Defense against node compromise in sensor network security

Recent advances in electronic and computer technologies lead to wide-spread deployment of wireless sensor networks (WSNs). WSNs have wide range applications, including military sensing and tracking, environment monitoring, smart environments, etc. Many WSNs have mission-critical tasks, such as military applications. Thus, the security issues in WSNs are kept in the foreground among research areas. Compared with other wireless networks, such as ad hoc, and cellular networks, security in WSNs is more complicated due to the constrained capabilities of sensor nodes and the properties of the deployment, such as large scale, hostile environment, etc. Security issues mainly come from attacks. In general, the attacks in WSNs can be classified as external attacks and internal attacks. In an external attack, the attacking node is not an authorized participant of the sensor network. Cryptography and other security methods can prevent some of external attacks. However, node compromise, the major and unique problem that leads to internal attacks, will eliminate all the efforts to prevent attacks. Knowing the probability of node compromise will help systems to detect and defend against it. Although there are some approaches that can be used to detect and defend against node compromise, few of them have the ability to estimate the probability of node compromise. Hence, we develop basic uniform, basic gradient, intelligent uniform and intelligent gradient models for node compromise distribution in order to adapt to different application environments by using probability theory. These models allow systems to estimate the probability of node compromise. Applying these models in system security designs can improve system security and decrease the overheads nearly in every security area. Moreover, based on these models, we design a novel secure routing algorithm to defend against the routing security issue that comes from the nodes that have already been compromised but have not been detected by the node compromise detecting mechanism. The routing paths in our algorithm detour those nodes which have already been detected as compromised nodes or have larger probabilities of being compromised. Simulation results show that our algorithm is effective to protect routing paths from node compromise whether detected or not.

The boundaries of acceptance: Do expectations for the complainant's psychological injury affect legal decisions in a sexual harassment case

Research indicates that people engaged in legal decision-making use a host of biases and preconceptions to guide their decisions about whether the evidence presented to them is reasonable. However, few theories address how such expectations affect legal decision-makers. The present study attempted to determine if social judgment theory (SJT) can explain how and when legal decision-makers rely on expectations for the complainant's psychological injury in a hostile environment sexual harassment case. Two experiments provided undergraduate participants with a written summary of a hostile work environment allegation that first manipulated participants' expectations about reasonable psychological injuries (mild v. severe), and then presented them with actual severity levels of psychological injury (ranging from minimal to extreme). Experiment 1 (N = 295) hypothesized and found that participants who expected severe injuries perceived a greater range of psychological injuries to be reasonable than participants expecting mild injury. Experiment 2 ( N = 202) used similar methodology and investigated whether perceived reasonableness for the injury allegations affected legal decisions. Experiment 2 hypothesized that participants expecting severe psychological injury should render more pro-complainant decisions than participants expecting mild psychological injury. This result should be most pronounced when participants receive a moderate injury allegation, since this allegation was perceived as reasonable by participants expecting severe injury, but unreasonable by participants expecting mild injury. Consistent with SJT, participants who received a moderate injury but expected a severe injury found more liability than participants who received a moderate injury but expected a mild injury. Inconsistent with SJT, participants' expectations did not affect their compensatory damage decisions. In fact, more severe injury allegations increased damage awards regardless of participants' expectations. Although the results provide mixed support for applying SJT to legal decisions in sexual harassment cases, they emphasize the continuing role of oft-unstudied extra-legal factors (juror's expectations and psychological injury severity) on legal decisions.

