176 research outputs found
A Case Study Approach for Assessing Operational and Silvicultural Performance of Whole-Tree Biomass Harvesting in Maine
In the Northeastern United States, re-emerging markets for renewable energy are driving interest in increasing the harvest of underutilized biomass material from Maine’s forest. These markets may offer opportunities for forest managers to implement silvicultural treatments that have previously been foregone due to their high cost. However, many operational challenges arise in using current harvesting systems to harvest biomass material profitably while simultaneously achieving silvicultrual objectives. This research uses a case study approach to analyzing some of the possibilities and obstacles in implementing biomass harvesting in Maine. The first three studies investigate a factorial silvicultural and operational case study involving whole-tree biomass harvesting in conjunction with herbicide injection. The first study investigated the use of combined biomass harvesting and herbicide treatment as a means of rehabilitating northern hardwood stands dominated by dense understory thickets of small diameter American beech (Fagus grandifolia Ehrh.) and striped maple (Acer pensylvanicum L.). Prior to being harvested, a portion of beech and striped maple trees were treated using glyphosate stem injection as a means of controlling post harvest regeneration. Efficacy of the herbicide treatment was evaluated the first growing season after harvesting. During the harvest operation, a second study evaluated the productivity and impact of the feller-buncher using two trail spacings to determine if operational efficiency could be increased. A third study was carried out after the harvest to quantify and evaluate the damage inflicted by the operation at each trail spacing. A related case study was then conducted that attempted to develop an organized methodology for analyzing and improving the long-term efficiency of whole-tree harvest operations using statistical process control (SPC) in order to better evaluate the long-term impacts of modifying harvesting systems. The methodology was developed using actual operation data collected on several whole-tree system machines used throughout Maine. Results from the combined herbicide injection and biomass harvest case study indicated that whole-tree harvesting could utilize most of the beech and striped maple component of the stand while also effectively controlling the density of post-harvest beech regeneration. The harvest study found that feller-buncher productivity was not significantly different when operating at either of the two trail spacings; however, a tradeoff was found between efficient bunching and bunching frequency, with the narrower trail spacing using less time per bunch but requiring more bunches to be produced. Trail occupancy levels resulting from use of the narrower trail spacing were considerable, which could pose potential difficulties in future management. However, the frequency and patter of damage to the residual trees caused by the harvest operation was not significantly different between the two trail spacings. The second case study demonstrated that Statistical Process Control could offer a unique perspective on evaluating operational variability and showed great potential as a tool for improving forest harvesting processes. The study revealed several challenges in applying this approach to whole-tree harvesting operations. These challenges are primarily related to how operational data is collected and organized, and how the underlying causes of variation are interpreted
Change-point Problem and Regression: An Annotated Bibliography
The problems of identifying changes at unknown times and of estimating the location of changes in stochastic processes are referred to as the change-point problem or, in the Eastern literature, as disorder .
The change-point problem, first introduced in the quality control context, has since developed into a fundamental problem in the areas of statistical control theory, stationarity of a stochastic process, estimation of the current position of a time series, testing and estimation of change in the patterns of a regression model, and most recently in the comparison and matching of DNA sequences in microarray data analysis.
Numerous methodological approaches have been implemented in examining change-point models. Maximum-likelihood estimation, Bayesian estimation, isotonic regression, piecewise regression, quasi-likelihood and non-parametric regression are among the methods which have been applied to resolving challenges in change-point problems. Grid-searching approaches have also been used to examine the change-point problem.
Statistical analysis of change-point problems depends on the method of data collection. If the data collection is ongoing until some random time, then the appropriate statistical procedure is called sequential. If, however, a large finite set of data is collected with the purpose of determining if at least one change-point occurred, then this may be referred to as non-sequential. Not surprisingly, both the former and the latter have a rich literature with much of the earlier work focusing on sequential methods inspired by applications in quality control for industrial processes. In the regression literature, the change-point model is also referred to as two- or multiple-phase regression, switching regression, segmented regression, two-stage least squares (Shaban, 1980), or broken-line regression.
The area of the change-point problem has been the subject of intensive research in the past half-century. The subject has evolved considerably and found applications in many different areas. It seems rather impossible to summarize all of the research carried out over the past 50 years on the change-point problem. We have therefore confined ourselves to those articles on change-point problems which pertain to regression.
