Zone Head Research Articles

Jaiveer Roy

Optifit, an international brand of fitness equipment, had entered the Indian market in 2010 and had rapidly opened 45 stores in 8 years in the four metros (NCR region, Mumbai, Chennai and Kolkata). Jaiveer Roy was identified by Pravin Gupta (South Zone head) and Raghav Mehta (HR head) to join as Optifit's Store Manager for its Alwarpet branch, Chennai, a store that had leadership difficulties from the day it started in May 2018. Roy joined the store in May 2018 and did very well soon after his appointment to the store. However, in less than three months, both Roy's and his store's performance began to suffer and his relationship with Gupta began to crumble. This case highlights issues in people management, especially support for people selected for leadership positions and examines the performance indicators of an individual's performance at a broader level. The case also points towards the mistakes or errors leaders may commit vis-a-vis their own role as a leader and mentor.

Detection of fault zone head waves and the fault interface imaging in the Xianshuihe–Anninghe Fault zone (Eastern Tibetan Plateau)

SUMMARY Fault zone head waves (FZHWs) are an essential diagnostic signal that provides high-resolution imaging of fault interface properties at seismogenic depth. In this study, we validate the existence of a bi-material interface in the Xianshuihe–Anninghe Fault (XAF) zone around their intersection and determine the cross-fault velocity contrast. We employ a semi-automatic workflow to detect and pick FZHWs and direct P waves. In addition, to improve the identification ability of potential FZHWs in the automatic picking process, we adopt a ‘forward-detecting and backward-picking’ strategy combining the short-term average/long-term average (STA/LTA) algorithm with a kurtosis detector. The polarization and characteristic periods of the waveforms are then used to manually refine the picks and evaluate the quality. The results indicate that the average velocity contrast along the southern Xianshuihe Fault is 3–5 per cent, with the northeast side characterizing a faster P-wave velocity, in agreement with tomographic results. A systematic moveout between FZHWs and the direct P waves over a 100 km long fault segment reveals a single continuous interface in the seismogenic zone. The single bi-material fault structure might be conducive to the preparation of large earthquakes and further influences the corresponding dynamic rupture processes.

The Variable Continuous Bimaterial Interface in the San Jacinto Fault Zone Revealed by Dense Seismic Array Analysis of Fault Zone Head Waves

AbstractKey factors controlling earthquake ruptures include fault geometry, continuity, and seismic velocity structure around the fault. We present a novel tool that better informs deep bimaterial fault geometry embedded in distributed damage and seismicity, associated velocity contrasts across the fault, and their correlations with surface complexities. The method employs fault zone head and direct body waves and is applied to recordings from five spatiotemporally different seismic arrays along the complex San Jacinto fault zone (SJFZ) in southern California. We detect and distinguish these signals based on instantaneous phase coherence and relative energy in a cascading manner from one scale array to another. The analysis reveals a >70‐km long continuous bimaterial interface within the SJFZ with several deep northeast dipping fault segments. The northern SJFZ, for instance, locates ∼7 km northeast of its surface expression at 18‐km depth. P‐wave velocity contrasts range from near 0% to >15%, consistent with other bimaterial faults, and differ by a few % depending on fault‐array azimuth, implying directional‐dependent velocity contrasts. S‐wave head waves and velocity contrasts are also imaged for the first time at the southern SJFZ, averaging to 2.9% in agreement with tomography results. The imaged geometry and continuity suggest the SJFZ initiated along remnant tectonic structures and translates to a rupture potential of M > 7.2, i.e., the sizes of its largest paleo‐earthquakes. The P and S contrasts, and their ratios, have important implications for earthquake rupture speed, mode, directivity, and frictional heating along the SJFZ and other major faults globally.

