bluuebunny/crossref_metadata_2025 huggingface dataset:
Morbidity and Mortality of Bilateral Femur Fractures
Authors: Lane Mark K. , Nahm Nickolas J. , Vallier Heather A.
Published: August 2015

Bilateral femur fractures have been associated with frequent morbidity and mortality. Associated injuries and massive hemorrhage contributed to mortality rates that were as high as 27% in previous reports. The goals of this study were to determine the frequency of associated complications, including mortality, and to identify which patient and injury features are associated with increased morbidity and mortality. The authors proposed that some patients with bilateral femur fractures may undergo early definitive fixation with an acceptable rate of complications. Patients who had bilateral femur fractures during the same injury event were retrospectively reviewed. Demographic characteristics, associated injuries, and the type and timing of treatment were determined. Complications were identified. The authors identified 50 men and 22 women, with a mean age of 41.5 years, who had high-energy bilateral femur fractures. These patients accounted for 5.5% of all femur fractures treated at the authors’ institution over a period of 11 years. Two patients died before fixation. In addition, 13 other patients (19%) had 21 complications, including pneumonia in 6 (8.6%) and deep venous thrombosis in 7 (10%). No patient had adult respiratory distress syndrome, but 2 died of multiple organ failure. All patients with pulmonary complications had an underlying chest injury (
P
=.004). The overall mortality rate was 6.9%, and mortality was associated with higher mean age and higher Injury Severity Score (ISS). Of the 60 patients who had definitive fixation within 24 hours of injury, 53 (88%) had no complications. Complication rates were similar to those reported in the literature, with a mortality rate of 6.9%, including 3 patients who died after femoral fixation. Mortality was associated with advanced age and higher ISS. Chest injuries were associated with pulmonary complications. Most patients had early definitive fixation without complications, but it is not possible to predict which patients may be safely treated on an early basis. [
Orthopedics.
2015; 38(7):e588–e592.]
In-hospital Mortality Risk for Femoral Neck Fractures Among Patients Receiving Medicare
Authors: Erickson Brandon J. , Nwachukwu Benedict U. , Kiriakopoulos Emmanouil , Frank Rachel M. , Levine Brett , Villarroel Leonardo , Mccormick Frank M.
Published: August 2015

Increased risk of mortality with time has been established in association with femoral neck fractures. However, little is known about the in-hospital mortality risk associated with femoral neck fractures in the US population. This study was conducted to determine the in-hospital mortality rate associated with femoral neck fractures and to identify independent demographic features associated with an increased risk of this primary outcome. The authors queried the PearlDiver database (PearlDiver Technologies, Inc, West Conshohocken, Pennsylvania) of Medicare patients from 2005 to 2010 for International Classification of Diseases, 9th Revision (ICD-9), diagnostic codes for femoral neck fractures and related conditions. Stratified sampling was conducted by creating a group within the data set that included patients with a death discharge using ICD-9-D-820.0 through ICD-9-D-820.13. Age, sex, and year of injury were analyzed as specific demographic variables related to mortality. A total of 751,232 femoral neck fractures occurred during the index study period. There were 11,420 deaths during the initial hospital stay, for an overall mortality rate of 1.52%. The mortality rate in patients older than 84 years was 2.06%. Of all deaths, 89% occurred in patients who were 75 years and older. The mortality rate for femoral neck fractures was 1.22% in women and 2.32% in men (odds ratio, 0.5; 95% confidence interval, 0.25–1.04). The overall mortality rate for patients in the Medicare population who were treated at an inpatient center for femoral neck fractures from 2005 to 2010 was 1.5%. Men had a mortality rate almost twice that of women. Patients older than 84 years were the most likely to die soon after sustaining a femoral neck fracture. [
Orthopedics.
2015; 38(7):e593–e596.]
Evaluating the Reliability and Reproducibility of the AO and Lauge-Hansen Classification Systems for Ankle Injuries
Authors: Yin Meng-chen , Yuan Xue-fei , Ma Jun-ming , Xia Ye , Wang Tao , Xu Xiao-li , Yan Yin-jie , Xu Jin-hai , Ye Jie , Tong Zheng-yi , Feng Yan-qi , Wang Hong-bo , Wu Xue-qun , Mo Wen
Published: August 2015