The important branch of sequential procedures in change-point problems has been left out entirely. We refer the readers to the seminal review papers by Lai (1995, 2001). The so called structural change models, which occupy a considerable portion of the research in the area of change-point, particularly among econometricians, have not been fully considered. We refer the reader to Perron (2005) for an updated review in this area. Articles on change-point in time series are considered only if the methodologies presented in the paper pertain to regression analysis
ENERGY CONSUMPTION OF MOBILE PHONES
Battery consumption in mobile applications development is a very important aspect and has to be considered by all the developers in their applications. This study will present an analysis of different relevant concepts and parameters that may have an impact on energy consumption of Windows Phone applications. This operating system was chosen because limited research related thereto has been conducted, even though there are related studies for Android and iOS operating systems. Furthermore, another reason is the increasing number of Windows Phone users. The objective of this research is to categorise the energy consumption parameters (e.g. use of one thread or several threads for the same output). The result for each group of experiments will be analysed and a rule will be derived. The set of derived rules will serve as a guide for developers who intend to develop energy efficient Windows Phone applications. For each experiment, one application is created for each concept and the results are presented in two ways; a table and a chart. The table presents the duration of the experiment, the battery consumed in the experiment, the expected battery lifetime, and the energy consumption, while the charts display the energy distribution based on the main threads: UI thread, application thread, and network thread
A WEB-BASED ENVIRONMENTAL TOOLKIT TO SUPPORT SMES IN THE IMPLEMENTATION OF AN ENVIRONMENTAL MANAGEMENT SYSTEM
With small and medium sized-enterprises (SMEs) taking up the majority of the global businesses, it is important they act in an environmentally responsible manner. Environmental management systems (EMS) help companies evaluate and improve their environmental impact but they often require human, financial, and temporary resources that not all SMEs can afford. This research encompasses interviews with representatives of two small enterprises in Germany to provide insights into their understanding, and knowledge of an EMS and how they perceive their responsibility towards the environment. Furthermore, it presents a toolkit created especially for small and medium-sized enterprises. It serves as a simplified version of an EMS based on the ISO 14001 standard and is evaluated by target users and appropriate representatives. Some of the findings are: while open to the idea of improving their environmental impact, SMEs do not always feel it is their responsibility to do so; they seem to lack the means to fully implement an EMS. The developed toolkit is considered useful and usable and recommendations are drawn for its future enhancement
Abstracts on Radio Direction Finding (1899 - 1995)
The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography).
Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM.
The contents of these files are:
1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format];
2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format];
3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion
Population-based cancer survival at small area level: methodological developments
Cancer survival is a key indicator of the overall effectiveness of a health system in man-aging treatment and care of cancer patients. At the national level, cancer survival statistics facilitate overall surveillance of strategic importance. At the local level, they provide valuable insights into the performance of local cancer services essential for public health planning. There are however recurring concerns regarding both the estimation and dis-semination of such survival outcomes, in particular at the smaller area level. The research presented in this thesis aimed to address some of these concerns. A summary indicator of cancer survival, named Index of Cancer Survival, is proposed for all cancers combined designed to act as an overall measure of the effectiveness of cancer services in England at both national and local level. To estimate the index a two-step analytical approach was implemented, in which cancer survival is first estimated for each small area separately followed by a joint smoothing and mapping technique to filter out excessive variation from the resulting cancer survival maps. Such smoothed maps were thought suitable for national health policy-makers to devise national surveillance strategies, as they display in a simple way, the overall patterns of survival for the whole country. Funnel plots were then extended to visualise the spread of individual small-area cancer survival outcomes, mostly thought suitable for local health managers as a tool for monitoring the performance of survival outcomes in their local areas. However, the estimation of cancer survival for small-health geographies remained challenging. The last part of this thesis explored how Bayesian approaches could be used to improve the estimation of cancer survival in the presence of sparse data, and when using more com-plex data structures, including spatially arranged and hierarchical data. The feasibility of an existing Bayesian model for the excess hazard using Poisson regression was explored to estimate small-area patterns in cancer survival accounting for the spatial structure of thedata. A Bayesian flexible excess hazard regression model was then proposed based on the full likelihood specification to improve the modelling of both the baseline excess hazard and the smooth effect of continuous covariates using a special type of splines. The new model also accommodates hierarchical data allowing more complex cancer data structures to be modelled, such as patient level data nested within area of residence or hospital of care level data. In summary, the cancer survival index and both data visualisation techniques for cancer survival greatly improved the interpretability and dissemination of such outcomes for non-technical audiences, in particular health policy-makers. Meanwhile, the Bayesian excess hazard model using Poisson regression improved the estimation when data were sparse by incorporating the spatial data structure. The Bayesian flexible excess hazard model in particular, enabled a better investigation of inequalities in cancer survival using a range of covariate effects and facilitated the study of more complex cancer data structures
MODELLING & SIMULATION HYBRID WARFARE Researches, Models and Tools for Hybrid Warfare and Population Simulation
The Hybrid Warfare phenomena, which is the subject of the current research, has been framed by the work of Professor Agostino Bruzzone (University of Genoa) and Professor Erdal Cayirci (University of Stavanger), that in June 2016 created in order to inquiry the subject a dedicated Exploratory Team, which was endorsed by NATO Modelling & Simulation Group (a panel of the NATO Science & Technology organization) and established with the participation as well of the author. The author brought his personal contribution within the ET43 by introducing meaningful insights coming from the lecture of \u201cFight by the minutes: Time and the Art of War (1994)\u201d, written by Lieutenant Colonel US Army (Rtd.) Robert Leonhard; in such work, Leonhard extensively developed the concept that \u201cTime\u201d, rather than geometry of the battlefield and/or firepower, is the critical factor to tackle in military operations and by extension in Hybrid Warfare. The critical reflection about the time - both in its quantitative and qualitative dimension - in a hybrid confrontation it is addressed and studied inside SIMCJOH, a software built around challenges that imposes literally to \u201cFight by the minutes\u201d, echoing the core concept expressed in the eponymous work.
