durable clinical benefit (DCB). In held-out patients, our model explains 79% of the variance of the log number of T-cell clones in the tumor that expand in the blood post-therapy. The magnitude of the predicted expansion is associated with DCB, as 100% of held-out patients with DCB have predicted scores above the median score of held-out patients without DCB. Notably, mutation load alone did not demonstrate significant association with DCB. We also evaluated the importance of the tumor, immune system, and clinical features to our model. Our model requires all three feature classes to make accurate predictions and can explain at most 23% of the held-out patient variance when at least one of the classes is removed. Taken together, these results show that models for immune response may be useful for predicting clinical response to immunotherapy and that noninvasive TCR sequencing in the blood may be an effective way to monitor patient response. Citation Format: Mark D. Leiserson, Vasilis Syrgkanis, Amy I. Gilson, Miroslav Dudik, Samuel A. Funt, Alexandra Snyder, Lester Mackey. A multifactorial model of T-cell expansion and durable clinical benefit in response to a PD-L1 inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1714.

Experimental and Analytical Investigation of Heat Transfer Coefficient of a Water Cooled Condenser for Different Water Flows and Condensation Pressures

In the phase change process, latent heat is transferred and the amount of heat transferred will be excessive high compared to the amount of sensible heat transfer. For that reason, condensation and evaporation processes are the main steps in the refrigeration cycle in order to increase the amount of heat transferred. The main objective of this study is to experimentally and analytically examine overall heat transfer coefficient and to present the effect of water flow and refrigerant pressure on condensation process. For this purpose, a refrigeration system where a water cooled condenser with a heat transfer surface area of 0.075 m2 was installed. R134a was used as a refrigerant and condenses on the outer surface of the pipe that water circulates through. In this study, experiments were repeated for water mass flow rates of 15, 20, 25, 30 and 35 g/s at constant 7.0 bar condensation pressure. Then, condensation pressures were changed to 6.5, 6.75, 7.0, 7.25 and 7.5 bar at constant water flow rates of 25 g/s. Correlation of condensation heat transfer coefficient has been applied to refrigerant side of the condenser unit. On the other side, logarithmic mean temperature difference (LMTD) and number of transfer unit (ε-NTU) methods have been applied to experimental results in order to calculate heat transfer coefficient. Experimental results for different water flow rates at constant refrigerant pressure and for different condensation pressures at constant water flow rate are taken from the refrigeration machine unit and have been compared with calculated values that are obtained from condensation heat transfer correlation.

Operational Performance of the Selective Cutting of Trees With Chainsaw

ABSTRACT The objective was to obtain a statistical model to estimate the operational performance of cutting trees with a chainsaw in the natural tropical forest north of Mato Grosso state. One-hundred-and-fifty-one operational cycles of selective logging for commercial purposes were registered. In each cycle, the effective time for cutting, the diameter of the trees, commercial height, the number of logs per tree, and the distance between trees was determined. A step-by-step regression analysis was performed to obtain the coefficients of the models and statistical parameters. The result of the analysis concluded that the most accurate model to estimate the operational performance is the one that transforms the diameter variable at breast height (DBH) squared and also includes the variables number of logs per tree and distance between logged trees.

Online Minimum Spanning Tree with Advice

In the online minimum spanning tree problem, a graph is revealed vertex by vertex; together with every vertex, all edges to vertices that are already known are given, and an online algorithm must irrevocably choose a subset of them as a part of its solution. The advice complexity of an online problem is a means to quantify the information that needs to be extracted from the input to achieve good results. For a graph of size [Formula: see text], we show an asymptotically tight bound of [Formula: see text] on the number of advice bits to produce an optimal solution for any given graph. For particular graph classes, e.g., with bounded degree or a restricted edge weight function, we prove that the upper bound can be drastically reduced; e.g., [Formula: see text] advice bits allow to compute an optimal result if the weight function equals the Euclidean distance; if the graph is complete and has two different edge weights, even a logarithmic number suffices. Some of these results make use of the optimality of Kruskal’s algorithm for the offline setting. We also study the trade-off between the number of advice bits and the achievable competitive ratio. To this end, we perform a reduction from another online problem to obtain a linear lower bound on the advice complexity for any near-optimal solution. Using our results finally allows us to give a lower bound on the expected competitive ratio of any randomized online algorithm for the problem, even on graphs with three different edge weights.