Ankle injuries are responsible for more than 5 million emergency department visits each year. The AO and Lauge-Hansen classification systems are widely used in the clinical diagnosis of ankle injuries. This study aimed to analyze the intraobserver reliability and interobserver reproducibility of the AO and Lauge-Hansen classification systems. In addition, the authors explored the differences among physicians’ classification responses and evaluated the clinical value for diagnosis. Fifty-six patients with an ankle injury with complete clinical and radiologic data were enrolled. The definition of injury type, the index score typing methods, and the specific study criteria were explained in detail. Five observers, who were orthopedic surgeons, determined the classifications according to both the AO and Lauge-Hansen systems. The classification was repeated 1 month later. Cronbach’s alpha and Cohen’s kappa test were used to determine interobserver reliability and intraobserver reproducibility. The physicians conducted 560 classifications (56 cases × 5 physicians × 2 times per patient). Average inter- and intraobserver kappa values for the AO system were 0.708 and 0.608, respectively. Average inter- and intraobserver kappa values for the Lauge-Hansen system were 0.402 and 0.398, respectively. Cronbach’s alpha coefficient was 96.7% for the AO system and 76.0% for the Lauge-Hansen system. The Lauge-Hansen classification system is a comprehensive yet cumbersome system. Comparatively, the AO classification system is easier to understand. This study shows that the AO classification system has more reliability and reproducibility, and thus has more value in clinical practice, than the Lauge-Hansen classification system. [
Orthopedics.
2015; 38(7):e626–e630.]
Recurrent Metacarpal Enchondroma Treated With Strut Allograft: 14-year Follow-up
Authors: Yalcinkaya Merter , Akman Yunus Emre , Bagatur A. Erdem
Published: August 2015

Enchondroma of the hand is a common lesion with a recurrence rate of up to 13.3% after curettage and bone grafting. Pathologic fractures often occur. Although allograft bone chips are widely used in the surgical treatment of enchondroma, the use of structural allograft bone has not been reported before. This case report presents a recurrent enchondroma of the fifth metacarpal with pathologic fracture in a 13-year-old girl who had 2 previous interventions and 2 more interventions for other enchondromas in the same hand. These interventions consisted of curettage and autogenous iliac crest bone grafting. The metacarpal diaphysis was resected and reconstructed with an intercalary freeze-dried strut allograft fibular bone segment to avoid further donor graft site morbidity. At 14 years of follow-up, the patient had full range of motion of the hand, with no symptoms, and the allograft bone had been incorporated completely, with no recurrence of the tumor. With strut allograft bone, healing occurs by creeping substitution at its ends that is limited to a few millimeters. Limited vascularization also occurs on the allograft surface, leaving most of the allograft segment devoid of vascularity and leading to the complications seen in massive bone allografts. However, because of their thin cortices and decreased total volume, smaller bone allografts show higher rates of osteointegration and revascularization. In selected cases, a strut allograft bone may be considered a suitable material for long-term reconstruction of the hand after enchondroma excision, especially in young patients, who have increased healing potential compared with older patients. [
Orthopedics.
2015; 38(7):e647–e650.]
A study on distribution and population size of Androcymbium hierrense (Colchicaceae) an endangered taxon, in La Palma Biosphere Reserve (Canary Islands)
Authors: Manuel Medina Félix , Fernández de León Raúl
Published: August 2015

The scarce knowledge on the distribution of the natural populations of the Canarian endemic Androcymbium hierrense (Colchicaceae), an endangered species in the island of La Palma hampers the identification of priorities for undertaking actions for its conservation. Here we present a survey in which, the species is distributed in 14 locations grouped into two differentiated areas. This result represents an increase of ca. 200% in the occupancy area known for the species until now. A total of 15010 individuals were recorded: 1294 individuals in the northern parts of the island (Garafía), and 13716 in the east (Mazo). The species exhibits an average density of 8.80±24.03 SD (n=1559) and an estimated population size of 21593-24851 individuals (with a 95% confidence interval), given a total population of 217995 plants for the entire species distribution area on the island. Considering these estimates and the current distribution of the species, it is important to analyse its actual conservation status in La Palma both at regional and global scales, taking into account that the main threat for the species is habitat destruction by human activities.
A Measure to Study Skin Reflectance using Non-Invasive Photosensor with Economic Design
Authors: Vittal Prabhu Ravikala , Sriraam N. , Mala C.K. , Saritha J.
Published: August 2015

Non-invasive mode of clinical testing has created a major impact on the society and finds huge demand in the clinical domain. There are several instances where such approach receives more co-operations from the patient. Replacing the traditional practice with such non-invasive procedure requires appropriate clinical investigation and validations, specifically exact location of veins for intravenous applications like venepuncture and other medical procedures. Collection of blood samples for bilirubin test for new-borns, blood sugar level detection also needs a special attention where such non-invasive procedure is highly preferred. Such clinical methodology highly relies on the selection/design of photo sensor and works on the principles of light that gets scattered from the human skin. This specific research study attempts to measure the effect of the photo sensor on the skin reflection and how the properties can be exploited for bilirubin test to detect jaundice for new-borns. Neonatal jaundice often referred as hyperbilirubinemia which indicates the concentration of serum bilirubin levels in blood stream. The higher and lower bilirubin levels can cause irreversible brain damage which is referred as kernicterus. The yellowish spot due to bilirubin deposition in the neonatal skin tissue indicates the presence or absence of jaundice. Several attempts have been made in the recent past to develop non-invasive mode of measuring the blood concentration level for recognition of bilirubin levels. The proposed research study involves in measuring the skin reflectance using photo sensor and to measure the bilirubin concentration in a non-invasive mode. A GaAsP yellow LED with a wavelength of 590nm with TEPT5700 light sensors was applied and Arduino real time processor was interfaced to the circuitry. The system was designed in such a manner that the buzzer activation indicates the severity of the bilirubin concentration. The lab based circuitry was converted in to indigenous prototype and was tested with newborn in a real time mode. The clinical validation was found to be quite promising. It can be concluded that the designed system was found to be more economic and can introduce in the primary healthcare sector.
An Architecture to Implement the Internet-of-Things using the Prometheus Methodology
Authors: Manațe Bogdan , Fortiş Florin , Moore Philip
Published: August 2015