Hybrid Warfare \u2013 which, by definition and purpose, aims to keep the military commitment of both aggressor and defender at the lowest - can gain enormous profit by employing a wide variety of non-military tools, turning them into a weapon, as in the case of the phenomena of \u201cweaponization of mass migrations\u201d, as it is examined in the \u201cDies Irae\u201d simulation architecture. Currently, since migration it is a very sensitive and divisive issue among the public opinions of many European countries, cynically leveraging on a humanitarian emergency caused by an exogenous, inducted migration, could result in a high level of political and social destabilization, which indeed favours the concurrent actions carried on by other hybrid tools. Other kind of disruption however, are already available in the arsenal of Hybrid Warfare, such cyber threats, information campaigns lead by troll factories for the diffusion of fake/altered news, etc. From this perspective the author examines how the TREX (Threat network simulation for REactive eXperience) simulator is able to offer insights about a hybrid scenario characterized by an intense level of social disruption, brought by cyber-attacks and systemic faking of news. Furthermore, the rising discipline of \u201cStrategic Engineering\u201d, as envisaged by Professor Agostino Bruzzone, when matched with the operational requirements to fulfil in order to counter Hybrid Threats, it brings another innovative, as much as powerful tool, into the professional luggage of the military and the civilian employed in Defence and Homeland security sectors.
Hybrid is not the New War. What is new is brought by globalization paired with the transition to the information age and rising geopolitical tensions, which have put new emphasis on hybrid hostilities that manifest themselves in a contemporary way. Hybrid Warfare is a deliberate choice of an aggressor. While militarily weak nations can resort to it in order to re-balance the odds, instead military strong nations appreciate its inherent effectiveness coupled with the denial of direct responsibility, thus circumventing the rules of the International Community (IC). In order to be successful, Hybrid Warfare should consist of a highly coordinated, sapient mix of diverse and dynamic combination of regular forces, irregular forces (even criminal elements), cyber disruption etc. all in order to achieve effects across the entire DIMEFIL/PMESII_PT spectrum.
However, the owner of the strategy, i.e. the aggressor, by keeping the threshold of impunity as high as possible and decreasing the willingness of the defender, can maintain his Hybrid Warfare at a diplomatically feasible level; so the model of the capacity, willingness and threshold, as proposed by Cayirci, Bruzzone and Gunneriusson (2016), remains critical to comprehend Hybrid Warfare. Its dynamicity is able to capture the evanescent, blurring line between Hybrid Warfare and Conventional Warfare. In such contest time is the critical factor: this because it is hard to foreseen for the aggressor how long he can keep up with such strategy without risking either the retaliation from the International Community or the depletion of resources across its own DIMEFIL/PMESII_PT spectrum. Similar discourse affects the defender: if he isn\u2019t able to cope with Hybrid Threats (i.e. taking no action), time works against him; if he is, he can start to develop counter narrative and address physical countermeasures. However, this can lead, in the medium long period, to an unforeseen (both for the attacker and the defender) escalation into a large, conventional, armed conflict.
The performance of operations that required more than kinetic effects drove the development of DIMEFIL/PMESII_PT models and in turn this drive the development of Human Social Culture Behavior Modelling (HCSB), which should stand at the core of the Hybrid Warfare modelling and simulation efforts. Multi Layers models are fundamental to evaluate Strategies and Support Decisions: currently there are favourable conditions to implement models of Hybrid Warfare, such as Dies Irae, SIMCJOH and TREX, in order to further develop tools and war-games for studying new tactics, execute collective training and to support decisions making and analysis planning. The proposed approach is based on the idea to create a mosaic made by HLA interoperable simulators able to be combined as tiles to cover an extensive part of the Hybrid Warfare, giving the users an interactive and intuitive environment based on the \u201cModelling interoperable Simulation and Serious Game\u201d (MS2G) approach. From this point of view, the impressive capabilities achieved by IA-CGF in human behavior modeling to support population simulation as well as their native HLA structure, suggests to adopt them as core engine in this application field.
