Exponential Pattern Research Articles

Characteristic distribution of the total and individual item scores on the Kessler Screening Scale for Psychological Distress (K6) in US adults

BackgroundThe distributional pattern of total scores on depression screening scales in the general population has not been well studied. Recent studies suggest that the total scores on depression screening scales follow an exponential pattern, with the exception of the lower end of the distribution. To further investigate the findings, we determined the distributions of the total and individual item scores on the Kessler Screening Scale for Psychological Distress (K6).MethodsData were obtained from the National Survey of Midlife Development in the United States. Participants comprised 6,223 individuals between the ages of 25 and 74. The distributions of the total and individual item scores in various combinations were investigated with histograms and regression analysis.ResultsIrrespective of the combination of items, the total and individual item scores followed an exponential pattern except at the lower scores. The estimated rate parameters of regression analysis were similar among distributions with the same number of chosen items. At the lower scores, the distributional patterns of total scores varied according to the ratio of “a little” to “none” for each item response.ConclusionsThe present results have the potential to estimate the distribution of depressive symptoms in the general population. While the degree of depressive symptoms varies from individual to individual, an entire population may show a certain mathematical distribution.

MD and BCA simulations of He and H bombardment of fuzz in bcc elements

We present results of MD simulations of low energy He ion bombardment of low density fuzz in bcc elements. He ions can penetrate several micrometers into sparse fuzz, which allows for a sufficient He flux through it to grow the fuzz further. He kinetic energy falls off exponentially with penetration depth. A BCA code was used to carry out the same ion bombardment on the same fuzz structures as in MD simulations, but with simpler, 10 million times faster calculations. Despite the poor theoretical basis of the BCA at low ion energies, and the use of somewhat different potentials in MD and BCA calculations, the ion penetration depths predicted by BCA are only ∼12% less than those predicted by MD. The MD-BCA differences are highly systematic and trends in the results of the two methods are very similar. We have carried out more than 200 BCA calculation runs of ion bombardment of fuzz, in which parameters in the ion bombardment process were varied. For most parameters, the results show that the ion bombardment process is quite generic. The ion species (He or H), ion mass, fuzz element (W, Ta, Mo, Fe) and fuzz element lattice parameter turned out to have a modest influence on ion penetration depths at most. An off-normal angle of incidence strongly reduces the ion penetration depth. Increasing the ion energy increases the ion penetration, but the rate by which ion energy drops off at high ion energies follows the same exponential pattern as at lower energies.

On the Universal Quantitative Pattern of the Distribution of Initial Characters in General Dictionaries: The Exponential Distribution is Valid for Various Languages

A language is treated as a formal set of characters built into words. The distribution of initial characters in various general dictionaries is uneven. We demonstrate the existence of a consistent general pattern in the distribution of initial characters appearing in various dictionaries. This distribution is satisfactorily described by exponential fitting. The affined languages (related to the same language group) demonstrate close parameters of the exponential fitting curve. A separate treatment of consonants and vowels is instructive. The exponential pattern was registered for the checked physical (paperback) and electronic dictionaries.

Translocation of the neonicotinoid seed treatment clothianidin in maize.

Neonicotinoid seed treatments, typically clothianidin or thiamethoxam, are routinely applied to >80% of maize (corn) seed grown in North America where they are marketed as a targeted pesticide delivery system. Despite this widespread use, the amount of compound translocated into plant tissue from the initial seed treatment to provide protection has not been reported. Our two year field study compared concentrations of clothianidin seed treatments in maize to that of maize without neonicotinoid seed treatments and found neonicotinoids present in root tissues up to 34 days post planting. Plant-bound clothianidin concentrations followed an exponential decay pattern with initially high values followed by a rapid decrease within the first ~20 days post planting. A maximum of 1.34% of the initial seed treatment was successfully recovered from plant tissues in both study years and a maximum of 0.26% was recovered from root tissue. Our findings show neonicotinoid seed treatments may provide protection from some early season secondary maize pests. However, the proportion of the neonicotinoid seed treatment clothianidin translocated into plant tissues throughout the growing season is low overall and this observation may provide a mechanism to explain reports of inconsistent efficacy of this pest management approach and increasing detections of environmental neonicotinoids.

