Search results for: electronic equipment failure

Authors: Motaz Alshawwa

Abstract:

This current study aims to know journalists' motives for dealing with electronic journalism more than paper journalism in Palestine. The participants of the study were (250) journalists. To achieve the study objective, a questionnaire was used that was composed of (18) questions. The results of the study showed that the motives dealing with electronic journalism were utilitarian motives that were represented by knowing the local news. We find a statistically significant relationship at the level of significance of 0.05 between the uses of electronic journalism and gender, and there are statistically significant differences at the level of 0.05 in the motives of dealing with electronic journalism. The study recommends the daily paper journals in Palestine should meet the various and different needs of the public.

Keywords: electronic journalism, journalist, paper journalism, utilitarian motives

Procedia PDF Downloads 54

Authors: V. V. Singh

Abstract:

We have studied the reliability measures of a system, which consists of two subsystems i.e. subsystem-1 and subsystem-2 in series configuration under different types of failure. The subsystem-1 has three identical units in parallel configuration and operating under 2-out-of-3: G policy and connected to subsystem-2 in series configuration. Each subsystem has different types of failure and repair rates. An important cause for failure of system is unsuitability of the environmental conditions, like overheating, weather conditions, heavy rainfall, storm etc. The environmental failure is taken into account in the proposed repairable system. Supplementary variable technique is used to study of system and some traditional measures such as; availability, reliability, MTTF and profit function are obtained for different values of parameters. In the proposed model, some particular cases of failure rates are explicitly studied.

Keywords: environmental failure, human failure, availability, MTTF, reliability, profit analysis, Gumbel-Hougaard family copula

Procedia PDF Downloads 322

Authors: Chia-Chi Chen, Tai-Sheng Huang

Abstract:

Ageing society has been spread around the world. The global population is not only ageing but also declining. The structure of population has changed, which has a significant impact on both the economies and industries. Thus, how to be a healthy senior citizen to relieve the burden to the family and society will be a popular issue. Although fitness equipment manufacturing industry has been mature, the ageing population is still increasing. Therefore, this study aims to design an innovative style of fitness equipment for senior citizens, based on BMLT presented by Dr. Koyama Hirofumi. The analysis of current fitness equipment on the market and the future trend will be applied in the study. With the coming of information age, senior citizens in the future are the users of information product for sure, and the new style of fitness equipment will be combined with information technology as well. Through this study, it is believed to design an innovative style of fitness equipment for seniors and help them live heartier and happier lives.

Keywords: aging society, BMLT (Beginning Movement Load Training), seniors, new style of fitness equipment

Procedia PDF Downloads 186

Authors: Altoumi Alndalusi

Abstract:

High-temperature hydrogen attack (HTHA) failure is the common phenomena at elevated temperature in hydrogen environment in oil and gas field. The failure occurred once after four years at the internal surface of Platforming elbow. Both visual and microscopic examinations revealed that the failure was initiated due to blistering forming followed by large cracking at the inner surface. Crack morphology showed that the crack depth was about 50% of material wall thickness and its behavior generally was intergranular. This study concluded that the main reason led to failure due to incorrect material selection comparing to the platforming conditions.

Keywords: decarburization, failure, heat affected zone, morphology, partial pressure, plate form

Procedia PDF Downloads 127

Authors: O. Bendermel, C. Seladji, M. Khaouani

Abstract:

In this work, we made a numerical study of the thermal and dynamic behaviour of air in a horizontal channel with electronic components. The influence to use baffles on the profiles of velocity and temperature is discussed. The finite volume method and the algorithm Simple are used for solving the equations of conservation of mass, momentum and energy. The results found show that baffles improve heat transfer between the cooling air and electronic components. The velocity will increase from 3 times per rapport of the initial velocity.