However, it necessary to highlight that, when modelling DIMEFIL/PMESII_PT domains, the researcher has to be aware of the bias introduced by the fact that especially Political and Social \u201cscience\u201d are accompanied and built around value judgement. From this perspective, the models proposed by Cayirci, Bruzzone, Guinnarson (2016) and by Balaban & Mileniczek (2018) are indeed a courageous tentative to import, into the domain of particularly poorly understood phenomena (social, politics, and to a lesser degree economics - Hartley, 2016), the mathematical and statistical instruments and the methodologies employed by the pure, hard sciences. Nevertheless, just using the instruments and the methodology of the hard sciences it is not enough to obtain the objectivity, and is such aspect the representations of Hybrid Warfare mechanics could meet their limit: this is posed by the fact that they use, as input for the equations that represents Hybrid Warfare, not physical data observed during a scientific experiment, but rather observation of the reality that assumes implicitly and explicitly a value judgment, which could lead to a biased output. Such value judgement it is subjective, and not objective like the mathematical and physical sciences; when this is not well understood and managed by the academic and the researcher, it can introduce distortions - which are unacceptable for the purpose of the Science - which could be used as well to enforce a narrative mainstream that contains a so called \u201ctruth\u201d, which lies inside the boundary of politics rather than Science. Those observations around subjectivity of social sciences vs objectivity of pure sciences, being nothing new, suggest however the need to examine the problem under a new perspective, less philosophical and more leaned toward the practical application. The suggestion that the author want make here is that the Verification and Validation process, in particular the methodology used by Professor Bruzzone in doing V&V for SIMCJOH (2016) and the one described in the Modelling & Simulation User Risk Methodology (MURM) developed by Pandolfini, Youngblood et all (2018), could be applied to evaluate if there is a bias and the extent of the it, or at least making clear the value judgment adopted in developing the DIMEFIL/PMESII_PT models. Such V&V research is however outside the scope of the present work, even though it is an offspring of it, and for such reason the author would like to make further inquiries on this particular subject in the future.
Then, the theoretical discourse around Hybrid Warfare has been completed addressing the need to establish a new discipline, Strategic Engineering, very much necessary because of the current a political and economic environment which allocates diminishing resources to Defense and Homeland Security (at least in Europe). However, Strategic Engineering can successfully address its challenges when coupled with the understanding and the management of the fourth dimension of military and hybrid operations, Time. For the reasons above, and as elaborated by Leonhard and extensively discussed in the present work, addressing the concern posed by Time dimension is necessary for the success of any military or Hybrid confrontation.
The SIMCJOH project, examined under the above perspective, proved that the simulator has the ability to address the fourth dimension of military and non-military confrontation. In operations, Time is the most critical factor during execution, and this was successfully transferred inside the simulator; as such, SIMCJOH can be viewed as a training tool and as well a dynamic generator of events for the MEL/MIL execution during any exercise. In conclusion, SIMCJOH Project successfully faces new challenging aspects, allowed to study and develop new simulation models in order to support decision makers, Commanders and their Staff.
Finally, the question posed by Leonhard in terms of recognition of the importance of time management of military operations - nowadays Hybrid Conflict - has not been answered yet; however, the author believes that Modelling and Simulation tools and techniques can represent the safe \u201ctank\u201d where innovative and advanced scientific solutions can be tested, exploiting the advantage of doing it in a synthetic environment
New Advances and Contributions to Forestry Research
New Advances and Contributions to Forestry Research consists of 14 chapters divided into three sections and is authored by 48 researchers from 16 countries and all five continents. Section Whither the Use of Forest Resources, authored by 16 researchers, describes negative and positive practices in forestry. Forest is a complex habitat for man, animals, insects and micro-organisms and their activities may impact positively or negatively on the forest. This complex relationship is explained in the section Forest and Organisms Interactions, consisting of contributions made by six researchers. Development of tree plantations has been man’s response to forest degradation and deforestation caused by human, animals and natural disasters. Plantations of beech, spruce, Eucalyptus and other species are described in the last section, Amelioration of Dwindling Forest Resources Through Plantation Development, a section consisting of five papers authored by 20 researchers. New Advances and Contributions to Forestry Research will appeal to forest scientists, researchers and allied professionals. It will be of interest to those who care about forest and who subscribe to the adage that the last tree dies with the last man on our planet. I recommend it to you; enjoy reading it, save the forest and save life
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