Weighted log-linear models for service delivery points in Ethiopia: a case of modern contraceptive users at health facilities

BackgroundEthiopia is among countries with low contraceptive usage prevalence rate and resulted in high total fertility rate and unwanted pregnancy which intern affects the maternal and child health status. This study aimed to investigate the major factors that affect the number of modern contraceptive users at service delivery point in Ethiopia.MethodsThe Performance Monitoring and Accountability2020/Ethiopia data collected between March and April 2016 at round-4 from 461 eligible service delivery points were in this study. The weighted log-linear negative binomial model applied to analyze the service delivery point’s data.ResultsFifty percent of service delivery points in Ethiopia given service for 61 modern contraceptive users with the interquartile range of 0.62. The expected log number of modern contraceptive users at rural was 1.05 (95% Wald CI: − 1.42 to − 0.68) lower than the expected log number of modern contraceptive users at urban. In addition, the expected log count of modern contraceptive users at others facility type was 0.58 lower than the expected log count of modern contraceptive users at the health center. The numbers of nurses/midwives were affecting the number of modern contraceptive users. Since, the incidence rate of modern contraceptive users increased by one due to an additional nurse in the delivery point.ConclusionAmong different factors considered in this study, residence, region, facility type, the number of days per week family planning offered, the number of nurses/midwives and number of medical assistants were to be associated with the number of modern contraceptive users. Thus, the Government of Ethiopia would take immediate steps to address causes of the number of modern contraceptive users in Ethiopia.

Implementation of new hybrid lightweight cryptosystem

Embedded systems, Internet of Things (IoT) and mobile computing devices are used in various domains which include public-private infrastructure, industrial installation and critical environment. Generally, information handled by these devices is private and critical. Therefore, it must be appropriately secured from different attacks and hackers. Lightweight cryptography is an aspiring field which investigates the implementation of cryptographic primitives and algorithms for resource constrained devices. In this paper, a new compact hybrid lightweight encryption technique has been proposed. Proposed technique uses the fastest bit permutation instruction PERMS with S-box of PRESENT block cipher for non-linearity. An arbitrary n-bit permutation is performed using PERMS instruction in less than log (n) number of instructions. This new hybrid system has been analyzed for software performance on Advanced RISC Machine (ARM) and Intel processor whereas Cadens tool is used to analyze the hardware performance. The result of the proposed technique is improved by the factor of eight as compared to the PRESENT-GRP hybrid block cipher. Moreover, PERMS instruction bit permutation properties result a very good avalanche effect and compact implementation in the both hardware and software environment.

Microbiological Condition of Retail Beef Steaks: A Canadian Survey

The second national baseline microbiological survey of beef steaks offered for retail in Canada was conducted in 2015. A total of 621 steaks of four types (cross rib, CR; inside round, IR; striploin, SL; top sirloin, TS) collected from 135 retail stores in five cities across Canada were tested. Swab samples each from swabbing the entire upper surface of each steak were processed for enumeration of seven groups of indicator organisms: total aerobes (AER), psychrotrophs (PSY), lactic acid bacteria (LAB), pseudomonads (PSE), Brochothrix thermosphacta (BRO), coliforms (COL) and Escherichia coli (ECO). The overall mean values (log CFU/100 cm2) were 5.17±1.29, 4.92±1.36, 4.79±1.42, 3.26±1.49, 2.34±1.88, and 0.80±1.05 for AER, PSY, LAB, PSE, BRO, and COL, respectively. ECO were not recovered from 87.3% of the steaks and when there was recovery, the numbers were mostly ≤ 1 log CFU/100 cm2. Strong correlation was found between the log numbers of AER and PSY, of AER and LAB, and of PSY and LAB, while the correlation between the log numbers of COL and ECO was weak. The numbers of COL and ECO from different groups of steak types or from different cities were not substantially different. Of the four types of steaks, IR had the lowest median values for AER, PSY, LAB, PSE and BRO, followed by CR. The microbiological condition of retail beef steaks in this survey was on par with that in the previous one, with very low numbers of generic E. coli being recovered from very few steaks and the indicators for microbial quality being at numbers much lower than the upper limit for shelf life of beef.