The IRS Collection Division: Contacts and Settlements

In his study -The IRS Collection Division: Contacts and Settlements - by John M. Tarras, Assistant Professor School of Hotel, Restaurant and Institutional Management, Michigan State University, Tarras initially states: “The collection division of the internal revenue service is often the point of contact for many hospitality businesses. The author describes how the division operates, what the hospitality firm can expect when contacted by it, and what types of strategies firms might find helpful when negotiating a settlement with the IRS.” The author will have you know that even though most chance meetings with the IRS Collection Division are due to unfortunate tax payment circumstances, there are actually more benign reasons for close encounters of the IRS kind. This does not mean, however, that brushes with the IRS Collection Division will end on an ever friendlier note. “…the Tax Reform Act of 1986 with its added complexity will cause some hospitality firms to inadvertently fail to make proper payments on a timely basis,” Tarras affords in illustrating a perhaps less pugnacious side of IRS relations. Should a hospitality business owner represent himself/herself before the IRS? Never, says Tarras. “Too many taxpayers ruin their chances of a fair settlement by making what to them seem innocent remarks, but ones that turn out to be far different,” warns Professor Tarras. Tarras makes the distinction between IRS the Collection Division, and IRS the Audit Division. “While the Audit Division is interested in how the tax liability arose, the Collection Division is generally only interested in collecting the liability,” he informs you. Either sounds firmly in hostile territory. They don’t bluff. Tarras does want you to know that when the IRS threatens to levy on the assets of a hospitality business, they will do so. Those assets may extend to personal and real property as well, he says. The levy action is generally the final resort in an IRS collection effort. Professor Tarras explains the lien process and the due process attached to that IRS collection tactic. “The IRS can also levy a hospitality firm owner's wages. In this case, it is important to realize that you are allowed to exempt from levy $75 per week, along with $25 per week for each of your dependents (unless your spouse works),” Professor Tarras says with the appropriate citation. What are the options available to the hospitality business owner who finds himself on the wrong side of the IRS Collection Division? Negotiate in good faith says Professor Tarras. “In many cases, a visit to the IRS office will greatly reduce the chances that a simple problem will turn into a major one,” Tarras advises. He dedicates the last pages of the discussion to negotiation strategies.

Transcriptome Analysis Reveals New Insights into the Modulation of Endometrial Stromal Cell Receptive Phenotype by Embryo-Derived Signals Interleukin-1 and Human Chorionic Gonadotropin: Possible Involvement in Early Embryo Implantation

The presence of the conceptus in uterine cavity necessitates an elaborate network of interactions between the implanting embryo and a receptive endometrial tissue. We believe that embryo-derived signals play an important role in the remodeling and the extension of endometrial receptivity period. Our previous studies provided original evidence that human Chorionic Gonadotropin (hCG) modulates and potentiates endometrial epithelial as well as stromal cell responsiveness to interleukin 1 (IL1), one of the earliest embryonic signals, which may represent a novel pathway by which the embryo favors its own implantation and growth within the maternal endometrial host. The present study was designed to gain a broader understanding of hCG impact on the modulation of endometrial cell receptivity, and in particular, cell responsiveness to IL1 and the acquisition of growth-promoting phenotype capable of receiving, sustaining, and promoting early and crucial steps of embryonic development. Our results showed significant changes in the expression of genes involved in cell proliferation, immune modulation, tissue remodeling, apoptotic and angiogenic processes. This points to a relevant impact of these embryonic signals on the receptivity of the maternal endometrium, its adaptation to the implanting embryo and the creation of an environment that is favorable for the implantation and the growth of this latter within a new and likely hostile host tissue. Interestingly our data further identified a complex interaction between IL1 and hCG, which, despite a synergistic action on several significant endometrial target genes, may encompass a tight control of endogenous IL1 and extends to other IL1 family members.