Internal Structure of the Central Garlock Fault Zone From Ridgecrest Aftershocks Recorded by Dense Linear Seismic Arrays

AbstractWe provide high‐resolution seismic imaging of the central Garlock fault using data recorded by two dense seismic arrays that cross the Ridgecrest rupture zone (B4) and the Garlock fault (A5). Analyses of fault zone head waves and P‐wave delay times at array A5 show that the Garlock fault is a sharp bimaterial interface with P waves traveling ∼5% faster in the northern crustal block. The across‐fault velocity contrast agrees with regional tomography models and generates clear P‐wave reflections in waveforms recorded by array B4. Kirchhoff migration of the reflected waves indicates a near‐vertical fault between 2 and 6 km depth. The P‐wave delay times imply a ∼300‐m‐wide transition zone near the Garlock fault surface trace beneath array A5, offset to the side with faster velocities. The results provide important constraints for derivations of earthquake properties, simulations of ruptures and ground motion, and future imaging studies associated with the Garlock fault.

MODELLING THE VARIATION IN THE MOBILITY PATTERN OF HOUSEHOLDS IN THE URBAN AND RURAL AREAS OF NIGERIA

There is evidence that rural areas are disadvantaged in mobility compared to urban areas. Hence, this study examined spatial variation in the travel pattern of households in urban and rural areas of Nigeria. This study used primary data obtained through questionnaire administration on household heads in the residential zones of both urban and rural areas studied, using the multi-stage sampling technique. Findings revealed that variations exist for age, education level, income level, and occupation in urban and rural areas, and household's average daily mean trip frequency showed a level of fewer trips being generated in the rural area than those in the urban area. Furthermore, the result of the stepwise multiple regression analysis showed that transport mode, household size, number of workers in the house, and occupation of household head were significant variables influencing trip making in urban areas while age, household size, the income of household head and number of employed people were significant in the rural areas. This study concludes that differences exist in the mobility pattern of urban and rural households, and as such, equal consideration and attention should be given to them in policy formulations.

Velocity Contrast across the Zhaotong-Ludian Fault in Southwest China from the Analysis of Fault Zone Head Waves and Teleseismic P-Wave Arrivals

Abstract We image the Zhaotong-Ludian fault (ZLF) in the southeastern margin of the Tibetan plateau (SE Tibetan plateau) using waveforms from local and teleseismic earthquakes recorded by 14 seismic stations. We identify two types of fault zone head wave (FZHW) from two clusters of earthquakes by applying an automatic picking algorithm and a horizontal particle motion analysis. The first type of FZHWs shows a linear time–distance moveout and is only observed at stations on the southeast side of the fault in the northeastern section of the ZLF. The moveout slope suggests an average cross-fault velocity contrast of ∼2.5%. The second type of FZHWs exhibits a constant moveout and is recorded by stations on both sides of the ZLF in the southwestern section from a cluster of earthquakes located in a low-velocity zone. The difference in cross-fault velocity contrast between the northeast and southwest segments of the ZLF is also confirmed by teleseismic P-wave travel-time data. We attribute the prominent velocity contrast in the northeast section to a lithological difference between the South China block in the southeast and the Daliangshan subblock on the northwest side of the fault. The striking difference between the northeast and southwest sections also implies that earthquakes nucleating in one segment would hardly rupture through the entire fault, which can significantly affect our estimates of the maximum magnitude of future earthquakes occurring on the fault.

Zone Head Selection Algorithm Based on Fuzzy Logic for Wireless Sensor Networks

Clustering extends energy resources, improves scalability and preserves communication bandwidth of the network. Clustering is either categorized as static and dynamic or as equal and unequal. Hot-spots issue needs a high overhead and is prone to connectivity problems in the wireless sensor network and this can be only possible because of unequal clustering. In this paper a zone divisional method based on fuzzy logic has been proposed. This method uses a fuzzy logic to form clusters and allot nodes to them for the reduction of energy consumption, and extends the age of the sensor network. The simulation and results section shows that the outperformance of the proposed algorithm, where the (EAUCF) energy-aware unequal clustering fuzzy, (LEACH) lowenergy adaptive clustering hierarchy, (EAMMH) energy-aware multi-hop multi-path hierarchical, and (TTDFP) two-tier distributed fuzzy logic-based protocol for efficient data aggregation in multi-hop wireless sensor networks algorithms. The proposed algorithm has better results in terms of energy consumption minimization, load balancing, and prolongation of the network lifetime.