Keywords: electronic components, baffles, cooling, fluids engineering

Procedia PDF Downloads 269

Authors: Aydin Azizi, Ahmed Al. Azizi

Abstract:

Mechanical seals are essential components in centrifugal pumps since they help in controlling leaking out of the liquid that is pumped under pressure. Unlike the common types of packaging, mechanical seals are highly efficient and they reduce leakage by a great extent. However, all multiphase mechanical seals leak and they are subject to failure. Some of the factors that have been recognized to their failure include excessive heating, open seal faces, as well as environment related factors that trigger failure of the materials used to manufacture seals. The proposed research study will explore the failure of multiphase mechanical seal in centrifugal pumps. The objective of the study includes how to reduce the failure in multiphase mechanical seals and to make them more efficient.

Keywords: mechanical seals, centrifugal pumps, multi phase failure, excessive heating

Procedia PDF Downloads 329

Authors: Liang Zhang, Gang Xu, Yue Wang, Chen Li, Shao Chong Zhou

Abstract:

Presently, more and more nuclear power plants are facing the issue of life extension. When a nuclear power plant applies for an extension of life, its condition needs to meet the current design standards, which is not fine for all old reactors, typically for seismic design. Seismic-grade equipment in nuclear power plants are now generally placed separately from the non-seismic-grade equipment, but it was not strictly required before. Therefore, it is very important to study whether non-seismic-grade equipment will affect the seismic-grade equipment when dropped down in an earthquake situation, which is related to the safety of nuclear power plants and future life extension applications. This research was based on the cooling water system with the seismic and non-seismic grade equipment installed together, as an example to study whether the non-seismic-grade equipment such as DN50 fire pipes and ventilation pipes arranged above will damage the DN300 pipes and valves arranged below when earthquakes occur. In the study, the simulation was carried out by ANSYS / LY-DYNA, and Johnson-Cook was used as the material model and failure model. For the experiments, the relative positions of objects in the room were restored by 1: 1. In the experiment, the pipes and valves were filled with water with a pressure of 0.785 MPa. The pressure-holding performance of the pipe was used as a criterion for damage. In addition to the pressure-holding performance, the opening torque was considered as well for the valves. The research results show that when the 10-meter-long DN50 pipe was dropped from the position of 8 meters height and the 8-meter-long air pipe dropped from a position of 3.6 meters height, they do not affect the integrity of DN300 pipe below. There is no failure phenomenon in the simulation as well. After the experiment, the pressure drop in two hours for the pipe is less than 0.1%. The main body of the valve does not fail either. The opening torque change after the experiment is less than 0.5%, but the handwheel of the valve may break, which affects the opening actions. In summary, impacts of the upper pipes and ventilation pipes dropdown on the integrity of the DN300 pipes and valves below in a cooling water system of a typical second-generation nuclear power plant under an earthquake was studied. As a result, the functionality of the DN300 pipeline and the valves themselves are not significantly affected, but the handwheel of the valve or similar articles can probably be broken and need to take care.

Keywords: cooling water system, earthquake, integrity, pipe and valve

Procedia PDF Downloads 86

Authors: Maziyar Nouraee

Abstract:

Electronic markets in recent decades contribute remarkably in business transactions. Many organizations consider traditional ways of trade non-economical and therefore they do trade only through electronic markets. There are different categorizations of electronic markets functions. In one classification, functions of electronic markets are categorized into classes as information, transactions, and value added. In the present paper, effects of the three classes on the two major elements of the supply chain management are measured. The two elements are decrease in the product unit cost and reduction in response time to the customer. The results of the current research show that among nine minor elements related to the three classes of electronic markets functions, six factors and three factors influence on reduction of the product unit cost and reduction of response time to the customer, respectively.