World-Class Service

In the discussion - World-Class Service - by W. Gerald Glover, Associate Professor, Restaurant, Hotel and Resort Management at Appalachian State University and Germaine W. Shames, Hilton International, New York, Glover and Shames initially state: “Providing world-class service to today's traveler may be the key for hospitality managers in the current competitive market. Although an ideal, this type of service provides a mandate for culturally aware managers. The authors provide insight into several areas of cultures in collision.” Up to the time this essay is written, the authors point to a less-than-ideal level of service as being the standard in the hospitality industry and experience. “Let's face it - if we're ever to resurrect service, it will not be by going back to anything,” Glover and Shames exclaim. “Whatever it was we did back then has contributed to the dilemma in which we find ourselves today, handicapped by a reactive service culture in an age that calls for adaptiveness and global strategies,” the authors fortify that thought. In amplifying the concept of world-class service Glover and Shames elaborate: “World-class service is an ideal. Proactive and adaptive, world-class service feels equally right to the North American dignitary occupying the Presidential Suite, and the Japanese tourist staying in a standard room in the same hotel.” To bracket that model the authors offer: “At a minimum, it is service perceived by each customer as appropriate and adequate. At its best, it may also make the customer feel at home, among friends, or pampered. Finally, it is service as if culture matters,” Glover and Shames expand and capture the rule of world-class service. Glover and Shames consider the link between cultures and service an imperative one. They say it is a principle lost on most hospitality managers. “Most [managers] have received service management education in the people are people school that teaches us to disregard cultural differences and assume that everyone we manage or serve is pretty much like ourselves,” say Glover and Shames. “Is it any wonder that we persist in setting service standards, marketing services, and managing service staff not only as if culture didn't matter, but as if it didn't exist?!” To offer legitimacy to their effort Glover and Shames present the case of the Sun and Sea Hotel, a 500-room first class hotel located on the outskirts of the capital city of a small Caribbean island nation. It is a bit difficult to tell whether this is a dramatization or a reality. It does, however, serve to illustrate their point in regard to management’s cognizance, or lack thereof, of culture when it comes to cordial service and guest satisfaction. Even more apropos is the tale of the Palace Hotel, “…one of the grande dames of hospitality constructed in the boom years of the 1920s in a mid-sized Midwestern city in the United States.” The authors relate what transpired during its takeover in mid-1980 by a U.S.-based international hotel corporation. The story makes for an interesting and informative case study.

Energy-efficient self -organization of wireless acoustic sensor networks for ground target tracking

With the developments in computing and communication technologies, wireless sensor networks have become popular in wide range of application areas such as health, military, environment and habitant monitoring. Moreover, wireless acoustic sensor networks have been widely used for target tracking applications due to their passive nature, reliability and low cost. Traditionally, acoustic sensor arrays built in linear, circular or other regular shapes are used for tracking acoustic sources. The maintaining of relative geometry of the acoustic sensors in the array is vital for accurate target tracking, which greatly reduces the flexibility of the sensor network. To overcome this limitation, we propose using only a single acoustic sensor at each sensor node. This design greatly improves the flexibility of the sensor network and makes it possible to deploy the sensor network in remote or hostile regions through air-drop or other stealth approaches. Acoustic arrays are capable of performing the target localization or generating the bearing estimations on their own. However, with only a single acoustic sensor, the sensor nodes will not be able to generate such measurements. Thus, self-organization of sensor nodes into virtual arrays to perform the target localization is essential. We developed an energy-efficient and distributed self-organization algorithm for target tracking using wireless acoustic sensor networks. The major error sources of the localization process were studied, and an energy-aware node selection criterion was developed to minimize the target localization errors. Using this node selection criterion, the self-organization algorithm selects a near-optimal localization sensor group to minimize the target tracking errors. In addition, a message passing protocol was developed to implement the self-organization algorithm in a distributed manner. In order to achieve extended sensor network lifetime, energy conservation was incorporated into the self-organization algorithm by incorporating a sleep-wakeup management mechanism with a novel cross layer adaptive wakeup probability adjustment scheme. The simulation results confirm that the developed self-organization algorithm provides satisfactory target tracking performance. Moreover, the energy saving analysis confirms the effectiveness of the cross layer power management scheme in achieving extended sensor network lifetime without degrading the target tracking performance.