Fuzzy Logic Based Zone Head Selection Algorithm for Wireless Sensor Networks

Hot-spots are a problem that comes in the cluster-based routing protocol that employs multi-hop communication due to this problem the energy among the sensor nodes is not balanced. The hot-spots issue requires high overhead and is prone to connectivity issues in the sensor network this can be only possible because of unequal clustering. In this method, we have to act on all the nodes of the sensor network for communication. This process consumes high system energy if the numbers of nodes are very high. To offer guaranteed connectivity, decrease high usage and complexity, a fuzzy logic-based zone divisional method has been proposed in this paper. Use fuzzy logic to create clusters and assign nodes to them to decrease the consumption of energy and the age of the network prolongation. The simulation and results section shows the outperformance of the proposed protocol, where the (LEACH) low-energy adaptive clustering hierarchy, (EAUCF) energy-aware unequal clustering fuzzy,(EAMMH) energy-aware multi-hop multi-path hierarchical, and (TTDFP) two-tier distributed fuzzy logic-based protocol for efficient data aggregation in multi-hop wireless sensor networks algorithms. The proposed algorithm has better results in terms of energy consumption minimization, and prolongation of the network lifetime.

EMSNDP: Energy Minimized Optimal Zone Selection of Sensor Network to Build the Data Path for IoTN

Wireless sensor network contains a huge volume of sensors that are capable of observing environmental data and conveying that information to the base station. The zone routing is a way to group sensors into multiple clusters in sensing field. In general, each zone has a single co-ordinator that operates as a zone head and accountable to collect the data from all sensors inside the zone and then forward it to the base station. Clustering and energy efficient path construction to base station is a major issue in sensor networks. This paper concentrates on clustering the sensing field into zones and further splitting it into zone quadrants to maximize the energy efficiency of sensor nodes with minimum delay transmission time. An “Energy Minimized optimal zone selection of Sensor Networks to build the Data Path” protocol is proposed in this paper to minimize the load on zone heads by using the zone coordinators to gather the information from different quadrants of zone. Distance-based communication with the minimum hop is opted to minimize the energy cost. A critical evaluation is carried out on the proposed protocol in the context of total energy consumption of network and average energy consumed per node, lifetime of the Network, delay in reception of packet and packet delivery ratio. The results of our research work and analyzed and benchmarked against similar protocols using Network Simulator 2. The outcome of this research is a reduced delay in packet processing with low energy consumption which significantly increases lifetime of sensor network.

Internal structure of the San Jacinto fault zone at the Ramona Reservation, north of Anza, California, from dense array seismic data

SUMMARYWe image the internal structure of the San Jacinto fault zone (SJFZ) near Anza, California, with seismic data recorded by two dense arrays (RA and RR) from ∼42 000 local and ∼180 teleseismic events occurring between 2012 and 2017. The RA linear array has short aperture (∼470 m long with 12 strong motion sensors) and recorded for the entire analysed time window, whereas the RR is a large three-component nodal array (97 geophones across a ∼2.4 km × 1.4 km area) that operated for about a month in September–October 2016. The SJFZ at the site contains three near-parallel surface traces F1, F2 and F3 from SW to NE that have accommodated several Mw > 6 earthquakes in the past 15 000 yr. Waveform changes in the fault normal direction indicate structural discontinuities that are consistent with the three fault surface traces. Relative slowness from local events and delay time analysis of teleseismic arrivals in the fault normal direction suggest a slower SW side than the NE with a core damage zone between F1 and F2. This core damage zone causes ∼0.05 s delay at stations RR26–31 in the teleseismic P arrivals compared with the SW-most station, and generates both P- and S-type fault zone trapped waves. Inversion of S trapped waves indicates the core damaged structure is ∼100 m wide, ∼4 km deep with a Q value of ∼20 and 40 per cent S-wave velocity reduction compared with bounding rocks. Fault zone head waves observed at stations SW of F3 indicate a local bimaterial interface that separates the locally faster NE block from the broad damage zone in the SW at shallow depth and merges with a deep interface that separates the regionally faster NE block from rocks to the SW with slower velocities at greater depth. The multiscale structural components observed at the site are related to the geological and earthquake rupture history at the site, and provide important information on the preferred NW propagation of earthquake ruptures on the San Jacinto fault.