Keywords: electronic commerce, electronic market, B2B trade, supply chain management

Procedia PDF Downloads 368

Authors: V. V. Singh

Abstract:

In this paper we have focused on the study of a Linux operating system connected in a LAN (local area network). We have considered two different topologies STAR topology (subsystem-1) and BUS topology (subsystem-2) which are placed at two different places and connected to a server through a hub. In both topologies BUS topology and STAR topology, we have assumed 'n' clients. The system has two types of failure partial failure and complete failure. Further the partial failure has been categorized as minor partial failure and major partial failure. It is assumed that minor partial failure degrades the subsystem and the major partial failure brings the subsystem to break down mode. The system can completely failed due to failure of server hacking and blocking etc. The system is studied by supplementary variable technique and Laplace transform by taking different types of failure and two types of repairs. The various measures of reliability like availability of system, MTTF, profit function for different parametric values has been discussed.

Keywords: star topology, bus topology, hacking, blocking, linux operating system, Gumbel-Hougaard family copula, supplementary variable

Procedia PDF Downloads 545

Authors: Ünal Kızıl, Levent Genç, Sefa Aksu, Ahmet Tapınç

Abstract:

The Figaro AM-1 sensor module which employs TGS 2600 model gas sensor in air quality assessment was used. The system was coupled with a microprocessor that enables sensor module to create warning message via telephone. This low cot sensor system’s performance was compared with a Diagnose II commercial electronic nose system. Both air quality sensor and electronic nose system employ metal oxide chemical gas sensors. In the study experimental setup, data acquisition methods for electronic nose system, and performance of the low cost air quality system were evaluated and explained.

Keywords: air quality, electronic nose, environmental quality, gas sensor

Procedia PDF Downloads 412

Authors: John Q. Todd

Abstract:

Given that modern equipment can provide comprehensive health, status, and error condition data via built-in sensors, maintenance organizations have a new and valuable source of insight to take advantage of. This presentation will expose what these data payloads might look like and how they can be filtered, visualized, calculated into metrics, used for machine learning, and generate alerts for further action.

Keywords: condition based maintenance, equipment data, metrics, alerts

Procedia PDF Downloads 155

Authors: Guoliang Fan, Aiping Li, Xuemei Liu, Liyun Xu

Abstract:

The performance of the tightening equipment will decline with the working process in manufacturing system. The main manifestations are the randomness and discretization degree increasing of the tightening performance. To evaluate the degradation tendency of the tightening performance accurately, a complexity measurement approach based on Kolmogorov entropy is presented. At first, the states of performance index are divided for calibrating the discrete degree. Then the complexity measurement model based on Kolmogorov entropy is built. The model describes the performance degradation tendency of tightening equipment quantitatively. At last, a study case is applied for verifying the efficiency and validity of the approach. The research achievement shows that the presented complexity measurement can effectively evaluate the degradation tendency of the tightening equipment. It can provide theoretical basis for preventive maintenance and life prediction of equipment.

Keywords: complexity measurement, Kolmogorov entropy, manufacturing system, performance evaluation, tightening equipment

Procedia PDF Downloads 236

Authors: Rajender Dahiya

Abstract:

Investigation outcomes of major process incidents have been consistent for decades and validate that the causes and consequences are often identical. The debate remains as we continue to experience similar process incidents even with enormous development of new tools, technologies, industry standards, codes, regulations, and learning processes? The objective of this paper is to investigate the most common causes of major industrial incidents and reveal industry challenges and best practices to prevent such incidents. The author, in his current role, performs audits and inspections of a variety of high-hazard industries in North America, including petroleum refineries, chemicals, petrochemicals, manufacturing, etc. In this paper, he shares real life scenarios, examples, and case studies from high hazards operating facilities including key challenges and best practices. This case study will provide a clear understanding of the importance of near miss incident investigation. The incident was a Safe operating limit excursion. The case describes the deficiencies in management programs, the competency of employees, and the culture of the corporation that includes hazard identification and risk assessment, maintaining the integrity of safety-critical equipment, operating discipline, learning from process safety near misses, process safety competency, process safety culture, audits, and performance measurement. Failure to identify the hazards and manage the risks of highly hazardous materials and processes is one of the primary root-causes of an incident, and failure to learn from past incidents is the leading cause of the recurrence of incidents. Several investigations of major incidents discovered that each showed several warning signs before occurring, and most importantly, all were preventable. The author will discuss why preventable incidents were not prevented and review the mutual causes of learning failures from past major incidents. The leading causes of past incidents are summarized below. Management failure to identify the hazard and/or mitigate the risk of hazardous processes or materials. This process starts early in the project stage and continues throughout the life cycle of the facility. For example, a poorly done hazard study such as HAZID, PHA, or LOPA is one of the leading causes of the failure. If this step is performed correctly, then the next potential cause is. Management failure to maintain the integrity of safety critical systems and equipment. In most of the incidents, mechanical integrity of the critical equipment was not maintained, safety barriers were either bypassed, disabled, or not maintained. The third major cause is Management failure to learn and/or apply learning from the past incidents. There were several precursors before those incidents. These precursors were either ignored altogether or not taken seriously. This paper will conclude by sharing how a well-implemented operating management system, good process safety culture, and competent leaders and staff contributed to managing the risks to prevent major incidents.