The rapid expansion of the Internet of Things (IoT) will generate a diverse range of data types that needs to be handled, processed and stored. This paper aims to create a multi-agent system that suits the needs introduced by the IoT expansion, thus being able to oversee the Big Data collection and processing and also to maintain the semantic links between the data sources and data consumers. In order to build a complex agent oriented architecture, we have assessed the existing agent oriented methodologies searching for the best solution that is not bound to a specific programming language of framework, and it is flexible enough to be applied in such a divers domain like IoT. As complex scenario, the proposed approach has been applied to medical diagnosis and motoring of mental disorders.
A Two-Dimensional SLA for Services Scheduling in Multiple IaaS Cloud Providers
Authors: Vieira Cristiano Costa Argemon , Bittencourt Luiz Fernando , Madeira Edmundo Roberto Mauro
Published: August 2015

Customers of cloud services choose the VMs profiles (SLAs) offered by the provider, and pay according to how long these VMs are utilized. Many works deal with how to decrease the cost of VM requests scheduling, but consider solely the charging models in the SLA. However, other characteristics in the SLA must be taken into account when choosing a VM to execute users' applications (e.g. processing capacity). In order to fulfill the user needs and allow proper utilization of resources available in IaaS providers, this paper models a two-dimension SLA, namely charging model and VM type. The problem is modeled as an integer linear program to compute the scheduling regarding this SLA model. Simulations show that the proposed approach computes schedules that better fits the user needs and allow better utilization of VMs, resulting in a higher number of fulfilled requests than alternative approaches.
The Impact of Virtualization on High Performance Computing Clustering in the Cloud
Authors: Achahbar Ouidad , Abid Mohamed Riduan
Published: August 2015

The ongoing pervasiveness of Internet access is intensively increasing Big Data production. This, in turn, increases demand on compute power to process this massive data, and thus rendering High Performance Computing (HPC) into a high solicited service. Based on the paradigm of providing computing as a utility, the Cloud is offering user-friendly infrastructures for processing Big Data, e.g., High Performance Computing as a Service (HPCaaS). Still, HPCaaS performance is tightly coupled with the underlying virtualization technique since the latter is responsible for the creation of virtual machines that carry out data processing jobs. In this paper, the authors evaluate the impact of virtualization on HPCaaS. They track HPC performance under different Cloud virtualization platforms, namely KVM and VMware-ESXi, and compare it against physical clusters. Each tested cluster provided different performance trends. Yet, the overall analysis of the findings proved that the selection of virtualization technology can lead to significant improvements when handling HPCaaS.
TCP/IP Reassembly in Network Intrusion Detection and Prevention Systems
Authors: Wang Xiaojun , Cronin Brendan
Published: August 2015

Deep Packet Inspection (DPI) in Network Intrusion Detection and Prevention Systems (NIDPS) typically involves the matching of packet payloads against attack signatures in the form of fixed strings and regular expressions. As an attack pattern may span multiple IP fragments or TCP segments, accurate DPI requires that the traffic is reassembled prior to analysis of the payload data stream. Although hardware acceleration of the TCP layer, including reassembly, is well known in the form of TCP Offload Engines for Network Interface Cards, only limited research has been conducted into reassembly architectures suited to the particular requirements of DPI systems. The challenging requirements include the tracking and fragment/segment reordering of a potentially very large number of streams in addition to dealing with subtle ambiguities in IP fragmentation and TCP segmentation using target based reassembly or traffic normalization. In this article, the authors present a combined hardware and software architecture which harnesses the resources of the latest FPGA technology to improve on existing research proposals.
The War against the Taliban
Authors: Ordóñez Lucía Martínez , Schimmelpfennig Jörg
Published: August 2015

Operation Enduring Freedom was hampered by a chronic shortage of attack helicopters available to ISAF forces in Afghanistan. Tactical operations into Taliban-held territory were launched even though close air support capable of dealing with “danger close” situations could not be assigned in advance. It led to significant ISAF casualties if the Taliban decided to fight back rather than withdraw. Departing from a Clausewitz-style, i.e. second-mover advantage, mixed-strategy equilibrium and taking account of the “Irregular Warfare” nature of the pay-offs, the paper looks into the existence of strategic moves. In particular, as playing a mixed strategy if rotary wing air support is unavailable merely incentivises a more aggressive Taliban response to any kind of operation due to the information asymmetry, it is argued that by moving away from the mixed-strategy equilibrium ISAF casualties in properly supported operations could be reduced, thus handing a first-mover advantage to ISAF.
The Effect of Organizational Commitment on Project Outcomes under Common Agency
Authors: Hurst Bruce E. , McGivern Michael H.
Published: August 2015