A note on some constants related to the zeta-function and their relationship with the Gregory coefficients

In this article, new series for the first and second Stieltjes constants (also known as generalized Euler’s constant), as well as for some closely related constants are obtained. These series contain rational terms only and involve the so-called Gregory coefficients, which are also known as the (reciprocal) logarithmic numbers, the Cauchy numbers of the first kind and the Bernoulli numbers of the second kind. In addition, two interesting series with rational terms for Euler’s constant $$\gamma $$ and the constant $$\ln 2\pi $$ are given, and yet another generalization of Euler’s constant is proposed and various formulas for the calculation of these constants are obtained. Finally, we mention in the paper that almost all the constants considered in this work admit simple representations via the Ramanujan summation.

At which spatial and temporal scales can fungi indicate habitat connectivity?

Isolation of habitats in space and time affects species globally and in a multitude of ecosystems. It is however often difficult to assess the level of isolation from the point of view of the focal species. Indicator species are often used to assess ‘conservation value’ of habitats. One such approach involves the use of wood-decaying fungal species as indicators of near-natural forests, continuity in old-forest characteristics over time, and/or presence of red-listed species, but not of spatial connectivity. The indicator species were commonly assigned based on expert opinions, but few scientific evaluations have been performed of what these species actually indicate. Building on previous classifications of wood-decaying fungal indicator species on Norway spruce, we hypothesized that indicator species would differ from non-indicator species in how they respond to local temporal connectivity (forest age, the intensity of historical selective logging and the presence of well-decomposed large logs), and to local and landscape-scale spatial connectivity (local forest area, local amount of deadwood and the connectivity to old forest in the surrounding landscape). Based on fungal occurrence data from a fixed number of spruce logs at 28 sites distributed across the Scandinavian Peninsula, we explored the spatiotemporal scales at which the local communities were affected by connectivity. Indicator species showed the strongest response to connectivity of old forest (≥80 years) within 100 km, while non-indicator species depended on connectivity of younger forest (≥40 years) at a smaller spatial scale (≤25 km). Indicator species increased and non-indicator species decreased in total abundance with the increasing age of the local forest stand. Landscape-scale old-forest connectivity was beneficial for indicator species in all sites except those with relatively low amount of deadwood, while non-indicator species showed the opposite pattern. We identify a threshold of around 29 m3 ha−1 in the amount of spruce logs where indicator species become abundant enough to influence non-indicator species through competitive interactions. There was a pronounced uniformity within each species group in the connectivity responses. We conclude that the studied indicator species indicate high forest age, high amount of resources and, given that the resources are plentiful, also high old-forest connectivity, but they do not indicate a long history without any logging operations or local deadwood continuity. The studied non-indicator species did not indicate any of the studied spatiotemporal connectivity variables. Indicator species are usually red-listed and may continue to decline in the future without habitat restoration efforts.