Keywords: incident investigation, risk management, loss prevention, process safety, accident prevention

Procedia PDF Downloads 24

Authors: Faten Khanfir, Mohamed Tlili, Ali Medeb Hamrouni, Raki Selmi, M. S. Khalfi, Faten Ben Amor

Abstract:

Introduction: dental implant failure is a major concern for the clinician and the patient. Objectives: The aim of our study is to investigate the way in which 100 Tunisian dentists carried implant treatment for their patients from the early phase of planning and selection of patients to the placement of the implant in order to look for the implant failure factors. Results: significant correlations were found between failure rates > 5 and their corresponding factors as the number of implants placed (p = 0.001<0, 05), smoking (0.046 <0.05), unbalanced diabetes (0.03<0.05), aseptic protocol (= 0.004< 0.05) and the drilling speed (0,002<0.05) Conclusion: It seems that the number of implant placed, smoking, diabetes, aseptic protocol, and the drilling speed may contribute to dental implant failure.

Keywords: failure, implants, survey, risk, osseointegration

Procedia PDF Downloads 145

Authors: Jinyong Yao, Hongzhi Li, Chao Du, Jiao Li

Abstract:

Reliability of long-term storage products is related to the availability of the whole system, and the evaluation of storage life is of great necessity. These products are usually highly reliable and little failure information can be collected. In this paper, an analytical method based on data from accelerated storage life test is proposed to evaluate the reliability index of the long-term storage products. Firstly, singularities are eliminated by data normalization and residual analysis. Secondly, with the pre-processed data, the degradation path model is built to obtain the pseudo life values. Then by life distribution hypothesis, we can get the estimator of parameters in high stress levels and verify failure mechanisms consistency. Finally, the life distribution under the normal stress level is extrapolated via the acceleration model and evaluation of the true average life available. An application example with the camera stabilization device is provided to illustrate the methodology we proposed.

Keywords: accelerated storage life test, failure mechanisms consistency, life distribution, reliability

Procedia PDF Downloads 364

Authors: Cornelius Femi Popoola

Abstract:

This study investigated logistics information systems in the distribution of flour in Nigeria. A case study design was used and 50 staff of Honeywell Flour Mill was sampled for the study. Data generated through a questionnaire were analysed using correlation and regression analysis. The findings of the study revealed that logistic information systems such as e-commerce, interactive telephone systems and electronic data interchange positively correlated with the distribution of flour in Honeywell Flour Mill. Finding also deduced that e-commerce, interactive telephone systems and electronic data interchange jointly and positively contribute to the distribution of flour in Honeywell Flour Mill in Nigeria (R = .935; Adj. R2 = .642; F (3,47) = 14.739; p < .05). The study therefore recommended that Honeywell Flour Mill should upgrade their logistic information systems to computer-to-computer communication of business transactions and documents, as well adopt new technology such as, tracking-and-tracing systems (barcode scanning for packages and palettes), tracking vehicles with Global Positioning System (GPS), measuring vehicle performance with ‘black boxes’ (containing logistic data), and Automatic Equipment Identification (AEI) into their systems.