Analytical Evaluation of Saturation Throughput of a Cognitive WLAN Overlaid on a Time-Scheduled OFDMA Network

In this paper, we analyze the saturation throughput of a cognitive WLAN overlaid on a primary OFDMA TDD network (e.g., LTE or WiMAX). In this scenario, after the contention among the secondary nodes, the winner node transmits its data packet in the empty resource blocks (RBs) of downlink and uplink subframes of the primary network. Regarding the OFDMA structure as well as time-scheduled resources in the primary network, the time duration of opportunities for the secondary network does not follow simple exponential on-off pattern. To model the dynamic behavior of opportunities for secondary nodes as well as contentions to exploit the opportunities, we propose an analytical model comprised of a discrete-time Markov chain and two inter-related open multi-class queueing networks (QNs). The effects of the random number of empty resource blocks at different frames as the result of random amount of download and upload data, random packet transmission time at WLAN, the dependency of the number of empty RBs at consecutive frames, and the details of 802.11 MAC protocol are included in our analytical approach. We include different resource allocations in the primary network in our analysis. Simulation results confirm the accuracy of our analytical approach in different conditions.

Understanding tree growth responses after partial cuttings: A new approach.

Forest ecosystem management heads towards the use of partial cuttings. However, the wide variation in growth response of residual trees remains unexplained, preventing a suitable prediction of forest productivity. The aim of the study was to assess individual growth and identify the driving factors involved in the responses of residual trees. Six study blocks in even-aged black spruce [Picea mariana (Mill.) B.S.P.] stands of the eastern Canadian boreal forest were submitted to experimental shelterwood and seed-tree treatments. Individual-tree models were applied to 1039 trees to analyze their patterns of radial growth during the 10 years after partial cutting by using the nonlinear Schnute function on tree-ring series. The trees exhibited different growth patterns. A sigmoid growth was detected in 32% of trees, mainly in control plots of older stands. Forty-seven percent of trees located in the interior of residual strips showed an S-shape, which was influenced by stand mortality, harvested intensity and dominant height. Individuals showing an exponential pattern produced the greatest radial growth after cutting and were edge trees of younger stands with higher dominant height. A steady growth decline was observed in 4% of trees, represented by the individuals suppressed and insensitive to the treatment. The analyses demonstrated that individual nonlinear models are able to assess the variability in growth within the stand and the factors involved in the occurrence of the different growth patterns, thus improving understanding of the tree responses to partial cutting. This new approach can sustain forest management strategies by defining the best conditions to optimize the growth yield of residual trees.

Pattern analysis of total item score and item response of the Kessler Screening Scale for Psychological Distress (K6) in a nationally representative sample of US adults.

BackgroundSeveral recent studies have shown that total scores on depressive symptom measures in a general population approximate an exponential pattern except for the lower end of the distribution. Furthermore, we confirmed that the exponential pattern is present for the individual item responses on the Center for Epidemiologic Studies Depression Scale (CES-D). To confirm the reproducibility of such findings, we investigated the total score distribution and item responses of the Kessler Screening Scale for Psychological Distress (K6) in a nationally representative study.MethodsData were drawn from the National Survey of Midlife Development in the United States (MIDUS), which comprises four subsamples: (1) a national random digit dialing (RDD) sample, (2) oversamples from five metropolitan areas, (3) siblings of individuals from the RDD sample, and (4) a national RDD sample of twin pairs. K6 items are scored using a 5-point scale: “none of the time,” “a little of the time,” “some of the time,” “most of the time,” and “all of the time.” The pattern of total score distribution and item responses were analyzed using graphical analysis and exponential regression model.ResultsThe total score distributions of the four subsamples exhibited an exponential pattern with similar rate parameters. The item responses of the K6 approximated a linear pattern from “a little of the time” to “all of the time” on log-normal scales, while “none of the time” response was not related to this exponential pattern.DiscussionThe total score distribution and item responses of the K6 showed exponential patterns, consistent with other depressive symptom scales.