Implementation of Efficient Intra- and Inter-Zone Routing for Extending Network Consistency in Wireless Sensor Networks

Wireless sensor network (WSN) consists of a large amount of limited battery-powered sensor nodes. In general, energy consumption will be a significant concern for WSN owing to irreplaceable battery constraints of sensor nodes. The zone formation approach could be an adequate data aggregation technique which efficiently minimizes the energy consumption by categorizing sensor nodes into zones. However, the main constraints like zone head (ZH) selection, frequent change of ZH, and multi-hop communication from ZH to the sink have a direct impact on the network consistency of WSN. In this paper, a novel efficient intra- and inter-zone routing scheme has been proposed in order to prolong the network consistency of WSN. In the proposed scheme, the hybrid algorithm is established in which harmony search algorithm incorporates with modified moth flame optimization algorithm. This hybrid algorithm provides the appropriate ZH selection for intra-zone routing that reduces the frequent change of ZH in the network. Furthermore, the path balancing in inter-zone routing is acquired through multi-criteria-based optimal path routing algorithm. The performance results confirm that the proposed scheme enhances the network consistency compared with an existing scheme.

Zone-based Energy Efficient Routing Protocols for Wireless Sensor Networks

This paper proposes a novel zone or grid-based network deployment framework for energy efficient selection and reselection process of Zone-Head (ZH) in the WSNs. The proposed zone head reselection process ensures energy efficiency, load balancing, and stability which further prolongs the network lifetime. Instead of carrying out periodic reselection of Zone-Head (ZH) that leads to extra energy consumption and network overhead, the protocol dynamically initiates the process of reselection based on residual energy level of ZH. In the proposed approach the process is segregated into four phases; deployment phase, the zone formation phase, zone head selection phase, data transmission phase and reselection phase. We implemented the proposed algorithm in MATLAB and its result outcomes reveal that the proposed method outperforms the competitive algorithms for parameters such as load balancing, total energy consumption and network lifetime.

Structural Properties of the San Jacinto Fault Zone at Blackburn Saddle from Seismic Data of a Dense Linear Array

We image the San Jacinto fault zone at Blackburn Saddle using earthquake waveforms recorded by a ~ 2-km across-fault linear array with 108 three-component sensors separated by ~ 10–30 m. The length and spatiotemporal sampling of the array allow us to derive high-resolution information on the internal fault zone structure with spatial extent that can be merged with regional tomography models. Across-fault variations in polarization, amplitude, and arrival time of teleseismic P waves indicate abrupt changes in subsurface structure near the surface trace of the fault (sensor BS55) and ~ 270 m to the northeast (sensor BS34). Analysis of fault zone head waves from local events reveals the existence of a deep bimaterial interface that extends from the array to at least 50 km southeast and has a section with > 10% velocity contrast. This analysis also corroborates the teleseismic results and indicates a broad damage zone primarily northeast of the fault bounded by a shallow bimaterial interface near BS34 that merges with the deep interface. Detection and waveform inversions of Love-type fault zone trapped waves generated by local events indicate a trapping structure within the broader damage zone with width of ~ 150 m, velocity reduction of ~ 55% from the surrounding rock and depth extent of ~ 2 km. The performed analyses provide consistent results on the subsurface location of the main seismogenic fault and properties of a major bimaterial interface and damage structure. The imaged fault zone properties are consistent with preferred propagation direction of earthquake ruptures in the area to the northwest.

Multi-criteria based zone head selection in Internet of Things based wireless sensor networks

The past few years have seen dramatic development and a great interest in efficient service delivery and better resource utilization in the Internet of Things (IoT) based constrained Wireless Sensor Network (WSN). The IoT is mainly dependent on optimal deployment of energy aware WSN and efficient communication architecture for data transfer among heterogeneous devices. In addition, energy efficient clustering techniques for WSN node deployment and routing have achieved great involvement for prolonging network lifetime. In clustering technique, where the network is partitioned into different segments (clusters or zones) and proper attention must be given to the cluster head (CH) selection procedure for maximizing node reachability inside the cluster and efficient communication to the base station. In this paper, we have proposed multi-criteria based cluster head/zone head selection scheme in Internet of Things based WSN by considering distinct parameters affecting node energy and network lifetime. These parameters; energy level, distance from neighboring nodes, distance from center of the zone, number of times a node has been zone head and whether a node is merged or not, have direct impact on overall performance of WSN. The relative impact of each parameter in CH/ZH selection is computed using the Analytical Network Process (ANP) which is widely used multi-criteria decision tool. Simulation results of the proposed scheme show relatively better performance than existing energy efficient clustering techniques. The obtained results have been analyzed by varying the number of parameters in ZH selection and their impact on network stability and lifetime.