Keywords: e-commerce, electronic data interchange, flour distribution, information system, interactive telephone systems

Procedia PDF Downloads 520

Authors: Maryam Safarirad

Abstract:

Fast and increasing growth of electronic commerce (e-commerce) in developed countries and its resulting competitive advantages mean that those countries should revise dramatically their trade and commercial strategies and policies. Regarding the importance of food industry in Iran, the current paper studies the feasibility of implementing the e-commerce system in Shiraz’s petrochemical unit. The statistical population of the study includes 29 senior managers and experts of the food industries. In the present Feasibility study of implementing electronic commerce 249 research, senior managers and experts’ opinions on feasibility have been examined and some feedbacks have resulted in from the opinions. The current research concludes that the organization under study does not have favorable state either in software or in hardware. Implementation of the e-commerce system in food industries would reduce the average value of the transaction costs.

Keywords: electronic trading, electronic commerce, electronic exchange of information, feasibility study, information technology, virtual shopping, computer networks, electronic commerce laws, food industry

Procedia PDF Downloads 384

Authors: Priyanka Verma, Vijaya Dixit, Rishabh Bajpai

Abstract:

This research paper is aimed at selecting appropriate material handling equipment among the given choices so that the automation level in material handling can be enhanced. This work is a practical case scenario of material handling systems in consumer electronic appliances manufacturing organization. The choices of material handling equipment among which the decision has to be made are Automated Guided Vehicle’s (AGV), Autonomous Mobile Robots (AMR), Overhead Conveyer’s (OC) and Battery Operated Trucks/Vehicle’s (BOT). There is a need of attaining a certain level of automation in order to reduce human interventions in the organization. This requirement of achieving certain degree of automation can be attained by material handling equipment’s mentioned above. The main motive for selecting above equipment’s for study was solely based on corporate financial strategy of investment and return obtained through that investment made in stipulated time framework. Since the low cost automation with respect to material handling devices has to be achieved hence these equipment’s were selected. Investment to be done on each unit of this equipment is less than 20 lakh rupees (INR) and the recovery period is less than that of five years. Fuzzy analytic hierarchic process (FAHP) is applied here for selecting equipment where the four choices are evaluated on basis of four major criteria’s and 13 sub criteria’s, and are prioritized on the basis of weight obtained. The FAHP used here make use of triangular fuzzy numbers (TFN). The inability of the traditional AHP in order to deal with the subjectiveness and impreciseness in the pair-wise comparison process has been improved in the FAHP. The range of values for general rating purposes for all decision making parameters is kept between 0 and 1 on the basis of expert opinions captured on shop floor. These experts were familiar with operating environment and shop floor activity control. Instead of generating exact value the FAHP generates the ranges of values to accommodate the uncertainty in decision-making process. The four major criteria’s selected for the evaluation of choices of material handling equipment’s available are materials, technical capabilities, cost and other features. The thirteen sub criteria’s listed under these following four major criteria’s are weighing capacity, load per hour, material compatibility, capital cost, operating cost and maintenance cost, speed, distance moved, space required, frequency of trips, control required, safety and reliability issues. The key finding shows that among the four major criteria selected, cost is emerged as the most important criteria and is one of the key decision making aspect on the basis of which material equipment selection is based on. While further evaluating the choices of equipment available for each sub criteria it is found that AGV scores the highest weight in most of the sub-criteria’s. On carrying out complete analysis the research shows that AGV is the best material handling equipment suiting all decision criteria’s selected in FAHP and therefore it is beneficial for the organization to carry out automated material handling in the facility using AGV’s.