J-pouch versus Roux-en-Y reconstruction after gastrectomy: functional assessment and quality of life (randomized trial).

PurposeThe aim of this study was to evaluate the quality of life and functional emptying of J-pouch versus Roux-en-Y reconstruction after total gastrectomy for malignancy.MethodsThis study was designed as a prospective, nonblinded, randomized, parallel clinical trial (Trial Number: MN Ostrava, 200604). With informed consent, patients undergoing gastrectomy for malignancy were randomized to J-pouch or Roux-en-Y reconstruction. The time taken for a test semisolid meal labeled with 99mTc-sulfur colloid to exit the reconstructed parts was measured by dynamic scintigraphy 1 year after resection. Quality of life was measured using the Eypasch questionnaire at the same time as functional emptying assessment. This trial was investigator-initiated.ResultsIn all, 72 patients were included into the study. The time taken for the test meal to exit the postgastrectomy reconstruction was 16.5±10.0 minutes (mean ± standard deviation) in the Roux-en-Y group and 89.4±37.8 minutes in the “J-pouch” group; the difference was statistically significant (P<0.001). Emptying of the J-pouch appeared to be a linear decreasing function compared to the exponential pattern seen in the Roux-en-Y group. The quality of life measurement showed scores of 106±18.8 points (mean ± standard deviation) in the Roux-en-Y group compared to 122±22.5 points in the J-pouch group; the difference was statistically significant (P=0.0016). There were no important adverse events.ConclusionAfter total gastrectomy, a J-pouch reconstruction empties more slowly and is associated with higher quality of life compared to Roux-en-Y reconstruction. Whether these two observations have a direct causative link remains unanswered.

The evolutionary traverse: a causal analysis.

This paper explores the process of adaptation to new methods in a simple model where the growth rate of labour supply is exogenously given and constant. It shows that competition for a primary input in short supply changes the mechanism of adaptation and its consequences: If surplus labour exists, differential capacity accumulation effectuates adaptation and leads to a logistic replacement pattern; but if labour is in short supply, ‘growth predation’ undermines the former mechanism and leads to an exponential replacement pattern. The consequences of the quantitative adjustment mechanisms for aggregate growth are discussed by means of a ‘causal analysis’, which focuses on the properties of the traverse between two full-employment steady states. The analysis reveals that different types of new methods lead to different adaptation paths and results. Overall, adaptation entails unsteady growth and it is not always the case that the diffusion of a new method boosts aggregate growth.

Relationship between Item Responses of Negative Affect Items and the Distribution of the Sum of the Item Scores in the General Population.

BackgroundSeveral studies have shown that total depressive symptom scores in the general population approximate an exponential pattern, except for the lower end of the distribution. The Center for Epidemiologic Studies Depression Scale (CES-D) consists of 20 items, each of which may take on four scores: “rarely,” “some,” “occasionally,” and “most of the time.” Recently, we reported that the item responses for 16 negative affect items commonly exhibit exponential patterns, except for the level of “rarely,” leading us to hypothesize that the item responses at the level of “rarely” may be related to the non-exponential pattern typical of the lower end of the distribution. To verify this hypothesis, we investigated how the item responses contribute to the distribution of the sum of the item scores.MethodsData collected from 21,040 subjects who had completed the CES-D questionnaire as part of a Japanese national survey were analyzed. To assess the item responses of negative affect items, we used a parameter r, which denotes the ratio of “rarely” to “some” in each item response. The distributions of the sum of negative affect items in various combinations were analyzed using log-normal scales and curve fitting.ResultsThe sum of the item scores approximated an exponential pattern regardless of the combination of items, whereas, at the lower end of the distributions, there was a clear divergence between the actual data and the predicted exponential pattern. At the lower end of the distributions, the sum of the item scores with high values of r exhibited higher scores compared to those predicted from the exponential pattern, whereas the sum of the item scores with low values of r exhibited lower scores compared to those predicted.ConclusionsThe distributional pattern of the sum of the item scores could be predicted from the item responses of such items.