This research was undertaken to look at possible ways to broaden the definition of project management success beyond the tradition measures of time, cost, and scope. The research was designed to determine if the human organization comprised of layers of relationships and governance would or could change and reduce the high failure rate attributed to IT projects. The human aspect of conflicting organizational goals, those established by the information technology principal and the business unit principal with the project manager acting as agent, was the foundation for the study. The study expanded project management theory as it related to three variables: organizational commitment, project governance, and complex agency relationships. This was accomplished through a survey distributed to 403 information technology project managers in the United States designed to measure the three variables against the dependent variable project success. The results indicated that governance, organizational commitment, and the effects of common agency on a project manager's performance in meeting what might be conflicting success criteria do have a positive correlation. This research could provide new directions for researchers, project management practitioners, and strategic corporate planners when establishing project success criterion.
Design and Implementation of LLC Resonant Converter for Photovoltaic Battery Charging Application
Authors: Theam Tan Adrian Soon , Iqbal Shahid
Published: August 2015

Photovoltaic power conditioning system (PVPCS) requires a high efficiency dc-dc converterstage capable of wide input voltage regulation and have the ease of maximum power point implementation for both stand alone photovoltaic system and grid-connected system. Galvanic isolation at the dc-dc stage can replace the isolation needed in the inverter stage and thus reduce the sizeof isolation transformer and increases overall system efficiency. This paper presents detailed analysis,design and implementation of a LLC resonant converter for photovoltaic battery charging application.The LLC resonant converter operate with zero voltage switching (ZVS) turn on and low current turnoff thus reducing switching losses. The experimental results are given to validate the operation andperformance of the converter.
Asymmetric Cascaded DC Sources Multilevel Inverter with Less Active Switches and Simpler Control Strategy
Authors: Tan Yee Chyan , Syed Hassan Syed Idris , Ong Siok Lan , Leong Jenn Hwai
Published: August 2015

Cascaded H-Bridge (CHB) multilevel inverter (MLI) is among the most preferred topology in solar PV systems. While traditional asymmetric CHB MLI is easy to achieve higher number of output voltage levels compared to traditional symmetric CHB MLI, charge balancing between the voltage sources remains a challenge for asymmetric CHB MLI. This drawback results in unsteady DC voltage levels due to unbalanced power drawn from each voltage sources. Besides that, in battery powered applications, unbalanced power drawn results in unequal discharged among the batteries. In this paper, an asymmetric half H-bridge (HHB) MLI topology is presented which is easy to modularize as for symmetric CHB MLI while maintaining the ease in charge balancing control. The performance of this proposed asymmetric HHB MLI with charge balance control has been evaluated using PSIM software.
Modelling and Simulation an AC-DC Rectifier Circuit Based on Piezoelectric Vibration Sensor for Energy Harvesting System
Authors: Sarker Mahidur R. , Mohamed Azah , Mohamed Ramizi
Published: August 2015

This paper presents the modeling of a full-wave rectifier circuit based on piezoelectric vibration transducer for energy-harvester system. Piezoelectric vibration crystals are a viable means of harvesting energy for low-power embedded systems e.g. wireless sensor network. Distinct power handling circuits are assessed with the presence of piezoelectric vibration based energy harvesting transducer. Inside the interface circuit, the voltage should be started up when the AC input voltage is very low to supply a regulated DC voltage up to 2V. An active technique is chosen to design an ultra-low power circuit from a piezoelectric vibration transducer. MOSFET bride ac–dc rectifier, energy storage device e.g. capacitor and boost converter with regulator are the common components of the energy harvesting circuits. An integrated promoter ac-dc rectifier circuit and boost converter that accept a maximum input voltage of 0.3V and provide a regulated output voltage of 2V serve as the supply. The MOSFET and thyristor are considered to develop the proposed circuit replacing conventional ac-dc rectifier due to low input voltage at which diode does not work.
A New Controller Scheme for Seven-Level Cascade Multilevel Converter Based Shunt Active Power Filter
Authors: Mohammed B.S. , Ibrahim R.
Published: August 2015

In this paper, a new controller scheme for seven-level cascade multilevel converter based shunt active power filter has been proposed aimed to overcome the disadvantages of the existing controller schemes by reducing the complexity, number of measurement signals and computing time. The feasibility of the proposed controller schemer is verified by the digital simulation in MATLAB/SIMULINK platform. The simulation results indicate that the proposed method can be used to compensate for balanced/ unbalanced current, reactive power beside neutral conductor current in case of four-wire distribution systems.
Three-Phase Asymmetric Multilevel Inverter Topologies with Better Charge Balancing
Authors: Tan Yee Chyan , Yusof M. Aizuddin , Syed Hassan Syed Idris , Ong Siok Lan , Leong Jenn Hwai
Published: August 2015