Using online media-sourced seizure data to assess the illegal wildlife trade in Siamese rosewood

SUMMARYThe illegal wildlife trade is covert by nature, and thus is often challenging to study. Seizure data is traditionally the most common means to gain insight into the trade for many species. Online media-sourced seizure records were applied to study the illegal trade of Siamese rosewood (Dalbergia cochinchinensis), one of 33 timber species of hongmu (rosewood), which is logged to produce luxury products predominantly for Chinese markets. Despite recent international pressure to strengthen the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regulations, illegal trade of Siamese rosewood is prevalent in its range states. This paper will explore seizure reports in Thai online media and analyse spatial, temporal and other factors that potentially explain the trade. Between January 2014 and April 2016, 835 independent seizures were reported in 37 of 76 provinces in Thailand. Seizures occurred mostly in the north-eastern and eastern provinces with higher numbers of seizures closer to the border. The number of seizure reports decreased over time, and the average number of logs seized per seizure was consistent over the 28-month study period. Inadequate domestic legislation is a key factor facilitating the trade. Improvements are needed to the legislation and enforcement ahead of implementing other regional timber-specific initiatives and regulations. In this specific context, CITES also appears to be unacknowledged and ineffective in hampering the Siamese rosewood trade. Importantly, we find that using media-sourced seizure data is highly apt in Thailand's context, considering Thailand's sensitive political state and the prevalence of trade in other non CITES-listed rosewood species. The approach demonstrated here is applicable to many other wildlife species.

An Improved Logarithmic Multiplier for Media Processing

As the modern computing systems become increasingly embedded and portable, a growing set of applications in media processing (graphics, audio, video, and image) has evolved. Multiplication is the operation that is most often used in these applications which when accomplished in logarithmic number system results in an area efficient and faster design. In this work, the authors describe a technique that combines Mitchell's approximation with a novel hardware truncation scheme resulting in an iterative multiplier with improved precision and reduced area. Further, a new fractional predictor combined with an existing truncated logarithmic shifter significantly reduces the overall hardware cost of the multiplier. Simulations carried out on benchmark image processing applications such as Lena, cameraman and pirate clearly indicate that the proposed technique performs better than those available in the literature.

Improved quantum backtracking algorithms using effective resistance estimates

We investigate quantum backtracking algorithms of a type previously introduced by Montanaro (arXiv:1509.02374). These algorithms explore trees of unknown structure, and in certain cases exponentially outperform classical procedures (such as DPLL). Some of the previous work focused on obtaining a quantum advantage for trees in which a unique marked vertex is promised to exist. We remove this restriction and re-characterise the problem in terms of the effective resistance of the search space. To this end, we present a generalisation of one of Montanaro's algorithms to trees containing $k \geq 1$ marked vertices, where $k$ is not necessarily known \textit{a priori}. Our approach involves using amplitude estimation to determine a near-optimal weighting of a diffusion operator, which can then be applied to prepare a superposition state that has support only on marked vertices and ancestors thereof. By repeatedly sampling this state and updating the input vertex, a marked vertex is reached in a logarithmic number of steps. The algorithm thereby achieves the conjectured bound of $\widetilde{\mathcal{O}}(\sqrt{TR_{\mathrm{max}}})$ for finding a single marked vertex and $\widetilde{\mathcal{O}}\left(k\sqrt{T R_{\mathrm{max}}}\right)$ for finding all $k$ marked vertices, where $T$ is an upper bound on the tree size and $R_{\mathrm{max}}$ is the maximum effective resistance encountered by the algorithm. This constitutes a speedup over Montanaro's original procedure in both the case of finding one and finding multiple marked vertices in an arbitrary tree. If there are no marked vertices, the effective resistance becomes infinite, and we recover the scaling of Montanaro's existence algorithm.

Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound.

Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic–terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

Seismic sedimentology of sand-gravel bodies on the steep slope of rift basins — A case study of the Shahejie Formation, Dongying Sag, Eastern China

A variety of genetic types of reservoirs with good hydrocarbon accumulation conditions have been developed in petroliferous rift basins. The near-provenance, coarse-grained depositional system on the steep slopes of rift basins has become an important oil and gas exploration area. However, due to the large changes in lithologies and difficulties in its identification and characterization, the challenges in oil/gas exploration are significant. Seismic sedimentology, in this case, provides an effective means of identifying and characterizing the complex, coarse-grained sediments. We use a large number of cores, logs, and seismic data and establish the third- and fourth-order sequence frameworks in the Shahejie Formation on the steep slope of the northern Dongying Sag in eastern China. Three types of lithofacies, including conglomerates, sandstones, and mudstones with 12 subspecies facies types have been identified and the relationship between different lithofacies types and depositional systems is determined. The relative changes of the lake level control the distribution of depositional systems in a sequence framework. Lowstand system tracts of SQ3 and SQ4 in the Shahejie Formation mainly developed near-shore subaqueous fans and a small number of slump turbidite fans. Small-scale offshore fans mainly develop in lacustrine transgressive systems tracts, and fan deltas, flood-type sublake fans, slump turbidite fans, and near-shore subaqueous fans mainly developed in highstand systems tracts. The study of seismic sedimentology, based on the theory of seismic lithology and seismic geomorphology, have been carried out. Stratal slices are used to identify and characterize the morphology and temporal-spatial distributions of various types of sand-gravel bodies on the steep slopes of the Dongying Sag based on core calibration and establish the model of seismic sedimentology for various types of sand-gravel bodies in different systems tracts.

Contextual factors influence work outcomes in employed patients with ankylosing spondylitis starting etanercept: 2-year results from AS@Work.

The aim was to determine changes over time in work outcomes and investigate the predictive value of baseline personal and work-related factors on the evolution of work outcomes among employed patients with AS initiating etanercept. Employment status, absenteeism and presenteeism were assessed using the Work Productivity and Activity Impairment for AS questionnaire in a 24-month open-label, observational study (NCT01421303). The potential effect of baseline factors on work outcomes was analysed using predictive modelling (Cox regression and linear mixed models). After 24 months, 11/75 (14.7%) patients had permanently withdrawn from employment (seven because of AS). Absenteeism and presenteeism decreased significantly within 6 months of etanercept treatment and remained stable thereafter. Predictive modelling indicated that male sex (hazard ratio = 0.18; 95% CI: 0.04, 0.85), (log) number of working hours per week (hazard ratio = 0.13; 95% CI: 0.03, 0.51) and the possibility of developing skills (hazard ratio = 0.42; 95% CI: 0.19, 0.91) positively influenced time in employment. Over time, lower absenteeism was significantly associated with the quality of contact with colleagues [coefficient (s.e.): -0.35 (0.10)] and importance of the job for quality of life [-0.49 (0.17)], and higher absenteeism with current smoking [1.66 (0.44)] and change in job because of illness [1.51 (0.66)]. Over time, lower presenteeism was associated with male sex [-14.5 (2.64)], the possibility of postponing work [-6.60 (2.73)], quality of contact with colleagues [-2.04 (0.96)] and >50 workers in the company [-7.65 (2.76)], and higher presenteeism with manual profession [8.41 (2.72)]. Contextual factors influence work outcomes over time and should not be ignored when aiming to improve work outcomes in patients with AS. ClinicalTrials.gov, http://clinicaltrials.gov, NCT01421303.

Equations to estimate processing and forwarding costs, while considering log size: clear-cutting operations in Nasunogahara, Tochigi prefecture, Japan

ABSTRACTThis study develops equations by which one can estimate processing and forwarding costs for clear-cutting operations, while considering log size and assuming moderately and gently sloping sites. Processing cycle times were estimated by using the average delimbing and bucking times related to average log volume and piling time related to the number of logs extracted from the stem. Forwarding cycle times were estimated by using the forwarding distance, the out-hauling and in-hauling travel velocities, and the loading and unloading time related to the number of loaded logs. The forwarding volume was estimated by using the relationship between the average log volume and the number of logs loaded on the forwarder. Differences in processing costs between 0.02 and 0.20 m3/log worked out to around USD 10.00/m3, whereas differences in forwarding costs between 0.02 and 0.20 m3/log worked out to around USD 4.00 and USD 7.00/m3 for thinning and clear-cutting operations, respectively. Finally, operational system costs were estimated: differences in operational system costs with the extraction of small-sized logs (and while not considering log size) between maximizing revenues and profits were USD 9.08, USD 9.05, and USD 9.36/m3 at Site A, Site B, and thinning operations, respectively. However, those costs ranged from USD 36.65 to USD 87.65/m3 for Site A, from USD 28.75 to USD 70.21/m3 for Site B, and from USD 27.71 to USD 70.81/m3 for thinning operations. Thus, costs should be estimated while duly considering log size.