Boundary curves of individual items in the distribution of total depressive symptom scores approximate an exponential pattern in a general population.

BackgroundPreviously, we proposed a model for ordinal scale scoring in which individual thresholds for each item constitute a distribution by each item. This lead us to hypothesize that the boundary curves of each depressive symptom score in the distribution of total depressive symptom scores follow a common mathematical model, which is expressed as the product of the frequency of the total depressive symptom scores and the probability of the cumulative distribution function of each item threshold. To verify this hypothesis, we investigated the boundary curves of the distribution of total depressive symptom scores in a general population.MethodsData collected from 21,040 subjects who had completed the Center for Epidemiologic Studies Depression Scale (CES-D) questionnaire as part of a national Japanese survey were analyzed. The CES-D consists of 20 items (16 negative items and four positive items). The boundary curves of adjacent item scores in the distribution of total depressive symptom scores for the 16 negative items were analyzed using log-normal scales and curve fitting.ResultsThe boundary curves of adjacent item scores for a given symptom approximated a common linear pattern on a log normal scale. Curve fitting showed that an exponential fit had a markedly higher coefficient of determination than either linear or quadratic fits. With negative affect items, the gap between the total score curve and boundary curve continuously increased with increasing total depressive symptom scores on a log-normal scale, whereas the boundary curves of positive affect items, which are not considered manifest variables of the latent trait, did not exhibit such increases in this gap.DiscussionThe results of the present study support the hypothesis that the boundary curves of each depressive symptom score in the distribution of total depressive symptom scores commonly follow the predicted mathematical model, which was verified to approximate an exponential mathematical pattern.

Open system models of isotopic evolution in Earth’s silicate reservoirs: Implications for crustal growth and mantle heterogeneity

An open system evolutionary model of the Earth, comprising continental crust (CC), upper and lower mantle (UM, LM), and an additional isolated reservoir (IR) has been developed to study the isotopic evolution of the silicate Earth. The model is solved numerically at 1Myr time steps over 4.55Gyr of Earth history to reproduce both the present-day concentrations and isotope ratios of key radioactive decay systems (Rb–Sr, Sm–Nd, and U–Th–Pb) in these terrestrial reservoirs. Various crustal growth scenarios – continuous versus episodic and early versus late crustal growth – and their effect on the evolution of Sr–Nd–Pb isotope systematics in the silicate reservoirs have been evaluated. Modeling results where the present-day UM is ∼60% of the total mantle mass and a lower mantle that is non-primitive reproduce the estimated geochemical composition and isotope ratios in Earth’s silicate reservoirs. The isotopic evolution of the silicate Earth is strongly affected by the mode of crustal growth; only an exponential crustal growth pattern with crustal growth since the early Archean satisfactorily explains the chemical and isotopic evolution of the crust–mantle system and accounts for the so-called Pb paradoxes. Assuming that the OIB source is located in the deeper mantle, our model could, however, not reproduce its target ɛNd of +4.6 for the UM, which has been estimated from the average isotope ratios of 32 individual ocean island localities. Hence, either mantle plumes sample the LM in a non-representative way, or the simplified model set-up does not capture the full complexity of Earth’s lower mantle (Nd isotope) evolution. Compared to the results obtained for a 4.55Ga Earth, a model assuming a protracted U–Pb evolution of silicate Earth by ca. 100Myr reproduces a slightly better fit for the Pb isotope ratios in Earth’s silicate reservoirs. One notable feature of successful models is the early depletion of incompatible elements (as well as rapid decrease in Th/U) in the UM within the initial 500Myr, as a result of early formation of CC, which supports other evidence in favor of the presence of Hadean continental crust. Therefore, a chondritic Th/U ratio (4±0.2) in the UM until 2Gyr appears rather unlikely. We find that the κ conundrum – the observation that measured Th/U ratios and those deduced from 208Pb–206Pb isotope systematics differ – is a natural outcome of an open system evolution in which preferential recycling of U for the past 2Gyr has played a dominant role. Overall, our simulations strongly favor exponential crustal growth, starting in the early Hadean, the transient preservation of compositionally distinct mantle reservoirs over billion year time periods, and a generally less incompatible element depleted, but non-primitive composition of the lower mantle.