Keywords: fuzzy analytic hierarchy process (FAHP), material handling equipment, subjectiveness, triangular fuzzy number (TFN)

Procedia PDF Downloads 409

Authors: Dale Daniel G. Bodo

Abstract:

This study investigated the status of the Laboratory Tools and Equipment of the BSHRT Program of Eastern Visayas State University, Tacloban City Campus. Descriptive-correlation method was used which Variables include profile age, gender, acquired NC II, competencies in HRT and the status of the laboratory facilities, tools, and equipment of the BSHRT program. The study also identified significant correlation between the profile of the respondents and the implementation of the BSHRT Program in terms of laboratory tools and equipment. A self-structured survey questionnaire was used to gather relevant data among eighty-seven (87) BSHRT-OJT students. To test the correlations of variables, Pearson Product Moment Coefficient Correlation or Pearson r was used. As a result, the study revealed very interesting results and various significant correlations among the paired variables and as to the implementation of the BSHRT Program. Hence, this study was done to update the status of laboratory tools and equipment of the program.

Keywords: status, BSHRT Program, laboratory tools and equipment, descriptive-correlation

Procedia PDF Downloads 157

Authors: Jiraphorn Satechan, Thanaphon Khamthieng, Warunee Phanwong

Abstract:

This action research aimed at designing and developing the cleaning equipment to preventing dust diffusion of bus air filter. Quantitative and qualitative data collection methods were used to conduct data from October 1st, 2018 to September 30th, 2019. All of participants were male (100.0%) with aged 40- 49 years and 57.15%, of them finish bachelor degree. 71.43% of them was a driver and 57.15% of them had the working experience between 10 and 15 years. Research revealed that the participants assessed the quality of the bus air filter cleaning equipment for preventing dust diffusion at a moderate level (σ= 0.29), and 71.43 of them also suggested the development methods in order to improve the quality of bus air filters cleaning equipment as follows: 1) to install the circuit breaker for cutting the electricity and controlling the on-off of the equipment and to change the motor to the DC system, 2) should install the display monitor for wind pressure and electricity system as well as to install the air pressure gauge, 3) should install the tank lid lock for preventing air leakage and dust diffusion by increasing the blowing force and sucking power, 4) to stabilize the holding points for preventing the filter shaking while rotating and blowing for cleaning and to reduce the rotation speed in order to allow the filters to move slowly for the air system to blow for cleaning more thoroughly, 5) the amount of dust should be measured before and after cleaning and should be designed the cleaning equipment to be able to clean with a variety of filters, and sizes. Moreover, the light-weight materials should be used to build the cleaning equipment and the wheels should be installed at the base of the equipment in order to make it easier to move.

Keywords: Cleaning Equipment, Bus Air Filters, Preventing Dust Diffusion, Innovation

Procedia PDF Downloads 84

Authors: Clara Oliver, Oibar Martinez

Abstract:

This paper is intended to reveal the severity of electrostatic discharge (ESD) effects in electronic and optoelectronic devices by performing sensitivity tests based on Human Body Model (HBM) standard. We explain here the HBM standard in detail together with the typical failure modes associated with electrostatic discharges. In addition, a prototype of electrostatic charge generator has been designed, fabricated, and verified to stress electronic devices, which features a compact high voltage source. This prototype is inexpensive and enables one to do a battery of pre-compliance tests aimed at detecting unexpected weaknesses to static discharges at the component level. Some tests with different devices were performed to illustrate the behavior of the proposed generator. A set of discharges was applied according to the HBM standard to commercially available bipolar transistors, complementary metal-oxide-semiconductor transistors and light emitting diodes. It is observed that high current and voltage ratings in electronic devices not necessarily provide a guarantee that the device will withstand high levels of electrostatic discharges. We have also compared the result obtained by performing the sensitivity tests based on HBM with a real discharge generated by a human. For this purpose, the charge accumulated in the person is monitored, and a direct discharge against the devices is generated by touching them. Every test has been performed under controlled relative humidity conditions. It is believed that this paper can be of interest for research teams involved in the development of electronic and optoelectronic devices which need to verify the reliability of their devices in terms of robustness to electrostatic discharges.