Russia's Islam: Discourse on Identity, Politics, and Security

Despite the long history of Muslims in Russia, most scholarly and political literatures on Russia’s Islam still narrowly interpret Muslim-Slavs relations in an ethnic-religious oppositional framework. In my work, I examine Russia’s discourse on Islam to argue that, in fact, the role of Islam in post-Soviet Russia is complex. Drawing from direct sources from academic, state, journalistic, and underground circles, often neglected by Western commentators, I identify ideational patterns in conceptualizations of Islam and reconstruct relational networks among authors. To explain complex intertextual relations within specific contexts, I utilize an analytically eclectic method that appropriately combines theories from different paradigms and/or disciplines. Thanks to my multi-dimensional approach, I show that, contrary to traditional views, Russia’s Muslims participate in processes of post-Soviet Russia’s identity formation. Starting from textual contents, avoiding pre-formed analytical frames, I argue that many Muslims in Russia perceive themselves as part of Russian civilization – even when they challenge the status-quo. Building on my initial findings, I state that a key element in Russia’s conceptualization of Islam is the definition, elaborated in the 1990s, of traditional Islam as part of Russian civilizational history, as opposed to extremist Islam as extraneous, hostile phenomenon. The differentiation creates an unprecedently safe, if confined, space for Islamic propositions, of which Muslims are taking advantage. Embedded in debates on Russian civilization, conceptualizations of Islam, then, influence Russia’s (geo)political self-perceptions and, consequently, its domestic and international policies. In particular, Russian so-far neglected Islamic doctrine supports views of Islamic terrorism as a political and not religious phenomenon. Hence, Russia interprets both terrorism and counterterrorism within its own historical tradition, causing its strategy to be at odds with Western views. Less apparently, these divergences affect Russian-U.S. broader relations. Finally, in revealing the civilizational value of Russia’s Islam, I expose intellectual relations among influential subjects who share the aim to devise a new civilizational model that should combine Slavic and non-Slavic, Orthodox and Islamic, Western, and Asian components. In this old Russian dilemma, the novelty is Muslims’ participation.

Defense Against Node Compromise in Sensor Network Security

Recent advances in electronic and computer technologies lead to wide-spread deployment of wireless sensor networks (WSNs). WSNs have wide range applications, including military sensing and tracking, environment monitoring, smart environments, etc. Many WSNs have mission-critical tasks, such as military applications. Thus, the security issues in WSNs are kept in the foreground among research areas. Compared with other wireless networks, such as ad hoc, and cellular networks, security in WSNs is more complicated due to the constrained capabilities of sensor nodes and the properties of the deployment, such as large scale, hostile environment, etc. Security issues mainly come from attacks. In general, the attacks in WSNs can be classified as external attacks and internal attacks. In an external attack, the attacking node is not an authorized participant of the sensor network. Cryptography and other security methods can prevent some of external attacks. However, node compromise, the major and unique problem that leads to internal attacks, will eliminate all the efforts to prevent attacks. Knowing the probability of node compromise will help systems to detect and defend against it. Although there are some approaches that can be used to detect and defend against node compromise, few of them have the ability to estimate the probability of node compromise. Hence, we develop basic uniform, basic gradient, intelligent uniform and intelligent gradient models for node compromise distribution in order to adapt to different application environments by using probability theory. These models allow systems to estimate the probability of node compromise. Applying these models in system security designs can improve system security and decrease the overheads nearly in every security area. Moreover, based on these models, we design a novel secure routing algorithm to defend against the routing security issue that comes from the nodes that have already been compromised but have not been detected by the node compromise detecting mechanism. The routing paths in our algorithm detour those nodes which have already been detected as compromised nodes or have larger probabilities of being compromised. Simulation results show that our algorithm is effective to protect routing paths from node compromise whether detected or not.

The decolonization of Northwest Community College

In 1996, the authors of the Canadian Royal Commission on Aboriginal Peoples concluded Canadian educational policy had been based on the false assumption of the superiority of European worldviews. The report authors recommended the transformation of curriculum and schools to recognize that European knowledge was not universal. Aboriginal researcher Battiste believes the current system of Canadian education causes Aboriginal children to face cognitive imperialism and cognitive assimilation and that this current practice of cultural racism in Canada makes educational institutions a hostile environment for Aboriginal learners. In order to counter this cultural racism, Battiste calls for the decolonization of education. ^ In 2005, the president of Northwest Community College (NWCC), publicly committed to decolonizing the college in order to address the continuing disparity in educational attainment between Aboriginal and non-Aboriginal learners. Upon the president’s departure in 2010, the employees of NWCC were left to define for themselves the meaning of decolonization. ^ This qualitative study was designed to build a NWCC definition of colonization and decolonization by collecting researcher observations, nine weeks of participant blog postings, and pre and post blog Word survey responses drawn from a purposeful sample of six Aboriginal and six non-Aboriginal NWCC employees selected from staff, instructor and administrator employee groups. The findings revealed NWCC employees held multiple definitions of colonization and decolonization which did not vary between employee groups, or based on participant gender; however, differences were found based on whether the participants were Aboriginal or non-Aboriginal. ^ Both Aboriginal and non-Aboriginal participants thought decolonization was a worthy goal for the college. Aboriginal participants felt hopeful that decolonization would happen in the future and thought decolonization had to do with moving forward to a time when they would be valued, respected, empowered, unashamed, safe, and viewed as equal to non-Aboriginals. Non-Aboriginal participants were unsure if decolonization was possible because it would require going back in time to restore the Aboriginal way of life. When non-Aboriginal participants felt their thoughts were not being valued or they were being associated with colonialism, they felt angry and guarded and were uncomfortable with Aboriginal participants expressing anger towards Colonizers.^