Water-table and discharge changes associated with the 2016\u20132017 seismic sequence in central Italy: hydrogeological data and a conceptual model for fractured carbonate aquifers

A seismic sequence in central Italy from August 2016 to January 2017 affected groundwater dynamics in fractured carbonate aquifers. Changes in spring discharge, water-table position, and streamflow were recorded for several months following nine Mw 5.0–6.5 seismic events. Data from 22 measurement sites, located within 100 km of the epicentral zones, were analyzed. The intensity of the induced changes were correlated with seismic magnitude and distance to epicenters. The additional post-seismic discharge from rivers and springs was found to be higher than 9 m3/s, totaling more than 0.1 km3 of groundwater release over 6 months. This huge and unexpected contribution increased streamflow in narrow mountainous valleys to previously unmeasured peak values. Analogously to the L’Aquila 2009 post-earthquake phenomenon, these hydrogeological changes might reflect an increase of bulk hydraulic conductivity at the aquifer scale, which would increase hydraulic heads in the discharge zones and lower them in some recharge areas. The observed changes may also be partly due to other mechanisms, such as shaking and/or squeezing effects related to intense subsidence in the core of the affected area, where effects had maximum extent, or breaching of hydraulic barriers.

Synthesized hybrid ZRP through aggregated routes

Routing issues pertaining to Mobile adhoc networks (MANET) have been under scrutiny over the past many years. The rigorous researches have yielded proactive and reactive protocols but with various pros and cons in different network conditions. A set of protocols combining the advantages of both reactive and proactive were designed to handle security and QOS issues. Out of the hybrid protocols, ZRP has emerged as a highly capable hybrid routing protocol with limited proactive scope due to the formation of zones. However, the existence of overlapping zones and a few more hindrances leave some scope for modifications, required to enhance the performance of ZRP. This paper focuses to resolve the drawback by aggregating the routes into a central entity chosen randomly. The algorithm for synthesizing route aggregation in ZRP starts with formation of additional zones where the participating nodes act as members of the aggregation. Then the zone head is selected for the newly formed nodes, followed by aggregation of all the routes and then buffering them to the link state table. This process is stopped with the active zone head otherwise the above procedure is continued.

Ten kilometer vertical Moho offset and shallow velocity contrast along the Denali fault zone from double-difference tomography, receiver functions, and fault zone head waves

We examine the structure of the Denali fault system in the crust and upper mantle using double-difference tomography, P-wave receiver functions, and analysis (spatial distribution and moveout) of fault zone head waves. The three methods have complementary sensitivity; tomography is sensitive to 3D seismic velocity structure but smooths sharp boundaries, receiver functions are sensitive to (quasi) horizontal interfaces, and fault zone head waves are sensitive to (quasi) vertical interfaces. The results indicate that the Mohorovičić discontinuity is vertically offset by 10 to 15km along the central 600km of the Denali fault in the imaged region, with the northern side having shallower Moho depths around 30km. An automated phase picker algorithm is used to identify ~1400 events that generate fault zone head waves only at near-fault stations. At shorter hypocentral distances head waves are observed at stations on the northern side of the fault, while longer propagation distances and deeper events produce head waves on the southern side. These results suggest a reversal of the velocity contrast polarity with depth, which we confirm by computing average 1D velocity models separately north and south of the fault. Using teleseismic events with M≥5.1, we obtain 31,400 P receiver functions and apply common-conversion-point stacking. The results are migrated to depth using the derived 3D tomography model. The imaged interfaces agree with the tomography model, showing a Moho offset along the central Denali fault and also the sub-parallel Hines Creek fault, a suture zone boundary 30km to the north. To the east, this offset follows the Totschunda fault, which ruptured during the M7.9 2002 earthquake, rather than the Denali fault itself. The combined results suggest that the Denali fault zone separates two distinct crustal blocks, and that the Totschunda and Hines Creeks segments are important components of the fault and Cretaceous-aged suture zone structure.