Cascaded H-bridge multilevel inverter is among the most preferred topology in solar systems. While traditional asymmetric cascaded H-bridge multilevel inverter is easy to achieve higher number of output voltage levels compared to traditional symmetric cascaded H-bridge multilevel inverter, charge balancing between the voltage sources remains a challenge for asymmetric cascaded H-bridge multilevel inverter. This drawback results in unsteady DC voltage levels due to unbalanced power drawn from each voltage sources. Besides that, in battery powered applications, unbalanced power drawn results in unequal discharged in the batteries. In this paper, two three-phase asymmetric cascaded H-bridge multilevel inverter topologies are proposed which offer easier in terms of modularity while maintaining the ease in charge balancing control. The performance of these two proposed topologies with charge balance control has been evaluated using PSIM software.
50 cm Air Gap Wireless Power Transfer by Magnetic Resonance Coupling
Authors: Fareq M. , Fitra M. , Irwanto Muhamad , Syafruddin H.S. , Gomesh Nair , Irwan Y.M. , Halim M.A. , Suwarno  , Herman A. , Hussain T.
Published: August 2015

In this paper, we have developed transmitter, receiver and 2 structure magnetic resonant couplings. Both of the Transmitter and Receiver couplings are made of copper tubing. Transmitter and Receiver circuits were build by using Multisim software. Transmitter in put by DC source 12 Volt, 0.5 Ampere, with 50 cm Air gap wireless power transfer can reach efficiency 25.2 % with DC 3.02 Volt, 50.01 mA, at Frequency 164.76 kHz.
Performance Evaluation of Various Adaptive Neuro Fuzzy Inference System Based Maximum Power Point Tracking for Photovoltaic System
Authors: Mutlag Ammar Hussein , Shareef Hussein , Mohamed Azah , Abd Ali Jamal , Ahmed Maytham S.
Published: August 2015

The maximum output power of a photovoltaic (PV) system with a DC-DC converter depends mainly on the solar irradiance (G) and the temperature (T). Therefore, a maximum power point tracking (MPPT) mechanism is required to improve the overall system. The conventional MPPT approaches such as the perturbation and observation (P&O) technique have difficulty in finding true maximum power point. Thus various intelligent MPPT systems such as fuzzy logic controllers (FLC) are recently introduced. In FLC based MPPT, selecting the type of the membership function (MF) and the number of the fuzzy sets (FS) is critical for better performance. Thus, in this paper various adaptive neuro fuzzy inference system (ANFIS) is utilized to automatically tune the FLC membership functions instead of adopting the trial and error method. To find suitable MF for FLC, ANFIS is developed in MATLAB/Simulink and the effect of different types MF investigated. Simulation result shows that the FLC with triangular MF and seven FS give the best result. The evaluation indices used in this study includes the maximum extracted energy, minimum standard deviation of the error, and minimum mean square error.
Optimization of Sun-Tracker Positioning Using Takagi-Sugeno Fuzzy-Logic Method
Authors: Hasanah Rini Nur , Putri Suci Imani , Suyono Hadi
Published: August 2015

The continuously increasing use of photovoltaic cells requires various efforts to maximize the harnessing of solar energy. This paper presents the research results of fuzzy-logic method implementation to maximize the absorption of solar energy. It is based on the optimization of solar panels position according to the sun direction. The Takagi-Sugeno method is chosen in the fuzzification stage. The control algorithm is implemented on a microcontroller ATMega-128 using BASCOM-AVR program. DC motor is used to actuate the solar panels. The results show an increase of 0.48V in the output of solar cells sensor using the fuzzy logic computation-based tracking system. The resulted tracking system proves to consume less power because the tracking process is halted while moving the DC motor continuously.
Regenerative Braking of Electric Vehicle with Brushless DC Motor
Authors: Ajmal Aidha Muhammad , Ramachandaramurthy V.K.
Published: August 2015

Given the volatile market prices and impending reduction in fuel supplies, electric vehicles (EV) have drawn increasing attention. The electric motor in EVs is an important component because it functions as an engine during acceleration and as a generator during deceleration or braking. Energy is saved in these processes when the kinetic energy is converted into electrical energy, which is then stored in a storage system by a regenerative braking system (RBS). In terms of highly efficient performance, ideal torque and speed, high-powered density, and cost-effective maintenance, brushless DC (BLDC) motors are preferred. This paper aims to explore and propose a seamless and effective method of RBS for a BLDC motor in an EV. In braking mode, the proposed method change the motor to act as a generator even without any additional converter, ultra-capacitor, or a complex winding-changeover technique. In this mechanism, the energy flows to the DC side. By using MATLAB/SIMULINK, the BLDC motor with speed and current controller is simulated. Accordingly, in the deceleration or braking mode, the motor functions as a generator and transports the power to the DC side. The proposed model is validated in both starting or no-load and load conditions.
Multi-Objective Optimization for Sizing of Distributed Generation Using Cuckoo Search Algorithm
Authors: Mohd Zaid Nurzahirah , Mokhtar Mohd Khairi , Musirin Ismail , Rahmat Nur Azzammudin
Published: August 2015