Energy-Efficient Self-Organization of Wireless Acoustic Sensor Networks for Ground Target Tracking

With the developments in computing and communication technologies, wireless sensor networks have become popular in wide range of application areas such as health, military, environment and habitant monitoring. Moreover, wireless acoustic sensor networks have been widely used for target tracking applications due to their passive nature, reliability and low cost. Traditionally, acoustic sensor arrays built in linear, circular or other regular shapes are used for tracking acoustic sources. The maintaining of relative geometry of the acoustic sensors in the array is vital for accurate target tracking, which greatly reduces the flexibility of the sensor network. To overcome this limitation, we propose using only a single acoustic sensor at each sensor node. This design greatly improves the flexibility of the sensor network and makes it possible to deploy the sensor network in remote or hostile regions through air-drop or other stealth approaches. Acoustic arrays are capable of performing the target localization or generating the bearing estimations on their own. However, with only a single acoustic sensor, the sensor nodes will not be able to generate such measurements. Thus, self-organization of sensor nodes into virtual arrays to perform the target localization is essential. We developed an energy-efficient and distributed self-organization algorithm for target tracking using wireless acoustic sensor networks. The major error sources of the localization process were studied, and an energy-aware node selection criterion was developed to minimize the target localization errors. Using this node selection criterion, the self-organization algorithm selects a near-optimal localization sensor group to minimize the target tracking errors. In addition, a message passing protocol was developed to implement the self-organization algorithm in a distributed manner. In order to achieve extended sensor network lifetime, energy conservation was incorporated into the self-organization algorithm by incorporating a sleep-wakeup management mechanism with a novel cross layer adaptive wakeup probability adjustment scheme. The simulation results confirm that the developed self-organization algorithm provides satisfactory target tracking performance. Moreover, the energy saving analysis confirms the effectiveness of the cross layer power management scheme in achieving extended sensor network lifetime without degrading the target tracking performance.

Neodymium and Strontium chemistry of Arctic Ocean sediments

The early oceanographic history of the Arctic Ocean is important in regulating, and responding to, climatic changes. However, constraints on its oceanographic history preceding the Quaternary (the past 1.8 Myr) have become available only recently, because of the difficulties associated with obtaining continuous sediment records in such a hostile setting. Here, we use the neodymium isotope compositions of two sediment cores recovered near the North Pole to reconstruct over the past ~5 Myr the sources contributing to Arctic Intermediate Water, a water mass found today at depths of 200 to 1,500 m. We interpret high neodymium ratios for the period between 15 and 2 Myr ago, and for the glacial periods thereafter, as indicative of weathering input from the Siberian Putoranan basalts into the Arctic Ocean. Arctic Intermediate Water was then derived from brine formation in the Eurasian shelf regions, with only a limited contribution of intermediate water from the North Atlantic. In contrast, the modern circulation pattern, with relatively high contributions of North Atlantic Intermediate Water and negligible input from brine formation, exhibits low neodymium isotope ratios and is typical for the interglacial periods of the past 2 Myr. We suggest that changes in climatic conditions and the tectonic setting were responsible for switches between these two modes.