Internal structure of the San Jacinto fault zone at Blackburn Saddle from seismic data of a linear array

Local and teleseismic earthquake waveforms recorded by a 180-m-long linear array (BB) with seven seismometers crossing the Clark fault of the San Jacinto fault zone northwest of Anza are used to image a deep bimaterial interface and core damage structure of the fault. Delay times of P waves across the array indicate an increase in slowness from the southwest most (BB01) to the northeast most (BB07) station. Automatic algorithms combined with visual inspection and additional analyses are used to identify local events generating fault zone head and trapped waves. The observed fault zone head waves imply that the Clark fault in the area is a sharp bimaterial interface, with lower seismic velocity on the southwest side. The moveout between the head and direct P arrivals for events within ∼40 km epicentral distance indicates an average velocity contrast across the fault over that section and the top 20 km of 3.2 per cent. A constant moveout for events beyond ∼40 km to the southeast is due to off-fault locations of these events or because the imaged deep bimaterial interface is discontinuous or ends at that distance. The lack of head waves from events beyond ∼20 km to the northwest is associated with structural complexity near the Hemet stepover. Events located in a broad region generate fault zone trapped waves at stations BB04–BB07. Waveform inversions indicate that the most likely parameters of the trapping structure are width of ∼200 m, S velocity reduction of 30–40 per cent with respect to the bounding blocks, Q value of 10–20 and depth of ∼3.5 km. The trapping structure and zone with largest slowness are on the northeast side of the fault. The observed sense of velocity contrast and asymmetric damage across the fault suggest preferred rupture direction of earthquakes to the northwest. This inference is consistent with results of other geological and seismological studies.

Nexus between the participation of residents in house design and residential satisfaction in Akure, Nigeria

This study examined the relationship between residents’ level of participation in house design and level of residential satisfaction in Akure, Nigeria. The study was based on the idea that the goal of housing projects is to provide satisfactory environments for users. A cross-sectional survey was conducted on 304 household heads in transitional and peripheral zones of the city. Data were obtained through a structured questionnaire and focus group discussions and observations. The obtained data were subsequently subjected to single-factor descriptive analysis, mean satisfaction scoring, and categorical regression analysis. Results showed a positive significant relationship between the level of resident participation in house design and the level of residential satisfaction. The significant participatory predictors of satisfaction were number of bedrooms, general house design, development of the brief for the design, arrangement of interior spaces, and selection of finishing materials. Space size and building materials were not significant predictors in this context. The obtained p-value of 0.000 indicated that the regression model was significant. This study recommends a high level of resident participation in house design to achieve a high level of residential housing satisfaction in Nigeria.

Internal structure of the San Jacinto fault zone at Jackass Flat from data recorded by a dense linear array

The internal structure of the Clark fault in the trifurcation area of the San Jacinto fault zone is imaged using seismograms recorded by a dense linear array (Jackass Flat, JF) crossing the surface trace of the fault and an adjacent array (TR) to the SW. Delay times between phase arrivals associated with ∼3500 local earthquakes and nine teleseismic events are used to estimate velocity variations within the arrays. The teleseismic P waves travel faster beneath the TR than the JF array, in contrast to larger scale tomographic results. Statistical analysis of local P-wave delay times indicates that the entire JF array, with an aperture of ∼400 m, is inside a low-velocity damage zone. This low-velocity zone is bounded on the NE side by a shallow bimaterial interface generating fault zone head waves, and it contains an inner zone of more intense damage generating fault zone trapped waves. The P-wave velocity contrast across the local bounding bimaterial interface is 10–15 per cent. The trapping structure is associated with a width of ∼200 m, S-wave velocity reduction of ∼35 per cent with respect to the surrounding rock, Q-value of ∼20 and depth of ∼3.5 km. The imaging results suggest that the main seismogenic fault is near the SW end of the JF array, in agreement with a prominent geomorphologic feature. The existence of intense local damage on the crustal block with faster larger scale velocity at depth is consistent with common propagation of earthquake ruptures in the area to the NW.