The dynamics of the rise and fall of empires

The rise of empires can be elucidated by treating them as living organisms, and the celebrated Verhulst or Lotka–Volterra dynamics can be used to understand the growth mechanisms of empires. The fast growth can be expressed by an exponential function as in the case of Macedonian empire of the Alexander the Great whereas a sigmoidal growth can be expressed by power-law equation as in the case of Roman and Ottoman empires. The superpowers Russia and the USA follow somehow different mechanisms, Russia displays two different exponential growth behaviors whereas the USA follows two different power-law behaviors. They did not disturb and mobilize their social capacity much during the course of their rise. The decline and the collapse of an empire occur through a kind of fragmentation process, and the consequently formed small states become rather free in their behavior. The lands of the new states formed exhibit a hierarchical pattern, and the number of the states having an area smaller than the largest one can be given either by an exponential or power-law function. The exponential distribution pattern occurs when the states are quite free in their pursuits, but the power-law behavior occurs when they are under the pressure of an empire or a strong state in the region. The geological and geographical conditions also affect whether there occurs exponential or power-law behavior. The new unions formed such as the European Union and the Shanghai Cooperation increase the power-law exponent implying that they increase the stress in the international affairs. The viscoelastic behavior of the empires can be found from the scattering diagrams, and the storage [Formula: see text]and loss modulus [Formula: see text], and the associated work-like and heat-like terms can be determined in the sense of thermodynamics. The [Formula: see text] of Ottomans was larger than that of Romans implying that they confronted severe resistance during their expansion. The [Formula: see text] of Russia is also larger than that of the USA; in fact the USA did not face severe resistance as they had an overwhelming superiority over native Americans. The [Formula: see text] indicates solidity in the social structure and Romans, Ottomans, and Russians all have [Formula: see text] larger than [Formula: see text]. The [Formula: see text] is slightly larger than [Formula: see text] for the USA indicating that they have had a very flexible social structure. By the same token the ratio of the work-like term to the internal energy is larger for Ottomans than that of Romans, and larger for the USA than that of Russia. That means the fraction of the total energy allocated to improve the social capacity is larger for Romans than that of Ottomans, and is larger for Russians than that of the USA.

Effects of Low Temperature Cooking on the Retention of 4-(Methylthio)-3-Butenyl Isothiocyanate (MTBITC) of Chinese White Radish (Raphanussativus L.)

This paper studied the effects of different cooking conditions (methods, temperatures and time) on the retention rate of 4-(methylthio)-3-butenyl isothiocyanate (MTBITC) in Chinese white radish by using a method of ultrasound extraction coupled with gas chromatography—flame ionization detector (GC-FID). Results showed that the retention rate of MTBITC decreased with increasing cooking time and temperatures. The retention rate of MTBITC declined dramatically after holding for 1 min at 85 or 95 °C. The fitted equations demonstrated that the degradation of MTBITC followed an exponential decay pattern for non-microwave (water bath or steam stove) cooking, while for microwave cooking, the degradation of MTBITC followed approximately a linear decay.