This paper presents multi-objective optimization for sizing of distributed generation using cuckoo search algorithm. The study involved the development of cuckoo search optimization engine. Prior to the development of multi-objective for cuckoo algorithm, a pre-developed voltage stability index termed asFVSIfor location identification is used in this study. Weighted sum technique is used as the fitness for the problem formulation. Objectives of the study are to minimize the total real power and improve its voltage stability condition. Test is done on IEEE 69-Bus Radial Distribution System. Results obtained from the study indicated that the proposed technique is feasible for further implementation in power system.
Proposed on Transformer-Less Dynamic Voltage Restorer
Authors: Rosli Eimi Diyana , bin Mustapa Rijalul Fahmi , Hidayat M.N.
Published: August 2015

Power delivered to consumer from utilities is susceptible to power quality problems. The most common power quality problems are voltage sag. Modern equipment nowadays are prone to problems associated with voltage sag. Such problems can be apprehended by several mitigation methods. This paper will discuss voltage sag mitigation method by eliminating the injection transformer in ordinary Dynamic Voltage Restorer (DVR) and applying Single Phase Matrix Converter (SPMC) in a single phase DVR topologies. The objective of this paper is to investigate the potential mitigation method without the injection transformer in the DVR topology. DVR circuit will be constructed and simulated using MATLAB/SIMULINK software. It is hoped that the result of this work will provide a simpler mitigation technique where existing DVR topology can be constructed with less component that provides unnecessary losses in the DVR itself.IndexTerms—Injection Transformer, DVR, SPMC, MATLAB/SIMULINK.
Bijective Differential Search Algorithm for Robust Design of Damping Controller in Multimachine Power System
Authors: Islam Naz Niamul , Hannan M.A. , Shareef Hussein , Mohamad Azah
Published: August 2015

Low frequency oscillation (LFO) is a serious threat to the interconnection of power system and its safe operation. In this paper, optimum damping performances over LFO is achieved by implementing Bijective Differential Search Algorithm (B-DSA) to large interconnected power system. Conventional two stages lead-lag compensator is optimized as the Power System Stabilizer (PSS) and Linear Time Invariant (LTI) State Space system models are used to conduct stability analysis of power system. The tuning problem of PSS in multimachine system was formulated as a multi-objectives function. The simulations are conducted in 5-AREA 16 Machine test power system for severe system fault in order to verify the robust design of damping controller. The obtained results are compared with standard DSA optimization technique. The findings show the improved damping achieved by B-DSA than DSA algorithm. The settling times achieved using B-DSA based designed PSSs are 3.74sec and 4.57sec for local mode and inter-area mode of oscillations respectively. The successful damping over oscillation modes of LFO justifies the proposed technique is efficient for the improvement of power system security in adverse condition.
Comparison between the System Cascading Collapse Based Hidden Failure and Fault Chain Theory in the Determination of Sensitive Transmission Lines
Authors: Salim Nur Ashida , Othman Muhammad Murtadha , Musirin Ismail , Serwan Mohd Salleh
Published: August 2015

This paper presents a computationally accurate technique used to determine the estimated average probability of a system cascading collapse in association with the effect of hidden failure on a protection system. This includes an accurate calculation of the probability of hidden failure as it will provide considerable effect on the results of the estimated average probability of system cascading collapse. The estimated average probability of a system cascading collapse is then used to determine the sensitive transmission contributing to a higher risk of a system cascading collapse. This information is important because it will assist the utility to determine the critical transmission lines before the occurrence of critical power system cascading collapse. Comparative study has been done with other techniques to verify the effectiveness of the proposed method used in the determination of sensitive transmission lines.
Coordinated Operation of Distribution Network and Distributed Energy Resources to Improve Reliability
Authors: Zhou Qin , Yang Zhi Hui , Li Ming
Published: August 2015

This paper presents a comprehensive analysis on coordinating the operation of distribution network and DERs to improve the distribution network reliability. Device failure models, system state sampling and modeling procedure, and minimized load shedding model are developed. Three categories of scenarios are studied, a) grid has enough supply capability; b) grid lacks of enough supply capability due to the load growth; c) line failure rate increased due to the integration of DERs. Overall the reliability is improved with DERs being integrated but under certain conditions the integration of DERs may have negative impact to the reliability.
The Effects of Solar Irradiance, Reflecting Material and Intercept Factor to the Solar Power Intercepted by Receiver 1kW Parabolic Dish
Authors: Affandi Rosnani , Geok Pheng Liaw , Ab Ghani Mohd Ruddin , Gan Chin Kim
Published: August 2015