Keywords: human body model, electrostatic discharge, sensitivity tests, static charge monitoring

Procedia PDF Downloads 121

Authors: Mehmet Yahsi, Ozkan Ugurlu, Ercan Yuksekyildiz

Abstract:

Assistant department among the electric and electronic officers on ships, has an important place for the maintenance of electric and electronic devices. From this perspective, ships must be employed with a sufficient number of assistant department. In this study, in order to research on the Turkish-flagged ships electric and electronic officers employment; Our national manning regulation compared with international regulations. The data used in this study were collected via visiting of the ships. 3000 gross tonnage and above engaged in international voyages 181 Turkish-flagged ship’s crew lists were compared with Minimum Safety Manning Certificates. According to the findings; employment rate, %54 electric and electronic officers. According to the results of the study; Turkish-flagged ships, although it is not obliged to electric and electronic officers, were employed on ships.

Keywords: manning, electric officer, electronic officer, minimum safety manning certificate

Procedia PDF Downloads 407

Authors: Idris Lawal

Abstract:

Electronic payment system is simply a payment or monetary transaction made over the internet or a network of computers. This study was carried out in order to assess how electronic payment system has impacted on banks service delivery, to examine the efficiency of electronic payment system in Nigeria and to determine the level of customer's satisfaction as a direct result of the deployment of electronic payment systems. It is an empirical study conducted using structured questionnaire distributed to officials and customers of Access Bank plc. Chi-square(x2) was adopted for the purpose of data analysis. The result of the study showed that the development of electronic payment system offer great benefit to bank customers including improved services, reduced turn-around time, ease of banking transaction, significant cost saving etc. The study recommends that customer protection laws should be properly put in place to safeguard the interest of end users of e-payment instruments.

Keywords: bank, electronic payment systems, service delivery, customer's satisfaction

Procedia PDF Downloads 371

Authors: D. Diaz, C. Guevara, P. Rey

Abstract:

This paper contains information about designing, shielding and protocols building in order to avoid ionizing radiation in X-Rays imaging areas as generated by X-Ray, mammography equipment, computed tomography equipment and digital subtraction angiography equipment, according to global standards. Furthermore, tools and elements about infrastructure to improve protection over patients, physicians and staff involved in a diagnostic imaging area are presented. In addition, technical parameters about each machine and the architecture designs and maps are described.

Keywords: imaging area, X-ray, shielding, dose

Procedia PDF Downloads 411

Authors: Vijay Vir Singh

Abstract:

This work is focused studying the Linux operating system connected in a LAN (local area network). The STAR topology (to be called subsystem-1) and BUS topology (to be called subsystem-2) are taken into account, which are placed at two different locations and connected to a server through a hub. In the both topologies BUS topology and STAR topology, we have assumed n clients. The system has two types of failures i.e. partial failure and complete failure. Further, the partial failure has been categorized as minor and major partial failure. It is assumed that the minor partial failure degrades the sub-systems and the major partial failure make the subsystem break down mode. The system may completely fail due to failure of server hacking and blocking etc. The system is studied using supplementary variable technique and Laplace transform by using different types of failure and two types of repair. The various measures of reliability for example, availability of system, reliability of system, MTTF, profit function for different parametric values have been discussed.