Composition, size and relative density of diatoms in the stomach of 4 to 75 day-old juvenile abalone Haliotis diversicolor (Reeve)

The diatom biofilm that naturally grow on polyvinyl chloride plates serve as food of postlarva and juvenile abalone Haliotis diversicolor Reeve, called “tokobushi” in Japanese. Composition, size and relative density of diatoms in the stomach of 4, 7, 10, 13, 17, 21, 27, 35, 50 and 75 day-old tokobushi were evaluated to characterize their diatom intake. Stomach in glycol methacrylate resin was sectioned and examined under the light microscope, then analyzed using an image processing software. The diatoms present in the stomach of tokobushi were Thalassiosira, Melosira, Triceratium, Odontella, Asterionella, Licmophora, Thalassionema, Cocconeis, Navicula and Nitzschia. Only four varieties of diatoms were observed in 4 to 10 day-old tokobushi which coincided with initial feeding. The number and size of diatoms increased in 13 to 75 day-old juvenile, which were exhibited in its exponential growth pattern. The stomach of 4 to 13 day-old tokobushi contained small-sized diatoms (&lt;67 µm) while both small and large-sized diatoms (&gt;123 µm) were observed in 17 to 75 day-old juveniles. Higher relative densities (8.7 – 15.8 diatom/1000 µm2) of diatoms were documented in 4 to 10 day-old tokobushi while 17 to 75 day-old exhibited lower relative densities (1.2 – 4.2 diatom/1000 µm2). Generally, as young tokobushi increases in size, the diatom intake increases in composition and size but density decreases with increasing size of diatom ingested.

Spatial Dynamics Model for Sustainability Landscape in Cimandiri Estuary, West Java, Indonesia

Population in Estuary Cimandiri area and the Pelabuhanratu Town increase continuously, which will cause an occurrence of land use changes from open space to built-up area. Due to the need of built up area, while the existing land area is very limited, so the shortage land will occur in the future. In this context, spatial dynamic model based on a combination between system dynamics and Geographic Information System (GIS) has to be elaborated for land availability model in Cimandiri Estuary, West Java. Thus, the existing surface can be a sustainability landscape. Population growth projection has an exponential growth pattern. Built-up area variable has a sigmoid pattern, which means that the land in estuarine area will be occupied for built-up activities in the future. Land availability variable has a decay pattern, which means that the available land will be run out to be used up by human settlement. The relationship between population growth and land availability will be contradictory. The intervention effect 60% ratio land restriction of built-up area will delay the development of built-up area, and after those delays it will remain constant. The projection of populations growth is implemented through projection development of built-up area which adapted by the landscape to be a sustainability landscape.

FLORISTIC-STRUCTURAL CHARACTERIZATION AND SUCCESSIONAL GROUP OF TREE SPECIES IN THE CERRADO BIOME OF TOCANTINS STATE, BRAZIL

ABSTRACT: The objective of this study was to characterize the floristic composition, vegetation structure and ecological group of tree species in a cerradão forest (Cerrado biome) of Palmas, Tocantins State, Brazil. A forest inventory was performed in an area of 10.15 hectares, using systematic sampling with plots of 400 m², in which all standing trees, alive and dead, that had diameter at breast height (DBH) ≥ 5 cm were sampled and identified. A linear plateau regression model (LPR) was used for sample sufficiency analysis. The Shannon index (H') was used for assess the floristic diversity, and the Importance Value Index (IVI) for assess the horizontal structure. The forest was classified in three strata according to vertical structure analysis. The LPR showed that the sampling size was adequate. The predominate species in the area were Myrcia splendens, Emmotum nitens and Qualea parviflora, and species from the families Fabaceae and Chrysobalanaceae. The pioneer (613 individuals ha-1) and climax (530 individuals ha-1) species were the predominating groups. Regarding the richness index, the number of climax (57 species) and pioneer (25 species) species stood out. The alpha floristic diversity was 3.35 nats individuals-1 and the Pielou equability value J = 0.76. The diametric distribution showed a negative and balanced exponential pattern. Regarding the vertical stratification, the smallest amount of individuals was in the upper stratum (13%) and the highest in the mid stratum (63%) and in the lower stratum (24%). The use of floristic composition tools with horizontal and vertical structure analysis was effective for understand the tree community, which may be considered structured and diverse, thus able to restructure possible disturbances when preserved.