Parabolic Dish (PD) system is one of the Concentrating Solar Power (CSP) technologies that converts the thermal energy from solar irradiance into mechanical energy and then to electrical energy. The concentrator in PD system works by focusing the solar radiation onto the receiver located at the focal point. The solar power that produced from the concentration process is intercepted by the receiver and then used for the energy conversion process in PD system. This study is carried out to understand the effect of the intercept factor, reflecting material and the DNI to the solar power intercepted by the receiver in PD 1kW system. Meanwhile, Matlab Simulink was used in this study as the simulation tool. The study shows that the solar power intercepted by the receiver in 1kW PD system are strongly depending on the intercept factor, DNI of the locations and reflecting material used for the concentrator. Whereas, the results from this study are useful for a better understanding especially on the effects of the intercept factor, reflecting material and the DNI to the solar power intercepted by the receiver for 1kW PD system in different locations with different DNI level.
Comparison of Different Options to Transport Energy in Photovoltaic Power Plant Using Centralized Inverter
Authors: Mohamed Nawawi Noorsharin , Gan Chin Kim , Tan Pi Hua
Published: August 2015

This paper presents a comparative study in terms of copper weight required and losses generated in transporting energy harvested in PV plant using different Centralized Inverter (CI) configurations. For the sake of simplicity, the Standard Test Conditions (STC) rated PV power value has been used in this study. The key findings suggest that different Combiner Box (CB) configurations in CI plays an important roles in determining the total conductor weight and losses attributed by each configuration. The outcome of this study will help the PV plant designers and system integrators to estimate the cost of solar cable of implementing different design configuration.
Assessment of Wind Energy Potential in Three Different Locations of Malaysia
Authors: Shamsipour R. , Fadaeenejad M. , Radzi M.A.M.
Published: August 2015

In this study, wind energy potential in three different stations in Malaysia in period of 5 years is analyzed. Base on Weibull distribution parameters, the mean wind speed, wind power density and wind energy density is estimated for each defined location. Although there are many works about wind potential in Malaysia, however a few of them have been provided a comprehensive study about wind power in different places in Malaysia. According to the findings, the annual mean wind speeds indicates that the highest wind speed variation is about 2 m/s and is belonged to the Subang station and the highest wind speed is 3.5 m/s in in Kudat. It is also found that the maximum wind power densities among these three sites are 22 W/m2, 24 W/m2 and 22 W/m2 in Kudat station in January, February and September respectively. The results of the study show that as the second parameter for Weibull model, the highest wind energy density has been 190 kWh/m2 per year in Kudat and the lowest one has been about 60 kWh/m2 in Kuching.
Structural Learning of Boltzmann Machine and its Application
Authors: Yaakob Shamshul Bahar , Hasan Mohd Zamri , Ahmed Amran
Published: August 2015

This study proposed a way to solve problem efficiently which is through structural learning of Boltzmann machine. This method used mixed integer quadratic programming to solve the problem. An analysis is conducted by using the ideas of the reliability and risks of units assessed using a variance-covariance matrix and the effect and expanses of replacement are determined. In this study, the mean-variance analysis is formulated as a mathematical program with two objectives: (1) minimization of risk and (2) maximization of expected return. Lastly, the effectiveness of proposed method is illustrated by way of a life cycle management example. The result of this suggested method was demonstrated at the end. By using this method, more effective selection of results is gathered. Thus, this prove that the effectiveness of the decision making process can be reinforced.
Potential Area to Harness the Tidal Energy at West Coast Peninsular Malaysia
Authors: Zainol Mohd Zaifulrizal , Rahim Haziatul Najihah Zana , Dahalan Wardiah , Abu Atzroulnizam , Ghani Muhamad Fadli , Zainol Ismail
Published: August 2015

Malaysia nowadays depends heavily on conventional energy resource for generating electricity and transportation. This will give negative impact and trigger other problems if not well managed. Therefore, it is very important to increase the use of renewable energy especially the tidal energy as the tidal energy is more predictable and reliable renewable energy source. A kinetic energy produced by the tidal differences will be used to generate electricity and involves the use of a tidal turbine. There are two approaches that are being used to harness the tidal energy for the generation of electricity which are barrage approach and tidal stream approach. This paper identify the potential region along west coast of peninsular Malaysia that has higher potential power generation for harnessing tidal energy and study which approach suitable to be applied. From the results, show that the highest potential power generation for harnessing tidal energy is at Pelabuhan Klang with the average power availability is 591.19kW while the lowest is at Tanjung Keling with the average potential power generation is 52.75kW.
A New Strategy for Multiple Chillers Plant Operation Using Fuzzy Inference System
Authors: Hamid Elnazeer , Nallagownden Perumal , Nor Nursyrizal Mohd , Muthuvalu Mohana Sundaram , Romlie Mohd Fakhizan
Published: August 2015