Keywords: star topology, bus topology, blocking, hacking, Linux operating system, Gumbel-Hougaard family copula, supplementary variable

Procedia PDF Downloads 334

Authors: Dilson Subedi

Abstract:

Current transformers are an integral part of power system because it provides a proportional safe amount of current for protection and measurement applications. However, due to upgradation of electromechanical relays to numerical relays and electromechanical energy meters to digital meters, the connected burden, which defines some of the CT characteristics, has drastically reduced. This has led to the system experiencing high currents damaging the connected relays and meters. Since the protection and metering equipment's are designed to withstand only certain amount of current with respect to time, these high currents pose a risk to man and equipment. Therefore, during such instances, the CT saturation characteristics have a huge influence on the safety of both man and equipment and on the reliability of the protection and metering system. This paper shows the effectiveness of a bank of parallel connected resistors, as a burden compensation technique, in compensating the burden of under-burdened CT’s. The response of the CT in the case of failure of one or more resistors at different levels of overcurrent will be captured using the LabVIEWTM data acquisition hardware (DAQ). The analysis is done on the real-time data gathered using LabVIEWTM. Variation of current transformer saturation characteristics with changes in burden will be discussed.

Keywords: accuracy limiting factor, burden, burden compensation, current transformer

Procedia PDF Downloads 218

Authors: Fariba Azizi, Firoozeh Haghighi, Viliam Makis

Abstract:

In this paper, we propose a method to model the relationship between failure time and degradation for a simple step stress test where underlying degradation path is linear and different causes of failure are possible. It is assumed that the intensity function depends only on the degradation value. No assumptions are made about the distribution of the failure times. A simple step-stress test is used to shorten failure time of products and a tampered failure rate (TFR) model is proposed to describe the effect of the changing stress on the intensities. We assume that some of the products that fail during the test have a cause of failure that is only known to belong to a certain subset of all possible failures. This case is known as masking. In the presence of masking, the maximum likelihood estimates (MLEs) of the model parameters are obtained through an expectation-maximization (EM) algorithm by treating the causes of failure as missing values. The effect of incomplete information on the estimation of parameters is studied through a Monte-Carlo simulation. Finally, a real example is analyzed to illustrate the application of the proposed methods.

Keywords: cause of failure, linear degradation path, reliability function, expectation-maximization algorithm, intensity, masked data

Procedia PDF Downloads 306

Authors: Masahiko Suzuki, Takashi Kato , Masahiro Kobayashi

Abstract:

In our company, the monitoring system for signal equipment has already implemented. So, we can know the state of signal equipment, sitting in the control room or the maintenance center. But this system was installed over 20 years ago, so it cannot stand the needs such as 'more stable operation', 'broadband data transfer', 'easy construction and easy maintenance'. To satisfy these needs, we studied the monitoring system using radio communication as a new method which can realize the operation in the terrible environment along railroads. In these studies, we have developed the terminals and repeaters based on the ZigBee protocol and have implemented the application using two different radio bands simultaneously. At last, we got the good results from the fundamental examinations using the developed equipment.

Keywords: monitoring, radio communication, 2 bands, ZigBee

Procedia PDF Downloads 557

Authors: Magdalena Meusburger, Caroline Hofer

Abstract:

The advancement of woman entrepreneurship in the last decade has been a vital driver for social and economic development. Despite the positive evolution, women entrepreneurs are still underrepresented in entrepreneurial ecosystems. Fear-of-failure is a major factor affecting their entrepreneurial activity. This survey-based research focuses on aspiring and established entrepreneurial women in Austria and in the USA. It explores and compares the extent to which fear-of-failure influences their self-employment and their aspirations to become self-employed.

Keywords: entrepreneurial ecosystems, fear-of-failure, female entrepreneurship, woman entrepreneurship

Procedia PDF Downloads 338

Authors: Gizem Yilmazel

Abstract:

Turkiye has been facing failure in English language teaching despite long years of English studies during mandatory education. A body of research studying the reasons of the failure in the literature exists yet the problem has not been solved and English language education is still a phenomenon in Turkiye. The failure is mostly attributed to the methods used in English education (Grammar Translation Method), lack of exposure to the language, inability to practice the language, financial difficulties, the belief of abroad experience necessity, national examinations, and conservative institutional policies. The findings are evident and tangible yet the problem persists. This paper aims to bring the issue a critical perspective and discuss the reasons of the failure.

Keywords: EFL, failure, critical perspective, language education

Procedia PDF Downloads 16