Growth kinetics and complex characterization of PECVD SiOxNy dielectric films

This paper is devoted to the study of patterns of dielectric film growth depending on the parameters of the plasma chemical deposition process. The study has revealed the influence of the basic reagents’ content on the changes in surface morphology, breakdown voltage and stoichiometry (transition to the intermediate oxidation states of silicon) of dielectric films. Furthermore, an exponential pattern of the change in the films’ growth rate has been registered. When increasing the N/Si ratio, a nonlinear dependence of the change in the dielectric films’ band gap has been recorded. When increasing the SiH4/N2O ratio, a shift of the peak positions of the interband interactions relative to the band gap boundaries has been detected. The dataset on breakdown voltage and band structure suggests a certain optimum of barrier properties of SiOxNy dielectric films at the basic reagents’ ratio close to 0.3–0.4.

Skimming Digits: Neuromorphic Classification of Spike-Encoded Images.

The growing demands placed upon the field of computer vision have renewed the focus on alternative visual scene representations and processing paradigms. Silicon retinea provide an alternative means of imaging the visual environment, and produce frame-free spatio-temporal data. This paper presents an investigation into event-based digit classification using N-MNIST, a neuromorphic dataset created with a silicon retina, and the Synaptic Kernel Inverse Method (SKIM), a learning method based on principles of dendritic computation. As this work represents the first large-scale and multi-class classification task performed using the SKIM network, it explores different training patterns and output determination methods necessary to extend the original SKIM method to support multi-class problems. Making use of SKIM networks applied to real-world datasets, implementing the largest hidden layer sizes and simultaneously training the largest number of output neurons, the classification system achieved a best-case accuracy of 92.87% for a network containing 10,000 hidden layer neurons. These results represent the highest accuracies achieved against the dataset to date and serve to validate the application of the SKIM method to event-based visual classification tasks. Additionally, the study found that using a square pulse as the supervisory training signal produced the highest accuracy for most output determination methods, but the results also demonstrate that an exponential pattern is better suited to hardware implementations as it makes use of the simplest output determination method based on the maximum value.

Suppressive effects of fire prevention campaign in China: A time series analysis

In China, post-accident fire prevention campaigns are highly popular; many extensive safety campaigns have been carried out after the deadliest fire accidents. The aim of this work is to explore the suppressive effect of six fire prevention campaigns initiated after disastrous fires that resulted in very high numbers of casualties and significant losses. Time series intervention models are employed to investigate the effects of fire prevention campaigns on a monthly time series of fires (1997–2010), fire deaths (1997–2010) and high-casualty fires (2000–2010). The suppressive effects produced by the campaigns that followed the Luoyang Dongdu mall fire and the CCTV new building fire are also determined. The effects of the campaigns on the fire series following both fires exhibit an exponential decay pattern with a sudden “pulse” decrement after the start of the intervention followed by a gradual deceleration back to the original pre-intervention level; the most significant finding is that there is no permanent effect from these interventions. The effect of the campaign precipitated by the Luoyang Dongdu mall fire on the fire series is greater than that from the campaign initiated after the CCTV new building fire. The campaign precipitated by the Luoyang Dongdu mall fire also produces an approximate damped sine wave suppressive effect with a permanent decrement of 43 deaths. However, the high-casualty fire series is demonstrated to not be influenced by fire prevention campaigns precipitated by disastrous fires, which is inconsistent with the campaigns’ hypotheses that high-casualty fires would decrease.