Reducing energy consumption is one of the most important things for optimal operation of the multiple-chillers. The storage system for chilled-water is used for cooling demand and shifting load consumption at peak hours. The case study in this work is based on the existing system for chillers plant in an industrial building. This paper adopts Fuzzy Inference System, in order to adjust the operating points setting for a period of 24 hours to keep the cooling demand satisfied. This is based on a new strategy for the scheduled operation of the chillers. The results have shown the effectiveness for the energy savings and also satisfying the cooling demand. This proposed control system has been simulated in Matlab and the simulation result is compared with the measured data from the existing system.
Whole Facility Measurement for Quantifying Energy Saving in an Office Building, Malaysia
Authors: Razali Nor Shahida , Dahlan Nofri Yenita
Published: August 2015

This paper presents the concept of International Performance Measurement and Verification Protocol (IPMVP) for determining energy saving at whole facility level for an office building in Malaysia. Regression analysis is used to develop baseline model from a set of baseline data which correlates baseline energy with appropriate independents variables, i.e. Cooling Degree Days (CDD) and Number of Working Days (NWD) in this paper. In determining energy savings, the baseline energy is adjusted to the same set condition of reporting period using energy cost avoidance approach. Two types of energy saving analyses have been presented in the case study; 1) Single linear regression for each independent variable, 2) Multiple linear regression for each independent variable. Results show that NWD has coefficient of determination, R2 higher than CDD which indicates that NWD has stronger correlation with the energy use than CDD in the building. Finding also shows that the R2 for multiple linear regression model are higher than single linear regression model. This shows the fact that more than one component are affecting the energy use in the building.
Where is the church on Monday? Awakening the church to the theology and practice of ministry and mission in the marketplace
Authors: Forster Dion A. , Oosterbrink Johann W.
Published: August 2015

Recent research by the Call42 group has shown that South African Christians experience that they are not adequately prepared or equipped for Christian living and discipleship in the world of work – here called the marketplace. This article has argued for the importance of a rediscovery of a theology of work that can empower and equip the church and individual Christians for ministry in the marketplace. The article traces why such a theological deficiency exists in the South African church by considering areas such as an inadequate theology of work and mission, a dualism between faith and work, and an unbalanced emphasis on the role of clergy and a lesser focus on the role of the laity in themissio Dei. Having considered these challenges to the mission and theological identity of the church, the article discusses the three general theological views of the church in South Africa as presented by Smit and adapted by Forster. It considers how the church could become an agent of mission and transformation in the marketplace in each of these three forms. The article comes to the conclusion that the church will need to revisit its missional theology, refocuses its efforts on broader society, and empowers and equips its members for ministry in the marketplace in order to be faithful in partnering with God in the missio Dei.Waar is die kerk op Maandag? Ontwaking van die kerk tot die teologie en praktyk vanbediening en sending in die markplein. Onlangse navorsing deur die Call42 groep het bevind dat Suid-Afrikaanse Christene ervaar dat hulle nie voldoende voorbereid en toegerus is vir die Christelike lewe en dissipelskap in die arbeidsmark - hier genoem die markplein – nie. Hierdie artikel poog om aan te toon dat ’n herontdekking van ’n teologie van werk belangrik is ten einde die kerk in die algemeen asook individuele Christene te bemagtig en toe te rus vir die bediening in die markplein. Hierdie artikel poog dus om die kwessie van die sodanige teologiese leemte in die Suid-Afrikaanse kerk na te vors. Terreine soos onvoldoende teologie van werk en sending word ondersoek, ’n dualisme tussen geloof en werk word uitgewys, en daar word aangetoon dat ’n oorspeling van die predikant se rol en ’n onderspeling van gewone kerklidmate se rol die kerk se betrokkenheid by die missio Dei benadeel. Met inagneming van hierdie uitdagings aan sending en die kerk se teologiese identiteit, bespreek die artikel drie algemene teologiese standpunte van die kerk in Suid Afrika, soos deur Smit aangebied en deur Forster aangepas. Die artikel besin hoe die kerk in elk van hierdie drie bestaansvorme ’n agent van sending en transformasie in die markplein kan wees. Die gevolgtrekking word gemaak dat die kerk die missionale of sendingteologie moet heroorweeg, opnuut moet fokus op die uitreik na die breër gemeenskap en lidmate vir bediening in die markplein moet bemagtig en toerus. Sodoende sal die kerk getrou wees aan die medewerking met God in die missio Dei.
The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth
Authors: Dula Linda J. , Shala Kujtim Sh. , Pustina-Krasniqi Teuta , Bicaj Teuta , Ahmedi Enis F.
Published: August 2015

Objective: The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth. Materials and Methods: A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probing depth (PD) (mm) and tooth mobility (TM) index. These clinical measurements were taken immediately before insertion the RPD, then one and 3 months after insertion. The level of significance was set at (P < 0.05). Results: The mean scores for PLI, CI, BOP, PD, and TM index, of the abutment teeth and non-abutment teeth were no statistically significant at the time of insertion of RPD. After 1-month, PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After 3 months, there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (P > 0.05). Conclusions: With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene, we can prevent the periodontal diseases.