The analysis and assessment of productivity in the processing of beech logs on the example of the selected production system in Serbia by applying statistical modeling

This paper presents the results of the study of the influence of the selected factors on the productivity of the processing of beech logs on the example of the selected producer of sawn timber in Serbia by applying statistical modeling. The analysis covered three basic factors that have an impact on productivity: the length, middle diameter and number of cuts on the logs of beech that were processed during the observed period. The research was carried out on a sample of 105 logs, and it contained various sizes of middle diameters, lengths and number of cuts. The research aimed to review the functional dependence of selected factors and productivity in order to reach appropriate conclusions, provide expert recommendations and measures to increase productivity and make appropriate forecasts of possible productivity values. In order to examine the functional dependence of the selected variables, statistical modeling was performed in SPSS, v.20 and MS Excel software packages, where the selected dependent variable is the number of logs processed in one hour, and as an independent variable the volume was taken into consideration (which contains the middle diameter and the length of the logs) and the number of cuts. Statistically obtained parameters showed a significant influence of the volume and number of cuts on the change of the number of logs which are processed in one hour. In the obtained regression model the correlation coefficient R is 0.994, while the coefficient of determination R2 = 0.988. Since in sawmill processing productivity is most often expressed as the volume of processed logs in the unit of time, a transformed form of the equation shows the dependence of the volume on the number of logs and the number of cuts. By setting the hypothesis and by interpreting the statistical indicators, it has been found that the impact of the analyzed factors is very high, but that, in addition to them, productivity is influenced by technical and organizational factors.

Analisis Kinerja High Pressure Heater (Hph) Tipe Shell and Tube Heat Exchanger

Heat exchanger is one of the supporting production equipment that move the heat energy from one of fluid to another fluid flow. One example of a heat exchanger in power plant industry is High Pressure Heater (HPH). HPH is high pressure feedwater heater that using hot steam turbine waste product used as heating medium before entering the economizer on boiler to reduce the work of boiler. This research was conducted to determine the effective efficiency of High Pressure Heater at Power Plant Industry. This efficiency determination is based on thermodynamics and heat transfer analysis with Log Mean Temperature Difference (LMTD) method and Number of Transfer Unit (NTU) method. The analysis is to determining the effective heat transfer, overall heat transfer coefficient (U), Effectiveness and the analysis of pressure drop (∆P). The analysis results obtained the efffective heat transfer of 37.013 kW, overall heat transfer coefficient (U) of 502,48, effectiveness of 0,47 and the number of pressure drop of 23.498,06 Pa.

The Analysis of the Influence Factors of China’s Outbound Tourism Market

Outbound tourism gets special attention from tourism academic circles and tourism companies recently. And now China has become the world’s largest outbound tourism consumer. So this paper is written to research the influence factors of China’s outbound tourism market, providing reference for the study of China’s outbound tourism market. The literature study have found that the number of China’s outbound tourism related to the duration of their leisure trips, exchange rate, residents’ deposits and the number of tourism agency. By using of the econometric methods and R-studio, we build a multiple linear regression model. In the end, we get a conclusion by quantitative analysis of data and qualitative analysis of tourism’s law. We found that there are linear relations exists in logarithm of the number of China’s outbound tourism, the residents’ deposits ,the logarithm of duration of their leisure trips and the logarithm of number of tourism agency.