Avaliação do desenvolvimento infantil e a influência dos fatores biopsicossociais em crianças com cardiopatia congênita

Child development is the result of the interaction of biological, psychological and social factors. Hostile environment, income, offered stimuli, as well as the presence of a chronic illness are issues that may interfere significantly. Considering the chronic diseases, we can identify congenital heart disease (CHD) is characterized by anatomical heart defects and functional and currently has presented an incidence of up to 1% of the population of live births. This research aimed to evaluate child development and verify an association with the commitment by biopsychosocial factors of children with and without CHD. Study participants were children from zero to six years, divided into three groups: Group1- 29 children pre-surgical congenital heart disease, Group2- 43 children post-surgical cardiac patients and Group3- 56 healthy children. The instruments used were a biopsychosocial questionnaire and the Screening Test Denver II. Of the total of 128 children evaluated, 66 (51.56%) are girls, and ages ranged from two months to six years (median 24.5 months). In G1 and G2 predominated acyanotic heart disease (55.2% and 58.1%). Regarding the Denver II reviews, children with heart disease had more development ratings "suspicious" and "suspect/abnormal", and 41.9% of children who have gone through surgery had characterized its development as "suspect/abnormal" . In the group of healthy children 53.6% were classified as developmental profile "normal" (p = ˂0,0001). On the areas of Denver II, among children with heart disease was greatest change in motor areas (p = 0.016, p = ˂0,001). The biopsychosocial variables that were related to a possible developmental delay were gender (p = 0.042), child's age (p = 0.0001) and income per capita (p = 0.019). There were no associations between the variables related to the treatment of disease, information, understanding of the disease and the way parents treat their children. In the group of healthy children showed that children who underwent hospitalization rates were more changes in development (p = 0.025) and the higher the number of admissions over these changes have intensified (p = 0.023). The results suggest that children with congenital heart disease have likely delayed development. It was also observed that there is a significant difference between the children who have gone through surgery, those who are still waiting for surgery only doing clinical follow-up. Changes in the development are more connected motor areas can be explained by the characteristic features of the disease and treatment, such as dyspnea, fatigue, care and limitations in daily activities. The gender and age appear to be decisive in the development as well as healthy children go through hospitalization experience. Already in children with heart disease, it was realized that social variables involved in the disease and the treatment did not affect the development. This question can be understood by means of protective factors and resiliency, as this population receives family and social support.

FTE-LEACH: um protocolo energeticamente eficiente e tolerante a falhas aplicado às redes industriais de sensores sem fio

A Wireless Sensor Network (WSN) consists of distributed devices in an area in order to monitor physical variables such as temperature, pressure, vibration, motion and environmental conditions in places where wired networks would be difficult or impractical to implement, for example, industrial applications of difficult access, monitoring and control of oil wells on-shore or off-shore, monitoring of large areas of agricultural and animal farming, among others. To be viable, a WSN should have important requirements such as low cost, low latency, and especially low power consumption. However, to ensure these requirements, these networks suffer from limited resources, and eventually being used in hostile environments, leading to high failure rates, such as segmented routing, mes sage loss, reducing efficiency, and compromising the entire network, inclusive. This work aims to present the FTE-LEACH, a fault tolerant and energy efficient routing protocol that maintains efficiency in communication and dissemination of data.This protocol was developed based on the IEEE 802.15.4 standard and suitable for industrial networks with limited energy resources

Vernaculares: a casa de fazenda seridoense do século XIX como exemplo de adaptação ao clima semiárido

The farm’s rural dwellings of creation from the Seridó Potiguar microregion, built in the nineteenth century, became a reference by its vernacular character, i.e. these buildings, besides having recognized relevance to the identity of the region, they are adapted to the conditions of the place in many aspects (economic, cultural, construction, physical, et.) and consist in protective spaces in relation to hostile characteristics of Seridó’s climate. Considering the above premise, the following question arises: What characteristics of the nineteenth century Seridó Potiguar’s cattle farms are crucial for them to be a protective space in relation to the semiarid climate? In order to answer the question, this research aim to identify which particularities of the Seridó’s farmhouses that contribute to adaptability in these buildings to semiarid climate, as protection environments; and contribute to the stock valuation of the architectural heritage concerned. Therefore, procedures were adopted divided into two stages. Were first identified the recurring characteristics in the studied buildings, through typological study performed from existing inventories (DINIZ, 2008; FEIJÓ, 2002; IPHAN, 2012). To define the type it worked up with the concept that merges Durand’s analytical typology that identifies the similarities and differences to classify buildings, having the character of historical survey and architectural documentation, with the definition proposed by Argan (1963) that the type is not defined a priory, but the deduction from a number of illustrative cases which have formal and functional similarity with each other. Then worked up in a sample of five different types with each other, defined by the possibility of access to the interior of the houses, proximity to other copies, good state of conservation and preservation. The contemplated farms were: Pitombeiras, Agenus e Garrotes in Acari’s town, and the municipality of Caicó, Palma and Penedo. The second stage consists of the architectural survey, photographic record, digital three-dimensional modeling (aiming to expand the existing documentation and registration) and thermal monitoring over approximately a representative day in five farmhouses, relating the thermal performance of the houses with their individual characteristics. The selected variables for analysis monitoring are based on the thermal comfort adaptive model (SPAGNOLO and DE DEAR, 2003 apud NEGREIROS, 2010). The characteristics of the houses were analyzed as meeting the passive thermal conditioning strategies recommended by NBR 15220 (ABNT, 2005), for the bioclimatic zone 7 where the municipalities of Caicó and Acari are located. The house’s analysis of the operating temperatures revealed that 90% of the times of day the environments are within the comfort range. The farmhouses, which had a higher degree of compliance with recommended bioclimatic strategies, had the best thermal performance. In environments (usually the kitchen and rooms with low ceiling heights, exposed to west radiation) which still had discomfort hours, the thermal comfort can be reached with air movement approximately 1,0 m/s.

Vernaculares: a casa de fazenda seridoense do século XIX como exemplo de adaptação ao clima semiárido

The farm’s rural dwellings of creation from the Seridó Potiguar microregion, built in the nineteenth century, became a reference by its vernacular character, i.e. these buildings, besides having recognized relevance to the identity of the region, they are adapted to the conditions of the place in many aspects (economic, cultural, construction, physical, et.) and consist in protective spaces in relation to hostile characteristics of Seridó’s climate. Considering the above premise, the following question arises: What characteristics of the nineteenth century Seridó Potiguar’s cattle farms are crucial for them to be a protective space in relation to the semiarid climate? In order to answer the question, this research aim to identify which particularities of the Seridó’s farmhouses that contribute to adaptability in these buildings to semiarid climate, as protection environments; and contribute to the stock valuation of the architectural heritage concerned. Therefore, procedures were adopted divided into two stages. Were first identified the recurring characteristics in the studied buildings, through typological study performed from existing inventories (DINIZ, 2008; FEIJÓ, 2002; IPHAN, 2012). To define the type it worked up with the concept that merges Durand’s analytical typology that identifies the similarities and differences to classify buildings, having the character of historical survey and architectural documentation, with the definition proposed by Argan (1963) that the type is not defined a priory, but the deduction from a number of illustrative cases which have formal and functional similarity with each other. Then worked up in a sample of five different types with each other, defined by the possibility of access to the interior of the houses, proximity to other copies, good state of conservation and preservation. The contemplated farms were: Pitombeiras, Agenus e Garrotes in Acari’s town, and the municipality of Caicó, Palma and Penedo. The second stage consists of the architectural survey, photographic record, digital three-dimensional modeling (aiming to expand the existing documentation and registration) and thermal monitoring over approximately a representative day in five farmhouses, relating the thermal performance of the houses with their individual characteristics. The selected variables for analysis monitoring are based on the thermal comfort adaptive model (SPAGNOLO and DE DEAR, 2003 apud NEGREIROS, 2010). The characteristics of the houses were analyzed as meeting the passive thermal conditioning strategies recommended by NBR 15220 (ABNT, 2005), for the bioclimatic zone 7 where the municipalities of Caicó and Acari are located. The house’s analysis of the operating temperatures revealed that 90% of the times of day the environments are within the comfort range. The farmhouses, which had a higher degree of compliance with recommended bioclimatic strategies, had the best thermal performance. In environments (usually the kitchen and rooms with low ceiling heights, exposed to west radiation) which still had discomfort hours, the thermal comfort can be reached with air movement approximately 1,0 m/s.